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 <[email protected]>
Tested-by: Francis Deslauriers <[email protected]>
Signed-off-by: Masami Hiramatsu <[email protected]>
Cc: Ananth N Mavinakayanahalli <[email protected]>
Cc: Anil S Keshavamurthy <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: David S . Miller <[email protected]>
Cc: Jesper Nilsson <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Mikael Starvik <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/150172795654.27216.9824039077047777477.stgit@devbox
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions