reliable stack trace support (x86-64 IRQ stack From: "Jan Beulich" Change the switching to/from the IRQ stack so that unwind annotations can be added for it without requiring CFA expressions. AK: I cleaned it up a bit, making it unconditional and removing the obsolete DEBUG_INFO full frame code. Signed-off-by: Jan Beulich Signed-off-by: Andi Kleen --- arch/x86_64/kernel/entry.S | 33 ++++++++------------------------- 1 files changed, 8 insertions(+), 25 deletions(-) Index: linux/arch/x86_64/kernel/entry.S =================================================================== --- linux.orig/arch/x86_64/kernel/entry.S +++ linux/arch/x86_64/kernel/entry.S @@ -473,29 +473,18 @@ END(stub_rt_sigreturn) /* 0(%rsp): interrupt number */ .macro interrupt func cld -#ifdef CONFIG_DEBUG_INFO - SAVE_ALL - movq %rsp,%rdi - /* - * Setup a stack frame pointer. This allows gdb to trace - * back to the original stack. - */ - movq %rsp,%rbp - CFI_DEF_CFA_REGISTER rbp -#else SAVE_ARGS leaq -ARGOFFSET(%rsp),%rdi # arg1 for handler -#endif + pushq %rbp + CFI_ADJUST_CFA_OFFSET 8 + CFI_REL_OFFSET rbp, 0 + movq %rsp,%rbp + CFI_DEF_CFA_REGISTER rbp testl $3,CS(%rdi) je 1f swapgs 1: incl %gs:pda_irqcount # RED-PEN should check preempt count - movq %gs:pda_irqstackptr,%rax - cmoveq %rax,%rsp /*todo This needs CFI annotation! */ - pushq %rdi # save old stack -#ifndef CONFIG_DEBUG_INFO - CFI_ADJUST_CFA_OFFSET 8 -#endif + cmoveq %gs:pda_irqstackptr,%rsp call \func .endm @@ -504,17 +493,11 @@ ENTRY(common_interrupt) interrupt do_IRQ /* 0(%rsp): oldrsp-ARGOFFSET */ ret_from_intr: - popq %rdi -#ifndef CONFIG_DEBUG_INFO - CFI_ADJUST_CFA_OFFSET -8 -#endif cli decl %gs:pda_irqcount -#ifdef CONFIG_DEBUG_INFO - movq RBP(%rdi),%rbp + leaveq CFI_DEF_CFA_REGISTER rsp -#endif - leaq ARGOFFSET(%rdi),%rsp /*todo This needs CFI annotation! */ + CFI_ADJUST_CFA_OFFSET -8 exit_intr: GET_THREAD_INFO(%rcx) testl $3,CS-ARGOFFSET(%rsp)