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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-13 20:49:20 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-14 00:20:28 +0400 |
| commit | 495b59364c67bc1f970a6229895ae15d1684d694 (patch) | |
| tree | 81af921fede7cedf70f7d70a50ec98d77726fb85 | |
| parent | ab832422673d1774c4ce3941f2ac87743d73bded (diff) | |
| download | linux-495b59364c67bc1f970a6229895ae15d1684d694.tar.xz | |
x86: don't send SIGBUS for kernel page faults
commit 96054569190bdec375fe824e48ca1f4e3b53dd36 upstream.
It's wrong for several reasons, but the most direct one is that the
fault may be for the stack accesses to set up a previous SIGBUS. When
we have a kernel exception, the kernel exception handler does all the
fixups, not some user-level signal handler.
Even apart from the nested SIGBUS issue, it's also wrong to give out
kernel fault addresses in the signal handler info block, or to send a
SIGBUS when a system call already returns EFAULT.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/x86/mm/fault.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index f4cee9028cf0..1739358b444d 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -801,8 +801,10 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, up_read(&mm->mmap_sem); /* Kernel mode? Handle exceptions or die: */ - if (!(error_code & PF_USER)) + if (!(error_code & PF_USER)) { no_context(regs, error_code, address); + return; + } /* User-space => ok to do another page fault: */ if (is_prefetch(regs, error_code, address)) |