arm64: kprobes: Avoid calling kprobes debug handlers explicitly

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Kprobes bypasses our debug hook registration code so that it doesn't
get tangled up with recursive debug exceptions from things like lockdep:

  http://lists.infradead.org/pipermail/linux-arm-kernel/2015-February/324385.html

However, since then, (a) the hook list has become RCU protected and (b)
the kprobes hooks were found not to filter out exceptions from userspace
correctly. On top of that, the step handler is invoked directly from
single_step_handler(), which *does* use the debug hook list, so it's
clearly not the end of the world.

For now, have kprobes use the debug hook registration API like everybody
else. We can revisit this in the future if this is found to limit
coverage significantly.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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This commit is contained in:

Will Deacon 2019-02-26 14:35:00 +00:00

parent 26a04d84bc

commit a22d570aee

3 changed files with 14 additions and 14 deletions

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2

arch/arm64/include/asm/kprobes.h

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arch/arm64/kernel/debug-monitors.c

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arch/arm64/kernel/probes/kprobes.c

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