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From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org, Martin KaFai Lau <martin.lau@linux.dev>,
	Eduard Zingerman <eddyz87@gmail.com>,
	Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
	Quentin Monnet <qmo@kernel.org>, Tao Chen <chen.dylane@linux.dev>,
	STAR Labs SG <info@starlabs.sg>
Subject: [PATCH bpf-next 0/9] bpf: Disable preemption in stack map code
Date: Mon, 20 Jul 2026 10:53:42 +0200	[thread overview]
Message-ID: <20260720085351.655075-1-jolsa@kernel.org> (raw)

hi,
we need to disable preemption for get_perf_callchain and keep it disabled
as long as we are accessing its returned trace entries buffer.

This patchset refactors both bpf_get_stack and bpf_get_stackid helpers as
suggested by Andrii [1] before applying the actual preemption fix.

Note the initial fix was sent by Tao Chen [2], but there was no follow up
on this since February, hence this post.

thanks,
jirka


[1] https://lore.kernel.org/bpf/CAEf4BzZwvAUgLwz-M0Y_NJLTmedyY9U6s7LrSmn751hQdTP4Uw@mail.gmail.com/
[2] https://lore.kernel.org/bpf/20260206090653.1336687-1-chen.dylane@linux.dev/
---
Daniel Borkmann (1):
      bpf: Disable preemption in __bpf_get_stack

Jiri Olsa (8):
      bpf: Factor stackid_init function from __bpf_get_stackid
      bpf: Factor stackid_fastpath function from __bpf_get_stackid
      bpf: Factor stackid_new_bucket from __bpf_get_stackid
      bpf: Use stack id functions instead of __bpf_get_stackid
      bpf: Disable preemption in bpf_get_stackid
      bpf: Factor callchain_store function from __bpf_get_stack
      bpf: Factor callchain_finalize function from __bpf_get_stack
      bpf: Remove trace_in argument from __bpf_get_stack

 kernel/bpf/stackmap.c | 292 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------
 1 file changed, 198 insertions(+), 94 deletions(-)

             reply	other threads:[~2026-07-20  8:53 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-20  8:53 Jiri Olsa [this message]
2026-07-20  8:53 ` [PATCH bpf-next 1/9] bpf: Factor stackid_init function from __bpf_get_stackid Jiri Olsa
2026-07-20  8:53 ` [PATCH bpf-next 2/9] bpf: Factor stackid_fastpath " Jiri Olsa
2026-07-20  9:09   ` sashiko-bot
2026-07-20 20:31     ` Jiri Olsa
2026-07-20  8:53 ` [PATCH bpf-next 3/9] bpf: Factor stackid_new_bucket " Jiri Olsa
2026-07-20  9:01   ` sashiko-bot
2026-07-20 20:31     ` Jiri Olsa
2026-07-20  8:53 ` [PATCH bpf-next 4/9] bpf: Use stack id functions instead of __bpf_get_stackid Jiri Olsa
2026-07-20  8:53 ` [PATCH bpf-next 5/9] bpf: Disable preemption in bpf_get_stackid Jiri Olsa
2026-07-20  9:04   ` sashiko-bot
2026-07-20 20:31     ` Jiri Olsa
2026-07-20  8:53 ` [PATCH bpf-next 6/9] bpf: Factor callchain_store function from __bpf_get_stack Jiri Olsa
2026-07-20  9:07   ` sashiko-bot
2026-07-20 20:31     ` Jiri Olsa
2026-07-20  8:53 ` [PATCH bpf-next 7/9] bpf: Factor callchain_finalize " Jiri Olsa
2026-07-20  9:08   ` sashiko-bot
2026-07-20 20:31     ` Jiri Olsa
2026-07-20  8:53 ` [PATCH bpf-next 8/9] bpf: Remove trace_in argument " Jiri Olsa
2026-07-20  9:09   ` sashiko-bot
2026-07-20 20:31     ` Jiri Olsa
2026-07-20  8:53 ` [PATCH bpf-next 9/9] bpf: Disable preemption in __bpf_get_stack Jiri Olsa
2026-07-20  9:18   ` sashiko-bot

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