x86/entry: Convert Divide Error to IDTENTRY

Convert #DE to IDTENTRY:
  - Implement the C entry point with DEFINE_IDTENTRY
  - Emit the ASM stub with DECLARE_IDTENTRY
  - Remove the ASM idtentry in 64bit
  - Remove the open coded ASM entry code in 32bit
  - Fixup the XEN/PV code

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/20200505134904.663914713@linutronix.de

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 8c0e07e2860f00b8bf11047ff7c7e10d2071f768..398fd3c5922848ed163309ac2d0dbcfb6e687cd1 100644 (file)
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1377,13 +1377,6 @@ SYM_CODE_START(alignment_check)
        jmp     common_exception
 SYM_CODE_END(alignment_check)
 
-SYM_CODE_START(divide_error)
-       ASM_CLAC
-       pushl   $0                              # no error code
-       pushl   $do_divide_error
-       jmp     common_exception
-SYM_CODE_END(divide_error)
-
 #ifdef CONFIG_X86_MCE
 SYM_CODE_START(machine_check)
        ASM_CLAC

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index ee0716290557475530e5d83d0003abb9f864cfb3..e18594d2dffd197acd428332e135307637fd21ed 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1072,7 +1072,6 @@ apicinterrupt IRQ_WORK_VECTOR                     irq_work_interrupt              smp_irq_work_interrupt
  * Exception entry points.
  */
 
-idtentry       X86_TRAP_DE             divide_error            do_divide_error                 has_error_code=0
 idtentry       X86_TRAP_OF             overflow                do_overflow                     has_error_code=0
 idtentry       X86_TRAP_BP             int3                    do_int3                         has_error_code=0
 idtentry       X86_TRAP_BR             bounds                  do_bounds                       has_error_code=0

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 2adfd80ea2f39a10d523c161539fb81cb53d6a75..e6f6e296bfec07b7b183270eb1fb4f1f06b89926 100644 (file)
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -67,4 +67,16 @@ static __always_inline void __##func(struct pt_regs *regs)
 
 #endif /* __ASSEMBLY__ */
 
+/*
+ * The actual entry points. Note that DECLARE_IDTENTRY*() serves two
+ * purposes:
+ *  - provide the function declarations when included from C-Code
+ *  - emit the ASM stubs when included from entry_32/64.S
+ *
+ * This avoids duplicate defines and ensures that everything is consistent.
+ */
+
+/* Simple exception entry points. No hardware error code */
+DECLARE_IDTENTRY(X86_TRAP_DE,          exc_divide_error);
+
 #endif

diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 814273f8b166aceeb7f9e8a22b57b90bd1a0d138..e68cbf87fe4a09327b8075aed9f077df053bf789 100644 (file)
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -11,7 +11,6 @@
 
 #define dotraplinkage __visible
 
-asmlinkage void divide_error(void);
 asmlinkage void debug(void);
 asmlinkage void nmi(void);
 asmlinkage void int3(void);
@@ -38,7 +37,6 @@ asmlinkage void machine_check(void);
 asmlinkage void simd_coprocessor_error(void);
 
 #if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
-asmlinkage void xen_divide_error(void);
 asmlinkage void xen_xennmi(void);
 asmlinkage void xen_xendebug(void);
 asmlinkage void xen_int3(void);
@@ -62,7 +60,6 @@ asmlinkage void xen_machine_check(void);
 asmlinkage void xen_simd_coprocessor_error(void);
 #endif
 
-dotraplinkage void do_divide_error(struct pt_regs *regs, long error_code);
 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_int3(struct pt_regs *regs, long error_code);

diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 95609ee4c8b3e1d7de18248d3c9f9347be9841e4..f2a751b10a01aa16222b1b9915901b2795d32da7 100644 (file)
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -73,7 +73,7 @@ static const __initconst struct idt_data early_idts[] = {
  * set up TSS.
  */
 static const __initconst struct idt_data def_idts[] = {
-       INTG(X86_TRAP_DE,               divide_error),
+       INTG(X86_TRAP_DE,               asm_exc_divide_error),
        INTG(X86_TRAP_NMI,              nmi),
        INTG(X86_TRAP_BR,               bounds),
        INTG(X86_TRAP_UD,               invalid_op),

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 3857c0fd3306d413217e35cda994fe7b95191fd4..37092f74ec42ac46797f31ea98d2bb002dc6a5bc 100644 (file)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -220,6 +220,12 @@ static __always_inline void __user *error_get_trap_addr(struct pt_regs *regs)
        return (void __user *)uprobe_get_trap_addr(regs);
 }
 
+DEFINE_IDTENTRY(exc_divide_error)
+{
+       do_error_trap(regs, 0, "divide_error", X86_TRAP_DE, SIGFPE,
+                     FPE_INTDIV, error_get_trap_addr(regs));
+}
+
 #define IP ((void __user *)uprobe_get_trap_addr(regs))
 #define DO_ERROR(trapnr, signr, sicode, addr, str, name)                  \
 dotraplinkage void do_##name(struct pt_regs *regs, long error_code)       \
@@ -227,7 +233,6 @@ dotraplinkage void do_##name(struct pt_regs *regs, long error_code)    \
        do_error_trap(regs, error_code, str, trapnr, signr, sicode, addr); \
 }
 
-DO_ERROR(X86_TRAP_DE,     SIGFPE,  FPE_INTDIV,   IP, "divide error",        divide_error)
 DO_ERROR(X86_TRAP_OF,     SIGSEGV,          0, NULL, "overflow",            overflow)
 DO_ERROR(X86_TRAP_UD,     SIGILL,  ILL_ILLOPN,   IP, "invalid opcode",      invalid_op)
 DO_ERROR(X86_TRAP_OLD_MF, SIGFPE,           0, NULL, "coprocessor segment overrun", coprocessor_segment_overrun)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index c2c97faaf004d9a0456b666563511434341286ff..06c53c94c813e72f49709a0afa26e428665e9118 100644 (file)
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -604,6 +604,11 @@ struct trap_array_entry {
        bool ist_okay;
 };
 
+#define TRAP_ENTRY(func, ist_ok) {                     \
+       .orig           = asm_##func,                   \
+       .xen            = xen_asm_##func,               \
+       .ist_okay       = ist_ok }
+
 static struct trap_array_entry trap_array[] = {
        { debug,                       xen_xendebug,                    true },
        { double_fault,                xen_double_fault,                true },
@@ -617,7 +622,7 @@ static struct trap_array_entry trap_array[] = {
        { entry_INT80_compat,          xen_entry_INT80_compat,          false },
 #endif
        { page_fault,                  xen_page_fault,                  false },
-       { divide_error,                xen_divide_error,                false },
+       TRAP_ENTRY(exc_divide_error,                    false ),
        { bounds,                      xen_bounds,                      false },
        { invalid_op,                  xen_invalid_op,                  false },
        { device_not_available,        xen_device_not_available,        false },

diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 0a0fd168683a75d033cb7737e3373729b2e6886f..48ac67ef094a8eafee91e1b9ac73db8a2c90e24c 100644 (file)
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -28,7 +28,7 @@ SYM_CODE_END(xen_\name)
 _ASM_NOKPROBE(xen_\name)
 .endm
 
-xen_pv_trap divide_error
+xen_pv_trap asm_exc_divide_error
 xen_pv_trap debug
 xen_pv_trap xendebug
 xen_pv_trap int3