Messages in this thread Patch in this message | | | Date | Thu, 03 Jun 2010 12:53:52 -0700 | From | Arjan van de Ven <> | Subject | Re: [PATCH 1/2] x86: make save_stack_address() !CONFIG_FRAME_POINTER friendly |
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On 6/3/2010 12:32 PM, Oleg Nesterov wrote: > If CONFIG_FRAME_POINTER=n, print_context_stack() shouldn't neglect the > non-reliable addresses on stack, this is all we have if dump_trace(bp) > is called with the wrong or zero bp. > > For example, /proc/pid/stack doesn't work if CONFIG_FRAME_POINTER=n. > > This patch obviously has no effect if CONFIG_FRAME_POINTER=y, otherwise > it reverts 1650743c "x86: don't save unreliable stack trace entries". >
would be nice if there was a compile time thing to detect if frame pointers are on ratehr than an ifdef.
you're now also changing the rules; until now, you would ALWAYS get a backtrace without noise.... now that's changing quite a bit. How are various tools (like perf and sysprof) going to cope with that?
> Also, remove the unnecessary type-cast. > > Signed-off-by: Oleg Nesterov<oleg@redhat.com> > --- > > arch/x86/kernel/stacktrace.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > --- 34-rc1/arch/x86/kernel/stacktrace.c~SAVE_STACK_WO_FP 2010-06-03 18:43:27.000000000 +0200 > +++ 34-rc1/arch/x86/kernel/stacktrace.c 2010-06-03 21:29:52.000000000 +0200 > @@ -26,8 +26,10 @@ static int save_stack_stack(void *data, > static void save_stack_address(void *data, unsigned long addr, int reliable) > { > struct stack_trace *trace = data; > +#ifdef CONFIG_FRAME_POINTER > if (!reliable) > return; > +#endif > if (trace->skip> 0) { > trace->skip--; > return; > @@ -39,9 +41,11 @@ static void save_stack_address(void *dat > static void > save_stack_address_nosched(void *data, unsigned long addr, int reliable) > { > - struct stack_trace *trace = (struct stack_trace *)data; > + struct stack_trace *trace = data; > +#ifdef CONFIG_FRAME_POINTER > if (!reliable) > return; > +#endif > if (in_sched_functions(addr)) > return; > if (trace->skip> 0) { > >
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