diff options
| author | Andi Kleen <ak@suse.de> | 2005-04-16 22:25:03 (GMT) |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:25:03 (GMT) |
| commit | 6fefb0d17599d63e9d30c23bcbe2d4e06477cd55 (patch) | |
| tree | d513ab7e0edfb2ee74adf15f2c7714ccdb179978 /arch/x86_64/kernel/entry.S | |
| parent | 11b854b2f10f398f9a18c65e202853f929dd3185 (diff) | |
| download | linux-fsl-qoriq-6fefb0d17599d63e9d30c23bcbe2d4e06477cd55.tar.xz | |
[PATCH] x86_64: Regularize exception stack handling
This fixes various issues in the return path for "paranoid"
handlers (= running on a private exception stack that act like NMIs).
Generalize previous hack to switch back to process stack for
scheduling/signal handling purposes.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64/kernel/entry.S')
| -rw-r--r-- | arch/x86_64/kernel/entry.S | 49 |
1 files changed, 27 insertions, 22 deletions
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S index 12a3071..3e888c2 100644 --- a/arch/x86_64/kernel/entry.S +++ b/arch/x86_64/kernel/entry.S @@ -579,6 +579,7 @@ ENTRY(spurious_interrupt) movq ORIG_RAX(%rsp),%rsi movq $-1,ORIG_RAX(%rsp) call \sym + cli .endm /* @@ -794,10 +795,6 @@ ENTRY(debug) pushq $0 CFI_ADJUST_CFA_OFFSET 8 paranoidentry do_debug - /* switch back to process stack to restore the state ptrace touched */ - movq %rax,%rsp - testl $3,CS(%rsp) - jnz paranoid_userspace jmp paranoid_exit CFI_ENDPROC @@ -807,35 +804,49 @@ ENTRY(nmi) pushq $-1 CFI_ADJUST_CFA_OFFSET 8 paranoidentry do_nmi + /* + * "Paranoid" exit path from exception stack. + * Paranoid because this is used by NMIs and cannot take + * any kernel state for granted. + * We don't do kernel preemption checks here, because only + * NMI should be common and it does not enable IRQs and + * cannot get reschedule ticks. + */ /* ebx: no swapgs flag */ paranoid_exit: testl %ebx,%ebx /* swapgs needed? */ jnz paranoid_restore + testl $3,CS(%rsp) + jnz paranoid_userspace paranoid_swapgs: - cli swapgs paranoid_restore: RESTORE_ALL 8 iretq paranoid_userspace: - cli GET_THREAD_INFO(%rcx) - movl threadinfo_flags(%rcx),%edx - testl $_TIF_WORK_MASK,%edx + movl threadinfo_flags(%rcx),%ebx + andl $_TIF_WORK_MASK,%ebx jz paranoid_swapgs - testl $_TIF_NEED_RESCHED,%edx - jnz paranoid_resched + movq %rsp,%rdi /* &pt_regs */ + call sync_regs + movq %rax,%rsp /* switch stack for scheduling */ + testl $_TIF_NEED_RESCHED,%ebx + jnz paranoid_schedule + movl %ebx,%edx /* arg3: thread flags */ sti - xorl %esi,%esi /* oldset */ - movq %rsp,%rdi /* &pt_regs */ + xorl %esi,%esi /* arg2: oldset */ + movq %rsp,%rdi /* arg1: &pt_regs */ call do_notify_resume - jmp paranoid_exit -paranoid_resched: + cli + jmp paranoid_userspace +paranoid_schedule: sti call schedule - jmp paranoid_exit + cli + jmp paranoid_userspace CFI_ENDPROC - + ENTRY(int3) zeroentry do_int3 @@ -858,9 +869,6 @@ ENTRY(reserved) ENTRY(double_fault) CFI_STARTPROC paranoidentry do_double_fault - movq %rax,%rsp - testl $3,CS(%rsp) - jnz paranoid_userspace jmp paranoid_exit CFI_ENDPROC @@ -874,9 +882,6 @@ ENTRY(segment_not_present) ENTRY(stack_segment) CFI_STARTPROC paranoidentry do_stack_segment - movq %rax,%rsp - testl $3,CS(%rsp) - jnz paranoid_userspace jmp paranoid_exit CFI_ENDPROC |