Messages in this thread | | | From | Guo Ren <> | Date | Tue, 26 Apr 2022 14:22:18 +0800 | Subject | Re: [PATCH 1/2] riscv: ftrace: Fix the comments about the number of ftrace instruction |
| |
On Tue, Apr 26, 2022 at 9:59 AM Li Huafei <lihuafei1@huawei.com> wrote: > > When DYNAMIC_FTRACE is enabled, we put four instructions in front of the > function for ftrace use, not five. > > Signed-off-by: Li Huafei <lihuafei1@huawei.com> > --- > arch/riscv/kernel/ftrace.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c > index 4716f4cdc038..63f457650fa4 100644 > --- a/arch/riscv/kernel/ftrace.c > +++ b/arch/riscv/kernel/ftrace.c > @@ -73,7 +73,7 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, > } > > /* > - * Put 5 instructions with 16 bytes at the front of function within > + * Put 4 instructions with 16 bytes at the front of function within Yeah, 5 instructions are for mcount, -fpatchable-function-entry=8 cause 8 16bit instructions.
Fixes: afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT")
I recommend just delete "4 instructions with" - * Put 5 instructions with 16 bytes at the front of function within - * patchable function entry nops' area. + * Put 16 bytes at the front of the function within the patchable + * function entry nops' area.
> * patchable function entry nops' area. > * > * 0: REG_S ra, -SZREG(sp) > -- > 2.17.1 >
-- Best Regards Guo Ren
ML: https://lore.kernel.org/linux-csky/
| |