bpf: fix nested bpf tracepoints with per-cpu data

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BPF_PROG_TYPE_RAW_TRACEPOINTs can be executed nested on the same CPU, as
they do not increment bpf_prog_active while executing.

This enables three levels of nesting, to support
  - a kprobe or raw tp or perf event,
  - another one of the above that irq context happens to call, and
  - another one in nmi context
(at most one of which may be a kprobe or perf event).

Fixes: 20b9d7ac48 ("bpf: avoid excessive stack usage for perf_sample_data")
Signed-off-by: Matt Mullins <mmullins@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

...

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Matt Mullins 2019-06-11 14:53:04 -07:00 • committed by Alexei Starovoitov

parent 85749218e3

commit 9594dc3c7e

1 changed files with 84 additions and 16 deletions

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kernel/trace/bpf_trace.c

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