Messages in this thread | | | Subject | Re: [PATCH 1/2] riscv: ftrace: Fix the comments about the number of ftrace instruction | From | Li Huafei <> | Date | Tue, 26 Apr 2022 16:52:55 +0800 |
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On 2022/4/26 14:22, Guo Ren wrote: > 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. I misunderstood, thanks for the clarification. > > Fixes: afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT") There is no functional fix here, do we need to add the fix tag? > > 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.
I agree and will use this modification for the next version, thanks!
Huafei > >> * patchable function entry nops' area. >> * >> * 0: REG_S ra, -SZREG(sp) >> -- >> 2.17.1 >> >
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