x86/entry: Convert SIMD coprocessor error exception to IDTENTRY

Convert #XF to IDTENTRY_ERRORCODE:
  - Implement the C entry point with DEFINE_IDTENTRY
  - Emit the ASM stub with DECLARE_IDTENTRY
  - Handle INVD_BUG in C
  - Remove the ASM idtentry in 64bit
  - Remove the open coded ASM entry code in 32bit
  - Fixup the XEN/PV code
  - Remove the old prototypes
  - Remove the RCU warning as the new entry macro ensures correctness

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/20200505134906.021552202@linutronix.de

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 7402890..c93fb73 100644 (file)
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1290,20 +1290,6 @@ SYM_FUNC_END(name)
 /* The include is where all of the SMP etc. interrupts come from */
 #include <asm/entry_arch.h>
 
-SYM_CODE_START(simd_coprocessor_error)
-       ASM_CLAC
-       pushl   $0
-#ifdef CONFIG_X86_INVD_BUG
-       /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
-       ALTERNATIVE "pushl      $exc_general_protection",       \
-                   "pushl      $do_simd_coprocessor_error",    \
-                   X86_FEATURE_XMM
-#else
-       pushl   $do_simd_coprocessor_error
-#endif
-       jmp     common_exception
-SYM_CODE_END(simd_coprocessor_error)
-
 #ifdef CONFIG_PARAVIRT
 SYM_CODE_START(native_iret)
        iret

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 3c95a63..1bada7b 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1073,7 +1073,6 @@ apicinterrupt IRQ_WORK_VECTOR                     irq_work_interrupt              smp_irq_work_interrupt
  */
 
 idtentry       X86_TRAP_BP             int3                    do_int3                         has_error_code=0
-idtentry       X86_TRAP_XF             simd_coprocessor_error  do_simd_coprocessor_error       has_error_code=0
 
 idtentry       X86_TRAP_PF             page_fault              do_page_fault                   has_error_code=1
 

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 531dbc0..99d4759 100644 (file)
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -131,6 +131,7 @@ DECLARE_IDTENTRY(X86_TRAP_NM,               exc_device_not_available);
 DECLARE_IDTENTRY(X86_TRAP_OLD_MF,      exc_coproc_segment_overrun);
 DECLARE_IDTENTRY(X86_TRAP_SPURIOUS,    exc_spurious_interrupt_bug);
 DECLARE_IDTENTRY(X86_TRAP_MF,          exc_coprocessor_error);
+DECLARE_IDTENTRY(X86_TRAP_XF,          exc_simd_coprocessor_error);
 
 /* Simple exception entries with error code pushed by hardware */
 DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_TS,        exc_invalid_tss);

diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 0f755e1..e7eb753 100644 (file)
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -22,7 +22,6 @@ asmlinkage void async_page_fault(void);
 #ifdef CONFIG_X86_MCE
 asmlinkage void machine_check(void);
 #endif /* CONFIG_X86_MCE */
-asmlinkage void simd_coprocessor_error(void);
 
 #if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
 asmlinkage void xen_xennmi(void);
@@ -33,7 +32,6 @@ asmlinkage void xen_page_fault(void);
 #ifdef CONFIG_X86_MCE
 asmlinkage void xen_machine_check(void);
 #endif /* CONFIG_X86_MCE */
-asmlinkage void xen_simd_coprocessor_error(void);
 #endif
 
 dotraplinkage void do_debug(struct pt_regs *regs, long error_code);
@@ -41,7 +39,6 @@ dotraplinkage void do_nmi(struct pt_regs *regs, long error_code);
 dotraplinkage void do_int3(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);
-dotraplinkage void do_simd_coprocessor_error(struct pt_regs *regs, long error_code);
 #ifdef CONFIG_X86_32
 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code);
 #endif

diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index af48196..38b565b 100644 (file)
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -86,7 +86,7 @@ static const __initconst struct idt_data def_idts[] = {
        INTG(X86_TRAP_SPURIOUS,         asm_exc_spurious_interrupt_bug),
        INTG(X86_TRAP_MF,               asm_exc_coprocessor_error),
        INTG(X86_TRAP_AC,               asm_exc_alignment_check),
-       INTG(X86_TRAP_XF,               simd_coprocessor_error),
+       INTG(X86_TRAP_XF,               asm_exc_simd_coprocessor_error),
 
 #ifdef CONFIG_X86_32
        TSKG(X86_TRAP_DF,               GDT_ENTRY_DOUBLEFAULT_TSS),

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 9f156c8..1702922 100644 (file)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -810,7 +810,7 @@ NOKPROBE_SYMBOL(do_debug);
  * the correct behaviour even in the presence of the asynchronous
  * IRQ13 behaviour
  */
-static void math_error(struct pt_regs *regs, int error_code, int trapnr)
+static void math_error(struct pt_regs *regs, int trapnr)
 {
        struct task_struct *task = current;
        struct fpu *fpu = &task->thread.fpu;
@@ -821,15 +821,15 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr)
        cond_local_irq_enable(regs);
 
        if (!user_mode(regs)) {
-               if (fixup_exception(regs, trapnr, error_code, 0))
+               if (fixup_exception(regs, trapnr, 0, 0))
                        goto exit;
 
-               task->thread.error_code = error_code;
+               task->thread.error_code = 0;
                task->thread.trap_nr = trapnr;
 
-               if (notify_die(DIE_TRAP, str, regs, error_code,
-                                       trapnr, SIGFPE) != NOTIFY_STOP)
-                       die(str, regs, error_code);
+               if (notify_die(DIE_TRAP, str, regs, 0, trapnr,
+                              SIGFPE) != NOTIFY_STOP)
+                       die(str, regs, 0);
                goto exit;
        }
 
@@ -839,7 +839,7 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr)
        fpu__save(fpu);
 
        task->thread.trap_nr    = trapnr;
-       task->thread.error_code = error_code;
+       task->thread.error_code = 0;
 
        si_code = fpu__exception_code(fpu, trapnr);
        /* Retry when we get spurious exceptions: */
@@ -854,14 +854,19 @@ exit:
 
 DEFINE_IDTENTRY(exc_coprocessor_error)
 {
-       math_error(regs, 0, X86_TRAP_MF);
+       math_error(regs, X86_TRAP_MF);
 }
 
-dotraplinkage void
-do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY(exc_simd_coprocessor_error)
 {
-       RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
-       math_error(regs, error_code, X86_TRAP_XF);
+       if (IS_ENABLED(CONFIG_X86_INVD_BUG)) {
+               /* AMD 486 bug: INVD in CPL 0 raises #XF instead of #GP */
+               if (!static_cpu_has(X86_FEATURE_XMM)) {
+                       __exc_general_protection(regs, 0);
+                       return;
+               }
+       }
+       math_error(regs, X86_TRAP_XF);
 }
 
 DEFINE_IDTENTRY(exc_spurious_interrupt_bug)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 1097e35..0a30fc0 100644 (file)
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -634,7 +634,7 @@ static struct trap_array_entry trap_array[] = {
        TRAP_ENTRY(exc_spurious_interrupt_bug,          false ),
        TRAP_ENTRY(exc_coprocessor_error,               false ),
        TRAP_ENTRY(exc_alignment_check,                 false ),
-       { simd_coprocessor_error,      xen_simd_coprocessor_error,      false },
+       TRAP_ENTRY(exc_simd_coprocessor_error,          false ),
 };
 
 static bool __ref get_trap_addr(void **addr, unsigned int ist)

diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index a591bec..6a91157 100644 (file)
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -50,7 +50,7 @@ xen_pv_trap asm_exc_alignment_check
 #ifdef CONFIG_X86_MCE
 xen_pv_trap machine_check
 #endif /* CONFIG_X86_MCE */
-xen_pv_trap simd_coprocessor_error
+xen_pv_trap asm_exc_simd_coprocessor_error
 #ifdef CONFIG_IA32_EMULATION
 xen_pv_trap entry_INT80_compat
 #endif