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authorMasami Hiramatsu <mhiramat@redhat.com>2009-02-05 17:12:39 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-02-05 17:01:50 -0800
commit9be260a646bf76fa418ee519afa10196b3164681 (patch)
tree8d829aa2c36cc81b62f9fbe36da83a3f89626db5
parent767b5828ad9a1b435488b5d39b5a66aeef4d25e4 (diff)
prevent kprobes from catching spurious page faults
Prevent kprobes from catching spurious faults which will cause infinite recursive page-fault and memory corruption by stack overflow. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: <stable@kernel.org> [2.6.28.x] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/x86/mm/fault.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 90dfae511a4..c76ef1d701c 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -603,8 +603,6 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
si_code = SEGV_MAPERR;
- if (notify_page_fault(regs))
- return;
if (unlikely(kmmio_fault(regs, address)))
return;
@@ -634,6 +632,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
if (spurious_fault(address, error_code))
return;
+ /* kprobes don't want to hook the spurious faults. */
+ if (notify_page_fault(regs))
+ return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
* fault we could otherwise deadlock.
@@ -641,6 +642,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
goto bad_area_nosemaphore;
}
+ /* kprobes don't want to hook the spurious faults. */
+ if (notify_page_fault(regs))
+ return;
/*
* It's safe to allow irq's after cr2 has been saved and the