diff options
author | Andi Kleen <ak@suse.de> | 2006-08-02 16:37:28 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-08-02 23:19:54 -0400 |
commit | 2699500b31f41fc25656c42548c8a388c8a329fe (patch) | |
tree | 6f7ccd0318b9e53394cb276819f2d358ce933afa | |
parent | ae74c3b69a08e1de20cb681ec959f3a48af0006a (diff) |
[PATCH] x86_64: Fix backtracing for interrupt stacks
Re-add backlink for old style unwinder to stack switching. Add proper
stack frame and CFI annotations to call_softirq
This prevents a oops when backtracing with fallback through the
interrupt stack top.
Suggested by Jan Beulich and Herbert Xu wanted it in 2.6.18.
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r-- | arch/x86_64/kernel/entry.S | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S index d464dded68c0..6f810424df44 100644 --- a/arch/x86_64/kernel/entry.S +++ b/arch/x86_64/kernel/entry.S | |||
@@ -513,6 +513,7 @@ END(stub_rt_sigreturn) | |||
513 | swapgs | 513 | swapgs |
514 | 1: incl %gs:pda_irqcount # RED-PEN should check preempt count | 514 | 1: incl %gs:pda_irqcount # RED-PEN should check preempt count |
515 | cmoveq %gs:pda_irqstackptr,%rsp | 515 | cmoveq %gs:pda_irqstackptr,%rsp |
516 | push %rbp # backlink for old unwinder | ||
516 | /* | 517 | /* |
517 | * We entered an interrupt context - irqs are off: | 518 | * We entered an interrupt context - irqs are off: |
518 | */ | 519 | */ |
@@ -1139,18 +1140,21 @@ ENTRY(machine_check) | |||
1139 | END(machine_check) | 1140 | END(machine_check) |
1140 | #endif | 1141 | #endif |
1141 | 1142 | ||
1143 | /* Call softirq on interrupt stack. Interrupts are off. */ | ||
1142 | ENTRY(call_softirq) | 1144 | ENTRY(call_softirq) |
1143 | CFI_STARTPROC | 1145 | CFI_STARTPROC |
1144 | movq %gs:pda_irqstackptr,%rax | 1146 | push %rbp |
1145 | movq %rsp,%rdx | 1147 | CFI_ADJUST_CFA_OFFSET 8 |
1146 | CFI_DEF_CFA_REGISTER rdx | 1148 | CFI_REL_OFFSET rbp,0 |
1149 | mov %rsp,%rbp | ||
1150 | CFI_DEF_CFA_REGISTER rbp | ||
1147 | incl %gs:pda_irqcount | 1151 | incl %gs:pda_irqcount |
1148 | cmove %rax,%rsp | 1152 | cmove %gs:pda_irqstackptr,%rsp |
1149 | pushq %rdx | 1153 | push %rbp # backlink for old unwinder |
1150 | /*todo CFI_DEF_CFA_EXPRESSION ...*/ | ||
1151 | call __do_softirq | 1154 | call __do_softirq |
1152 | popq %rsp | 1155 | leaveq |
1153 | CFI_DEF_CFA_REGISTER rsp | 1156 | CFI_DEF_CFA_REGISTER rsp |
1157 | CFI_ADJUST_CFA_OFFSET -8 | ||
1154 | decl %gs:pda_irqcount | 1158 | decl %gs:pda_irqcount |
1155 | ret | 1159 | ret |
1156 | CFI_ENDPROC | 1160 | CFI_ENDPROC |