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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2019-02-18 16:51:28 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2019-05-02 13:54:11 +0200
commitec7bf4789d95a0053bac0dfa36fbefd8cc584eea (patch)
tree5ad08bd5f30c065e312944baf8eafd0b4766f654 /arch/s390/kernel
parents390/unwind: introduce stack unwind API (diff)
downloadlinux-ec7bf4789d95a0053bac0dfa36fbefd8cc584eea.tar.xz
linux-ec7bf4789d95a0053bac0dfa36fbefd8cc584eea.zip
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 <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel')
-rw-r--r--arch/s390/kernel/entry.h2
-rw-r--r--arch/s390/kernel/ftrace.c9
-rw-r--r--arch/s390/kernel/mcount.S4
-rw-r--r--arch/s390/kernel/unwind_bc.c2
4 files changed, 9 insertions, 8 deletions
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(&current->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 */