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From: Martin Kelly <martin.kelly@crowdstrike.com>
To: "bpf@vger.kernel.org" <bpf@vger.kernel.org>
Cc: "daniel@iogearbox.net" <daniel@iogearbox.net>,
	"ast@kernel.org" <ast@kernel.org>,
	"andrii@kernel.org" <andrii@kernel.org>,
	"john.fastabend@gmail.com" <john.fastabend@gmail.com>
Subject: Re: CONFIG_X86_X32_ABI silently breaks some fentry hooks
Date: Fri, 6 Dec 2024 23:08:25 +0000	[thread overview]
Message-ID: <ddedd6fdd8865d885ee141c33ebb03d83fc3d897.camel@crowdstrike.com> (raw)
In-Reply-To: <7136605d24de9b1fc62d02a355ef11c950a94153.camel@crowdstrike.com>

On Wed, 2024-10-09 at 11:58 -0700, Martin Kelly wrote:
> Hi all, I want to report a very strange issues I found. Specifically,
> on latest master, I found that setting CONFIG_X86_X32_ABI=y causes
> some
> fentry BPF hooks to be silently ignored. Most hooks still work fine,
> but some do not, and the same function works fine as a kprobe. The
> issue appears to be 100% reproducible for a given function hook.
> 

This was root-caused to be the same issue as the one addressed in this
(unmerged) patch series:
https://lore.kernel.org/lkml/20240723063258.2240610-1-zhengyejian@huaweicloud.com/

Essentially this has to do with ftrace and weak functions.

      reply	other threads:[~2024-12-06 23:46 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-09 18:58 CONFIG_X86_X32_ABI silently breaks some fentry hooks Martin Kelly
2024-12-06 23:08 ` Martin Kelly [this message]

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