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authorPrakash Gupta <guptap@codeaurora.org>2017-09-13 16:28:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-13 18:53:16 -0700
commitbb53c820c5b0f1a52804e32683aa7874db27392d (patch)
tree83692dbb890f7a7f5b0fbda2c77d8f59a4095663
parent0ee931c4e31a5efb134c76440405e9219f896e33 (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 commit 3683f44c42e9 ("ARM: stacktrace: avoid listing stacktrace functions in stacktrace") Link: http://lkml.kernel.org/r/1504078343-28754-1-git-send-email-guptap@codeaurora.org Signed-off-by: Prakash Gupta <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: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/arm64/kernel/stacktrace.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 3144584617e7..76809ccd309c 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -140,7 +140,8 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
-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;
@@ -150,15 +151,16 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
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.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.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;
@@ -172,9 +174,15 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
}
EXPORT_SYMBOL_GPL(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