Commits
Masami Hiramatsu committed 464846888d9
x86/kprobes: Fix a bug which can modify kernel code permanently Fix a bug in kprobes which can modify kernel code permanently at run-time. In the result, kernel can crash when it executes the modified code. This bug can happen when we put two probes enough near and the first probe is optimized. When the second probe is set up, it copies a byte which is already modified by the first probe, and executes it when the probe is hit. Even worse, the first probe and the second probe are removed respectively, the second probe writes back the copied (modified) instruction. To fix this bug, kprobes always recovers the original code and copies the first byte from recovered instruction. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: yrl.pp-manager.tt@hitachi.com Cc: systemtap@sourceware.org Cc: anderson@redhat.com Link: http://lkml.kernel.org/r/20120305133215.5982.31991.stgit@localhost.localdomain Signed-off-by: Ingo Molnar <mingo@elte.hu>