[GIT PULL] x86/debug change for v4.15

From: Ingo Molnar
Date: Mon Nov 13 2017 - 03:34:33 EST


Linus,

Please pull the latest x86-debug-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-debug-for-linus

# HEAD: 77072f09eab19326dd2424c8dad0a443341a228f x86/stacktrace: Avoid recording save_stack_trace() wrappers

A single change enhancing stack traces by hiding wrapper function entries.

Thanks,

Ingo

------------------>
Vlastimil Babka (1):
x86/stacktrace: Avoid recording save_stack_trace() wrappers


arch/x86/kernel/stacktrace.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 8dabd7bf1673..77835bc021c7 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -30,7 +30,7 @@ static int save_stack_address(struct stack_trace *trace, unsigned long addr,
return 0;
}

-static void __save_stack_trace(struct stack_trace *trace,
+static void noinline __save_stack_trace(struct stack_trace *trace,
struct task_struct *task, struct pt_regs *regs,
bool nosched)
{
@@ -56,6 +56,7 @@ static void __save_stack_trace(struct stack_trace *trace,
*/
void save_stack_trace(struct stack_trace *trace)
{
+ trace->skip++;
__save_stack_trace(trace, current, NULL, false);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
@@ -70,6 +71,8 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
if (!try_get_task_stack(tsk))
return;

+ if (tsk == current)
+ trace->skip++;
__save_stack_trace(trace, tsk, NULL, true);

put_task_stack(tsk);
@@ -88,8 +91,9 @@ EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
} \
})

-static int __save_stack_trace_reliable(struct stack_trace *trace,
- struct task_struct *task)
+static int __always_inline
+__save_stack_trace_reliable(struct stack_trace *trace,
+ struct task_struct *task)
{
struct unwind_state state;
struct pt_regs *regs;