Re: [PATCH v3] riscv : select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY

From: Conor Dooley
Date: Thu Dec 01 2022 - 10:28:39 EST


On Thu, Dec 01, 2022 at 11:13:36PM +0800, Song Shuai wrote:
> In RISC-V, -fpatchable-function-entry option is used to support
> dynamic ftrace in this commit afc76b8b8011 ("riscv: Using
> PATCHABLE_FUNCTION_ENTRY instead of MCOUNT"). So recordmcount
> don't have to be called to create the __mcount_loc section before
> the vmlinux linking.
>
> Here selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY to tell
> Makefile not to run recordmcount.
>
> Link_v1: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@xxxxxxxxxxxxxx/T/#t
> Link_v2: https://lore.kernel.org/linux-riscv/CAAYs2=iYn8sLQB8oh+RzTKd2VKs8MXOLX6Mwpamx5gdVVN6mkA@xxxxxxxxxxxxxx/T/#m62138d7a76664798d00051818a438a601eff4cf1

Hey Song Shuai,

For future patches, please use normal "Link:" tags. If you're just
linking to prior versions of the patch, just put them below the ---
line so they don't end up in the git history.

Please don't resend for this alone :)

Thanks,
Conor.

> Signed-off-by: Song Shuai <suagrfillet@xxxxxxxxx>
> Tested-by: Guo Ren <guoren@xxxxxxxxxx>
> ---
> arch/riscv/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 572973103d73..c19cddb8feb9 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -277,6 +277,7 @@ config ARCH_RV64I
> select 64BIT
> select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
> select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
> + select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
> select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
> select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
> select HAVE_SAMPLE_FTRACE_DIRECT
> --
> 2.20.1
>