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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-13 09:49:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-13 09:49:20 -0700 |
| commit | 96054569190bdec375fe824e48ca1f4e3b53dd36 (patch) | |
| tree | 13e249da75a0667e2c9d195e9c125fb14d721e71 | |
| parent | 5528f9132cf65d4d892bcbc5684c61e7822b21e9 (diff) | |
| download | linux-96054569190bdec375fe824e48ca1f4e3b53dd36.tar.bz2 | |
x86: don't send SIGBUS for kernel page faults
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>
| -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 f62777940dfb..4c4508e8a204 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -802,8 +802,10 @@ 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)) |