x86/entry: Convert NMI to IDTENTRY_NMI

Convert #NMI to IDTENTRY_NMI:
  - Implement the C entry point with DEFINE_IDTENTRY_NMI
  - Fixup the XEN/PV code
  - Remove the old prototypes

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200505135314.609932306@linutronix.de

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 4dd3d706d9fcbbfd1f5ddb2ef89e6b68db81e617..d4961cac73f64d3ee91fd5e28fe1e2898abab57f 100644 (file)
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1545,7 +1545,7 @@ SYM_CODE_END(double_fault)
  * switched stacks.  We handle both conditions by simply checking whether we
  * interrupted kernel code running on the SYSENTER stack.
  */
-SYM_CODE_START(nmi)
+SYM_CODE_START(asm_exc_nmi)
        ASM_CLAC
 
 #ifdef CONFIG_X86_ESPFIX32
@@ -1574,7 +1574,7 @@ SYM_CODE_START(nmi)
        jb      .Lnmi_from_sysenter_stack
 
        /* Not on SYSENTER stack. */
-       call    do_nmi
+       call    exc_nmi
        jmp     .Lnmi_return
 
 .Lnmi_from_sysenter_stack:
@@ -1584,7 +1584,7 @@ SYM_CODE_START(nmi)
         */
        movl    %esp, %ebx
        movl    PER_CPU_VAR(cpu_current_top_of_stack), %esp
-       call    do_nmi
+       call    exc_nmi
        movl    %ebx, %esp
 
 .Lnmi_return:
@@ -1638,7 +1638,7 @@ SYM_CODE_START(nmi)
        lss     (1+5+6)*4(%esp), %esp                   # back to espfix stack
        jmp     .Lirq_return
 #endif
-SYM_CODE_END(nmi)
+SYM_CODE_END(asm_exc_nmi)
 
 .pushsection .text, "ax"
 SYM_CODE_START(rewind_stack_do_exit)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 5007b975ca7cc5581d1afae0396ab063ecaacd8d..3d7f2cc29be3709b419397606625b96cd0cdbf74 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1079,7 +1079,6 @@ idtentry_df       X86_TRAP_DF             double_fault            do_double_fault
 
 #ifdef CONFIG_XEN_PV
 idtentry       512 /* dummy */         hypervisor_callback     xen_do_hypervisor_callback      has_error_code=0
-idtentry       X86_TRAP_NMI            xennmi                  do_nmi                          has_error_code=0
 idtentry       X86_TRAP_DB             xendebug                do_debug                        has_error_code=0
 #endif
 
@@ -1414,7 +1413,7 @@ SYM_CODE_END(error_return)
  *     %r14: Used to save/restore the CR3 of the interrupted context
  *           when PAGE_TABLE_ISOLATION is in use.  Do not clobber.
  */
-SYM_CODE_START(nmi)
+SYM_CODE_START(asm_exc_nmi)
        UNWIND_HINT_IRET_REGS
 
        /*
@@ -1499,7 +1498,7 @@ SYM_CODE_START(nmi)
 
        movq    %rsp, %rdi
        movq    $-1, %rsi
-       call    do_nmi
+       call    exc_nmi
 
        /*
         * Return back to user mode.  We must *not* do the normal exit
@@ -1556,7 +1555,7 @@ SYM_CODE_START(nmi)
         * end_repeat_nmi, then we are a nested NMI.  We must not
         * modify the "iret" frame because it's being written by
         * the outer NMI.  That's okay; the outer NMI handler is
-        * about to about to call do_nmi anyway, so we can just
+        * about to about to call exc_nmi() anyway, so we can just
         * resume the outer NMI.
         */
 
@@ -1675,7 +1674,7 @@ repeat_nmi:
         * RSP is pointing to "outermost RIP".  gsbase is unknown, but, if
         * we're repeating an NMI, gsbase has the same value that it had on
         * the first iteration.  paranoid_entry will load the kernel
-        * gsbase if needed before we call do_nmi.  "NMI executing"
+        * gsbase if needed before we call exc_nmi().  "NMI executing"
         * is zero.
         */
        movq    $1, 10*8(%rsp)          /* Set "NMI executing". */
@@ -1709,10 +1708,10 @@ end_repeat_nmi:
        call    paranoid_entry
        UNWIND_HINT_REGS
 
-       /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */
+       /* paranoidentry exc_nmi(), 0; without TRACE_IRQS_OFF */
        movq    %rsp, %rdi
        movq    $-1, %rsi
-       call    do_nmi
+       call    exc_nmi
 
        /* Always restore stashed CR3 value (see paranoid_entry) */
        RESTORE_CR3 scratch_reg=%r15 save_reg=%r14
@@ -1749,7 +1748,7 @@ nmi_restore:
         * about espfix64 on the way back to kernel mode.
         */
        iretq
-SYM_CODE_END(nmi)
+SYM_CODE_END(asm_exc_nmi)
 
 #ifndef CONFIG_IA32_EMULATION
 /*

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 2315eecf04fdcaef4b8aa39c1ea0a44a254df11b..1f067e6c4051adb8a88ed77459f8d768928c42a5 100644 (file)
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -258,4 +258,8 @@ DECLARE_IDTENTRY_RAW(X86_TRAP_BP,   exc_int3);
 DECLARE_IDTENTRY_MCE(X86_TRAP_MC,      exc_machine_check);
 #endif
 
+/* NMI */
+DECLARE_IDTENTRY_NMI(X86_TRAP_NMI,     exc_nmi);
+DECLARE_IDTENTRY_XEN(X86_TRAP_NMI,     nmi);
+
 #endif

diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 6096db912625fcbed9afb410074058ae70c79dd7..57b83ae19c15f250f10994f7548a4438d3f4b42e 100644 (file)
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -12,7 +12,6 @@
 #define dotraplinkage __visible
 
 asmlinkage void debug(void);
-asmlinkage void nmi(void);
 #ifdef CONFIG_X86_64
 asmlinkage void double_fault(void);
 #endif
@@ -20,14 +19,12 @@ asmlinkage void page_fault(void);
 asmlinkage void async_page_fault(void);
 
 #if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
-asmlinkage void xen_xennmi(void);
 asmlinkage void xen_xendebug(void);
 asmlinkage void xen_double_fault(void);
 asmlinkage void xen_page_fault(void);
 #endif
 
 dotraplinkage void do_debug(struct pt_regs *regs, long error_code);
-dotraplinkage void do_nmi(struct pt_regs *regs, long error_code);
 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2);
 dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address);
 

diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 6b93840784d52763c866f4708c28f798f1841009..d3fecd88677c4653ca98b0f8b0457aaf74345f22 100644 (file)
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -74,7 +74,7 @@ static const __initconst struct idt_data early_idts[] = {
  */
 static const __initconst struct idt_data def_idts[] = {
        INTG(X86_TRAP_DE,               asm_exc_divide_error),
-       INTG(X86_TRAP_NMI,              nmi),
+       INTG(X86_TRAP_NMI,              asm_exc_nmi),
        INTG(X86_TRAP_BR,               asm_exc_bounds),
        INTG(X86_TRAP_UD,               asm_exc_invalid_op),
        INTG(X86_TRAP_NM,               asm_exc_device_not_available),
@@ -186,7 +186,7 @@ gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss;
  */
 static const __initconst struct idt_data ist_idts[] = {
        ISTG(X86_TRAP_DB,       debug,                  IST_INDEX_DB),
-       ISTG(X86_TRAP_NMI,      nmi,                    IST_INDEX_NMI),
+       ISTG(X86_TRAP_NMI,      asm_exc_nmi,            IST_INDEX_NMI),
        ISTG(X86_TRAP_DF,       double_fault,           IST_INDEX_DF),
 #ifdef CONFIG_X86_MCE
        ISTG(X86_TRAP_MC,       asm_exc_machine_check,  IST_INDEX_MCE),

diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index bdcc5146de96cd1faa585f7ad586393e7c7c93fa..3b05cc802abbaa7d703a5a5c4b77b19aae320c58 100644 (file)
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -503,8 +503,7 @@ static bool notrace is_debug_stack(unsigned long addr)
 NOKPROBE_SYMBOL(is_debug_stack);
 #endif
 
-dotraplinkage notrace void
-do_nmi(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY_NMI(exc_nmi)
 {
        if (IS_ENABLED(CONFIG_SMP) && cpu_is_offline(smp_processor_id()))
                return;
@@ -554,7 +553,6 @@ nmi_restart:
        if (user_mode(regs))
                mds_user_clear_cpu_buffers();
 }
-NOKPROBE_SYMBOL(do_nmi);
 
 void stop_nmi(void)
 {

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 267583f9b20749b5d78f4a7618bdf4998642713c..0d6c2789e6768ca6410fb09390d6b0c329da5542 100644 (file)
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -609,13 +609,18 @@ struct trap_array_entry {
        .xen            = xen_asm_##func,               \
        .ist_okay       = ist_ok }
 
+#define TRAP_ENTRY_REDIR(func, xenfunc, ist_ok) {      \
+       .orig           = asm_##func,                   \
+       .xen            = xen_asm_##xenfunc,            \
+       .ist_okay       = ist_ok }
+
 static struct trap_array_entry trap_array[] = {
        { debug,                       xen_xendebug,                    true },
        { double_fault,                xen_double_fault,                true },
 #ifdef CONFIG_X86_MCE
        TRAP_ENTRY(exc_machine_check,                   true  ),
 #endif
-       { nmi,                         xen_xennmi,                      true },
+       TRAP_ENTRY_REDIR(exc_nmi, exc_xennmi,           true  ),
        TRAP_ENTRY(exc_int3,                            false ),
        TRAP_ENTRY(exc_overflow,                        false ),
 #ifdef CONFIG_IA32_EMULATION

diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 617ef3f981604e485dc61129a196396a4d30d23a..04fa01b096ee3aeff0c9112a567cdb6e50288c12 100644 (file)
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -32,7 +32,7 @@ xen_pv_trap asm_exc_divide_error
 xen_pv_trap debug
 xen_pv_trap xendebug
 xen_pv_trap asm_exc_int3
-xen_pv_trap xennmi
+xen_pv_trap asm_exc_xennmi
 xen_pv_trap asm_exc_overflow
 xen_pv_trap asm_exc_bounds
 xen_pv_trap asm_exc_invalid_op