From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <kafai@fb.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [RFC] Revert "bpf: Fix ORC unwinding in non-JIT BPF code"
Date: Mon, 8 Jul 2019 08:11:10 -0500 [thread overview]
Message-ID: <20190708130010.pnxlzi5vptuyppxz@treble> (raw)
In-Reply-To: <20190708124547.3515538-1-arnd@arndb.de>
On Mon, Jul 08, 2019 at 02:45:23PM +0200, Arnd Bergmann wrote:
> Apparently this was a bit premature, at least I still get this
> warning with gcc-8.1:
>
> kernel/bpf/core.o: warning: objtool: ___bpf_prog_run()+0x44d2: sibling call from callable instruction with modified stack frame
>
> This reverts commit b22cf36c189f31883ad0238a69ccf82aa1f3b16b.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Yes, I have been working on a fix.
The impact is that ORC unwinding is broken in this function for
CONFIG_RETPOLINE=n.
I don't think we want to revert this patch though, because that will
broaden the impact to the CONFIG_RETPOLINE=y case. Anyway I hope to
have fixes soon.
--
Josh
next prev parent reply other threads:[~2019-07-08 13:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-08 12:45 [PATCH] [RFC] Revert "bpf: Fix ORC unwinding in non-JIT BPF code" Arnd Bergmann
2019-07-08 13:11 ` Josh Poimboeuf [this message]
2019-07-08 13:17 ` Arnd Bergmann
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