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| author | Roland McGrath <roland@redhat.com> | 2008-02-06 22:39:43 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-02-06 22:39:43 +0100 |
| commit | 3aa4b37d3e899cfe7a9cbdcda2b277df4c1f210d (patch) | |
| tree | f0a7c5ddaf7e38c7305096b1dba8b12b4f1b8c27 | |
| parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6 (diff) | |
| download | linux-3aa4b37d3e899cfe7a9cbdcda2b277df4c1f210d.tar.xz linux-3aa4b37d3e899cfe7a9cbdcda2b277df4c1f210d.zip | |
x86: make traps on entry code be debuggable in user space, 64-bit
Unify the x86-64 behavior for 32-bit processes that set
bogus %cs/%ss values (the only ones that can fault in iret)
match what the native i386 behavior is. (do not kill the task
via do_exit but generate a SIGSEGV signal)
[ tglx@linutronix.de: build fix ]
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index bea8474744ff..e518928114db 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -593,13 +593,22 @@ ENTRY(native_iret) .quad native_iret, bad_iret .previous .section .fixup,"ax" - /* force a signal here? this matches i386 behaviour */ - /* running with kernel gs */ bad_iret: - movq $11,%rdi /* SIGSEGV */ - TRACE_IRQS_ON - ENABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI)) - jmp do_exit + /* + * The iret traps when the %cs or %ss being restored is bogus. + * We've lost the original trap vector and error code. + * #GPF is the most likely one to get for an invalid selector. + * So pretend we completed the iret and took the #GPF in user mode. + * + * We are now running with the kernel GS after exception recovery. + * But error_entry expects us to have user GS to match the user %cs, + * so swap back. + */ + pushq $0 + + SWAPGS + jmp general_protection + .previous /* edi: workmask, edx: work */ |