diff options
| author | Prakash Gupta <guptap@codeaurora.org> | 2017-09-07 10:25:35 +1000 |
|---|---|---|
| committer | Prakash Gupta <guptap@codeaurora.org> | 2017-09-07 16:14:56 +0530 |
| commit | d6bb6d333cc9bb030d27f459c2e6ce1e4a2d0043 (patch) | |
| tree | 6254d318c25f3fcbdbc9be0bed9158b810840057 /arch/arm64/kernel/stacktrace.c | |
| parent | bf6d3e63f9fae49b40596ce91549ec45d1f62522 (diff) | |
arm64: stacktrace: avoid listing stacktrace functions in stacktrace
The stacktraces always begin as follows:
[<c00117b4>] save_stack_trace_tsk+0x0/0x98
[<c0011870>] save_stack_trace+0x24/0x28
...
This is because the stack trace code includes the stack frames for itself.
This is incorrect behaviour, and also leads to "skip" doing the wrong
thing (which is the number of stack frames to avoid recording.)
Perversely, it does the right thing when passed a non-current thread. Fix
this by ensuring that we have a known constant number of frames above the
main stack trace function, and always skip these.
This was fixed for arch arm by 3683f44c42e9 ("ARM: stacktrace: avoid
listing stacktrace functions in stacktrace")
Change-Id: I1a65ee011f022227204b406bb0288828a7beb0b8
Link: http://lkml.kernel.org/r/1504078343-28754-1-git-send-email-guptap@codeaurora.org
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Git-commit: 457b9ab50babff7100fe7902d195069561bc1db7
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
[guptap@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>
Diffstat (limited to 'arch/arm64/kernel/stacktrace.c')
| -rw-r--r-- | arch/arm64/kernel/stacktrace.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index 1fd1a9a6596f..770d64547a6a 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -157,24 +157,26 @@ static int save_trace(struct stackframe *frame, void *d) return trace->nr_entries >= trace->max_entries; } -void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) +static noinline void __save_stack_trace(struct task_struct *tsk, + struct stack_trace *trace, unsigned int nosched) { struct stack_trace_data data; struct stackframe frame; data.trace = trace; data.skip = trace->skip; + data.no_sched_functions = nosched; if (tsk != current) { - data.no_sched_functions = 1; frame.fp = thread_saved_fp(tsk); frame.sp = thread_saved_sp(tsk); frame.pc = thread_saved_pc(tsk); } else { - data.no_sched_functions = 0; + /* We don't want this function nor the caller */ + data.skip += 2; frame.fp = (unsigned long)__builtin_frame_address(0); frame.sp = current_stack_pointer; - frame.pc = (unsigned long)save_stack_trace_tsk; + frame.pc = (unsigned long)__save_stack_trace; } #ifdef CONFIG_FUNCTION_GRAPH_TRACER frame.graph = tsk->curr_ret_stack; @@ -186,9 +188,15 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) } EXPORT_SYMBOL(save_stack_trace_tsk); +void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) +{ + __save_stack_trace(tsk, trace, 1); +} + void save_stack_trace(struct stack_trace *trace) { - save_stack_trace_tsk(current, trace); + __save_stack_trace(current, trace, 0); } + EXPORT_SYMBOL_GPL(save_stack_trace); #endif |