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| author | Masami Hiramatsu <mhiramat@redhat.com> | 2009-02-06 01:12:39 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-02-06 04:01:50 +0300 |
| commit | 9be260a646bf76fa418ee519afa10196b3164681 (patch) | |
| tree | 8d829aa2c36cc81b62f9fbe36da83a3f89626db5 | |
| parent | 767b5828ad9a1b435488b5d39b5a66aeef4d25e4 (diff) | |
| download | linux-9be260a646bf76fa418ee519afa10196b3164681.tar.xz | |
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.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 90dfae511a41..c76ef1d701c9 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 |