From ec7bf4789d95a0053bac0dfa36fbefd8cc584eea Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 18 Feb 2019 16:51:28 +0100 Subject: [PATCH] s390/ftrace: use HAVE_FUNCTION_GRAPH_RET_ADDR_PTR Make the call chain more reliable by tagging the ftrace stack entries with the stack pointer that is associated with the return address. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/ftrace.h | 2 ++ arch/s390/kernel/entry.h | 2 +- arch/s390/kernel/ftrace.c | 9 +++++---- arch/s390/kernel/mcount.S | 4 ++-- arch/s390/kernel/unwind_bc.c | 2 +- 5 files changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h index 6e0ed0338785..68d362f8d6c1 100644 --- a/arch/s390/include/asm/ftrace.h +++ b/arch/s390/include/asm/ftrace.h @@ -11,6 +11,8 @@ #define MCOUNT_RETURN_FIXUP 18 #endif +#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR + #ifndef __ASSEMBLY__ #ifdef CONFIG_CC_IS_CLANG diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h index c3816ae108b0..20420c2b8a14 100644 --- a/arch/s390/kernel/entry.h +++ b/arch/s390/kernel/entry.h @@ -65,7 +65,7 @@ int setup_profiling_timer(unsigned int multiplier); void __init time_init(void); int pfn_is_nosave(unsigned long); void s390_early_resume(void); -unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip); +unsigned long prepare_ftrace_return(unsigned long parent, unsigned long sp, unsigned long ip); struct s390_mmap_arg_struct; struct fadvise64_64_args; diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index 39b13d71a8fe..1bb85f60c0dd 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -201,17 +201,18 @@ device_initcall(ftrace_plt_init); * Hook the return address and push it in the stack of return addresses * in current thread info. */ -unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip) +unsigned long prepare_ftrace_return(unsigned long ra, unsigned long sp, + unsigned long ip) { if (unlikely(ftrace_graph_is_dead())) goto out; if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; ip -= MCOUNT_INSN_SIZE; - if (!function_graph_enter(parent, ip, 0, NULL)) - parent = (unsigned long) return_to_handler; + if (!function_graph_enter(ra, ip, 0, (void *) sp)) + ra = (unsigned long) return_to_handler; out: - return parent; + return ra; } NOKPROBE_SYMBOL(prepare_ftrace_return); diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S index 09ae6da0aaa5..9e1660a6b9db 100644 --- a/arch/s390/kernel/mcount.S +++ b/arch/s390/kernel/mcount.S @@ -65,8 +65,8 @@ ENTRY(ftrace_caller) .globl ftrace_graph_caller ftrace_graph_caller: j ftrace_graph_caller_end - lg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) - lg %r3,(STACK_PTREGS_PSW+8)(%r15) + lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15) + lg %r4,(STACK_PTREGS_PSW+8)(%r15) brasl %r14,prepare_ftrace_return stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) ftrace_graph_caller_end: diff --git a/arch/s390/kernel/unwind_bc.c b/arch/s390/kernel/unwind_bc.c index cf5a630f3aa9..57fd4e902f1f 100644 --- a/arch/s390/kernel/unwind_bc.c +++ b/arch/s390/kernel/unwind_bc.c @@ -84,7 +84,7 @@ bool unwind_next_frame(struct unwind_state *state) /* Decode any ftrace redirection */ if (ip == (unsigned long) return_to_handler) ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, - ip, NULL); + ip, (void *) sp); #endif /* Update unwind state */