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| author |   Song Liu <songliubraving@fb.com> | 2018-05-07 10:50:48 -0700 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2018-05-14 23:29:45 +0200 |
| commit | bae77c5eb5b2107e300fb02da2311f2aa0d8ee3c (patch) | |
| tree | 54161e53098e6b684e7eb03bab0082626f0307fe /tools/testing/selftests/bpf/urandom_read.c | |
| parent | Merge branch 'bpf-perf-rb-libbpf' (diff) | |
| download | linux-dev-bae77c5eb5b2107e300fb02da2311f2aa0d8ee3c.tar.xz linux-dev-bae77c5eb5b2107e300fb02da2311f2aa0d8ee3c.zip | |
bpf: enable stackmap with build_id in nmi context
Currently, we cannot parse build_id in nmi context because of
up_read(¤t->mm->mmap_sem), this makes stackmap with build_id
less useful. This patch enables parsing build_id in nmi by putting
the up_read() call in irq_work. To avoid memory allocation in nmi
context, we use per cpu variable for the irq_work. As a result, only
one irq_work per cpu is allowed. If the irq_work is in-use, we
fallback to only report ips.
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/testing/selftests/bpf/urandom_read.c')
0 files changed, 0 insertions, 0 deletions