diff options
| -rw-r--r-- | arch/x86/ia32/ia32entry.S | 45 |
1 files changed, 27 insertions, 18 deletions
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 5d2641ce9957..7502ff0b938e 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -112,13 +112,16 @@ ENTRY(ia32_sysenter_target) CFI_SIGNAL_FRAME CFI_DEF_CFA rsp,0 CFI_REGISTER rsp,rbp - SWAPGS_UNSAFE_STACK - movq PER_CPU_VAR(cpu_tss + TSS_sp0), %rsp + /* - * No need to follow this irqs on/off section: the syscall - * disabled irqs, here we enable it straight after entry: + * Interrupts are off on entry. + * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON, + * it is too small to ever cause noticeable irq latency. */ + SWAPGS_UNSAFE_STACK + movq PER_CPU_VAR(cpu_tss + TSS_sp0), %rsp ENABLE_INTERRUPTS(CLBR_NONE) + /* Construct iret frame (ss,rsp,rflags,cs,rip) */ movl %ebp,%ebp /* zero extension */ pushq_cfi $__USER32_DS @@ -314,15 +317,18 @@ ENTRY(ia32_cstar_target) CFI_DEF_CFA rsp,0 CFI_REGISTER rip,rcx /*CFI_REGISTER rflags,r11*/ + + /* + * Interrupts are off on entry. + * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON, + * it is too small to ever cause noticeable irq latency. + */ SWAPGS_UNSAFE_STACK movl %esp,%r8d CFI_REGISTER rsp,r8 movq PER_CPU_VAR(kernel_stack),%rsp - /* - * No need to follow this irqs on/off section: the syscall - * disabled irqs and here we enable it straight after entry: - */ ENABLE_INTERRUPTS(CLBR_NONE) + ALLOC_PT_GPREGS_ON_STACK 6*8 /* 6*8: space for orig_ax and iret frame */ SAVE_C_REGS_EXCEPT_RCX_R891011 movl %eax,%eax /* zero extension */ @@ -449,19 +455,22 @@ ia32_badarg: ENTRY(ia32_syscall) CFI_STARTPROC32 simple CFI_SIGNAL_FRAME - CFI_DEF_CFA rsp,SS+8-RIP - /*CFI_REL_OFFSET ss,SS-RIP*/ - CFI_REL_OFFSET rsp,RSP-RIP - /*CFI_REL_OFFSET rflags,EFLAGS-RIP*/ - /*CFI_REL_OFFSET cs,CS-RIP*/ - CFI_REL_OFFSET rip,RIP-RIP - PARAVIRT_ADJUST_EXCEPTION_FRAME - SWAPGS + CFI_DEF_CFA rsp,5*8 + /*CFI_REL_OFFSET ss,4*8 */ + CFI_REL_OFFSET rsp,3*8 + /*CFI_REL_OFFSET rflags,2*8 */ + /*CFI_REL_OFFSET cs,1*8 */ + CFI_REL_OFFSET rip,0*8 + /* - * No need to follow this irqs on/off section: the syscall - * disabled irqs and here we enable it straight after entry: + * Interrupts are off on entry. + * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON, + * it is too small to ever cause noticeable irq latency. */ + PARAVIRT_ADJUST_EXCEPTION_FRAME + SWAPGS ENABLE_INTERRUPTS(CLBR_NONE) + movl %eax,%eax pushq_cfi %rax /* store orig_ax */ cld |