[patch V4 part 5 30/31] x86/entry: Move paranoid irq tracing out of ASM code

[Thomas Gleixner]

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
 arch/x86/entry/entry_64.S |   13 -------------
 arch/x86/kernel/nmi.c     |   11 +++++++----
 2 files changed, 7 insertions(+), 17 deletions(-)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -16,7 +16,6 @@
  *
  * Some macro usage:
  * - SYM_FUNC_START/END:Define functions in the symbol table.
- * - TRACE_IRQ_*:      Trace hardirq state for lock debugging.
  * - idtentry:         Define exception entry points.
  */
 #include <linux/linkage.h>
@@ -107,11 +106,6 @@ SYM_CODE_END(native_usergs_sysret64)
 
 SYM_CODE_START(entry_SYSCALL_64)
        UNWIND_HINT_EMPTY
-       /*
-        * 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
        /* tss.sp2 is scratch space. */
@@ -463,8 +457,6 @@ SYM_CODE_START(\asmsym)
 
        UNWIND_HINT_REGS
 
-       TRACE_IRQS_OFF
-
        movq    %rsp, %rdi              /* pt_regs pointer */
 
        .if \vector == X86_TRAP_DB
@@ -842,17 +834,13 @@ SYM_CODE_END(paranoid_entry)
  */
 SYM_CODE_START_LOCAL(paranoid_exit)
        UNWIND_HINT_REGS
-       DISABLE_INTERRUPTS(CLBR_ANY)
-       TRACE_IRQS_OFF
        testl   %ebx, %ebx                      /* swapgs needed? */
        jnz     .Lparanoid_exit_no_swapgs
-       TRACE_IRQS_IRETQ
        /* Always restore stashed CR3 value (see paranoid_entry) */
        RESTORE_CR3     scratch_reg=%rbx save_reg=%r14
        SWAPGS_UNSAFE_STACK
        jmp     restore_regs_and_return_to_kernel
 .Lparanoid_exit_no_swapgs:
-       TRACE_IRQS_IRETQ
        /* Always restore stashed CR3 value (see paranoid_entry) */
        RESTORE_CR3     scratch_reg=%rbx save_reg=%r14
        jmp restore_regs_and_return_to_kernel
@@ -1254,7 +1242,6 @@ SYM_CODE_START(asm_exc_nmi)
        call    paranoid_entry
        UNWIND_HINT_REGS
 
-       /* paranoidentry exc_nmi(), 0; without TRACE_IRQS_OFF */
        movq    %rsp, %rdi
        movq    $-1, %rsi
        call    exc_nmi
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -334,6 +334,8 @@ static noinstr void default_do_nmi(struc
        __this_cpu_write(last_nmi_rip, regs->ip);
 
        instr_begin();
+       trace_hardirqs_off_prepare();
+
        handled = nmi_handle(NMI_LOCAL, regs);
        __this_cpu_add(nmi_stats.normal, handled);
        if (handled) {
@@ -347,8 +349,7 @@ static noinstr void default_do_nmi(struc
                 */
                if (handled > 1)
                        __this_cpu_write(swallow_nmi, true);
-               instr_end();
-               return;
+               goto out;
        }
 
        /*
@@ -380,8 +381,7 @@ static noinstr void default_do_nmi(struc
 #endif
                __this_cpu_add(nmi_stats.external, 1);
                raw_spin_unlock(&nmi_reason_lock);
-               instr_end();
-               return;
+               goto out;
        }
        raw_spin_unlock(&nmi_reason_lock);
 
@@ -419,6 +419,9 @@ static noinstr void default_do_nmi(struc
                __this_cpu_add(nmi_stats.swallow, 1);
        else
                unknown_nmi_error(reason, regs);
+out:
+       if (regs->flags & X86_EFLAGS_IF)
+               trace_hardirqs_on_prepare();
        instr_end();
 }