Messages in this thread | | | Date | Thu, 18 Aug 2022 16:50:24 -0400 | From | Steven Rostedt <> | Subject | Re: [RFC] ftrace: Add support to keep some functions out of ftrace |
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On Thu, 18 Aug 2022 22:27:07 +0200 Jiri Olsa <olsajiri@gmail.com> wrote:
> ok, so the problem with __attribute__((patchable_function_entry(5))) is that > it puts function address into __patchable_function_entries section, which is > one of ftrace locations source: > > #define MCOUNT_REC() . = ALIGN(8); \ > __start_mcount_loc = .; \ > KEEP(*(__mcount_loc)) \ > KEEP(*(__patchable_function_entries)) \ > __stop_mcount_loc = .; \ > ... > > > it looks like __patchable_function_entries is used for other than x86 archs, > so we perhaps we could have x86 specific MCOUNT_REC macro just with > __mcount_loc section?
So something like this:
#ifdef CONFIG_X86 # define NON_MCOUNT_PATCHABLE KEEP(*(__patchable_function_entries)) # define MCOUNT_PATCHABLE #else # define NON_MCOUNT_PATCHABLE # define MCOUNT_PATCHABLE KEEP(*(__patchable_function_entries)) #endif
#define MCOUNT_REC() . = ALIGN(8); \ __start_mcount_loc = .; \ KEEP(*(__mcount_loc)) \ MCOUNT_PATCHABLE \ __stop_mcount_loc = .; \ NON_MCOUNT_PATCHABLE \ ...
??
-- Steve
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