diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 8aa85e39f50b..9f2ff4a54aff 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -156,25 +156,6 @@ struct thread_struct { typedef struct thread_struct thread_struct; -/* - * Stack layout of a C stack frame. - */ -#ifndef __PACK_STACK -struct stack_frame { - unsigned long back_chain; - unsigned long empty1[5]; - unsigned long gprs[10]; - unsigned int empty2[8]; -}; -#else -struct stack_frame { - unsigned long empty1[5]; - unsigned int empty2[8]; - unsigned long gprs[10]; - unsigned long back_chain; -}; -#endif - #define ARCH_MIN_TASKALIGN 8 #define INIT_THREAD { \ @@ -206,11 +187,7 @@ struct mm_struct; struct seq_file; struct pt_regs; -typedef int (*dump_trace_func_t)(void *data, unsigned long address, int reliable); -void dump_trace(dump_trace_func_t func, void *data, - struct task_struct *task, unsigned long sp); void show_registers(struct pt_regs *regs); - void show_cacheinfo(struct seq_file *m); /* Free all resources held by a thread. */ @@ -244,55 +221,6 @@ static __no_kasan_or_inline unsigned short stap(void) return cpu_address; } -#define CALL_ARGS_0() \ - register unsigned long r2 asm("2") -#define CALL_ARGS_1(arg1) \ - register unsigned long r2 asm("2") = (unsigned long)(arg1) -#define CALL_ARGS_2(arg1, arg2) \ - CALL_ARGS_1(arg1); \ - register unsigned long r3 asm("3") = (unsigned long)(arg2) -#define CALL_ARGS_3(arg1, arg2, arg3) \ - CALL_ARGS_2(arg1, arg2); \ - register unsigned long r4 asm("4") = (unsigned long)(arg3) -#define CALL_ARGS_4(arg1, arg2, arg3, arg4) \ - CALL_ARGS_3(arg1, arg2, arg3); \ - register unsigned long r4 asm("5") = (unsigned long)(arg4) -#define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5) \ - CALL_ARGS_4(arg1, arg2, arg3, arg4); \ - register unsigned long r4 asm("6") = (unsigned long)(arg5) - -#define CALL_FMT_0 "=&d" (r2) : -#define CALL_FMT_1 "+&d" (r2) : -#define CALL_FMT_2 CALL_FMT_1 "d" (r3), -#define CALL_FMT_3 CALL_FMT_2 "d" (r4), -#define CALL_FMT_4 CALL_FMT_3 "d" (r5), -#define CALL_FMT_5 CALL_FMT_4 "d" (r6), - -#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory" -#define CALL_CLOBBER_4 CALL_CLOBBER_5 -#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5" -#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4" -#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3" -#define CALL_CLOBBER_0 CALL_CLOBBER_1 - -#define CALL_ON_STACK(fn, stack, nr, args...) \ -({ \ - CALL_ARGS_##nr(args); \ - unsigned long prev; \ - \ - asm volatile( \ - " la %[_prev],0(15)\n" \ - " la 15,0(%[_stack])\n" \ - " stg %[_prev],%[_bc](15)\n" \ - " brasl 14,%[_fn]\n" \ - " la 15,0(%[_prev])\n" \ - : [_prev] "=&a" (prev), CALL_FMT_##nr \ - [_stack] "a" (stack), \ - [_bc] "i" (offsetof(struct stack_frame, back_chain)), \ - [_fn] "X" (fn) : CALL_CLOBBER_##nr); \ - r2; \ -}) - /* * Give up the time slice of the virtual PU. */ diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h new file mode 100644 index 000000000000..49634bfbecdd --- /dev/null +++ b/arch/s390/include/asm/stacktrace.h @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_S390_STACKTRACE_H +#define _ASM_S390_STACKTRACE_H + +#include +#include +#include + +enum stack_type { + STACK_TYPE_UNKNOWN, + STACK_TYPE_TASK, + STACK_TYPE_IRQ, + STACK_TYPE_NODAT, + STACK_TYPE_RESTART, +}; + +struct stack_info { + enum stack_type type; + unsigned long begin, end; +}; + +const char *stack_type_name(enum stack_type type); +int get_stack_info(unsigned long sp, struct task_struct *task, + struct stack_info *info, unsigned long *visit_mask); + +static inline bool on_stack(struct stack_info *info, + unsigned long addr, size_t len) +{ + if (info->type == STACK_TYPE_UNKNOWN) + return false; + if (addr + len < addr) + return false; + return addr >= info->begin && addr + len < info->end; +} + +static inline unsigned long get_stack_pointer(struct task_struct *task, + struct pt_regs *regs) +{ + if (regs) + return (unsigned long) kernel_stack_pointer(regs); + if (task == current) + return current_stack_pointer(); + return (unsigned long) task->thread.ksp; +} + +/* + * Stack layout of a C stack frame. + */ +#ifndef __PACK_STACK +struct stack_frame { + unsigned long back_chain; + unsigned long empty1[5]; + unsigned long gprs[10]; + unsigned int empty2[8]; +}; +#else +struct stack_frame { + unsigned long empty1[5]; + unsigned int empty2[8]; + unsigned long gprs[10]; + unsigned long back_chain; +}; +#endif + +#define CALL_ARGS_0() \ + register unsigned long r2 asm("2") +#define CALL_ARGS_1(arg1) \ + register unsigned long r2 asm("2") = (unsigned long)(arg1) +#define CALL_ARGS_2(arg1, arg2) \ + CALL_ARGS_1(arg1); \ + register unsigned long r3 asm("3") = (unsigned long)(arg2) +#define CALL_ARGS_3(arg1, arg2, arg3) \ + CALL_ARGS_2(arg1, arg2); \ + register unsigned long r4 asm("4") = (unsigned long)(arg3) +#define CALL_ARGS_4(arg1, arg2, arg3, arg4) \ + CALL_ARGS_3(arg1, arg2, arg3); \ + register unsigned long r4 asm("5") = (unsigned long)(arg4) +#define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5) \ + CALL_ARGS_4(arg1, arg2, arg3, arg4); \ + register unsigned long r4 asm("6") = (unsigned long)(arg5) + +#define CALL_FMT_0 "=&d" (r2) : +#define CALL_FMT_1 "+&d" (r2) : +#define CALL_FMT_2 CALL_FMT_1 "d" (r3), +#define CALL_FMT_3 CALL_FMT_2 "d" (r4), +#define CALL_FMT_4 CALL_FMT_3 "d" (r5), +#define CALL_FMT_5 CALL_FMT_4 "d" (r6), + +#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory" +#define CALL_CLOBBER_4 CALL_CLOBBER_5 +#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5" +#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4" +#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3" +#define CALL_CLOBBER_0 CALL_CLOBBER_1 + +#define CALL_ON_STACK(fn, stack, nr, args...) \ +({ \ + CALL_ARGS_##nr(args); \ + unsigned long prev; \ + \ + asm volatile( \ + " la %[_prev],0(15)\n" \ + " la 15,0(%[_stack])\n" \ + " stg %[_prev],%[_bc](15)\n" \ + " brasl 14,%[_fn]\n" \ + " la 15,0(%[_prev])\n" \ + : [_prev] "=&a" (prev), CALL_FMT_##nr \ + [_stack] "a" (stack), \ + [_bc] "i" (offsetof(struct stack_frame, back_chain)), \ + [_fn] "X" (fn) : CALL_CLOBBER_##nr); \ + r2; \ +}) + +#endif /* _ASM_S390_STACKTRACE_H */ diff --git a/arch/s390/include/asm/unwind.h b/arch/s390/include/asm/unwind.h new file mode 100644 index 000000000000..6eb2ef105d87 --- /dev/null +++ b/arch/s390/include/asm/unwind.h @@ -0,0 +1,101 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_S390_UNWIND_H +#define _ASM_S390_UNWIND_H + +#include +#include +#include +#include + +/* + * To use the stack unwinder it has to be initialized with unwind_start. + * There four combinations for task and regs: + * 1) task==NULL, regs==NULL: the unwind starts for the task that is currently + * running, sp/ip picked up from the CPU registers + * 2) task==NULL, regs!=NULL: the unwind starts from the sp/ip found in + * the struct pt_regs of an interrupt frame for the current task + * 3) task!=NULL, regs==NULL: the unwind starts for an inactive task with + * the sp picked up from task->thread.ksp and the ip picked up from the + * return address stored by __switch_to + * 4) task!=NULL, regs!=NULL: the sp/ip are picked up from the interrupt + * frame 'regs' of a inactive task + * If 'first_frame' is not zero unwind_start skips unwind frames until it + * reaches the specified stack pointer. + * The end of the unwinding is indicated with unwind_done, this can be true + * right after unwind_start, e.g. with first_frame!=0 that can not be found. + * unwind_next_frame skips to the next frame. + * Once the unwind is completed unwind_error() can be used to check if there + * has been a situation where the unwinder could not correctly understand + * the tasks call chain. + */ + +struct unwind_state { + struct stack_info stack_info; + unsigned long stack_mask; + struct task_struct *task; + struct pt_regs *regs; + unsigned long sp, ip; + int graph_idx; + bool reliable; + bool error; +}; + +void __unwind_start(struct unwind_state *state, struct task_struct *task, + struct pt_regs *regs, unsigned long first_frame); +bool unwind_next_frame(struct unwind_state *state); +unsigned long unwind_get_return_address(struct unwind_state *state); + +static inline bool unwind_done(struct unwind_state *state) +{ + return state->stack_info.type == STACK_TYPE_UNKNOWN; +} + +static inline bool unwind_error(struct unwind_state *state) +{ + return state->error; +} + +static inline void unwind_start(struct unwind_state *state, + struct task_struct *task, + struct pt_regs *regs, + unsigned long sp) +{ + sp = sp ? : get_stack_pointer(task, regs); + __unwind_start(state, task, regs, sp); +} + +static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state) +{ + return unwind_done(state) ? NULL : state->regs; +} + +#define unwind_for_each_frame(state, task, regs, first_frame) \ + for (unwind_start(state, task, regs, first_frame); \ + !unwind_done(state); \ + unwind_next_frame(state)) + +static inline void unwind_init(void) {} +static inline void unwind_module_init(struct module *mod, void *orc_ip, + size_t orc_ip_size, void *orc, + size_t orc_size) {} + +#ifdef CONFIG_KASAN +/* + * This disables KASAN checking when reading a value from another task's stack, + * since the other task could be running on another CPU and could have poisoned + * the stack in the meantime. + */ +#define READ_ONCE_TASK_STACK(task, x) \ +({ \ + unsigned long val; \ + if (task == current) \ + val = READ_ONCE(x); \ + else \ + val = READ_ONCE_NOCHECK(x); \ + val; \ +}) +#else +#define READ_ONCE_TASK_STACK(task, x) READ_ONCE(x) +#endif + +#endif /* _ASM_S390_UNWIND_H */ diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 19425605a83d..b0478d01a0c5 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -39,6 +39,7 @@ CFLAGS_smp.o := -Wno-nonnull # CFLAGS_stacktrace.o += -fno-optimize-sibling-calls CFLAGS_dumpstack.o += -fno-optimize-sibling-calls +CFLAGS_unwind_bc.o += -fno-optimize-sibling-calls # # Pass UTS_MACHINE for user_regset definition @@ -51,7 +52,7 @@ obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o early_nobss.o obj-y += sysinfo.o lgr.o os_info.o machine_kexec.o pgm_check.o obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o -obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o +obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o extra-y += head64.o vmlinux.lds diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index 164bec175628..41ac4ad21311 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -16,6 +16,7 @@ #include #include #include +#include int main(void) { diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c index cb7f55bbe06e..9e87b68be21c 100644 --- a/arch/s390/kernel/dumpstack.c +++ b/arch/s390/kernel/dumpstack.c @@ -21,95 +21,124 @@ #include #include #include +#include -/* - * For dump_trace we have tree different stack to consider: - * - the panic stack which is used if the kernel stack has overflown - * - the asynchronous interrupt stack (cpu related) - * - the synchronous kernel stack (process related) - * The stack trace can start at any of the three stacks and can potentially - * touch all of them. The order is: panic stack, async stack, sync stack. - */ -static unsigned long __no_sanitize_address -__dump_trace(dump_trace_func_t func, void *data, unsigned long sp, - unsigned long low, unsigned long high) +const char *stack_type_name(enum stack_type type) { - struct stack_frame *sf; - struct pt_regs *regs; - - while (1) { - if (sp < low || sp > high - sizeof(*sf)) - return sp; - sf = (struct stack_frame *) sp; - if (func(data, sf->gprs[8], 0)) - return sp; - /* Follow the backchain. */ - while (1) { - low = sp; - sp = sf->back_chain; - if (!sp) - break; - if (sp <= low || sp > high - sizeof(*sf)) - return sp; - sf = (struct stack_frame *) sp; - if (func(data, sf->gprs[8], 1)) - return sp; - } - /* Zero backchain detected, check for interrupt frame. */ - sp = (unsigned long) (sf + 1); - if (sp <= low || sp > high - sizeof(*regs)) - return sp; - regs = (struct pt_regs *) sp; - if (!user_mode(regs)) { - if (func(data, regs->psw.addr, 1)) - return sp; - } - low = sp; - sp = regs->gprs[15]; + switch (type) { + case STACK_TYPE_TASK: + return "task"; + case STACK_TYPE_IRQ: + return "irq"; + case STACK_TYPE_NODAT: + return "nodat"; + case STACK_TYPE_RESTART: + return "restart"; + default: + return "unknown"; } } -void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task, - unsigned long sp) +static inline bool in_stack(unsigned long sp, struct stack_info *info, + enum stack_type type, unsigned long low, + unsigned long high) { - unsigned long frame_size; + if (sp < low || sp >= high) + return false; + info->type = type; + info->begin = low; + info->end = high; + return true; +} + +static bool in_task_stack(unsigned long sp, struct task_struct *task, + struct stack_info *info) +{ + unsigned long stack; + + stack = (unsigned long) task_stack_page(task); + return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE); +} + +static bool in_irq_stack(unsigned long sp, struct stack_info *info) +{ + unsigned long frame_size, top; frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); -#ifdef CONFIG_CHECK_STACK - sp = __dump_trace(func, data, sp, - S390_lowcore.nodat_stack + frame_size - THREAD_SIZE, - S390_lowcore.nodat_stack + frame_size); -#endif - sp = __dump_trace(func, data, sp, - S390_lowcore.async_stack + frame_size - THREAD_SIZE, - S390_lowcore.async_stack + frame_size); - task = task ?: current; - __dump_trace(func, data, sp, - (unsigned long)task_stack_page(task), - (unsigned long)task_stack_page(task) + THREAD_SIZE); + top = S390_lowcore.async_stack + frame_size; + return in_stack(sp, info, STACK_TYPE_IRQ, top - THREAD_SIZE, top); } -EXPORT_SYMBOL_GPL(dump_trace); -static int show_address(void *data, unsigned long address, int reliable) +static bool in_nodat_stack(unsigned long sp, struct stack_info *info) { - if (reliable) - printk(" [<%016lx>] %pSR \n", address, (void *)address); - else - printk("([<%016lx>] %pSR)\n", address, (void *)address); + unsigned long frame_size, top; + + frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); + top = S390_lowcore.nodat_stack + frame_size; + return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top); +} + +static bool in_restart_stack(unsigned long sp, struct stack_info *info) +{ + unsigned long frame_size, top; + + frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); + top = S390_lowcore.restart_stack + frame_size; + return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top); +} + +int get_stack_info(unsigned long sp, struct task_struct *task, + struct stack_info *info, unsigned long *visit_mask) +{ + if (!sp) + goto unknown; + + task = task ? : current; + + /* Check per-task stack */ + if (in_task_stack(sp, task, info)) + goto recursion_check; + + if (task != current) + goto unknown; + + /* Check per-cpu stacks */ + if (!in_irq_stack(sp, info) && + !in_nodat_stack(sp, info) && + !in_restart_stack(sp, info)) + goto unknown; + +recursion_check: + /* + * Make sure we don't iterate through any given stack more than once. + * If it comes up a second time then there's something wrong going on: + * just break out and report an unknown stack type. + */ + if (*visit_mask & (1UL << info->type)) { + printk_deferred_once(KERN_WARNING + "WARNING: stack recursion on stack type %d\n", + info->type); + goto unknown; + } + *visit_mask |= 1UL << info->type; return 0; +unknown: + info->type = STACK_TYPE_UNKNOWN; + return -EINVAL; } void show_stack(struct task_struct *task, unsigned long *stack) { - unsigned long sp = (unsigned long) stack; + struct unwind_state state; - if (!sp) - sp = task ? task->thread.ksp : current_stack_pointer(); printk("Call Trace:\n"); - dump_trace(show_address, NULL, task, sp); if (!task) task = current; - debug_show_held_locks(task); + unwind_for_each_frame(&state, task, NULL, (unsigned long) stack) + printk(state.reliable ? " [<%016lx>] %pSR \n" : + "([<%016lx>] %pSR)\n", + state.ip, (void *) state.ip); + debug_show_held_locks(task ? : current); } static void show_last_breaking_event(struct pt_regs *regs) diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c index 150964f91183..8371855042dc 100644 --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -26,6 +26,7 @@ #include #include #include +#include #include "entry.h" DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat); diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c index e2ba7b7f574e..2f3a742a71a5 100644 --- a/arch/s390/kernel/machine_kexec.c +++ b/arch/s390/kernel/machine_kexec.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c index 0d770e513abf..fcb6c2e92b07 100644 --- a/arch/s390/kernel/perf_event.c +++ b/arch/s390/kernel/perf_event.c @@ -21,6 +21,7 @@ #include #include #include +#include const char *perf_pmu_name(void) { @@ -219,20 +220,13 @@ static int __init service_level_perf_register(void) } arch_initcall(service_level_perf_register); -static int __perf_callchain_kernel(void *data, unsigned long address, int reliable) -{ - struct perf_callchain_entry_ctx *entry = data; - - perf_callchain_store(entry, address); - return 0; -} - void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - if (user_mode(regs)) - return; - dump_trace(__perf_callchain_kernel, entry, NULL, regs->gprs[15]); + struct unwind_state state; + + unwind_for_each_frame(&state, current, regs, 0) + perf_callchain_store(entry, state.ip); } /* Perf definitions for PMU event attributes in sysfs */ diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 6e758bb6cd29..63873aa6693f 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include "entry.h" diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 64e4bc9dd130..f8544d517430 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -66,6 +66,7 @@ #include #include #include +#include #include #include #include diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 88634fb0cc50..35fafa2b91a8 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -53,6 +53,7 @@ #include #include #include +#include #include #include "entry.h" diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c index 460dcfba7d4e..89f9f63dca18 100644 --- a/arch/s390/kernel/stacktrace.c +++ b/arch/s390/kernel/stacktrace.c @@ -11,40 +11,21 @@ #include #include #include - -static int __save_address(void *data, unsigned long address, int nosched) -{ - struct stack_trace *trace = data; - - if (nosched && in_sched_functions(address)) - return 0; - if (trace->skip > 0) { - trace->skip--; - return 0; - } - if (trace->nr_entries < trace->max_entries) { - trace->entries[trace->nr_entries++] = address; - return 0; - } - return 1; -} - -static int save_address(void *data, unsigned long address, int reliable) -{ - return __save_address(data, address, 0); -} - -static int save_address_nosched(void *data, unsigned long address, int reliable) -{ - return __save_address(data, address, 1); -} +#include +#include void save_stack_trace(struct stack_trace *trace) { - unsigned long sp; + struct unwind_state state; - sp = current_stack_pointer(); - dump_trace(save_address, trace, NULL, sp); + unwind_for_each_frame(&state, current, NULL, 0) { + if (trace->nr_entries >= trace->max_entries) + break; + if (trace->skip > 0) + trace->skip--; + else + trace->entries[trace->nr_entries++] = state.ip; + } if (trace->nr_entries < trace->max_entries) trace->entries[trace->nr_entries++] = ULONG_MAX; } @@ -52,12 +33,18 @@ EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { - unsigned long sp; + struct unwind_state state; - sp = tsk->thread.ksp; - if (tsk == current) - sp = current_stack_pointer(); - dump_trace(save_address_nosched, trace, tsk, sp); + unwind_for_each_frame(&state, tsk, NULL, 0) { + if (trace->nr_entries >= trace->max_entries) + break; + if (in_sched_functions(state.ip)) + continue; + if (trace->skip > 0) + trace->skip--; + else + trace->entries[trace->nr_entries++] = state.ip; + } if (trace->nr_entries < trace->max_entries) trace->entries[trace->nr_entries++] = ULONG_MAX; } @@ -65,10 +52,16 @@ EXPORT_SYMBOL_GPL(save_stack_trace_tsk); void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) { - unsigned long sp; + struct unwind_state state; - sp = kernel_stack_pointer(regs); - dump_trace(save_address, trace, NULL, sp); + unwind_for_each_frame(&state, current, regs, 0) { + if (trace->nr_entries >= trace->max_entries) + break; + if (trace->skip > 0) + trace->skip--; + else + trace->entries[trace->nr_entries++] = state.ip; + } if (trace->nr_entries < trace->max_entries) trace->entries[trace->nr_entries++] = ULONG_MAX; } diff --git a/arch/s390/kernel/unwind_bc.c b/arch/s390/kernel/unwind_bc.c new file mode 100644 index 000000000000..cf5a630f3aa9 --- /dev/null +++ b/arch/s390/kernel/unwind_bc.c @@ -0,0 +1,155 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +unsigned long unwind_get_return_address(struct unwind_state *state) +{ + if (unwind_done(state)) + return 0; + return __kernel_text_address(state->ip) ? state->ip : 0; +} +EXPORT_SYMBOL_GPL(unwind_get_return_address); + +static bool outside_of_stack(struct unwind_state *state, unsigned long sp) +{ + return (sp <= state->sp) || + (sp + sizeof(struct stack_frame) > state->stack_info.end); +} + +static bool update_stack_info(struct unwind_state *state, unsigned long sp) +{ + struct stack_info *info = &state->stack_info; + unsigned long *mask = &state->stack_mask; + + /* New stack pointer leaves the current stack */ + if (get_stack_info(sp, state->task, info, mask) != 0 || + !on_stack(info, sp, sizeof(struct stack_frame))) + /* 'sp' does not point to a valid stack */ + return false; + return true; +} + +bool unwind_next_frame(struct unwind_state *state) +{ + struct stack_info *info = &state->stack_info; + struct stack_frame *sf; + struct pt_regs *regs; + unsigned long sp, ip; + bool reliable; + + regs = state->regs; + if (unlikely(regs)) { + sp = READ_ONCE_TASK_STACK(state->task, regs->gprs[15]); + if (unlikely(outside_of_stack(state, sp))) { + if (!update_stack_info(state, sp)) + goto out_err; + } + sf = (struct stack_frame *) sp; + ip = READ_ONCE_TASK_STACK(state->task, sf->gprs[8]); + reliable = false; + regs = NULL; + } else { + sf = (struct stack_frame *) state->sp; + sp = READ_ONCE_TASK_STACK(state->task, sf->back_chain); + if (likely(sp)) { + /* Non-zero back-chain points to the previous frame */ + if (unlikely(outside_of_stack(state, sp))) { + if (!update_stack_info(state, sp)) + goto out_err; + } + sf = (struct stack_frame *) sp; + ip = READ_ONCE_TASK_STACK(state->task, sf->gprs[8]); + reliable = true; + } else { + /* No back-chain, look for a pt_regs structure */ + sp = state->sp + STACK_FRAME_OVERHEAD; + if (!on_stack(info, sp, sizeof(struct pt_regs))) + goto out_stop; + regs = (struct pt_regs *) sp; + if (user_mode(regs)) + goto out_stop; + ip = READ_ONCE_TASK_STACK(state->task, regs->psw.addr); + reliable = true; + } + } + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + /* Decode any ftrace redirection */ + if (ip == (unsigned long) return_to_handler) + ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, + ip, NULL); +#endif + + /* Update unwind state */ + state->sp = sp; + state->ip = ip; + state->regs = regs; + state->reliable = reliable; + return true; + +out_err: + state->error = true; +out_stop: + state->stack_info.type = STACK_TYPE_UNKNOWN; + return false; +} +EXPORT_SYMBOL_GPL(unwind_next_frame); + +void __unwind_start(struct unwind_state *state, struct task_struct *task, + struct pt_regs *regs, unsigned long sp) +{ + struct stack_info *info = &state->stack_info; + unsigned long *mask = &state->stack_mask; + struct stack_frame *sf; + unsigned long ip; + bool reliable; + + memset(state, 0, sizeof(*state)); + state->task = task; + state->regs = regs; + + /* Don't even attempt to start from user mode regs: */ + if (regs && user_mode(regs)) { + info->type = STACK_TYPE_UNKNOWN; + return; + } + + /* Get current stack pointer and initialize stack info */ + if (get_stack_info(sp, task, info, mask) != 0 || + !on_stack(info, sp, sizeof(struct stack_frame))) { + /* Something is wrong with the stack pointer */ + info->type = STACK_TYPE_UNKNOWN; + state->error = true; + return; + } + + /* Get the instruction pointer from pt_regs or the stack frame */ + if (regs) { + ip = READ_ONCE_TASK_STACK(state->task, regs->psw.addr); + reliable = true; + } else { + sf = (struct stack_frame *) sp; + ip = READ_ONCE_TASK_STACK(state->task, sf->gprs[8]); + reliable = false; + } + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + /* Decode any ftrace redirection */ + if (ip == (unsigned long) return_to_handler) + ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, + ip, NULL); +#endif + + /* Update unwind state */ + state->sp = sp; + state->ip = ip; + state->reliable = reliable; +} +EXPORT_SYMBOL_GPL(__unwind_start); diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c index 97b3ee53852b..818deeb1ebc3 100644 --- a/arch/s390/mm/maccess.c +++ b/arch/s390/mm/maccess.c @@ -16,6 +16,7 @@ #include #include #include +#include static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t size) { diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c index 43d9525c36fc..7441857df51b 100644 --- a/arch/s390/oprofile/init.c +++ b/arch/s390/oprofile/init.c @@ -13,23 +13,17 @@ #include #include #include - -static int __s390_backtrace(void *data, unsigned long address, int reliable) -{ - unsigned int *depth = data; - - if (*depth == 0) - return 1; - (*depth)--; - oprofile_add_trace(address); - return 0; -} +#include static void s390_backtrace(struct pt_regs *regs, unsigned int depth) { - if (user_mode(regs)) - return; - dump_trace(__s390_backtrace, &depth, NULL, regs->gprs[15]); + struct unwind_state state; + + unwind_for_each_frame(&state, current, regs, 0) { + if (depth-- == 0) + break; + oprofile_add_trace(state.ip); + } } int __init oprofile_arch_init(struct oprofile_operations *ops)