From: Daniel Borkmann <daniel@iogearbox.net>
To: Alexei Starovoitov <ast@kernel.org>, davem@davemloft.net
Cc: peterz@infradead.org, edumazet@google.com, longman@redhat.com,
jannh@google.com, netdev@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH v2 bpf] bpf: fix lockdep false positive in stackmap
Date: Mon, 11 Feb 2019 16:39:46 +0100 [thread overview]
Message-ID: <d6d3bf01-4c8f-8b4d-073c-a8222f5ba677@iogearbox.net> (raw)
In-Reply-To: <20190210205235.392478-1-ast@kernel.org>
On 02/10/2019 09:52 PM, Alexei Starovoitov wrote:
> Lockdep warns about false positive:
> [ 11.211460] ------------[ cut here ]------------
> [ 11.211936] DEBUG_LOCKS_WARN_ON(depth <= 0)
> [ 11.211985] WARNING: CPU: 0 PID: 141 at ../kernel/locking/lockdep.c:3592 lock_release+0x1ad/0x280
> [ 11.213134] Modules linked in:
> [ 11.214954] RIP: 0010:lock_release+0x1ad/0x280
> [ 11.223508] Call Trace:
> [ 11.223705] <IRQ>
> [ 11.223874] ? __local_bh_enable+0x7a/0x80
> [ 11.224199] up_read+0x1c/0xa0
> [ 11.224446] do_up_read+0x12/0x20
> [ 11.224713] irq_work_run_list+0x43/0x70
> [ 11.225030] irq_work_run+0x26/0x50
> [ 11.225310] smp_irq_work_interrupt+0x57/0x1f0
> [ 11.225662] irq_work_interrupt+0xf/0x20
>
> since rw_semaphore is released in a different task vs task that locked the sema.
> It is expected behavior.
> Fix the warning with up_read_non_owner() and rwsem_release() annotation.
>
> Fixes: bae77c5eb5b2 ("bpf: enable stackmap with build_id in nmi context")
> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Applied, thanks!
next prev parent reply other threads:[~2019-02-11 15:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-10 20:52 [PATCH v2 bpf] bpf: fix lockdep false positive in stackmap Alexei Starovoitov
2019-02-11 15:39 ` Daniel Borkmann [this message]
2019-02-11 16:35 ` Eric Dumazet
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d6d3bf01-4c8f-8b4d-073c-a8222f5ba677@iogearbox.net \
--to=daniel@iogearbox.net \
--cc=ast@kernel.org \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=jannh@google.com \
--cc=kernel-team@fb.com \
--cc=longman@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).