x86/entry: Move paranoid irq tracing out of ASM code

The last step to remove the irq tracing cruft from ASM. Ignore #DF as the
maschine is going to die anyway.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202120.414043330@linutronix.de

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index fb7f126..2566554 100644 (file)
--- 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. */
@@ -462,8 +456,6 @@ SYM_CODE_START(\asmsym)
 
        UNWIND_HINT_REGS
 
-       TRACE_IRQS_OFF
-
        movq    %rsp, %rdi              /* pt_regs pointer */
 
        .if \vector == X86_TRAP_DB
@@ -881,17 +873,13 @@ 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
@@ -1292,7 +1280,6 @@ end_repeat_nmi:
        call    paranoid_entry
        UNWIND_HINT_REGS
 
-       /* paranoidentry exc_nmi(), 0; without TRACE_IRQS_OFF */
        movq    %rsp, %rdi
        movq    $-1, %rsi
        call    exc_nmi

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index c47f004..068e6ca 100644 (file)
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1922,7 +1922,10 @@ static __always_inline void exc_machine_check_kernel(struct pt_regs *regs)
         * that out because it's an indirect call. Annotate it.
         */
        instrumentation_begin();
+       trace_hardirqs_off_prepare();
        machine_check_vector(regs);
+       if (regs->flags & X86_EFLAGS_IF)
+               trace_hardirqs_on_prepare();
        instrumentation_end();
        nmi_exit();
 }

diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 3052c78..5df4e7f 100644 (file)
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -330,6 +330,7 @@ static noinstr void default_do_nmi(struct pt_regs *regs)
        __this_cpu_write(last_nmi_rip, regs->ip);
 
        instrumentation_begin();
+       trace_hardirqs_off_prepare();
 
        handled = nmi_handle(NMI_LOCAL, regs);
        __this_cpu_add(nmi_stats.normal, handled);
@@ -416,6 +417,8 @@ static noinstr void default_do_nmi(struct pt_regs *regs)
                unknown_nmi_error(reason, regs);
 
 out:
+       if (regs->flags & X86_EFLAGS_IF)
+               trace_hardirqs_on_prepare();
        instrumentation_end();
 }
 

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index f28be3e..50fb9cd 100644 (file)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -634,8 +634,11 @@ DEFINE_IDTENTRY_RAW(exc_int3)
        } else {
                nmi_enter();
                instrumentation_begin();
+               trace_hardirqs_off_prepare();
                if (!do_int3(regs))
                        die("int3", regs, 0);
+               if (regs->flags & X86_EFLAGS_IF)
+                       trace_hardirqs_on_prepare();
                instrumentation_end();
                nmi_exit();
        }
@@ -850,6 +853,10 @@ static __always_inline void exc_debug_kernel(struct pt_regs *regs,
                                             unsigned long dr6)
 {
        nmi_enter();
+       instrumentation_begin();
+       trace_hardirqs_off_prepare();
+       instrumentation_end();
+
        /*
         * The SDM says "The processor clears the BTF flag when it
         * generates a debug exception."  Clear TIF_BLOCKSTEP to keep
@@ -871,6 +878,10 @@ static __always_inline void exc_debug_kernel(struct pt_regs *regs,
        if (dr6)
                handle_debug(regs, dr6, false);
 
+       instrumentation_begin();
+       if (regs->flags & X86_EFLAGS_IF)
+               trace_hardirqs_on_prepare();
+       instrumentation_end();
        nmi_exit();
 }