| Message ID | 1444298504-10392-6-git-send-email-takahiro.akashi@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, 8 Oct 2015 19:01:42 +0900 AKASHI Takahiro <takahiro.akashi@linaro.org> wrote: > include/linux/ftrace.h | 10 ++++++++++ > kernel/trace/trace_stack.c | 22 ++++++++++++++-------- > 2 files changed, 24 insertions(+), 8 deletions(-) > > diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h > index d77b195..e538400 100644 > --- a/include/linux/ftrace.h > +++ b/include/linux/ftrace.h > @@ -270,7 +270,17 @@ static inline void ftrace_kill(void) { } > #define FTRACE_STACK_FRAME_OFFSET 0 > #endif > > +#define STACK_TRACE_ENTRIES 500 > + > +struct stack_trace; > + > +extern unsigned stack_dump_index[]; > +extern struct stack_trace max_stack_trace; > +extern unsigned long max_stack_size; > +extern arch_spinlock_t max_stack_lock; > + > extern int stack_tracer_enabled; > +void print_max_stack(void); OK, if we are making these external, they need to have better name space naming. stack_dump_index => stack_trace_index max_stack_trace => stack_trace_max max_stack_size => stack_trace_max_size print_max_stack() => stack_trace_print() -- Steve > int > stack_trace_sysctl(struct ctl_table *table, int write, > void __user *buffer, size_t *lenp, > diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c > index 30521ea..ff1a191 100644 > --- a/kernel/trace/trace_stack.c > +++ b/kernel/trace/trace_stack.c > @@ -16,24 +16,22 @@ > > #include "trace.h" > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index d77b195..e538400 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -270,7 +270,17 @@ static inline void ftrace_kill(void) { } #define FTRACE_STACK_FRAME_OFFSET 0 #endif +#define STACK_TRACE_ENTRIES 500 + +struct stack_trace; + +extern unsigned stack_dump_index[]; +extern struct stack_trace max_stack_trace; +extern unsigned long max_stack_size; +extern arch_spinlock_t max_stack_lock; + extern int stack_tracer_enabled; +void print_max_stack(void); int stack_trace_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 30521ea..ff1a191 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -16,24 +16,22 @@ #include "trace.h" -#define STACK_TRACE_ENTRIES 500 - static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] = { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX }; -static unsigned stack_dump_index[STACK_TRACE_ENTRIES]; +unsigned stack_dump_index[STACK_TRACE_ENTRIES]; /* * Reserve one entry for the passed in ip. This will allow * us to remove most or all of the stack size overhead * added by the stack tracer itself. */ -static struct stack_trace max_stack_trace = { +struct stack_trace max_stack_trace = { .max_entries = STACK_TRACE_ENTRIES - 1, .entries = &stack_dump_trace[0], }; -static unsigned long max_stack_size; -static arch_spinlock_t max_stack_lock = +unsigned long max_stack_size; +arch_spinlock_t max_stack_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; static DEFINE_PER_CPU(int, trace_active); @@ -42,7 +40,7 @@ static DEFINE_MUTEX(stack_sysctl_mutex); int stack_tracer_enabled; static int last_stack_tracer_enabled; -static inline void print_max_stack(void) +void print_max_stack(void) { long i; int size; @@ -65,7 +63,15 @@ static inline void print_max_stack(void) } } -static inline void +/* + * When arch-specific code overides this function, the following + * data should be filled up, assuming max_stack_lock is held to + * prevent concurrent updates. + * stack_dump_index[] + * max_stack_trace + * max_stack_size + */ +void __weak check_stack(unsigned long ip, unsigned long *stack) { unsigned long this_size, flags; unsigned long *p, *top, *start;
A stack frame may be used in a different way depending on cpu architecture. Thus it is not always appropriate to slurp the stack contents, as current check_stack() does, in order to calcurate a stack index (height) at a given function call. At least not on arm64. In addition, there is a possibility that we will mistakenly detect a stale stack frame which has not been overwritten. This patch makes check_stack() a weak function so as to later implement arch-specific version. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> --- include/linux/ftrace.h | 10 ++++++++++ kernel/trace/trace_stack.c | 22 ++++++++++++++-------- 2 files changed, 24 insertions(+), 8 deletions(-)