Re: [PATCH] Revert "bpf: Take return from set_memory_rox() into account with bpf_jit_binary_lock_ro()" for linux-6.6.37

Greg KH
2024-07-06T09:30:04Z

On Sat, Jul 06, 2024 at 11:11:01AM +0800, WangYuli wrote:
> This reverts commit 08f6c05feb1db21653e98ca84ea04ca032d014c7.
>
> Upstream commit e60adf513275 ("bpf: Take return from set_memory_rox() into account with bpf_jit_binary_lock_ro()")
> depends on
> upstream commit 1dad391daef1 ("bpf, arm64: use bpf_prog_pack for memory management").
>
> It will cause a compilation warning on the arm64 if it's not merged:
> arch/arm64/net/bpf_jit_comp.c: In function ‘bpf_int_jit_compile’:
> arch/arm64/net/bpf_jit_comp.c:1651:17: warning: ignoring return value of ‘bpf_jit_binary_lock_ro’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
> 1651 | bpf_jit_binary_lock_ro(header);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> This will prevent the kernel with the '-Werror' compile option from
> being compiled successfully.
>
> We might as well revert this commit in linux-6.6.37 to solve the
> problem in a simple way.

This makes it sound like you are reverting this because of a build
error, which is not the case here, right? Isn't this because of the
powerpc issue reported here:
https://lore.kernel.org/r/20240705203413.wbv2nw3747vjeibk@altlinux.org
?

If not, why not just backport the single missing arm64 commit, and why
didn't this show up in testing?

confused,

greg k-h