From fdc7833964d83b7f7f39a03e2ee48a229ba0291f Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:27:55 +0200 Subject: [PATCH 01/45] um/stacktrace: Remove the pointless ULONG_MAX marker Terminating the last trace entry with ULONG_MAX is a completely pointless exercise and none of the consumers can rely on it because it's inconsistently implemented across architectures. In fact quite some of the callers remove the entry and adjust stack_trace.nr_entries afterwards. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Richard Weinberger Cc: linux-um@lists.infradead.org Link: https://lkml.kernel.org/r/20190410103643.662853876@linutronix.de --- arch/um/kernel/stacktrace.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/um/kernel/stacktrace.c b/arch/um/kernel/stacktrace.c index ebe7bcf62684..bd95e020d509 100644 --- a/arch/um/kernel/stacktrace.c +++ b/arch/um/kernel/stacktrace.c @@ -63,8 +63,6 @@ static const struct stacktrace_ops dump_ops = { static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace) { dump_trace(tsk, &dump_ops, trace); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } void save_stack_trace(struct stack_trace *trace) From c5c27a0a583844c69a433039e4fd6396ba23551b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:27:56 +0200 Subject: [PATCH 02/45] x86/stacktrace: Remove the pointless ULONG_MAX marker Terminating the last trace entry with ULONG_MAX is a completely pointless exercise and none of the consumers can rely on it because it's inconsistently implemented across architectures. In fact quite some of the callers remove the entry and adjust stack_trace.nr_entries afterwards. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Link: https://lkml.kernel.org/r/20190410103643.750954603@linutronix.de --- arch/x86/kernel/stacktrace.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index 5c2d71a1dc06..b2f706f1e0b7 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -46,9 +46,6 @@ static void noinline __save_stack_trace(struct stack_trace *trace, if (!addr || save_stack_address(trace, addr, nosched)) break; } - - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } /* @@ -97,7 +94,7 @@ __save_stack_trace_reliable(struct stack_trace *trace, if (regs) { /* Success path for user tasks */ if (user_mode(regs)) - goto success; + return 0; /* * Kernel mode registers on the stack indicate an @@ -132,10 +129,6 @@ __save_stack_trace_reliable(struct stack_trace *trace, if (!(task->flags & (PF_KTHREAD | PF_IDLE))) return -EINVAL; -success: - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; - return 0; } @@ -221,9 +214,6 @@ void save_stack_trace_user(struct stack_trace *trace) /* * Trace user stack if we are not a kernel thread */ - if (current->mm) { + if (current->mm) __save_stack_trace_user(trace); - } - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } From 2a2bcfa0c94d8bc4770676a6799928036296c037 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:27:57 +0200 Subject: [PATCH 03/45] arm/stacktrace: Remove the pointless ULONG_MAX marker Terminating the last trace entry with ULONG_MAX is a completely pointless exercise and none of the consumers can rely on it because it's inconsistently implemented across architectures. In fact quite some of the callers remove the entry and adjust stack_trace.nr_entries afterwards. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Russell King Cc: linux-arm-kernel@lists.infradead.org Link: https://lkml.kernel.org/r/20190410103643.843075256@linutronix.de --- arch/arm/kernel/stacktrace.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index a56e7c856ab5..86870f40f9a0 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -115,8 +115,6 @@ static noinline void __save_stack_trace(struct task_struct *tsk, * running on another CPU? For now, ignore it as we * can't guarantee we won't explode. */ - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; return; #else frame.fp = thread_saved_fp(tsk); @@ -134,8 +132,6 @@ static noinline void __save_stack_trace(struct task_struct *tsk, } walk_stackframe(&frame, save_trace, &data); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) @@ -153,8 +149,6 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) frame.pc = regs->ARM_pc; walk_stackframe(&frame, save_trace, &data); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) From b01f6d368d296cac099383a3eb200e135420f885 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:27:58 +0200 Subject: [PATCH 04/45] sh/stacktrace: Remove the pointless ULONG_MAX marker Terminating the last trace entry with ULONG_MAX is a completely pointless exercise and none of the consumers can rely on it because it's inconsistently implemented across architectures. In fact quite some of the callers remove the entry and adjust stack_trace.nr_entries afterwards. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Rich Felker Cc: Yoshinori Sato Cc: Kuninori Morimoto Cc: linux-sh@vger.kernel.org Cc: Simon Horman Link: https://lkml.kernel.org/r/20190410103643.932464393@linutronix.de --- arch/sh/kernel/stacktrace.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/sh/kernel/stacktrace.c b/arch/sh/kernel/stacktrace.c index f3cb2cccb262..2950b19ad077 100644 --- a/arch/sh/kernel/stacktrace.c +++ b/arch/sh/kernel/stacktrace.c @@ -49,8 +49,6 @@ void save_stack_trace(struct stack_trace *trace) unsigned long *sp = (unsigned long *)current_stack_pointer; unwind_stack(current, NULL, sp, &save_stack_ops, trace); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace); @@ -84,7 +82,5 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) unsigned long *sp = (unsigned long *)tsk->thread.sp; unwind_stack(current, NULL, sp, &save_stack_ops_nosched, trace); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace_tsk); From f8a9a269c28ddd5d741e747ceca753af01c828f2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:27:59 +0200 Subject: [PATCH 05/45] unicore32/stacktrace: Remove the pointless ULONG_MAX marker Terminating the last trace entry with ULONG_MAX is a completely pointless exercise and none of the consumers can rely on it because it's inconsistently implemented across architectures. In fact quite some of the callers remove the entry and adjust stack_trace.nr_entries afterwards. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Guan Xuetao Link: https://lkml.kernel.org/r/20190410103644.036077691@linutronix.de --- arch/unicore32/kernel/stacktrace.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/unicore32/kernel/stacktrace.c b/arch/unicore32/kernel/stacktrace.c index 9976e767d51c..e37da8c6837b 100644 --- a/arch/unicore32/kernel/stacktrace.c +++ b/arch/unicore32/kernel/stacktrace.c @@ -120,8 +120,6 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) } walk_stackframe(&frame, save_trace, &data); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } void save_stack_trace(struct stack_trace *trace) From fa9833992d5ff3c0d6e81d708bec363bce2fb54c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:00 +0200 Subject: [PATCH 06/45] riscv/stacktrace: Remove the pointless ULONG_MAX marker Terminating the last trace entry with ULONG_MAX is a completely pointless exercise and none of the consumers can rely on it because it's inconsistently implemented across architectures. In fact quite some of the callers remove the entry and adjust stack_trace.nr_entries afterwards. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: linux-riscv@lists.infradead.org Cc: Palmer Dabbelt Cc: Albert Ou Link: https://lkml.kernel.org/r/20190410103644.131061192@linutronix.de --- arch/riscv/kernel/stacktrace.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c index a4b1d94371a0..4d403274c2e8 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -169,8 +169,6 @@ static bool save_trace(unsigned long pc, void *arg) void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { walk_stackframe(tsk, NULL, save_trace, trace); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace_tsk); From 7b2c7b6233497bfab8826ece574bc1c26e97478d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:01 +0200 Subject: [PATCH 07/45] arm64/stacktrace: Remove the pointless ULONG_MAX marker Terminating the last trace entry with ULONG_MAX is a completely pointless exercise and none of the consumers can rely on it because it's inconsistently implemented across architectures. In fact quite some of the callers remove the entry and adjust stack_trace.nr_entries afterwards. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Catalin Marinas Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Link: https://lkml.kernel.org/r/20190410103644.220247845@linutronix.de --- arch/arm64/kernel/stacktrace.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index d908b5e9e949..b00ec7d483d1 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -140,8 +140,6 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) #endif walk_stackframe(current, &frame, save_trace, &data); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace_regs); @@ -172,8 +170,6 @@ static noinline void __save_stack_trace(struct task_struct *tsk, #endif walk_stackframe(tsk, &frame, save_trace, &data); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; put_task_stack(tsk); } From 4f3bd6ca310b594df09c8f1e319cda9baf502ec8 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:02 +0200 Subject: [PATCH 08/45] parisc/stacktrace: Remove the pointless ULONG_MAX marker Terminating the last trace entry with ULONG_MAX is a completely pointless exercise and none of the consumers can rely on it because it's inconsistently implemented across architectures. In fact quite some of the callers remove the entry and adjust stack_trace.nr_entries afterwards. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: linux-parisc@vger.kernel.org Link: https://lkml.kernel.org/r/20190410103644.308534788@linutronix.de --- arch/parisc/kernel/stacktrace.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/arch/parisc/kernel/stacktrace.c b/arch/parisc/kernel/stacktrace.c index ec5835e83a7a..6f0b9c8d8052 100644 --- a/arch/parisc/kernel/stacktrace.c +++ b/arch/parisc/kernel/stacktrace.c @@ -29,22 +29,17 @@ static void dump_trace(struct task_struct *task, struct stack_trace *trace) } } - /* * Save stack-backtrace addresses into a stack_trace buffer. */ void save_stack_trace(struct stack_trace *trace) { dump_trace(current, trace); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { dump_trace(tsk, trace); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace_tsk); From 6a28b4c2d93b812512d8d2e5179e61a14f578560 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:03 +0200 Subject: [PATCH 09/45] s390/stacktrace: Remove the pointless ULONG_MAX marker Terminating the last trace entry with ULONG_MAX is a completely pointless exercise and none of the consumers can rely on it because it's inconsistently implemented across architectures. In fact quite some of the callers remove the entry and adjust stack_trace.nr_entries afterwards. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Martin Schwidefsky Cc: linux-s390@vger.kernel.org Cc: Heiko Carstens Link: https://lkml.kernel.org/r/20190410103644.396788431@linutronix.de --- arch/s390/kernel/stacktrace.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c index 460dcfba7d4e..cc9ed9787068 100644 --- a/arch/s390/kernel/stacktrace.c +++ b/arch/s390/kernel/stacktrace.c @@ -45,8 +45,6 @@ void save_stack_trace(struct stack_trace *trace) sp = current_stack_pointer(); dump_trace(save_address, trace, NULL, sp); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace); @@ -58,8 +56,6 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) if (tsk == current) sp = current_stack_pointer(); dump_trace(save_address_nosched, trace, tsk, sp); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace_tsk); @@ -69,7 +65,5 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) sp = kernel_stack_pointer(regs); dump_trace(save_address, trace, NULL, sp); - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace_regs); From 2dfed4565afe263751d2451ad22336ad806c25a6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:04 +0200 Subject: [PATCH 10/45] lockdep: Remove the ULONG_MAX stack trace hackery No architecture terminates the stack trace with ULONG_MAX anymore. Remove the cruft. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Will Deacon Link: https://lkml.kernel.org/r/20190410103644.485737321@linutronix.de --- kernel/locking/lockdep.c | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index e16766ff184b..2edf9501d906 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -444,17 +444,6 @@ static int save_trace(struct stack_trace *trace) save_stack_trace(trace); - /* - * Some daft arches put -1 at the end to indicate its a full trace. - * - * this is buggy anyway, since it takes a whole extra entry so a - * complete trace that maxes out the entries provided will be reported - * as incomplete, friggin useless - */ - if (trace->nr_entries != 0 && - trace->entries[trace->nr_entries-1] == ULONG_MAX) - trace->nr_entries--; - trace->max_entries = trace->nr_entries; nr_stack_trace_entries += trace->nr_entries; From b8ca7ff7731f57b256fcc13a9b7d4913f5282e5c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:05 +0200 Subject: [PATCH 11/45] mm/slub: Remove the ULONG_MAX stack trace hackery No architecture terminates the stack trace with ULONG_MAX anymore. Remove the cruft. While at it remove the pointless loop of clearing the stack array completely. It's sufficient to clear the last entry as the consumers break out on the first zeroed entry anyway. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Andrew Morton Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Christoph Lameter Link: https://lkml.kernel.org/r/20190410103644.574058244@linutronix.de --- mm/slub.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index d30ede89f4a6..e2ccd12b6faa 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -553,7 +553,6 @@ static void set_track(struct kmem_cache *s, void *object, if (addr) { #ifdef CONFIG_STACKTRACE struct stack_trace trace; - int i; trace.nr_entries = 0; trace.max_entries = TRACK_ADDRS_COUNT; @@ -563,20 +562,16 @@ static void set_track(struct kmem_cache *s, void *object, save_stack_trace(&trace); metadata_access_disable(); - /* See rant in lockdep.c */ - if (trace.nr_entries != 0 && - trace.entries[trace.nr_entries - 1] == ULONG_MAX) - trace.nr_entries--; - - for (i = trace.nr_entries; i < TRACK_ADDRS_COUNT; i++) - p->addrs[i] = 0; + if (trace.nr_entries < TRACK_ADDRS_COUNT) + p->addrs[trace.nr_entries] = 0; #endif p->addr = addr; p->cpu = smp_processor_id(); p->pid = current->pid; p->when = jiffies; - } else + } else { memset(p, 0, sizeof(struct track)); + } } static void init_tracking(struct kmem_cache *s, void *object) From 4621c9858f05ab08434221e3a15cc8098645ef2a Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:06 +0200 Subject: [PATCH 12/45] mm/page_owner: Remove the ULONG_MAX stack trace hackery No architecture terminates the stack trace with ULONG_MAX anymore. Remove the cruft. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Michal Hocko Cc: linux-mm@kvack.org Cc: Mike Rapoport Cc: Andrew Morton Link: https://lkml.kernel.org/r/20190410103644.661974663@linutronix.de --- mm/page_owner.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/page_owner.c b/mm/page_owner.c index 925b6f44a444..df277e6bc3c6 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -148,9 +148,6 @@ static noinline depot_stack_handle_t save_stack(gfp_t flags) depot_stack_handle_t handle; save_stack_trace(&trace); - if (trace.nr_entries != 0 && - trace.entries[trace.nr_entries-1] == ULONG_MAX) - trace.nr_entries--; /* * We need to check recursion here because our request to stackdepot From ead97a49ec3a3cb9b5133acbfed9a49b91ebf37c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:07 +0200 Subject: [PATCH 13/45] mm/kasan: Remove the ULONG_MAX stack trace hackery No architecture terminates the stack trace with ULONG_MAX anymore. Remove the cruft. Signed-off-by: Thomas Gleixner Acked-by: Dmitry Vyukov Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: linux-mm@kvack.org Link: https://lkml.kernel.org/r/20190410103644.750219625@linutronix.de --- mm/kasan/common.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 80bbe62b16cd..38e5f20a775a 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -74,9 +74,6 @@ static inline depot_stack_handle_t save_stack(gfp_t flags) save_stack_trace(&trace); filter_irq_stacks(&trace); - if (trace.nr_entries != 0 && - trace.entries[trace.nr_entries-1] == ULONG_MAX) - trace.nr_entries--; return depot_save_stack(&trace, flags); } From accddc41b96915ab4e5d37796c6d17d70805999c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:08 +0200 Subject: [PATCH 14/45] latency_top: Remove the ULONG_MAX stack trace hackery No architecture terminates the stack trace with ULONG_MAX anymore. The consumer terminates on the first zero entry or at the number of entries, so no functional change. Remove the cruft. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Link: https://lkml.kernel.org/r/20190410103644.853527514@linutronix.de --- fs/proc/base.c | 3 +-- kernel/latencytop.c | 12 ++++++------ 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 6a803a0b75df..5569f215fc54 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -489,10 +489,9 @@ static int lstats_show_proc(struct seq_file *m, void *v) lr->count, lr->time, lr->max); for (q = 0; q < LT_BACKTRACEDEPTH; q++) { unsigned long bt = lr->backtrace[q]; + if (!bt) break; - if (bt == ULONG_MAX) - break; seq_printf(m, " %ps", (void *)bt); } seq_putc(m, '\n'); diff --git a/kernel/latencytop.c b/kernel/latencytop.c index 96b4179cee6a..f5a90ab3c6b9 100644 --- a/kernel/latencytop.c +++ b/kernel/latencytop.c @@ -120,8 +120,8 @@ account_global_scheduler_latency(struct task_struct *tsk, break; } - /* 0 and ULONG_MAX entries mean end of backtrace: */ - if (record == 0 || record == ULONG_MAX) + /* 0 entry marks end of backtrace: */ + if (!record) break; } if (same) { @@ -210,8 +210,8 @@ __account_scheduler_latency(struct task_struct *tsk, int usecs, int inter) break; } - /* 0 and ULONG_MAX entries mean end of backtrace: */ - if (record == 0 || record == ULONG_MAX) + /* 0 entry is end of backtrace */ + if (!record) break; } if (same) { @@ -252,10 +252,10 @@ static int lstats_show(struct seq_file *m, void *v) lr->count, lr->time, lr->max); for (q = 0; q < LT_BACKTRACEDEPTH; q++) { unsigned long bt = lr->backtrace[q]; + if (!bt) break; - if (bt == ULONG_MAX) - break; + seq_printf(m, " %ps", (void *)bt); } seq_puts(m, "\n"); From fa49e2eac9aa8259e1ea540d1bd301448d5b735d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:09 +0200 Subject: [PATCH 15/45] drm: Remove the ULONG_MAX stack trace hackery No architecture terminates the stack trace with ULONG_MAX anymore. Remove the cruft. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Daniel Vetter Cc: Rodrigo Vivi Link: https://lkml.kernel.org/r/20190410103644.945059666@linutronix.de --- drivers/gpu/drm/drm_mm.c | 3 --- drivers/gpu/drm/i915/intel_runtime_pm.c | 4 ---- 2 files changed, 7 deletions(-) diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index 2b4f373736c7..69552777e13a 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -113,9 +113,6 @@ static noinline void save_stack(struct drm_mm_node *node) }; save_stack_trace(&trace); - if (trace.nr_entries != 0 && - trace.entries[trace.nr_entries-1] == ULONG_MAX) - trace.nr_entries--; /* May be called under spinlock, so avoid sleeping */ node->stack = depot_save_stack(&trace, GFP_NOWAIT); diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index a017a4232c0f..1f8acbb332c9 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -67,10 +67,6 @@ static noinline depot_stack_handle_t __save_depot_stack(void) }; save_stack_trace(&trace); - if (trace.nr_entries && - trace.entries[trace.nr_entries - 1] == ULONG_MAX) - trace.nr_entries--; - return depot_save_stack(&trace, GFP_NOWAIT | __GFP_NOWARN); } From 4285f2fcef8001ead0f1c9315ba50302cab68cda Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Apr 2019 12:28:10 +0200 Subject: [PATCH 16/45] tracing: Remove the ULONG_MAX stack trace hackery No architecture terminates the stack trace with ULONG_MAX anymore. As the code checks the number of entries stored anyway there is no point in keeping all that ULONG_MAX magic around. The histogram code zeroes the storage before saving the stack, so if the trace is shorter than the maximum number of entries it can terminate the print loop if a zero entry is detected. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Link: https://lkml.kernel.org/r/20190410103645.048761764@linutronix.de --- kernel/trace/trace_events_hist.c | 2 +- kernel/trace/trace_stack.c | 20 +++++--------------- 2 files changed, 6 insertions(+), 16 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 795aa2038377..21ceae299f7e 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5246,7 +5246,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m, unsigned int i; for (i = 0; i < max_entries; i++) { - if (stacktrace_entries[i] == ULONG_MAX) + if (!stacktrace_entries[i]) return; seq_printf(m, "%*c", 1 + spaces, ' '); diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index eec648a0d673..c6e54ff25cae 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -18,8 +18,7 @@ #include "trace.h" -static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] = - { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX }; +static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES + 1]; unsigned stack_trace_index[STACK_TRACE_ENTRIES]; /* @@ -52,10 +51,7 @@ void stack_trace_print(void) stack_trace_max.nr_entries); for (i = 0; i < stack_trace_max.nr_entries; i++) { - if (stack_dump_trace[i] == ULONG_MAX) - break; - if (i+1 == stack_trace_max.nr_entries || - stack_dump_trace[i+1] == ULONG_MAX) + if (i + 1 == stack_trace_max.nr_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; @@ -150,8 +146,6 @@ check_stack(unsigned long ip, unsigned long *stack) p = start; for (; p < top && i < stack_trace_max.nr_entries; p++) { - if (stack_dump_trace[i] == ULONG_MAX) - break; /* * The READ_ONCE_NOCHECK is used to let KASAN know that * this is not a stack-out-of-bounds error. @@ -183,8 +177,6 @@ check_stack(unsigned long ip, unsigned long *stack) } stack_trace_max.nr_entries = x; - for (; x < i; x++) - stack_dump_trace[x] = ULONG_MAX; if (task_stack_end_corrupted(current)) { stack_trace_print(); @@ -286,7 +278,7 @@ __next(struct seq_file *m, loff_t *pos) { long n = *pos - 1; - if (n >= stack_trace_max.nr_entries || stack_dump_trace[n] == ULONG_MAX) + if (n >= stack_trace_max.nr_entries) return NULL; m->private = (void *)n; @@ -360,12 +352,10 @@ static int t_show(struct seq_file *m, void *v) i = *(long *)v; - if (i >= stack_trace_max.nr_entries || - stack_dump_trace[i] == ULONG_MAX) + if (i >= stack_trace_max.nr_entries) return 0; - if (i+1 == stack_trace_max.nr_entries || - stack_dump_trace[i+1] == ULONG_MAX) + if (i + 1 == stack_trace_max.nr_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; From 3d9a8072915366b5932beeed97f158f8d4955768 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:44:54 +0200 Subject: [PATCH 17/45] tracing: Cleanup stack trace code - Remove the extra array member of stack_dump_trace[] along with the ARRAY_SIZE - 1 initialization for struct stack_trace :: max_entries. Both are historical leftovers of no value. The stack tracer never exceeds the array and there is no extra storage requirement either. - Make variables which are only used in trace_stack.c static. - Simplify the enable/disable logic. - Rename stack_trace_print() as it's using the stack_trace_ namespace. Free the name up for stack trace related functions. Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094801.230654524@linutronix.de --- include/linux/ftrace.h | 18 ++++------------ kernel/trace/trace_stack.c | 42 ++++++++++++-------------------------- 2 files changed, 17 insertions(+), 43 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 730876187344..20899919ead8 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -241,21 +241,11 @@ static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { #ifdef CONFIG_STACK_TRACER -#define STACK_TRACE_ENTRIES 500 - -struct stack_trace; - -extern unsigned stack_trace_index[]; -extern struct stack_trace stack_trace_max; -extern unsigned long stack_trace_max_size; -extern arch_spinlock_t stack_trace_max_lock; - extern int stack_tracer_enabled; -void stack_trace_print(void); -int -stack_trace_sysctl(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos); + +int stack_trace_sysctl(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ DECLARE_PER_CPU(int, disable_stack_tracer); diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index c6e54ff25cae..4efda5f75a0f 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -18,30 +18,26 @@ #include "trace.h" -static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES + 1]; -unsigned stack_trace_index[STACK_TRACE_ENTRIES]; +#define STACK_TRACE_ENTRIES 500 + +static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES]; +static unsigned stack_trace_index[STACK_TRACE_ENTRIES]; -/* - * Reserve one entry for the passed in ip. This will allow - * us to remove most or all of the stack size overhead - * added by the stack tracer itself. - */ struct stack_trace stack_trace_max = { - .max_entries = STACK_TRACE_ENTRIES - 1, + .max_entries = STACK_TRACE_ENTRIES, .entries = &stack_dump_trace[0], }; -unsigned long stack_trace_max_size; -arch_spinlock_t stack_trace_max_lock = +static unsigned long stack_trace_max_size; +static arch_spinlock_t stack_trace_max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; DEFINE_PER_CPU(int, disable_stack_tracer); static DEFINE_MUTEX(stack_sysctl_mutex); int stack_tracer_enabled; -static int last_stack_tracer_enabled; -void stack_trace_print(void) +static void print_max_stack(void) { long i; int size; @@ -61,16 +57,7 @@ void stack_trace_print(void) } } -/* - * When arch-specific code overrides this function, the following - * data should be filled up, assuming stack_trace_max_lock is held to - * prevent concurrent updates. - * stack_trace_index[] - * stack_trace_max - * stack_trace_max_size - */ -void __weak -check_stack(unsigned long ip, unsigned long *stack) +static void check_stack(unsigned long ip, unsigned long *stack) { unsigned long this_size, flags; unsigned long *p, *top, *start; static int tracer_frame; @@ -179,7 +166,7 @@ check_stack(unsigned long ip, unsigned long *stack) stack_trace_max.nr_entries = x; if (task_stack_end_corrupted(current)) { - stack_trace_print(); + print_max_stack(); BUG(); } @@ -412,23 +399,21 @@ stack_trace_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { + int was_enabled; int ret; mutex_lock(&stack_sysctl_mutex); + was_enabled = !!stack_tracer_enabled; ret = proc_dointvec(table, write, buffer, lenp, ppos); - if (ret || !write || - (last_stack_tracer_enabled == !!stack_tracer_enabled)) + if (ret || !write || (was_enabled == !!stack_tracer_enabled)) goto out; - last_stack_tracer_enabled = !!stack_tracer_enabled; - if (stack_tracer_enabled) register_ftrace_function(&trace_ops); else unregister_ftrace_function(&trace_ops); - out: mutex_unlock(&stack_sysctl_mutex); return ret; @@ -444,7 +429,6 @@ static __init int enable_stacktrace(char *str) strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE); stack_tracer_enabled = 1; - last_stack_tracer_enabled = 1; return 1; } __setup("stacktrace", enable_stacktrace); From e9b98e162aa53cbea7c8b0d6c9d5dc6e0f822b9c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:44:55 +0200 Subject: [PATCH 18/45] stacktrace: Provide helpers for common stack trace operations All operations with stack traces are based on struct stack_trace. That's a horrible construct as the struct is a kitchen sink for input and output. Quite some usage sites embed it into their own data structures which creates weird indirections. There is absolutely no point in doing so. For all use cases a storage array and the number of valid stack trace entries in the array is sufficient. Provide helper functions which avoid the struct stack_trace indirection so the usage sites can be cleaned up. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094801.324810708@linutronix.de --- include/linux/stacktrace.h | 27 ++++++ kernel/stacktrace.c | 170 +++++++++++++++++++++++++++++++++---- 2 files changed, 182 insertions(+), 15 deletions(-) diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h index ba29a0613e66..a24340b3e9e1 100644 --- a/include/linux/stacktrace.h +++ b/include/linux/stacktrace.h @@ -3,11 +3,26 @@ #define __LINUX_STACKTRACE_H #include +#include struct task_struct; struct pt_regs; #ifdef CONFIG_STACKTRACE +void stack_trace_print(unsigned long *trace, unsigned int nr_entries, + int spaces); +int stack_trace_snprint(char *buf, size_t size, unsigned long *entries, + unsigned int nr_entries, int spaces); +unsigned int stack_trace_save(unsigned long *store, unsigned int size, + unsigned int skipnr); +unsigned int stack_trace_save_tsk(struct task_struct *task, + unsigned long *store, unsigned int size, + unsigned int skipnr); +unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store, + unsigned int size, unsigned int skipnr); +unsigned int stack_trace_save_user(unsigned long *store, unsigned int size); + +/* Internal interfaces. Do not use in generic code */ struct stack_trace { unsigned int nr_entries, max_entries; unsigned long *entries; @@ -41,4 +56,16 @@ extern void save_stack_trace_user(struct stack_trace *trace); # define save_stack_trace_tsk_reliable(tsk, trace) ({ -ENOSYS; }) #endif /* CONFIG_STACKTRACE */ +#if defined(CONFIG_STACKTRACE) && defined(CONFIG_HAVE_RELIABLE_STACKTRACE) +int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store, + unsigned int size); +#else +static inline int stack_trace_save_tsk_reliable(struct task_struct *tsk, + unsigned long *store, + unsigned int size) +{ + return -ENOSYS; +} +#endif + #endif /* __LINUX_STACKTRACE_H */ diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index f8edee9c792d..b38333b3bc18 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -11,35 +11,54 @@ #include #include -void print_stack_trace(struct stack_trace *trace, int spaces) +/** + * stack_trace_print - Print the entries in the stack trace + * @entries: Pointer to storage array + * @nr_entries: Number of entries in the storage array + * @spaces: Number of leading spaces to print + */ +void stack_trace_print(unsigned long *entries, unsigned int nr_entries, + int spaces) { - int i; + unsigned int i; - if (WARN_ON(!trace->entries)) + if (WARN_ON(!entries)) return; - for (i = 0; i < trace->nr_entries; i++) - printk("%*c%pS\n", 1 + spaces, ' ', (void *)trace->entries[i]); + for (i = 0; i < nr_entries; i++) + printk("%*c%pS\n", 1 + spaces, ' ', (void *)entries[i]); +} +EXPORT_SYMBOL_GPL(stack_trace_print); + +void print_stack_trace(struct stack_trace *trace, int spaces) +{ + stack_trace_print(trace->entries, trace->nr_entries, spaces); } EXPORT_SYMBOL_GPL(print_stack_trace); -int snprint_stack_trace(char *buf, size_t size, - struct stack_trace *trace, int spaces) +/** + * stack_trace_snprint - Print the entries in the stack trace into a buffer + * @buf: Pointer to the print buffer + * @size: Size of the print buffer + * @entries: Pointer to storage array + * @nr_entries: Number of entries in the storage array + * @spaces: Number of leading spaces to print + * + * Return: Number of bytes printed. + */ +int stack_trace_snprint(char *buf, size_t size, unsigned long *entries, + unsigned int nr_entries, int spaces) { - int i; - int generated; - int total = 0; + unsigned int generated, i, total = 0; - if (WARN_ON(!trace->entries)) + if (WARN_ON(!entries)) return 0; - for (i = 0; i < trace->nr_entries; i++) { + for (i = 0; i < nr_entries && size; i++) { generated = snprintf(buf, size, "%*c%pS\n", 1 + spaces, ' ', - (void *)trace->entries[i]); + (void *)entries[i]); total += generated; - - /* Assume that generated isn't a negative number */ if (generated >= size) { buf += size; size = 0; @@ -51,6 +70,14 @@ int snprint_stack_trace(char *buf, size_t size, return total; } +EXPORT_SYMBOL_GPL(stack_trace_snprint); + +int snprint_stack_trace(char *buf, size_t size, + struct stack_trace *trace, int spaces) +{ + return stack_trace_snprint(buf, size, trace->entries, + trace->nr_entries, spaces); +} EXPORT_SYMBOL_GPL(snprint_stack_trace); /* @@ -77,3 +104,116 @@ save_stack_trace_tsk_reliable(struct task_struct *tsk, WARN_ONCE(1, KERN_INFO "save_stack_tsk_reliable() not implemented yet.\n"); return -ENOSYS; } + +/** + * stack_trace_save - Save a stack trace into a storage array + * @store: Pointer to storage array + * @size: Size of the storage array + * @skipnr: Number of entries to skip at the start of the stack trace + * + * Return: Number of trace entries stored + */ +unsigned int stack_trace_save(unsigned long *store, unsigned int size, + unsigned int skipnr) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + .skip = skipnr + 1, + }; + + save_stack_trace(&trace); + return trace.nr_entries; +} +EXPORT_SYMBOL_GPL(stack_trace_save); + +/** + * stack_trace_save_tsk - Save a task stack trace into a storage array + * @task: The task to examine + * @store: Pointer to storage array + * @size: Size of the storage array + * @skipnr: Number of entries to skip at the start of the stack trace + * + * Return: Number of trace entries stored + */ +unsigned int stack_trace_save_tsk(struct task_struct *task, + unsigned long *store, unsigned int size, + unsigned int skipnr) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + .skip = skipnr + 1, + }; + + save_stack_trace_tsk(task, &trace); + return trace.nr_entries; +} + +/** + * stack_trace_save_regs - Save a stack trace based on pt_regs into a storage array + * @regs: Pointer to pt_regs to examine + * @store: Pointer to storage array + * @size: Size of the storage array + * @skipnr: Number of entries to skip at the start of the stack trace + * + * Return: Number of trace entries stored + */ +unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store, + unsigned int size, unsigned int skipnr) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + .skip = skipnr, + }; + + save_stack_trace_regs(regs, &trace); + return trace.nr_entries; +} + +#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE +/** + * stack_trace_save_tsk_reliable - Save task stack with verification + * @tsk: Pointer to the task to examine + * @store: Pointer to storage array + * @size: Size of the storage array + * + * Return: An error if it detects any unreliable features of the + * stack. Otherwise it guarantees that the stack trace is + * reliable and returns the number of entries stored. + * + * If the task is not 'current', the caller *must* ensure the task is inactive. + */ +int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store, + unsigned int size) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + }; + int ret = save_stack_trace_tsk_reliable(tsk, &trace); + + return ret ? ret : trace.nr_entries; +} +#endif + +#ifdef CONFIG_USER_STACKTRACE_SUPPORT +/** + * stack_trace_save_user - Save a user space stack trace into a storage array + * @store: Pointer to storage array + * @size: Size of the storage array + * + * Return: Number of trace entries stored + */ +unsigned int stack_trace_save_user(unsigned long *store, unsigned int size) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + }; + + save_stack_trace_user(&trace); + return trace.nr_entries; +} +#endif /* CONFIG_USER_STACKTRACE_SUPPORT */ From c0cfc337264c5e02e0bc79de6b62857999588879 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:44:56 +0200 Subject: [PATCH 19/45] lib/stackdepot: Provide functions which operate on plain storage arrays The struct stack_trace indirection in the stack depot functions is a truly pointless excercise which requires horrible code at the callsites. Provide interfaces based on plain storage arrays. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Alexander Potapenko Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094801.414574828@linutronix.de --- include/linux/stackdepot.h | 4 +++ lib/stackdepot.c | 70 +++++++++++++++++++++++++++----------- 2 files changed, 55 insertions(+), 19 deletions(-) diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index 7978b3e2c1e1..4297c6d2991d 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -26,7 +26,11 @@ typedef u32 depot_stack_handle_t; struct stack_trace; depot_stack_handle_t depot_save_stack(struct stack_trace *trace, gfp_t flags); +depot_stack_handle_t stack_depot_save(unsigned long *entries, + unsigned int nr_entries, gfp_t gfp_flags); void depot_fetch_stack(depot_stack_handle_t handle, struct stack_trace *trace); +unsigned int stack_depot_fetch(depot_stack_handle_t handle, + unsigned long **entries); #endif diff --git a/lib/stackdepot.c b/lib/stackdepot.c index e513459a5601..e84f8e58495c 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -194,40 +194,60 @@ static inline struct stack_record *find_stack(struct stack_record *bucket, return NULL; } -void depot_fetch_stack(depot_stack_handle_t handle, struct stack_trace *trace) +/** + * stack_depot_fetch - Fetch stack entries from a depot + * + * @handle: Stack depot handle which was returned from + * stack_depot_save(). + * @entries: Pointer to store the entries address + * + * Return: The number of trace entries for this depot. + */ +unsigned int stack_depot_fetch(depot_stack_handle_t handle, + unsigned long **entries) { union handle_parts parts = { .handle = handle }; void *slab = stack_slabs[parts.slabindex]; size_t offset = parts.offset << STACK_ALLOC_ALIGN; struct stack_record *stack = slab + offset; - trace->nr_entries = trace->max_entries = stack->size; - trace->entries = stack->entries; - trace->skip = 0; + *entries = stack->entries; + return stack->size; +} +EXPORT_SYMBOL_GPL(stack_depot_fetch); + +void depot_fetch_stack(depot_stack_handle_t handle, struct stack_trace *trace) +{ + unsigned int nent = stack_depot_fetch(handle, &trace->entries); + + trace->max_entries = trace->nr_entries = nent; } EXPORT_SYMBOL_GPL(depot_fetch_stack); /** - * depot_save_stack - save stack in a stack depot. - * @trace - the stacktrace to save. - * @alloc_flags - flags for allocating additional memory if required. + * stack_depot_save - Save a stack trace from an array * - * Returns the handle of the stack struct stored in depot. + * @entries: Pointer to storage array + * @nr_entries: Size of the storage array + * @alloc_flags: Allocation gfp flags + * + * Return: The handle of the stack struct stored in depot */ -depot_stack_handle_t depot_save_stack(struct stack_trace *trace, - gfp_t alloc_flags) +depot_stack_handle_t stack_depot_save(unsigned long *entries, + unsigned int nr_entries, + gfp_t alloc_flags) { - u32 hash; - depot_stack_handle_t retval = 0; struct stack_record *found = NULL, **bucket; - unsigned long flags; + depot_stack_handle_t retval = 0; struct page *page = NULL; void *prealloc = NULL; + unsigned long flags; + u32 hash; - if (unlikely(trace->nr_entries == 0)) + if (unlikely(nr_entries == 0)) goto fast_exit; - hash = hash_stack(trace->entries, trace->nr_entries); + hash = hash_stack(entries, nr_entries); bucket = &stack_table[hash & STACK_HASH_MASK]; /* @@ -235,8 +255,8 @@ depot_stack_handle_t depot_save_stack(struct stack_trace *trace, * The smp_load_acquire() here pairs with smp_store_release() to * |bucket| below. */ - found = find_stack(smp_load_acquire(bucket), trace->entries, - trace->nr_entries, hash); + found = find_stack(smp_load_acquire(bucket), entries, + nr_entries, hash); if (found) goto exit; @@ -264,10 +284,10 @@ depot_stack_handle_t depot_save_stack(struct stack_trace *trace, spin_lock_irqsave(&depot_lock, flags); - found = find_stack(*bucket, trace->entries, trace->nr_entries, hash); + found = find_stack(*bucket, entries, nr_entries, hash); if (!found) { struct stack_record *new = - depot_alloc_stack(trace->entries, trace->nr_entries, + depot_alloc_stack(entries, nr_entries, hash, &prealloc, alloc_flags); if (new) { new->next = *bucket; @@ -297,4 +317,16 @@ exit: fast_exit: return retval; } +EXPORT_SYMBOL_GPL(stack_depot_save); + +/** + * depot_save_stack - save stack in a stack depot. + * @trace - the stacktrace to save. + * @alloc_flags - flags for allocating additional memory if required. + */ +depot_stack_handle_t depot_save_stack(struct stack_trace *trace, + gfp_t alloc_flags) +{ + return stack_depot_save(trace->entries, trace->nr_entries, alloc_flags); +} EXPORT_SYMBOL_GPL(depot_save_stack); From 1b59562d3ab09dcef188eb8055d05f0336380394 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:44:57 +0200 Subject: [PATCH 20/45] backtrace-test: Simplify stack trace handling Replace the indirection through struct stack_trace by using the storage array based interfaces. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094801.501919093@linutronix.de --- kernel/backtracetest.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/kernel/backtracetest.c b/kernel/backtracetest.c index 1323360d90e3..a563c8fdad0d 100644 --- a/kernel/backtracetest.c +++ b/kernel/backtracetest.c @@ -48,19 +48,14 @@ static void backtrace_test_irq(void) #ifdef CONFIG_STACKTRACE static void backtrace_test_saved(void) { - struct stack_trace trace; unsigned long entries[8]; + unsigned int nr_entries; pr_info("Testing a saved backtrace.\n"); pr_info("The following trace is a kernel self test and not a bug!\n"); - trace.nr_entries = 0; - trace.max_entries = ARRAY_SIZE(entries); - trace.entries = entries; - trace.skip = 0; - - save_stack_trace(&trace); - print_stack_trace(&trace, 0); + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); + stack_trace_print(entries, nr_entries, 0); } #else static void backtrace_test_saved(void) From e988e5ec18d6081efbef645fc2690298ee23a8db Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:44:58 +0200 Subject: [PATCH 21/45] proc: Simplify task stack retrieval Replace the indirection through struct stack_trace with an invocation of the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Alexey Dobriyan Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Andrew Morton Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094801.589304463@linutronix.de --- fs/proc/base.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 5569f215fc54..f179568b4c76 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -407,7 +407,6 @@ static void unlock_trace(struct task_struct *task) static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { - struct stack_trace trace; unsigned long *entries; int err; @@ -430,20 +429,17 @@ static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, if (!entries) return -ENOMEM; - trace.nr_entries = 0; - trace.max_entries = MAX_STACK_TRACE_DEPTH; - trace.entries = entries; - trace.skip = 0; - err = lock_trace(task); if (!err) { - unsigned int i; + unsigned int i, nr_entries; - save_stack_trace_tsk(task, &trace); + nr_entries = stack_trace_save_tsk(task, entries, + MAX_STACK_TRACE_DEPTH, 0); - for (i = 0; i < trace.nr_entries; i++) { + for (i = 0; i < nr_entries; i++) { seq_printf(m, "[<0>] %pB\n", (void *)entries[i]); } + unlock_trace(task); } kfree(entries); From f93877214a83e88373b20801c2d671923d03d07d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:44:59 +0200 Subject: [PATCH 22/45] latency_top: Simplify stack trace handling Replace the indirection through struct stack_trace with an invocation of the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094801.683039030@linutronix.de --- kernel/latencytop.c | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-) diff --git a/kernel/latencytop.c b/kernel/latencytop.c index f5a90ab3c6b9..99a5b5f46dc5 100644 --- a/kernel/latencytop.c +++ b/kernel/latencytop.c @@ -141,20 +141,6 @@ account_global_scheduler_latency(struct task_struct *tsk, memcpy(&latency_record[i], lat, sizeof(struct latency_record)); } -/* - * Iterator to store a backtrace into a latency record entry - */ -static inline void store_stacktrace(struct task_struct *tsk, - struct latency_record *lat) -{ - struct stack_trace trace; - - memset(&trace, 0, sizeof(trace)); - trace.max_entries = LT_BACKTRACEDEPTH; - trace.entries = &lat->backtrace[0]; - save_stack_trace_tsk(tsk, &trace); -} - /** * __account_scheduler_latency - record an occurred latency * @tsk - the task struct of the task hitting the latency @@ -191,7 +177,8 @@ __account_scheduler_latency(struct task_struct *tsk, int usecs, int inter) lat.count = 1; lat.time = usecs; lat.max = usecs; - store_stacktrace(tsk, &lat); + + stack_trace_save_tsk(tsk, lat.backtrace, LT_BACKTRACEDEPTH, 0); raw_spin_lock_irqsave(&latency_lock, flags); From 7971679994d3a239538ddcfea9f89468f0bd65e2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:00 +0200 Subject: [PATCH 23/45] mm/slub: Simplify stack trace retrieval Replace the indirection through struct stack_trace with an invocation of the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Christoph Lameter Cc: Andy Lutomirski Cc: Andrew Morton Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094801.771410441@linutronix.de --- mm/slub.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index e2ccd12b6faa..6b28cd2b5a58 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -552,18 +552,14 @@ static void set_track(struct kmem_cache *s, void *object, if (addr) { #ifdef CONFIG_STACKTRACE - struct stack_trace trace; + unsigned int nr_entries; - trace.nr_entries = 0; - trace.max_entries = TRACK_ADDRS_COUNT; - trace.entries = p->addrs; - trace.skip = 3; metadata_access_enable(); - save_stack_trace(&trace); + nr_entries = stack_trace_save(p->addrs, TRACK_ADDRS_COUNT, 3); metadata_access_disable(); - if (trace.nr_entries < TRACK_ADDRS_COUNT) - p->addrs[trace.nr_entries] = 0; + if (nr_entries < TRACK_ADDRS_COUNT) + p->addrs[nr_entries] = 0; #endif p->addr = addr; p->cpu = smp_processor_id(); From 07984aad1c7ed679596f849c0e7d5e029f76e0eb Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:01 +0200 Subject: [PATCH 24/45] mm/kmemleak: Simplify stacktrace handling Replace the indirection through struct stack_trace by using the storage array based interfaces. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Catalin Marinas Cc: Andy Lutomirski Cc: linux-mm@kvack.org Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094801.863716911@linutronix.de --- mm/kmemleak.c | 24 +++--------------------- 1 file changed, 3 insertions(+), 21 deletions(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 6c318f5ac234..d12b35de1e7e 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -410,11 +410,6 @@ static void print_unreferenced(struct seq_file *seq, */ static void dump_object_info(struct kmemleak_object *object) { - struct stack_trace trace; - - trace.nr_entries = object->trace_len; - trace.entries = object->trace; - pr_notice("Object 0x%08lx (size %zu):\n", object->pointer, object->size); pr_notice(" comm \"%s\", pid %d, jiffies %lu\n", @@ -424,7 +419,7 @@ static void dump_object_info(struct kmemleak_object *object) pr_notice(" flags = 0x%x\n", object->flags); pr_notice(" checksum = %u\n", object->checksum); pr_notice(" backtrace:\n"); - print_stack_trace(&trace, 4); + stack_trace_print(object->trace, object->trace_len, 4); } /* @@ -553,15 +548,7 @@ static struct kmemleak_object *find_and_remove_object(unsigned long ptr, int ali */ static int __save_stack_trace(unsigned long *trace) { - struct stack_trace stack_trace; - - stack_trace.max_entries = MAX_TRACE; - stack_trace.nr_entries = 0; - stack_trace.entries = trace; - stack_trace.skip = 2; - save_stack_trace(&stack_trace); - - return stack_trace.nr_entries; + return stack_trace_save(trace, MAX_TRACE, 2); } /* @@ -2019,13 +2006,8 @@ early_param("kmemleak", kmemleak_boot_config); static void __init print_log_trace(struct early_log *log) { - struct stack_trace trace; - - trace.nr_entries = log->trace_len; - trace.entries = log->trace; - pr_notice("Early log backtrace:\n"); - print_stack_trace(&trace, 2); + stack_trace_print(log->trace, log->trace_len, 2); } /* From 880e049c9ce9020384ce305c71375aa1cb54addb Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:02 +0200 Subject: [PATCH 25/45] mm/kasan: Simplify stacktrace handling Replace the indirection through struct stack_trace by using the storage array based interfaces. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Dmitry Vyukov Acked-by: Andrey Ryabinin Cc: Andy Lutomirski Cc: Alexander Potapenko Cc: kasan-dev@googlegroups.com Cc: linux-mm@kvack.org Cc: Steven Rostedt Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Catalin Marinas Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094801.963261479@linutronix.de --- mm/kasan/common.c | 30 ++++++++++++------------------ mm/kasan/report.c | 7 ++++--- 2 files changed, 16 insertions(+), 21 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 38e5f20a775a..303a7379d2a3 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -48,34 +48,28 @@ static inline int in_irqentry_text(unsigned long ptr) ptr < (unsigned long)&__softirqentry_text_end); } -static inline void filter_irq_stacks(struct stack_trace *trace) +static inline unsigned int filter_irq_stacks(unsigned long *entries, + unsigned int nr_entries) { - int i; + unsigned int i; - if (!trace->nr_entries) - return; - for (i = 0; i < trace->nr_entries; i++) - if (in_irqentry_text(trace->entries[i])) { + for (i = 0; i < nr_entries; i++) { + if (in_irqentry_text(entries[i])) { /* Include the irqentry function into the stack. */ - trace->nr_entries = i + 1; - break; + return i + 1; } + } + return nr_entries; } static inline depot_stack_handle_t save_stack(gfp_t flags) { unsigned long entries[KASAN_STACK_DEPTH]; - struct stack_trace trace = { - .nr_entries = 0, - .entries = entries, - .max_entries = KASAN_STACK_DEPTH, - .skip = 0 - }; + unsigned int nr_entries; - save_stack_trace(&trace); - filter_irq_stacks(&trace); - - return depot_save_stack(&trace, flags); + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); + nr_entries = filter_irq_stacks(entries, nr_entries); + return stack_depot_save(entries, nr_entries, flags); } static inline void set_track(struct kasan_track *track, gfp_t flags) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index ca9418fe9232..882d77568e7e 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -100,10 +100,11 @@ static void print_track(struct kasan_track *track, const char *prefix) { pr_err("%s by task %u:\n", prefix, track->pid); if (track->stack) { - struct stack_trace trace; + unsigned long *entries; + unsigned int nr_entries; - depot_fetch_stack(track->stack, &trace); - print_stack_trace(&trace, 0); + nr_entries = stack_depot_fetch(track->stack, &entries); + stack_trace_print(entries, nr_entries, 0); } else { pr_err("(stack is not available)\n"); } From af52bf6b92f7d8783c1e712cad6ef7d37cd773b2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:03 +0200 Subject: [PATCH 26/45] mm/page_owner: Simplify stack trace handling Replace the indirection through struct stack_trace by using the storage array based interfaces. The original code in all printing functions is really wrong. It allocates a storage array on stack which is unused because depot_fetch_stack() does not store anything in it. It overwrites the entries pointer in the stack_trace struct so it points to the depot storage. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: linux-mm@kvack.org Cc: Mike Rapoport Cc: David Rientjes Cc: Andrew Morton Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Christoph Lameter Cc: Pekka Enberg Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.067210525@linutronix.de --- mm/page_owner.c | 79 ++++++++++++++++++------------------------------- 1 file changed, 28 insertions(+), 51 deletions(-) diff --git a/mm/page_owner.c b/mm/page_owner.c index df277e6bc3c6..addcbb2ae4e4 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -58,15 +58,10 @@ static bool need_page_owner(void) static __always_inline depot_stack_handle_t create_dummy_stack(void) { unsigned long entries[4]; - struct stack_trace dummy; + unsigned int nr_entries; - dummy.nr_entries = 0; - dummy.max_entries = ARRAY_SIZE(entries); - dummy.entries = &entries[0]; - dummy.skip = 0; - - save_stack_trace(&dummy); - return depot_save_stack(&dummy, GFP_KERNEL); + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); + return stack_depot_save(entries, nr_entries, GFP_KERNEL); } static noinline void register_dummy_stack(void) @@ -120,46 +115,39 @@ void __reset_page_owner(struct page *page, unsigned int order) } } -static inline bool check_recursive_alloc(struct stack_trace *trace, - unsigned long ip) +static inline bool check_recursive_alloc(unsigned long *entries, + unsigned int nr_entries, + unsigned long ip) { - int i; + unsigned int i; - if (!trace->nr_entries) - return false; - - for (i = 0; i < trace->nr_entries; i++) { - if (trace->entries[i] == ip) + for (i = 0; i < nr_entries; i++) { + if (entries[i] == ip) return true; } - return false; } static noinline depot_stack_handle_t save_stack(gfp_t flags) { unsigned long entries[PAGE_OWNER_STACK_DEPTH]; - struct stack_trace trace = { - .nr_entries = 0, - .entries = entries, - .max_entries = PAGE_OWNER_STACK_DEPTH, - .skip = 2 - }; depot_stack_handle_t handle; + unsigned int nr_entries; - save_stack_trace(&trace); + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2); /* - * We need to check recursion here because our request to stackdepot - * could trigger memory allocation to save new entry. New memory - * allocation would reach here and call depot_save_stack() again - * if we don't catch it. There is still not enough memory in stackdepot - * so it would try to allocate memory again and loop forever. + * We need to check recursion here because our request to + * stackdepot could trigger memory allocation to save new + * entry. New memory allocation would reach here and call + * stack_depot_save_entries() again if we don't catch it. There is + * still not enough memory in stackdepot so it would try to + * allocate memory again and loop forever. */ - if (check_recursive_alloc(&trace, _RET_IP_)) + if (check_recursive_alloc(entries, nr_entries, _RET_IP_)) return dummy_handle; - handle = depot_save_stack(&trace, flags); + handle = stack_depot_save(entries, nr_entries, flags); if (!handle) handle = failure_handle; @@ -337,16 +325,10 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, struct page *page, struct page_owner *page_owner, depot_stack_handle_t handle) { - int ret; - int pageblock_mt, page_mt; + int ret, pageblock_mt, page_mt; + unsigned long *entries; + unsigned int nr_entries; char *kbuf; - unsigned long entries[PAGE_OWNER_STACK_DEPTH]; - struct stack_trace trace = { - .nr_entries = 0, - .entries = entries, - .max_entries = PAGE_OWNER_STACK_DEPTH, - .skip = 0 - }; count = min_t(size_t, count, PAGE_SIZE); kbuf = kmalloc(count, GFP_KERNEL); @@ -375,8 +357,8 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, if (ret >= count) goto err; - depot_fetch_stack(handle, &trace); - ret += snprint_stack_trace(kbuf + ret, count - ret, &trace, 0); + nr_entries = stack_depot_fetch(handle, &entries); + ret += stack_trace_snprint(kbuf + ret, count - ret, entries, nr_entries, 0); if (ret >= count) goto err; @@ -407,14 +389,9 @@ void __dump_page_owner(struct page *page) { struct page_ext *page_ext = lookup_page_ext(page); struct page_owner *page_owner; - unsigned long entries[PAGE_OWNER_STACK_DEPTH]; - struct stack_trace trace = { - .nr_entries = 0, - .entries = entries, - .max_entries = PAGE_OWNER_STACK_DEPTH, - .skip = 0 - }; depot_stack_handle_t handle; + unsigned long *entries; + unsigned int nr_entries; gfp_t gfp_mask; int mt; @@ -438,10 +415,10 @@ void __dump_page_owner(struct page *page) return; } - depot_fetch_stack(handle, &trace); + nr_entries = stack_depot_fetch(handle, &entries); pr_alert("page allocated via order %u, migratetype %s, gfp_mask %#x(%pGg)\n", page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask); - print_stack_trace(&trace, 0); + stack_trace_print(entries, nr_entries, 0); if (page_owner->last_migrate_reason != -1) pr_alert("page has been migrated, last migrate reason: %s\n", From 30191250c2b3ef772cc6125e1c31ac84123f1d20 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:04 +0200 Subject: [PATCH 27/45] fault-inject: Simplify stacktrace retrieval Replace the indirection through struct stack_trace with an invocation of the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Akinobu Mita Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.158306076@linutronix.de --- lib/fault-inject.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/lib/fault-inject.c b/lib/fault-inject.c index cf7b129b0b2b..e26aa4f65eb9 100644 --- a/lib/fault-inject.c +++ b/lib/fault-inject.c @@ -65,22 +65,16 @@ static bool fail_task(struct fault_attr *attr, struct task_struct *task) static bool fail_stacktrace(struct fault_attr *attr) { - struct stack_trace trace; int depth = attr->stacktrace_depth; unsigned long entries[MAX_STACK_TRACE_DEPTH]; - int n; + int n, nr_entries; bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX); if (depth == 0) return found; - trace.nr_entries = 0; - trace.entries = entries; - trace.max_entries = depth; - trace.skip = 1; - - save_stack_trace(&trace); - for (n = 0; n < trace.nr_entries; n++) { + nr_entries = stack_trace_save(entries, depth, 1); + for (n = 0; n < nr_entries; n++) { if (attr->reject_start <= entries[n] && entries[n] < attr->reject_end) return false; From 746017ed8d4d3c2070bb03aee9536f24da43c778 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:05 +0200 Subject: [PATCH 28/45] dma/debug: Simplify stracktrace retrieval Replace the indirection through struct stack_trace with an invocation of the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Christoph Hellwig Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.248658135@linutronix.de --- kernel/dma/debug.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index a218e43cc382..badd77670d00 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -89,8 +89,8 @@ struct dma_debug_entry { int sg_mapped_ents; enum map_err_types map_err_type; #ifdef CONFIG_STACKTRACE - struct stack_trace stacktrace; - unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES]; + unsigned int stack_len; + unsigned long stack_entries[DMA_DEBUG_STACKTRACE_ENTRIES]; #endif }; @@ -174,7 +174,7 @@ static inline void dump_entry_trace(struct dma_debug_entry *entry) #ifdef CONFIG_STACKTRACE if (entry) { pr_warning("Mapped at:\n"); - print_stack_trace(&entry->stacktrace, 0); + stack_trace_print(entry->stack_entries, entry->stack_len, 0); } #endif } @@ -704,12 +704,10 @@ static struct dma_debug_entry *dma_entry_alloc(void) spin_unlock_irqrestore(&free_entries_lock, flags); #ifdef CONFIG_STACKTRACE - entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES; - entry->stacktrace.entries = entry->st_entries; - entry->stacktrace.skip = 1; - save_stack_trace(&entry->stacktrace); + entry->stack_len = stack_trace_save(entry->stack_entries, + ARRAY_SIZE(entry->stack_entries), + 1); #endif - return entry; } From 6924f5feba21ea2bba64b4dc316ee046c48355ca Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:06 +0200 Subject: [PATCH 29/45] btrfs: ref-verify: Simplify stack trace retrieval Replace the indirection through struct stack_trace with an invocation of the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Johannes Thumshirn Reviewed-by: Josh Poimboeuf Acked-by: David Sterba Cc: Andy Lutomirski Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.338890064@linutronix.de --- fs/btrfs/ref-verify.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c index d09b6cdb785a..b283d3a6e837 100644 --- a/fs/btrfs/ref-verify.c +++ b/fs/btrfs/ref-verify.c @@ -205,28 +205,17 @@ static struct root_entry *lookup_root_entry(struct rb_root *root, u64 objectid) #ifdef CONFIG_STACKTRACE static void __save_stack_trace(struct ref_action *ra) { - struct stack_trace stack_trace; - - stack_trace.max_entries = MAX_TRACE; - stack_trace.nr_entries = 0; - stack_trace.entries = ra->trace; - stack_trace.skip = 2; - save_stack_trace(&stack_trace); - ra->trace_len = stack_trace.nr_entries; + ra->trace_len = stack_trace_save(ra->trace, MAX_TRACE, 2); } static void __print_stack_trace(struct btrfs_fs_info *fs_info, struct ref_action *ra) { - struct stack_trace trace; - if (ra->trace_len == 0) { btrfs_err(fs_info, " ref-verify: no stacktrace"); return; } - trace.nr_entries = ra->trace_len; - trace.entries = ra->trace; - print_stack_trace(&trace, 2); + stack_trace_print(ra->trace, ra->trace_len, 2); } #else static void inline __save_stack_trace(struct ref_action *ra) From 741b58f3e23673a666c700361711a91022a69e56 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:07 +0200 Subject: [PATCH 30/45] dm bufio: Simplify stack trace retrieval Replace the indirection through struct stack_trace with an invocation of the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.446326191@linutronix.de --- drivers/md/dm-bufio.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 1ecef76225a1..2a48ea3f1b30 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -150,7 +150,7 @@ struct dm_buffer { void (*end_io)(struct dm_buffer *, blk_status_t); #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING #define MAX_STACK 10 - struct stack_trace stack_trace; + unsigned int stack_len; unsigned long stack_entries[MAX_STACK]; #endif }; @@ -232,11 +232,7 @@ static DEFINE_MUTEX(dm_bufio_clients_lock); #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING static void buffer_record_stack(struct dm_buffer *b) { - b->stack_trace.nr_entries = 0; - b->stack_trace.max_entries = MAX_STACK; - b->stack_trace.entries = b->stack_entries; - b->stack_trace.skip = 2; - save_stack_trace(&b->stack_trace); + b->stack_len = stack_trace_save(b->stack_entries, MAX_STACK, 2); } #endif @@ -438,7 +434,7 @@ static struct dm_buffer *alloc_buffer(struct dm_bufio_client *c, gfp_t gfp_mask) adjust_total_allocated(b->data_mode, (long)c->block_size); #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING - memset(&b->stack_trace, 0, sizeof(b->stack_trace)); + b->stack_len = 0; #endif return b; } @@ -1520,8 +1516,9 @@ static void drop_buffers(struct dm_bufio_client *c) DMERR("leaked buffer %llx, hold count %u, list %d", (unsigned long long)b->block, b->hold_count, i); #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING - print_stack_trace(&b->stack_trace, 1); - b->hold_count = 0; /* mark unclaimed to avoid BUG_ON below */ + stack_trace_print(b->stack_entries, b->stack_len, 1); + /* mark unclaimed to avoid BUG_ON below */ + b->hold_count = 0; #endif } From be9c52ed84eb0949fed3d4140e35ea70eecb02a2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:08 +0200 Subject: [PATCH 31/45] dm persistent data: Simplify stack trace handling Replace the indirection through struct stack_trace with an invocation of the storage array based interface. This results in less storage space and indirection. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.533968922@linutronix.de --- drivers/md/persistent-data/dm-block-manager.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c index 3972232b8037..749ec268d957 100644 --- a/drivers/md/persistent-data/dm-block-manager.c +++ b/drivers/md/persistent-data/dm-block-manager.c @@ -35,7 +35,10 @@ #define MAX_HOLDERS 4 #define MAX_STACK 10 -typedef unsigned long stack_entries[MAX_STACK]; +struct stack_store { + unsigned int nr_entries; + unsigned long entries[MAX_STACK]; +}; struct block_lock { spinlock_t lock; @@ -44,8 +47,7 @@ struct block_lock { struct task_struct *holders[MAX_HOLDERS]; #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING - struct stack_trace traces[MAX_HOLDERS]; - stack_entries entries[MAX_HOLDERS]; + struct stack_store traces[MAX_HOLDERS]; #endif }; @@ -73,7 +75,7 @@ static void __add_holder(struct block_lock *lock, struct task_struct *task) { unsigned h = __find_holder(lock, NULL); #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING - struct stack_trace *t; + struct stack_store *t; #endif get_task_struct(task); @@ -81,11 +83,7 @@ static void __add_holder(struct block_lock *lock, struct task_struct *task) #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING t = lock->traces + h; - t->nr_entries = 0; - t->max_entries = MAX_STACK; - t->entries = lock->entries[h]; - t->skip = 2; - save_stack_trace(t); + t->nr_entries = stack_trace_save(t->entries, MAX_STACK, 2); #endif } @@ -106,7 +104,8 @@ static int __check_holder(struct block_lock *lock) DMERR("recursive lock detected in metadata"); #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING DMERR("previously held here:"); - print_stack_trace(lock->traces + i, 4); + stack_trace_print(lock->traces[i].entries, + lock->traces[i].nr_entries, 4); DMERR("subsequent acquisition attempted here:"); dump_stack(); From 487f3c7fb1a07ceff78bb18688eb8538a4775227 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:09 +0200 Subject: [PATCH 32/45] drm: Simplify stacktrace handling Replace the indirection through struct stack_trace by using the storage array based interfaces. The original code in all printing functions is really wrong. It allocates a storage array on stack which is unused because depot_fetch_stack() does not store anything in it. It overwrites the entries pointer in the stack_trace struct so it points to the depot storage. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Daniel Vetter Cc: Andy Lutomirski Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.622094226@linutronix.de --- drivers/gpu/drm/drm_mm.c | 22 +++++++--------------- drivers/gpu/drm/i915/i915_vma.c | 11 ++++------- drivers/gpu/drm/i915/intel_runtime_pm.c | 21 +++++++-------------- 3 files changed, 18 insertions(+), 36 deletions(-) diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index 69552777e13a..8b4cd31ce7bd 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -106,22 +106,19 @@ static noinline void save_stack(struct drm_mm_node *node) { unsigned long entries[STACKDEPTH]; - struct stack_trace trace = { - .entries = entries, - .max_entries = STACKDEPTH, - .skip = 1 - }; + unsigned int n; - save_stack_trace(&trace); + n = stack_trace_save(entries, ARRAY_SIZE(entries), 1); /* May be called under spinlock, so avoid sleeping */ - node->stack = depot_save_stack(&trace, GFP_NOWAIT); + node->stack = stack_depot_save(entries, n, GFP_NOWAIT); } static void show_leaks(struct drm_mm *mm) { struct drm_mm_node *node; - unsigned long entries[STACKDEPTH]; + unsigned long *entries; + unsigned int nr_entries; char *buf; buf = kmalloc(BUFSZ, GFP_KERNEL); @@ -129,19 +126,14 @@ static void show_leaks(struct drm_mm *mm) return; list_for_each_entry(node, drm_mm_nodes(mm), node_list) { - struct stack_trace trace = { - .entries = entries, - .max_entries = STACKDEPTH - }; - if (!node->stack) { DRM_ERROR("node [%08llx + %08llx]: unknown owner\n", node->start, node->size); continue; } - depot_fetch_stack(node->stack, &trace); - snprint_stack_trace(buf, BUFSZ, &trace, 0); + nr_entries = stack_depot_fetch(node->stack, &entries); + stack_trace_snprint(buf, BUFSZ, entries, nr_entries, 0); DRM_ERROR("node [%08llx + %08llx]: inserted at\n%s", node->start, node->size, buf); } diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index b713bed20c38..41b5bcb803cb 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -36,11 +36,8 @@ static void vma_print_allocator(struct i915_vma *vma, const char *reason) { - unsigned long entries[12]; - struct stack_trace trace = { - .entries = entries, - .max_entries = ARRAY_SIZE(entries), - }; + unsigned long *entries; + unsigned int nr_entries; char buf[512]; if (!vma->node.stack) { @@ -49,8 +46,8 @@ static void vma_print_allocator(struct i915_vma *vma, const char *reason) return; } - depot_fetch_stack(vma->node.stack, &trace); - snprint_stack_trace(buf, sizeof(buf), &trace, 0); + nr_entries = stack_depot_fetch(vma->node.stack, &entries); + stack_trace_snprint(buf, sizeof(buf), entries, nr_entries, 0); DRM_DEBUG_DRIVER("vma.node [%08llx + %08llx] %s: inserted at %s\n", vma->node.start, vma->node.size, reason, buf); } diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index 1f8acbb332c9..20c4434474e3 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -60,27 +60,20 @@ static noinline depot_stack_handle_t __save_depot_stack(void) { unsigned long entries[STACKDEPTH]; - struct stack_trace trace = { - .entries = entries, - .max_entries = ARRAY_SIZE(entries), - .skip = 1, - }; + unsigned int n; - save_stack_trace(&trace); - return depot_save_stack(&trace, GFP_NOWAIT | __GFP_NOWARN); + n = stack_trace_save(entries, ARRAY_SIZE(entries), 1); + return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN); } static void __print_depot_stack(depot_stack_handle_t stack, char *buf, int sz, int indent) { - unsigned long entries[STACKDEPTH]; - struct stack_trace trace = { - .entries = entries, - .max_entries = ARRAY_SIZE(entries), - }; + unsigned long *entries; + unsigned int nr_entries; - depot_fetch_stack(stack, &trace); - snprint_stack_trace(buf, sz, &trace, indent); + nr_entries = stack_depot_fetch(stack, &entries); + stack_trace_snprint(buf, sz, entries, nr_entries, indent); } static void init_intel_runtime_pm_wakeref(struct drm_i915_private *i915) From b1abe4622d4cc32b3b37cfefbc7ac070a8f868e0 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:10 +0200 Subject: [PATCH 33/45] lockdep: Remove unused trace argument from print_circular_bug() Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.716274532@linutronix.de --- kernel/locking/lockdep.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 2edf9501d906..d7615d299d08 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1522,10 +1522,9 @@ static inline int class_equal(struct lock_list *entry, void *data) } static noinline int print_circular_bug(struct lock_list *this, - struct lock_list *target, - struct held_lock *check_src, - struct held_lock *check_tgt, - struct stack_trace *trace) + struct lock_list *target, + struct held_lock *check_src, + struct held_lock *check_tgt) { struct task_struct *curr = current; struct lock_list *parent; @@ -2206,7 +2205,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, */ save(trace); } - return print_circular_bug(&this, target_entry, next, prev, trace); + return print_circular_bug(&this, target_entry, next, prev); } else if (unlikely(ret < 0)) return print_bfs_bug(ret); From 76b14436b4d98903fef723365170bedd6f28ab2c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:11 +0200 Subject: [PATCH 34/45] lockdep: Remove save argument from check_prev_add() There is only one caller which hands in save_trace as function pointer. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Peter Zijlstra (Intel) Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.803362058@linutronix.de --- kernel/locking/lockdep.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index d7615d299d08..3603893d5bbd 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2158,8 +2158,7 @@ check_deadlock(struct task_struct *curr, struct held_lock *next, */ static int check_prev_add(struct task_struct *curr, struct held_lock *prev, - struct held_lock *next, int distance, struct stack_trace *trace, - int (*save)(struct stack_trace *trace)) + struct held_lock *next, int distance, struct stack_trace *trace) { struct lock_list *uninitialized_var(target_entry); struct lock_list *entry; @@ -2199,11 +2198,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, if (unlikely(!ret)) { if (!trace->entries) { /* - * If @save fails here, the printing might trigger - * a WARN but because of the !nr_entries it should - * not do bad things. + * If save_trace fails here, the printing might + * trigger a WARN but because of the !nr_entries it + * should not do bad things. */ - save(trace); + save_trace(trace); } return print_circular_bug(&this, target_entry, next, prev); } @@ -2253,7 +2252,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, return print_bfs_bug(ret); - if (!trace->entries && !save(trace)) + if (!trace->entries && !save_trace(trace)) return 0; /* @@ -2318,7 +2317,8 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) * added: */ if (hlock->read != 2 && hlock->check) { - int ret = check_prev_add(curr, hlock, next, distance, &trace, save_trace); + int ret = check_prev_add(curr, hlock, next, distance, + &trace); if (!ret) return 0; From c120bce78065cbea460a58b1572c215db9c148ba Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:12 +0200 Subject: [PATCH 35/45] lockdep: Simplify stack trace handling Replace the indirection through struct stack_trace by using the storage array based interfaces and storing the information is a small lockdep specific data structure. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Peter Zijlstra (Intel) Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.891724020@linutronix.de --- include/linux/lockdep.h | 9 +++++-- kernel/locking/lockdep.c | 55 ++++++++++++++++++++-------------------- 2 files changed, 35 insertions(+), 29 deletions(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 79c3873d58ac..6f165d625320 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -66,6 +66,11 @@ struct lock_class_key { extern struct lock_class_key __lockdep_no_validate__; +struct lock_trace { + unsigned int nr_entries; + unsigned int offset; +}; + #define LOCKSTAT_POINTS 4 /* @@ -100,7 +105,7 @@ struct lock_class { * IRQ/softirq usage tracking bits: */ unsigned long usage_mask; - struct stack_trace usage_traces[XXX_LOCK_USAGE_STATES]; + struct lock_trace usage_traces[XXX_LOCK_USAGE_STATES]; /* * Generation counter, when doing certain classes of graph walking, @@ -188,7 +193,7 @@ struct lock_list { struct list_head entry; struct lock_class *class; struct lock_class *links_to; - struct stack_trace trace; + struct lock_trace trace; int distance; /* diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 3603893d5bbd..45bcaf2e4cb6 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -434,18 +434,14 @@ static void print_lockdep_off(const char *bug_msg) #endif } -static int save_trace(struct stack_trace *trace) +static int save_trace(struct lock_trace *trace) { - trace->nr_entries = 0; - trace->max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries; - trace->entries = stack_trace + nr_stack_trace_entries; - - trace->skip = 3; - - save_stack_trace(trace); - - trace->max_entries = trace->nr_entries; + unsigned long *entries = stack_trace + nr_stack_trace_entries; + unsigned int max_entries; + trace->offset = nr_stack_trace_entries; + max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries; + trace->nr_entries = stack_trace_save(entries, max_entries, 3); nr_stack_trace_entries += trace->nr_entries; if (nr_stack_trace_entries >= MAX_STACK_TRACE_ENTRIES-1) { @@ -1196,7 +1192,7 @@ static struct lock_list *alloc_list_entry(void) static int add_lock_to_list(struct lock_class *this, struct lock_class *links_to, struct list_head *head, unsigned long ip, int distance, - struct stack_trace *trace) + struct lock_trace *trace) { struct lock_list *entry; /* @@ -1415,6 +1411,13 @@ static inline int __bfs_backwards(struct lock_list *src_entry, * checking. */ +static void print_lock_trace(struct lock_trace *trace, unsigned int spaces) +{ + unsigned long *entries = stack_trace + trace->offset; + + stack_trace_print(entries, trace->nr_entries, spaces); +} + /* * Print a dependency chain entry (this is only done when a deadlock * has been detected): @@ -1427,8 +1430,7 @@ print_circular_bug_entry(struct lock_list *target, int depth) printk("\n-> #%u", depth); print_lock_name(target->class); printk(KERN_CONT ":\n"); - print_stack_trace(&target->trace, 6); - + print_lock_trace(&target->trace, 6); return 0; } @@ -1740,7 +1742,7 @@ static void print_lock_class_header(struct lock_class *class, int depth) len += printk("%*s %s", depth, "", usage_str[bit]); len += printk(KERN_CONT " at:\n"); - print_stack_trace(class->usage_traces + bit, len); + print_lock_trace(class->usage_traces + bit, len); } } printk("%*s }\n", depth, ""); @@ -1765,7 +1767,7 @@ print_shortest_lock_dependencies(struct lock_list *leaf, do { print_lock_class_header(entry->class, depth); printk("%*s ... acquired at:\n", depth, ""); - print_stack_trace(&entry->trace, 2); + print_lock_trace(&entry->trace, 2); printk("\n"); if (depth == 0 && (entry != root)) { @@ -1878,14 +1880,14 @@ print_bad_irq_dependency(struct task_struct *curr, print_lock_name(backwards_entry->class); pr_warn("\n... which became %s-irq-safe at:\n", irqclass); - print_stack_trace(backwards_entry->class->usage_traces + bit1, 1); + print_lock_trace(backwards_entry->class->usage_traces + bit1, 1); pr_warn("\nto a %s-irq-unsafe lock:\n", irqclass); print_lock_name(forwards_entry->class); pr_warn("\n... which became %s-irq-unsafe at:\n", irqclass); pr_warn("..."); - print_stack_trace(forwards_entry->class->usage_traces + bit2, 1); + print_lock_trace(forwards_entry->class->usage_traces + bit2, 1); pr_warn("\nother info that might help us debug this:\n\n"); print_irq_lock_scenario(backwards_entry, forwards_entry, @@ -2158,7 +2160,7 @@ check_deadlock(struct task_struct *curr, struct held_lock *next, */ static int check_prev_add(struct task_struct *curr, struct held_lock *prev, - struct held_lock *next, int distance, struct stack_trace *trace) + struct held_lock *next, int distance, struct lock_trace *trace) { struct lock_list *uninitialized_var(target_entry); struct lock_list *entry; @@ -2196,7 +2198,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, this.parent = NULL; ret = check_noncircular(&this, hlock_class(prev), &target_entry); if (unlikely(!ret)) { - if (!trace->entries) { + if (!trace->nr_entries) { /* * If save_trace fails here, the printing might * trigger a WARN but because of the !nr_entries it @@ -2252,7 +2254,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, return print_bfs_bug(ret); - if (!trace->entries && !save_trace(trace)) + if (!trace->nr_entries && !save_trace(trace)) return 0; /* @@ -2284,14 +2286,9 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, static int check_prevs_add(struct task_struct *curr, struct held_lock *next) { + struct lock_trace trace = { .nr_entries = 0 }; int depth = curr->lockdep_depth; struct held_lock *hlock; - struct stack_trace trace = { - .nr_entries = 0, - .max_entries = 0, - .entries = NULL, - .skip = 0, - }; /* * Debugging checks. @@ -2719,6 +2716,10 @@ static inline int validate_chain(struct task_struct *curr, { return 1; } + +static void print_lock_trace(struct lock_trace *trace, unsigned int spaces) +{ +} #endif /* @@ -2815,7 +2816,7 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this, print_lock(this); pr_warn("{%s} state was registered at:\n", usage_str[prev_bit]); - print_stack_trace(hlock_class(this)->usage_traces + prev_bit, 1); + print_lock_trace(hlock_class(this)->usage_traces + prev_bit, 1); print_irqtrace_events(curr); pr_warn("\nother info that might help us debug this:\n"); From e7d916632b528e8cccc8e9ccca81acfc591a5fde Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:13 +0200 Subject: [PATCH 36/45] tracing: Simplify stacktrace retrieval in histograms The indirection through struct stack_trace is not necessary at all. Use the storage array based interface. Signed-off-by: Thomas Gleixner Tested-by: Tom Zanussi Reviewed-by: Tom Zanussi Reviewed-by: Josh Poimboeuf Acked-by: Steven Rostedt (VMware) Cc: Andy Lutomirski Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.979089273@linutronix.de --- kernel/trace/trace_events_hist.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 21ceae299f7e..a1d20421f4b0 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5186,7 +5186,6 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec, u64 var_ref_vals[TRACING_MAP_VARS_MAX]; char compound_key[HIST_KEY_SIZE_MAX]; struct tracing_map_elt *elt = NULL; - struct stack_trace stacktrace; struct hist_field *key_field; u64 field_contents; void *key = NULL; @@ -5198,14 +5197,9 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec, key_field = hist_data->fields[i]; if (key_field->flags & HIST_FIELD_FL_STACKTRACE) { - stacktrace.max_entries = HIST_STACKTRACE_DEPTH; - stacktrace.entries = entries; - stacktrace.nr_entries = 0; - stacktrace.skip = HIST_STACKTRACE_SKIP; - - memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE); - save_stack_trace(&stacktrace); - + memset(entries, 0, HIST_STACKTRACE_SIZE); + stack_trace_save(entries, HIST_STACKTRACE_DEPTH, + HIST_STACKTRACE_SKIP); key = entries; } else { field_contents = key_field->fn(key_field, elt, rbe, rec); From 2a820bf74918d61ea54f7c1001f4a6a2e457577c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:14 +0200 Subject: [PATCH 37/45] tracing: Use percpu stack trace buffer more intelligently The per cpu stack trace buffer usage pattern is odd at best. The buffer has place for 512 stack trace entries on 64-bit and 1024 on 32-bit. When interrupts or exceptions nest after the per cpu buffer was acquired the stacktrace length is hardcoded to 8 entries. 512/1024 stack trace entries in kernel stacks are unrealistic so the buffer is a complete waste. Split the buffer into 4 nest levels, which are 128/256 entries per level. This allows nesting contexts (interrupts, exceptions) to utilize the cpu buffer for stack retrieval and avoids the fixed length allocation along with the conditional execution pathes. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094803.066064076@linutronix.de --- kernel/trace/trace.c | 73 ++++++++++++++++++++++---------------------- 1 file changed, 37 insertions(+), 36 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 21153e64bf1c..4fc93004feab 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2749,12 +2749,21 @@ trace_function(struct trace_array *tr, #ifdef CONFIG_STACKTRACE -#define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long)) +/* Allow 4 levels of nesting: normal, softirq, irq, NMI */ +#define FTRACE_KSTACK_NESTING 4 + +#define FTRACE_KSTACK_ENTRIES (PAGE_SIZE / FTRACE_KSTACK_NESTING) + struct ftrace_stack { - unsigned long calls[FTRACE_STACK_MAX_ENTRIES]; + unsigned long calls[FTRACE_KSTACK_ENTRIES]; }; -static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack); + +struct ftrace_stacks { + struct ftrace_stack stacks[FTRACE_KSTACK_NESTING]; +}; + +static DEFINE_PER_CPU(struct ftrace_stacks, ftrace_stacks); static DEFINE_PER_CPU(int, ftrace_stack_reserve); static void __ftrace_trace_stack(struct ring_buffer *buffer, @@ -2763,10 +2772,11 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, { struct trace_event_call *call = &event_kernel_stack; struct ring_buffer_event *event; + struct ftrace_stack *fstack; struct stack_entry *entry; struct stack_trace trace; - int use_stack; - int size = FTRACE_STACK_ENTRIES; + int size = FTRACE_KSTACK_ENTRIES; + int stackidx; trace.nr_entries = 0; trace.skip = skip; @@ -2788,29 +2798,32 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, */ preempt_disable_notrace(); - use_stack = __this_cpu_inc_return(ftrace_stack_reserve); + stackidx = __this_cpu_inc_return(ftrace_stack_reserve) - 1; + + /* This should never happen. If it does, yell once and skip */ + if (WARN_ON_ONCE(stackidx > FTRACE_KSTACK_NESTING)) + goto out; + /* - * We don't need any atomic variables, just a barrier. - * If an interrupt comes in, we don't care, because it would - * have exited and put the counter back to what we want. - * We just need a barrier to keep gcc from moving things - * around. + * The above __this_cpu_inc_return() is 'atomic' cpu local. An + * interrupt will either see the value pre increment or post + * increment. If the interrupt happens pre increment it will have + * restored the counter when it returns. We just need a barrier to + * keep gcc from moving things around. */ barrier(); - if (use_stack == 1) { - trace.entries = this_cpu_ptr(ftrace_stack.calls); - trace.max_entries = FTRACE_STACK_MAX_ENTRIES; - if (regs) - save_stack_trace_regs(regs, &trace); - else - save_stack_trace(&trace); + fstack = this_cpu_ptr(ftrace_stacks.stacks) + stackidx; + trace.entries = fstack->calls; + trace.max_entries = FTRACE_KSTACK_ENTRIES; - if (trace.nr_entries > size) - size = trace.nr_entries; - } else - /* From now on, use_stack is a boolean */ - use_stack = 0; + if (regs) + save_stack_trace_regs(regs, &trace); + else + save_stack_trace(&trace); + + if (trace.nr_entries > size) + size = trace.nr_entries; size *= sizeof(unsigned long); @@ -2820,19 +2833,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, goto out; entry = ring_buffer_event_data(event); - memset(&entry->caller, 0, size); - - if (use_stack) - memcpy(&entry->caller, trace.entries, - trace.nr_entries * sizeof(unsigned long)); - else { - trace.max_entries = FTRACE_STACK_ENTRIES; - trace.entries = entry->caller; - if (regs) - save_stack_trace_regs(regs, &trace); - else - save_stack_trace(&trace); - } + memcpy(&entry->caller, trace.entries, size); entry->size = trace.nr_entries; From c438f140cc16d47fac808d893f5017f6d641cb46 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:15 +0200 Subject: [PATCH 38/45] tracing: Make ftrace_trace_userstack() static and conditional It's only used in trace.c and there is absolutely no point in compiling it in when user space stack traces are not supported. Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094803.162400595@linutronix.de --- kernel/trace/trace.c | 14 ++++++++------ kernel/trace/trace.h | 8 -------- 2 files changed, 8 insertions(+), 14 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4fc93004feab..d8369d27c1af 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -159,6 +159,8 @@ static union trace_eval_map_item *trace_eval_maps; #endif /* CONFIG_TRACE_EVAL_MAP_FILE */ static int tracing_set_tracer(struct trace_array *tr, const char *buf); +static void ftrace_trace_userstack(struct ring_buffer *buffer, + unsigned long flags, int pc); #define MAX_TRACER_SIZE 100 static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; @@ -2905,9 +2907,10 @@ void trace_dump_stack(int skip) } EXPORT_SYMBOL_GPL(trace_dump_stack); +#ifdef CONFIG_USER_STACKTRACE_SUPPORT static DEFINE_PER_CPU(int, user_stack_count); -void +static void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) { struct trace_event_call *call = &event_user_stack; @@ -2958,13 +2961,12 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) out: preempt_enable(); } - -#ifdef UNUSED -static void __trace_userstack(struct trace_array *tr, unsigned long flags) +#else /* CONFIG_USER_STACKTRACE_SUPPORT */ +static void ftrace_trace_userstack(struct ring_buffer *buffer, + unsigned long flags, int pc) { - ftrace_trace_userstack(tr, flags, preempt_count()); } -#endif /* UNUSED */ +#endif /* !CONFIG_USER_STACKTRACE_SUPPORT */ #endif /* CONFIG_STACKTRACE */ diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index d80cee49e0eb..639047b259d7 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -782,17 +782,9 @@ void update_max_tr_single(struct trace_array *tr, #endif /* CONFIG_TRACER_MAX_TRACE */ #ifdef CONFIG_STACKTRACE -void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, - int pc); - void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, int pc); #else -static inline void ftrace_trace_userstack(struct ring_buffer *buffer, - unsigned long flags, int pc) -{ -} - static inline void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, int pc) { From ee6dd0db4d8de41a0a0bc37d8d87a0b1623f83b0 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:16 +0200 Subject: [PATCH 39/45] tracing: Simplify stack trace retrieval Replace the indirection through struct stack_trace by using the storage array based interfaces. Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094803.248604594@linutronix.de --- kernel/trace/trace.c | 40 +++++++++++++--------------------------- 1 file changed, 13 insertions(+), 27 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d8369d27c1af..0ce8515dd470 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2774,22 +2774,18 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, { struct trace_event_call *call = &event_kernel_stack; struct ring_buffer_event *event; + unsigned int size, nr_entries; struct ftrace_stack *fstack; struct stack_entry *entry; - struct stack_trace trace; - int size = FTRACE_KSTACK_ENTRIES; int stackidx; - trace.nr_entries = 0; - trace.skip = skip; - /* * Add one, for this function and the call to save_stack_trace() * If regs is set, then these functions will not be in the way. */ #ifndef CONFIG_UNWINDER_ORC if (!regs) - trace.skip++; + skip++; #endif /* @@ -2816,28 +2812,24 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, barrier(); fstack = this_cpu_ptr(ftrace_stacks.stacks) + stackidx; - trace.entries = fstack->calls; - trace.max_entries = FTRACE_KSTACK_ENTRIES; + size = ARRAY_SIZE(fstack->calls); - if (regs) - save_stack_trace_regs(regs, &trace); - else - save_stack_trace(&trace); - - if (trace.nr_entries > size) - size = trace.nr_entries; - - size *= sizeof(unsigned long); + if (regs) { + nr_entries = stack_trace_save_regs(regs, fstack->calls, + size, skip); + } else { + nr_entries = stack_trace_save(fstack->calls, size, skip); + } + size = nr_entries * sizeof(unsigned long); event = __trace_buffer_lock_reserve(buffer, TRACE_STACK, sizeof(*entry) + size, flags, pc); if (!event) goto out; entry = ring_buffer_event_data(event); - memcpy(&entry->caller, trace.entries, size); - - entry->size = trace.nr_entries; + memcpy(&entry->caller, fstack->calls, size); + entry->size = nr_entries; if (!call_filter_check_discard(call, entry, buffer, event)) __buffer_unlock_commit(buffer, event); @@ -2916,7 +2908,6 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) struct trace_event_call *call = &event_user_stack; struct ring_buffer_event *event; struct userstack_entry *entry; - struct stack_trace trace; if (!(global_trace.trace_flags & TRACE_ITER_USERSTACKTRACE)) return; @@ -2947,12 +2938,7 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) entry->tgid = current->tgid; memset(&entry->caller, 0, sizeof(entry->caller)); - trace.nr_entries = 0; - trace.max_entries = FTRACE_STACK_ENTRIES; - trace.skip = 0; - trace.entries = entry->caller; - - save_stack_trace_user(&trace); + stack_trace_save_user(entry->caller, FTRACE_STACK_ENTRIES); if (!call_filter_check_discard(call, entry, buffer, event)) __buffer_unlock_commit(buffer, event); From 9f50c91b1195dfffd183d5d8505e45af86623532 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:17 +0200 Subject: [PATCH 40/45] tracing: Remove the last struct stack_trace usage Simplify the stack retrieval code by using the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094803.340000461@linutronix.de --- kernel/trace/trace_stack.c | 37 ++++++++++++++++--------------------- 1 file changed, 16 insertions(+), 21 deletions(-) diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 4efda5f75a0f..5d16f73898db 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -23,11 +23,7 @@ static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES]; static unsigned stack_trace_index[STACK_TRACE_ENTRIES]; -struct stack_trace stack_trace_max = { - .max_entries = STACK_TRACE_ENTRIES, - .entries = &stack_dump_trace[0], -}; - +static unsigned int stack_trace_nr_entries; static unsigned long stack_trace_max_size; static arch_spinlock_t stack_trace_max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; @@ -44,10 +40,10 @@ static void print_max_stack(void) pr_emerg(" Depth Size Location (%d entries)\n" " ----- ---- --------\n", - stack_trace_max.nr_entries); + stack_trace_nr_entries); - for (i = 0; i < stack_trace_max.nr_entries; i++) { - if (i + 1 == stack_trace_max.nr_entries) + for (i = 0; i < stack_trace_nr_entries; i++) { + if (i + 1 == stack_trace_nr_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; @@ -93,13 +89,12 @@ static void check_stack(unsigned long ip, unsigned long *stack) stack_trace_max_size = this_size; - stack_trace_max.nr_entries = 0; - stack_trace_max.skip = 0; - - save_stack_trace(&stack_trace_max); + stack_trace_nr_entries = stack_trace_save(stack_dump_trace, + ARRAY_SIZE(stack_dump_trace) - 1, + 0); /* Skip over the overhead of the stack tracer itself */ - for (i = 0; i < stack_trace_max.nr_entries; i++) { + for (i = 0; i < stack_trace_nr_entries; i++) { if (stack_dump_trace[i] == ip) break; } @@ -108,7 +103,7 @@ static void check_stack(unsigned long ip, unsigned long *stack) * Some archs may not have the passed in ip in the dump. * If that happens, we need to show everything. */ - if (i == stack_trace_max.nr_entries) + if (i == stack_trace_nr_entries) i = 0; /* @@ -126,13 +121,13 @@ static void check_stack(unsigned long ip, unsigned long *stack) * loop will only happen once. This code only takes place * on a new max, so it is far from a fast path. */ - while (i < stack_trace_max.nr_entries) { + while (i < stack_trace_nr_entries) { int found = 0; stack_trace_index[x] = this_size; p = start; - for (; p < top && i < stack_trace_max.nr_entries; p++) { + for (; p < top && i < stack_trace_nr_entries; p++) { /* * The READ_ONCE_NOCHECK is used to let KASAN know that * this is not a stack-out-of-bounds error. @@ -163,7 +158,7 @@ static void check_stack(unsigned long ip, unsigned long *stack) i++; } - stack_trace_max.nr_entries = x; + stack_trace_nr_entries = x; if (task_stack_end_corrupted(current)) { print_max_stack(); @@ -265,7 +260,7 @@ __next(struct seq_file *m, loff_t *pos) { long n = *pos - 1; - if (n >= stack_trace_max.nr_entries) + if (n >= stack_trace_nr_entries) return NULL; m->private = (void *)n; @@ -329,7 +324,7 @@ static int t_show(struct seq_file *m, void *v) seq_printf(m, " Depth Size Location" " (%d entries)\n" " ----- ---- --------\n", - stack_trace_max.nr_entries); + stack_trace_nr_entries); if (!stack_tracer_enabled && !stack_trace_max_size) print_disabled(m); @@ -339,10 +334,10 @@ static int t_show(struct seq_file *m, void *v) i = *(long *)v; - if (i >= stack_trace_max.nr_entries) + if (i >= stack_trace_nr_entries) return 0; - if (i + 1 == stack_trace_max.nr_entries) + if (i + 1 == stack_trace_nr_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; From 25e39e32b0a3f99b9db320605f20f91d425b6a65 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:18 +0200 Subject: [PATCH 41/45] livepatch: Simplify stack trace retrieval Replace the indirection through struct stack_trace by using the storage array based interfaces. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Miroslav Benes Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094803.437950229@linutronix.de --- kernel/livepatch/transition.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index 9c89ae8b337a..c53370d596be 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -202,15 +202,15 @@ void klp_update_patch_state(struct task_struct *task) * Determine whether the given stack trace includes any references to a * to-be-patched or to-be-unpatched function. */ -static int klp_check_stack_func(struct klp_func *func, - struct stack_trace *trace) +static int klp_check_stack_func(struct klp_func *func, unsigned long *entries, + unsigned int nr_entries) { unsigned long func_addr, func_size, address; struct klp_ops *ops; int i; - for (i = 0; i < trace->nr_entries; i++) { - address = trace->entries[i]; + for (i = 0; i < nr_entries; i++) { + address = entries[i]; if (klp_target_state == KLP_UNPATCHED) { /* @@ -254,29 +254,25 @@ static int klp_check_stack_func(struct klp_func *func, static int klp_check_stack(struct task_struct *task, char *err_buf) { static unsigned long entries[MAX_STACK_ENTRIES]; - struct stack_trace trace; struct klp_object *obj; struct klp_func *func; - int ret; + int ret, nr_entries; - trace.skip = 0; - trace.nr_entries = 0; - trace.max_entries = MAX_STACK_ENTRIES; - trace.entries = entries; - ret = save_stack_trace_tsk_reliable(task, &trace); + ret = stack_trace_save_tsk_reliable(task, entries, ARRAY_SIZE(entries)); WARN_ON_ONCE(ret == -ENOSYS); - if (ret) { + if (ret < 0) { snprintf(err_buf, STACK_ERR_BUF_SIZE, "%s: %s:%d has an unreliable stack\n", __func__, task->comm, task->pid); return ret; } + nr_entries = ret; klp_for_each_object(klp_transition_patch, obj) { if (!obj->patched) continue; klp_for_each_func(obj, func) { - ret = klp_check_stack_func(func, &trace); + ret = klp_check_stack_func(func, entries, nr_entries); if (ret) { snprintf(err_buf, STACK_ERR_BUF_SIZE, "%s: %s:%d is sleeping on function %s\n", From 988ec8841ca1e22b2978fce0134d8267e838770e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:19 +0200 Subject: [PATCH 42/45] stacktrace: Remove obsolete functions No more users of the struct stack_trace based interfaces. Remove them. Remove the macro stubs for !CONFIG_STACKTRACE as well as they are pointless because the storage on the call sites is conditional on CONFIG_STACKTRACE already. No point to be 'smart'. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094803.524796783@linutronix.de --- include/linux/stacktrace.h | 17 ----------------- kernel/stacktrace.c | 14 -------------- 2 files changed, 31 deletions(-) diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h index a24340b3e9e1..40decfbb9a24 100644 --- a/include/linux/stacktrace.h +++ b/include/linux/stacktrace.h @@ -36,24 +36,7 @@ extern void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace); extern int save_stack_trace_tsk_reliable(struct task_struct *tsk, struct stack_trace *trace); - -extern void print_stack_trace(struct stack_trace *trace, int spaces); -extern int snprint_stack_trace(char *buf, size_t size, - struct stack_trace *trace, int spaces); - -#ifdef CONFIG_USER_STACKTRACE_SUPPORT extern void save_stack_trace_user(struct stack_trace *trace); -#else -# define save_stack_trace_user(trace) do { } while (0) -#endif - -#else /* !CONFIG_STACKTRACE */ -# define save_stack_trace(trace) do { } while (0) -# define save_stack_trace_tsk(tsk, trace) do { } while (0) -# define save_stack_trace_user(trace) do { } while (0) -# define print_stack_trace(trace, spaces) do { } while (0) -# define snprint_stack_trace(buf, size, trace, spaces) do { } while (0) -# define save_stack_trace_tsk_reliable(tsk, trace) ({ -ENOSYS; }) #endif /* CONFIG_STACKTRACE */ #if defined(CONFIG_STACKTRACE) && defined(CONFIG_HAVE_RELIABLE_STACKTRACE) diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index b38333b3bc18..dd55312f3fe9 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -30,12 +30,6 @@ void stack_trace_print(unsigned long *entries, unsigned int nr_entries, } EXPORT_SYMBOL_GPL(stack_trace_print); -void print_stack_trace(struct stack_trace *trace, int spaces) -{ - stack_trace_print(trace->entries, trace->nr_entries, spaces); -} -EXPORT_SYMBOL_GPL(print_stack_trace); - /** * stack_trace_snprint - Print the entries in the stack trace into a buffer * @buf: Pointer to the print buffer @@ -72,14 +66,6 @@ int stack_trace_snprint(char *buf, size_t size, unsigned long *entries, } EXPORT_SYMBOL_GPL(stack_trace_snprint); -int snprint_stack_trace(char *buf, size_t size, - struct stack_trace *trace, int spaces) -{ - return stack_trace_snprint(buf, size, trace->entries, - trace->nr_entries, spaces); -} -EXPORT_SYMBOL_GPL(snprint_stack_trace); - /* * Architectures that do not implement save_stack_trace_*() * get these weak aliases and once-per-bootup warnings From 56d8f079c51afc8b564b9fb0252d48e7b437c1e5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:20 +0200 Subject: [PATCH 43/45] lib/stackdepot: Remove obsolete functions No more users of the struct stack_trace based interfaces. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Alexander Potapenko Cc: Andy Lutomirski Cc: Steven Rostedt Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094803.617937448@linutronix.de --- include/linux/stackdepot.h | 4 ---- lib/stackdepot.c | 20 -------------------- 2 files changed, 24 deletions(-) diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index 4297c6d2991d..0805dee1b6b8 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -23,13 +23,9 @@ typedef u32 depot_stack_handle_t; -struct stack_trace; - -depot_stack_handle_t depot_save_stack(struct stack_trace *trace, gfp_t flags); depot_stack_handle_t stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t gfp_flags); -void depot_fetch_stack(depot_stack_handle_t handle, struct stack_trace *trace); unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries); diff --git a/lib/stackdepot.c b/lib/stackdepot.c index e84f8e58495c..605c61f65d94 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -216,14 +216,6 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle, } EXPORT_SYMBOL_GPL(stack_depot_fetch); -void depot_fetch_stack(depot_stack_handle_t handle, struct stack_trace *trace) -{ - unsigned int nent = stack_depot_fetch(handle, &trace->entries); - - trace->max_entries = trace->nr_entries = nent; -} -EXPORT_SYMBOL_GPL(depot_fetch_stack); - /** * stack_depot_save - Save a stack trace from an array * @@ -318,15 +310,3 @@ fast_exit: return retval; } EXPORT_SYMBOL_GPL(stack_depot_save); - -/** - * depot_save_stack - save stack in a stack depot. - * @trace - the stacktrace to save. - * @alloc_flags - flags for allocating additional memory if required. - */ -depot_stack_handle_t depot_save_stack(struct stack_trace *trace, - gfp_t alloc_flags) -{ - return stack_depot_save(trace->entries, trace->nr_entries, alloc_flags); -} -EXPORT_SYMBOL_GPL(depot_save_stack); From 214d8ca6ee854f696f75e75511fe66b409e656db Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:21 +0200 Subject: [PATCH 44/45] stacktrace: Provide common infrastructure All architectures which support stacktrace carry duplicated code and do the stack storage and filtering at the architecture side. Provide a consolidated interface with a callback function for consuming the stack entries provided by the architecture specific stack walker. This removes lots of duplicated code and allows to implement better filtering than 'skip number of entries' in the future without touching any architecture specific code. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: linux-arch@vger.kernel.org Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Link: https://lkml.kernel.org/r/20190425094803.713568606@linutronix.de --- include/linux/stacktrace.h | 39 +++++++++ kernel/stacktrace.c | 173 +++++++++++++++++++++++++++++++++++++ lib/Kconfig | 4 + 3 files changed, 216 insertions(+) diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h index 40decfbb9a24..f0cfd12cb45e 100644 --- a/include/linux/stacktrace.h +++ b/include/linux/stacktrace.h @@ -23,6 +23,44 @@ unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store, unsigned int stack_trace_save_user(unsigned long *store, unsigned int size); /* Internal interfaces. Do not use in generic code */ +#ifdef CONFIG_ARCH_STACKWALK + +/** + * stack_trace_consume_fn - Callback for arch_stack_walk() + * @cookie: Caller supplied pointer handed back by arch_stack_walk() + * @addr: The stack entry address to consume + * @reliable: True when the stack entry is reliable. Required by + * some printk based consumers. + * + * Return: True, if the entry was consumed or skipped + * False, if there is no space left to store + */ +typedef bool (*stack_trace_consume_fn)(void *cookie, unsigned long addr, + bool reliable); +/** + * arch_stack_walk - Architecture specific function to walk the stack + * @consume_entry: Callback which is invoked by the architecture code for + * each entry. + * @cookie: Caller supplied pointer which is handed back to + * @consume_entry + * @task: Pointer to a task struct, can be NULL + * @regs: Pointer to registers, can be NULL + * + * ============ ======= ============================================ + * task regs + * ============ ======= ============================================ + * task NULL Stack trace from task (can be current) + * current regs Stack trace starting on regs->stackpointer + * ============ ======= ============================================ + */ +void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, + struct task_struct *task, struct pt_regs *regs); +int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, void *cookie, + struct task_struct *task); +void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, + const struct pt_regs *regs); + +#else /* CONFIG_ARCH_STACKWALK */ struct stack_trace { unsigned int nr_entries, max_entries; unsigned long *entries; @@ -37,6 +75,7 @@ extern void save_stack_trace_tsk(struct task_struct *tsk, extern int save_stack_trace_tsk_reliable(struct task_struct *tsk, struct stack_trace *trace); extern void save_stack_trace_user(struct stack_trace *trace); +#endif /* !CONFIG_ARCH_STACKWALK */ #endif /* CONFIG_STACKTRACE */ #if defined(CONFIG_STACKTRACE) && defined(CONFIG_HAVE_RELIABLE_STACKTRACE) diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index dd55312f3fe9..27bafc1e271e 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -5,6 +5,8 @@ * * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar */ +#include +#include #include #include #include @@ -66,6 +68,175 @@ int stack_trace_snprint(char *buf, size_t size, unsigned long *entries, } EXPORT_SYMBOL_GPL(stack_trace_snprint); +#ifdef CONFIG_ARCH_STACKWALK + +struct stacktrace_cookie { + unsigned long *store; + unsigned int size; + unsigned int skip; + unsigned int len; +}; + +static bool stack_trace_consume_entry(void *cookie, unsigned long addr, + bool reliable) +{ + struct stacktrace_cookie *c = cookie; + + if (c->len >= c->size) + return false; + + if (c->skip > 0) { + c->skip--; + return true; + } + c->store[c->len++] = addr; + return c->len < c->size; +} + +static bool stack_trace_consume_entry_nosched(void *cookie, unsigned long addr, + bool reliable) +{ + if (in_sched_functions(addr)) + return true; + return stack_trace_consume_entry(cookie, addr, reliable); +} + +/** + * stack_trace_save - Save a stack trace into a storage array + * @store: Pointer to storage array + * @size: Size of the storage array + * @skipnr: Number of entries to skip at the start of the stack trace + * + * Return: Number of trace entries stored. + */ +unsigned int stack_trace_save(unsigned long *store, unsigned int size, + unsigned int skipnr) +{ + stack_trace_consume_fn consume_entry = stack_trace_consume_entry; + struct stacktrace_cookie c = { + .store = store, + .size = size, + .skip = skipnr + 1, + }; + + arch_stack_walk(consume_entry, &c, current, NULL); + return c.len; +} +EXPORT_SYMBOL_GPL(stack_trace_save); + +/** + * stack_trace_save_tsk - Save a task stack trace into a storage array + * @task: The task to examine + * @store: Pointer to storage array + * @size: Size of the storage array + * @skipnr: Number of entries to skip at the start of the stack trace + * + * Return: Number of trace entries stored. + */ +unsigned int stack_trace_save_tsk(struct task_struct *tsk, unsigned long *store, + unsigned int size, unsigned int skipnr) +{ + stack_trace_consume_fn consume_entry = stack_trace_consume_entry_nosched; + struct stacktrace_cookie c = { + .store = store, + .size = size, + .skip = skipnr + 1, + }; + + if (!try_get_task_stack(tsk)) + return 0; + + arch_stack_walk(consume_entry, &c, tsk, NULL); + put_task_stack(tsk); + return c.len; +} + +/** + * stack_trace_save_regs - Save a stack trace based on pt_regs into a storage array + * @regs: Pointer to pt_regs to examine + * @store: Pointer to storage array + * @size: Size of the storage array + * @skipnr: Number of entries to skip at the start of the stack trace + * + * Return: Number of trace entries stored. + */ +unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store, + unsigned int size, unsigned int skipnr) +{ + stack_trace_consume_fn consume_entry = stack_trace_consume_entry; + struct stacktrace_cookie c = { + .store = store, + .size = size, + .skip = skipnr, + }; + + arch_stack_walk(consume_entry, &c, current, regs); + return c.len; +} + +#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE +/** + * stack_trace_save_tsk_reliable - Save task stack with verification + * @tsk: Pointer to the task to examine + * @store: Pointer to storage array + * @size: Size of the storage array + * + * Return: An error if it detects any unreliable features of the + * stack. Otherwise it guarantees that the stack trace is + * reliable and returns the number of entries stored. + * + * If the task is not 'current', the caller *must* ensure the task is inactive. + */ +int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store, + unsigned int size) +{ + stack_trace_consume_fn consume_entry = stack_trace_consume_entry; + struct stacktrace_cookie c = { + .store = store, + .size = size, + }; + int ret; + + /* + * If the task doesn't have a stack (e.g., a zombie), the stack is + * "reliably" empty. + */ + if (!try_get_task_stack(tsk)) + return 0; + + ret = arch_stack_walk_reliable(consume_entry, &c, tsk); + put_task_stack(tsk); + return ret; +} +#endif + +#ifdef CONFIG_USER_STACKTRACE_SUPPORT +/** + * stack_trace_save_user - Save a user space stack trace into a storage array + * @store: Pointer to storage array + * @size: Size of the storage array + * + * Return: Number of trace entries stored. + */ +unsigned int stack_trace_save_user(unsigned long *store, unsigned int size) +{ + stack_trace_consume_fn consume_entry = stack_trace_consume_entry; + struct stacktrace_cookie c = { + .store = store, + .size = size, + }; + + /* Trace user stack if not a kernel thread */ + if (!current->mm) + return 0; + + arch_stack_walk_user(consume_entry, &c, task_pt_regs(current)); + return c.len; +} +#endif + +#else /* CONFIG_ARCH_STACKWALK */ + /* * Architectures that do not implement save_stack_trace_*() * get these weak aliases and once-per-bootup warnings @@ -203,3 +374,5 @@ unsigned int stack_trace_save_user(unsigned long *store, unsigned int size) return trace.nr_entries; } #endif /* CONFIG_USER_STACKTRACE_SUPPORT */ + +#endif /* !CONFIG_ARCH_STACKWALK */ diff --git a/lib/Kconfig b/lib/Kconfig index a9e56539bd11..e86975bfca6a 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -597,6 +597,10 @@ config ARCH_HAS_UACCESS_FLUSHCACHE config ARCH_HAS_UACCESS_MCSAFE bool +# Temporary. Goes away when all archs are cleaned up +config ARCH_STACKWALK + bool + config STACKDEPOT bool select STACKTRACE From 3599fe12a125fa7118da2bcc5033d7741fb5f3a1 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:22 +0200 Subject: [PATCH 45/45] x86/stacktrace: Use common infrastructure Replace the stack_trace_save*() functions with the new arch_stack_walk() interfaces. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: linux-arch@vger.kernel.org Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Link: https://lkml.kernel.org/r/20190425094803.816485461@linutronix.de --- arch/x86/Kconfig | 1 + arch/x86/kernel/stacktrace.c | 116 ++++++----------------------------- 2 files changed, 20 insertions(+), 97 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5ad92419be19..b5978e35a8a8 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -74,6 +74,7 @@ config X86 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI select ARCH_MIGHT_HAVE_PC_PARPORT select ARCH_MIGHT_HAVE_PC_SERIO + select ARCH_STACKWALK select ARCH_SUPPORTS_ACPI select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index b2f706f1e0b7..2abf27d7df6b 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -12,75 +12,31 @@ #include #include -static int save_stack_address(struct stack_trace *trace, unsigned long addr, - bool nosched) -{ - if (nosched && in_sched_functions(addr)) - return 0; - - if (trace->skip > 0) { - trace->skip--; - return 0; - } - - if (trace->nr_entries >= trace->max_entries) - return -1; - - trace->entries[trace->nr_entries++] = addr; - return 0; -} - -static void noinline __save_stack_trace(struct stack_trace *trace, - struct task_struct *task, struct pt_regs *regs, - bool nosched) +void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, + struct task_struct *task, struct pt_regs *regs) { struct unwind_state state; unsigned long addr; - if (regs) - save_stack_address(trace, regs->ip, nosched); + if (regs && !consume_entry(cookie, regs->ip, false)) + return; for (unwind_start(&state, task, regs, NULL); !unwind_done(&state); unwind_next_frame(&state)) { addr = unwind_get_return_address(&state); - if (!addr || save_stack_address(trace, addr, nosched)) + if (!addr || !consume_entry(cookie, addr, false)) break; } } /* - * Save stack-backtrace addresses into a stack_trace buffer. + * This function returns an error if it detects any unreliable features of the + * stack. Otherwise it guarantees that the stack trace is reliable. + * + * If the task is not 'current', the caller *must* ensure the task is inactive. */ -void save_stack_trace(struct stack_trace *trace) -{ - trace->skip++; - __save_stack_trace(trace, current, NULL, false); -} -EXPORT_SYMBOL_GPL(save_stack_trace); - -void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) -{ - __save_stack_trace(trace, current, regs, false); -} - -void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) -{ - if (!try_get_task_stack(tsk)) - return; - - if (tsk == current) - trace->skip++; - __save_stack_trace(trace, tsk, NULL, true); - - put_task_stack(tsk); -} -EXPORT_SYMBOL_GPL(save_stack_trace_tsk); - -#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE - -static int __always_inline -__save_stack_trace_reliable(struct stack_trace *trace, - struct task_struct *task) +int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, + void *cookie, struct task_struct *task) { struct unwind_state state; struct pt_regs *regs; @@ -117,7 +73,7 @@ __save_stack_trace_reliable(struct stack_trace *trace, if (!addr) return -EINVAL; - if (save_stack_address(trace, addr, false)) + if (!consume_entry(cookie, addr, false)) return -EINVAL; } @@ -132,32 +88,6 @@ __save_stack_trace_reliable(struct stack_trace *trace, return 0; } -/* - * This function returns an error if it detects any unreliable features of the - * stack. Otherwise it guarantees that the stack trace is reliable. - * - * If the task is not 'current', the caller *must* ensure the task is inactive. - */ -int save_stack_trace_tsk_reliable(struct task_struct *tsk, - struct stack_trace *trace) -{ - int ret; - - /* - * If the task doesn't have a stack (e.g., a zombie), the stack is - * "reliably" empty. - */ - if (!try_get_task_stack(tsk)) - return 0; - - ret = __save_stack_trace_reliable(trace, tsk); - - put_task_stack(tsk); - - return ret; -} -#endif /* CONFIG_HAVE_RELIABLE_STACKTRACE */ - /* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */ struct stack_frame_user { @@ -182,15 +112,15 @@ copy_stack_frame(const void __user *fp, struct stack_frame_user *frame) return ret; } -static inline void __save_stack_trace_user(struct stack_trace *trace) +void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, + const struct pt_regs *regs) { - const struct pt_regs *regs = task_pt_regs(current); const void __user *fp = (const void __user *)regs->bp; - if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = regs->ip; + if (!consume_entry(cookie, regs->ip, false)) + return; - while (trace->nr_entries < trace->max_entries) { + while (1) { struct stack_frame_user frame; frame.next_fp = NULL; @@ -200,8 +130,8 @@ static inline void __save_stack_trace_user(struct stack_trace *trace) if ((unsigned long)fp < regs->sp) break; if (frame.ret_addr) { - trace->entries[trace->nr_entries++] = - frame.ret_addr; + if (!consume_entry(cookie, frame.ret_addr, false)) + return; } if (fp == frame.next_fp) break; @@ -209,11 +139,3 @@ static inline void __save_stack_trace_user(struct stack_trace *trace) } } -void save_stack_trace_user(struct stack_trace *trace) -{ - /* - * Trace user stack if we are not a kernel thread - */ - if (current->mm) - __save_stack_trace_user(trace); -}