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| author | Douglas Anderson <dianders@chromium.org> | 2023-08-04 07:00:42 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-08-18 10:19:00 -0700 |
| commit | 8d539b84f1e3478436f978ceaf55a0b6cab497b5 (patch) | |
| tree | 305d70872637b1eb8f771dba5b4b408a469ea3b4 /lib/nmi_backtrace.c | |
| parent | 3c9d017cc283df0dabf6b16a6cb4574426cbd53b (diff) | |
| download | linux-stable-8d539b84f1e3478436f978ceaf55a0b6cab497b5.tar.gz linux-stable-8d539b84f1e3478436f978ceaf55a0b6cab497b5.tar.bz2 linux-stable-8d539b84f1e3478436f978ceaf55a0b6cab497b5.zip | |
nmi_backtrace: allow excluding an arbitrary CPU
The APIs that allow backtracing across CPUs have always had a way to
exclude the current CPU. This convenience means callers didn't need to
find a place to allocate a CPU mask just to handle the common case.
Let's extend the API to take a CPU ID to exclude instead of just a
boolean. This isn't any more complex for the API to handle and allows the
hardlockup detector to exclude a different CPU (the one it already did a
trace for) without needing to find space for a CPU mask.
Arguably, this new API also encourages safer behavior. Specifically if
the caller wants to avoid tracing the current CPU (maybe because they
already traced the current CPU) this makes it more obvious to the caller
that they need to make sure that the current CPU ID can't change.
[akpm@linux-foundation.org: fix trigger_allbutcpu_cpu_backtrace() stub]
Link: https://lkml.kernel.org/r/20230804065935.v4.1.Ia35521b91fc781368945161d7b28538f9996c182@changeid
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/nmi_backtrace.c')
| -rw-r--r-- | lib/nmi_backtrace.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c index 5274bbb026d7..33c154264bfe 100644 --- a/lib/nmi_backtrace.c +++ b/lib/nmi_backtrace.c @@ -34,7 +34,7 @@ static unsigned long backtrace_flag; * they are passed being updated as a side effect of this call. */ void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, - bool exclude_self, + int exclude_cpu, void (*raise)(cpumask_t *mask)) { int i, this_cpu = get_cpu(); @@ -49,8 +49,8 @@ void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, } cpumask_copy(to_cpumask(backtrace_mask), mask); - if (exclude_self) - cpumask_clear_cpu(this_cpu, to_cpumask(backtrace_mask)); + if (exclude_cpu != -1) + cpumask_clear_cpu(exclude_cpu, to_cpumask(backtrace_mask)); /* * Don't try to send an NMI to this cpu; it may work on some |