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Jiri Olsa authored
You can crash the kernel (with root/admin privileges) using kprobe tracer by running: echo "p system_call_after_swapgs" > ./kprobe_events echo 1 > ./events/kprobes/enable The reason is that at the system_call_after_swapgs label, the kernel stack is not set up. If optimized kprobes are enabled, the user space stack is being used in this case (see optimized kprobe template) and this might result in a crash. There are several places like this over the entry code (entry_$BIT). As it seems there's no any reasonable/maintainable way to disable only those places where the stack is not ready, I switched off the whole entry code from kprobe optimizing. Signed-off-by:
Jiri Olsa <jolsa@redhat.com> Acked-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: acme@redhat.com Cc: fweisbec@gmail.com Cc: ananth@in.ibm.com Cc: davem@davemloft.net Cc: a.p.zijlstra@chello.nl Cc: eric.dumazet@gmail.com Cc: 2nddept-manager@sdl.hitachi.co.jp LKML-Reference: <1298298313-5980-3-git-send-email-jolsa@redhat.com> Signed-off-by:
Ingo Molnar <mingo@elte.hu>
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