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author | Daniel Thompson <daniel.thompson@linaro.org> | 2020-05-06 19:42:23 +0300 |
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committer | Daniel Thompson <daniel.thompson@linaro.org> | 2020-05-07 17:12:27 +0300 |
commit | 3fec4aecb311995189217e64d725cfe84a568de3 (patch) | |
tree | 2f5e9d9bcb2fe20a664fc26f9683f06117374fde /kernel/debug/debug_core.c | |
parent | 6a8b55ed4056ea5559ebe4f6a4b247f627870d4c (diff) | |
download | linux-3fec4aecb311995189217e64d725cfe84a568de3.tar.xz |
kgdb: Fix spurious true from in_dbg_master()
Currently there is a small window where a badly timed migration could
cause in_dbg_master() to spuriously return true. Specifically if we
migrate to a new core after reading the processor id and the previous
core takes a breakpoint then we will evaluate true if we read
kgdb_active before we get the IPI to bring us to halt.
Fix this by checking irqs_disabled() first. Interrupts are always
disabled when we are executing the kgdb trap so this is an acceptable
prerequisite. This also allows us to replace raw_smp_processor_id()
with smp_processor_id() since the short circuit logic will prevent
warnings from PREEMPT_DEBUG.
Fixes: dcc7871128e9 ("kgdb: core changes to support kdb")
Suggested-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200506164223.2875760-1-daniel.thompson@linaro.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Diffstat (limited to 'kernel/debug/debug_core.c')
0 files changed, 0 insertions, 0 deletions