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authorMasami Hiramatsu <mhiramat@redhat.com>2009-02-05 17:12:39 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2009-02-12 09:31:03 -0800
commitbdb6a508be1efd20d813f4e09203d42da94c9f54 (patch)
treed422b4243b2f1f9b0f197bdb5799db725fea9b99 /arch
parentc8e7fd2807c76ec171fee6bce142cd06b5745497 (diff)
prevent kprobes from catching spurious page faults
commit 9be260a646bf76fa418ee519afa10196b3164681 upstream. 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> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
-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 da1973b9a6e..33842556ce7 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -607,8 +607,6 @@ 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;
@@ -638,6 +636,9 @@ 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.
@@ -645,6 +646,9 @@ 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;
#ifdef CONFIG_X86_32
/* It's safe to allow irq's after cr2 has been saved and the vmalloc