Re: [PATCH v12 4/8] powerpc/bpf: Remove bpf_jit_free()

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 06/05/2021 à 04:34, Jordan Niethe a écrit :
> Commit 74451e66d516 ("bpf: make jited programs visible in traces") added
> a default bpf_jit_free() implementation. Powerpc did not use the default
> bpf_jit_free() as powerpc did not set the images read-only. The default
> bpf_jit_free() called bpf_jit_binary_unlock_ro() is why it could not be
> used for powerpc.
> 
> Commit d53d2f78cead ("bpf: Use vmalloc special flag") moved keeping
> track of read-only memory to vmalloc. This included removing
> bpf_jit_binary_unlock_ro(). Therefore there is no reason powerpc needs
> its own bpf_jit_free(). Remove it.
> 
> Signed-off-by: Jordan Niethe <jniethe5@gmail.com>

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>

> ---
> v11: New to series
> ---
>   arch/powerpc/net/bpf_jit_comp.c | 12 ------------
>   1 file changed, 12 deletions(-)
> 
> diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
> index 798ac4350a82..6c8c268e4fe8 100644
> --- a/arch/powerpc/net/bpf_jit_comp.c
> +++ b/arch/powerpc/net/bpf_jit_comp.c
> @@ -257,15 +257,3 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
>   
>   	return fp;
>   }
> -
> -/* Overriding bpf_jit_free() as we don't set images read-only. */
> -void bpf_jit_free(struct bpf_prog *fp)
> -{
> -	unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
> -	struct bpf_binary_header *bpf_hdr = (void *)addr;
> -
> -	if (fp->jited)
> -		bpf_jit_binary_free(bpf_hdr);
> -
> -	bpf_prog_unlock_free(fp);
> -}
>