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H A D | opt.c | diff d9f5f32a7d17f4906a21ad59589853639a1328a0 Thu Aug 03 04:39:26 CEST 2017 Masami Hiramatsu <mhiramat@kernel.org> kprobes/x86: Do not jump-optimize kprobes on irq entry code
Since the kernel segment registers are not prepared at the entry of irq-entry code, if a kprobe on such code is jump-optimized, accessing per-CPU variables may cause a kernel panic.
However, if the kprobe is not optimized, it triggers an int3 exception and sets segment registers correctly.
With this patch we check the probe-address and if it is in the irq-entry code, it prohibits optimizing such kprobes.
This means we can continue probing such interrupt handlers by kprobes but it is not optimized anymore.
Reported-by: Francis Deslauriers <francis.deslauriers@efficios.com> Tested-by: Francis Deslauriers <francis.deslauriers@efficios.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Chris Zankel <chris@zankel.net> Cc: David S . Miller <davem@davemloft.net> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: linux-arch@vger.kernel.org Cc: linux-cris-kernel@axis.com Cc: mathieu.desnoyers@efficios.com Link: http://lkml.kernel.org/r/150172795654.27216.9824039077047777477.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
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