[PATCH 0/4] x86: Merge fpu and simd exception handlers (v2)

[PATCH 0/4] x86: Merge fpu and simd exception handlers (v2)

[Brian Gerst]

This patch series merges the fpu and simd exception handlers into one
function.  The only difference is where the status bits are read from.
This also applies a fix for multiple simd exceptions that was already
done for fpu.

v2:
Changed the cache flush denied handler to simply redirect to general
protection fault.
Squashed patch to remove die_if_kernel() into patch #1.

[PATCH 1/4] x86-32: Rework cache flush denied handler
[PATCH 2/4] x86: Merge simd_math_error() into math_error()
[PATCH 3/4] x86: Merge kernel_math_error() into math_error()
[PATCH 4/4] x86-32: Don't set ignore_fpu_irq in simd exception

 arch/x86/Kconfig.cpu         |    4 +
 arch/x86/include/asm/traps.h |    2 +-
 arch/x86/kernel/entry_32.S   |   19 +++++
 arch/x86/kernel/irqinit.c    |    2 +-
 arch/x86/kernel/traps.c      |  173 ++++++++++++------------------------------
 5 files changed, 73 insertions(+), 127 deletions(-)

[PATCH 1/4] x86-32: Rework cache flush denied handler

[Brian Gerst]

The cache flush denied error is an erratum on some AMD 486 clones.  If an invd
instruction is executed in userspace, the processor calls exception 19 (13 hex)
instead of #GP (13 decimal).  On cpus where XMM is not supported, redirect
exception 19 to do_general_protection().  Also, remove die_if_kernel(), since
this was the last user.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/Kconfig.cpu       |    4 ++++
 arch/x86/kernel/entry_32.S |   19 +++++++++++++++++++
 arch/x86/kernel/traps.c    |   31 +++----------------------------
 3 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index f20ddf8..1012e8a 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -338,6 +338,10 @@ config X86_F00F_BUG
 	def_bool y
 	depends on M586MMX || M586TSC || M586 || M486 || M386
 
+config X86_INVD_BUG
+	def_bool y
+	depends on M486 || M386
+
 config X86_WP_WORKS_OK
 	def_bool y
 	depends on !M386
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 44a8e0d..1e958b8 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -53,6 +53,7 @@
 #include <asm/processor-flags.h>
 #include <asm/ftrace.h>
 #include <asm/irq_vectors.h>
+#include <asm/cpufeature.h>
 
 /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this.  */
 #include <linux/elf-em.h>
@@ -905,7 +906,25 @@ ENTRY(simd_coprocessor_error)
 	RING0_INT_FRAME
 	pushl $0
 	CFI_ADJUST_CFA_OFFSET 4
+#ifdef CONFIG_X86_INVD_BUG
+	/* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
+661:	pushl $do_general_protection
+662:
+.section .altinstructions,"a"
+	.balign 4
+	.long 661b
+	.long 663f
+	.byte X86_FEATURE_XMM
+	.byte 662b-661b
+	.byte 664f-663f
+.previous
+.section .altinstr_replacement,"ax"	
+663:	pushl $do_simd_coprocessor_error
+664:
+.previous
+#else
 	pushl $do_simd_coprocessor_error
+#endif
 	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
 	CFI_ENDPROC
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 3339917..bb4a7b3 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -108,15 +108,6 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
 	dec_preempt_count();
 }
 
-#ifdef CONFIG_X86_32
-static inline void
-die_if_kernel(const char *str, struct pt_regs *regs, long err)
-{
-	if (!user_mode_vm(regs))
-		die(str, regs, err);
-}
-#endif
-
 static void __kprobes
 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
 	long error_code, siginfo_t *info)
@@ -726,30 +717,14 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 	conditional_sti(regs);
 
 #ifdef CONFIG_X86_32
-	if (cpu_has_xmm) {
-		/* Handle SIMD FPU exceptions on PIII+ processors. */
-		ignore_fpu_irq = 1;
-		simd_math_error((void __user *)regs->ip);
-		return;
-	}
-	/*
-	 * Handle strange cache flush from user space exception
-	 * in all other cases.  This is undocumented behaviour.
-	 */
-	if (regs->flags & X86_VM_MASK) {
-		handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
-		return;
-	}
-	current->thread.trap_no = 19;
-	current->thread.error_code = error_code;
-	die_if_kernel("cache flush denied", regs, error_code);
-	force_sig(SIGSEGV, current);
+	ignore_fpu_irq = 1;
 #else
 	if (!user_mode(regs) &&
 			kernel_math_error(regs, "kernel simd math error", 19))
 		return;
-	simd_math_error((void __user *)regs->ip);
 #endif
+
+	simd_math_error((void __user *)regs->ip);
 }
 
 dotraplinkage void
-- 
1.6.6.1

[tip:x86/fpu] x86-32: Rework cache flush denied handler

[tip-bot for Brian Gerst]

Commit-ID:  40d2e76315da38993129090dc5d56377e573c312
Gitweb:     http://git.kernel.org/tip/40d2e76315da38993129090dc5d56377e573c312
Author:     Brian Gerst <brgerst@gmail.com>
AuthorDate: Sun, 21 Mar 2010 09:00:43 -0400
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Mon, 3 May 2010 13:39:26 -0700

x86-32: Rework cache flush denied handler

The cache flush denied error is an erratum on some AMD 486 clones.  If an invd
instruction is executed in userspace, the processor calls exception 19 (13 hex)
instead of #GP (13 decimal).  On cpus where XMM is not supported, redirect
exception 19 to do_general_protection().  Also, remove die_if_kernel(), since
this was the last user.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1269176446-2489-2-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/Kconfig.cpu       |    4 ++++
 arch/x86/kernel/entry_32.S |   19 +++++++++++++++++++
 arch/x86/kernel/traps.c    |   31 +++----------------------------
 3 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index a198293..6f6792c 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -338,6 +338,10 @@ config X86_F00F_BUG
 	def_bool y
 	depends on M586MMX || M586TSC || M586 || M486 || M386
 
+config X86_INVD_BUG
+	def_bool y
+	depends on M486 || M386
+
 config X86_WP_WORKS_OK
 	def_bool y
 	depends on !M386
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 44a8e0d..cd49141 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -53,6 +53,7 @@
 #include <asm/processor-flags.h>
 #include <asm/ftrace.h>
 #include <asm/irq_vectors.h>
+#include <asm/cpufeature.h>
 
 /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this.  */
 #include <linux/elf-em.h>
@@ -905,7 +906,25 @@ ENTRY(simd_coprocessor_error)
 	RING0_INT_FRAME
 	pushl $0
 	CFI_ADJUST_CFA_OFFSET 4
+#ifdef CONFIG_X86_INVD_BUG
+	/* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
+661:	pushl $do_general_protection
+662:
+.section .altinstructions,"a"
+	.balign 4
+	.long 661b
+	.long 663f
+	.byte X86_FEATURE_XMM
+	.byte 662b-661b
+	.byte 664f-663f
+.previous
+.section .altinstr_replacement,"ax"
+663:	pushl $do_simd_coprocessor_error
+664:
+.previous
+#else
 	pushl $do_simd_coprocessor_error
+#endif
 	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
 	CFI_ENDPROC
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 1168e44..a16c9df 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -108,15 +108,6 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
 	dec_preempt_count();
 }
 
-#ifdef CONFIG_X86_32
-static inline void
-die_if_kernel(const char *str, struct pt_regs *regs, long err)
-{
-	if (!user_mode_vm(regs))
-		die(str, regs, err);
-}
-#endif
-
 static void __kprobes
 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
 	long error_code, siginfo_t *info)
@@ -729,30 +720,14 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 	conditional_sti(regs);
 
 #ifdef CONFIG_X86_32
-	if (cpu_has_xmm) {
-		/* Handle SIMD FPU exceptions on PIII+ processors. */
-		ignore_fpu_irq = 1;
-		simd_math_error((void __user *)regs->ip);
-		return;
-	}
-	/*
-	 * Handle strange cache flush from user space exception
-	 * in all other cases.  This is undocumented behaviour.
-	 */
-	if (regs->flags & X86_VM_MASK) {
-		handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
-		return;
-	}
-	current->thread.trap_no = 19;
-	current->thread.error_code = error_code;
-	die_if_kernel("cache flush denied", regs, error_code);
-	force_sig(SIGSEGV, current);
+	ignore_fpu_irq = 1;
 #else
 	if (!user_mode(regs) &&
 			kernel_math_error(regs, "kernel simd math error", 19))
 		return;
-	simd_math_error((void __user *)regs->ip);
 #endif
+
+	simd_math_error((void __user *)regs->ip);
 }
 
 dotraplinkage void

[PATCH 2/4] x86: Merge simd_math_error() into math_error()

[Brian Gerst]

The only difference between FPU and SIMD exceptions is where the
status bits are read from (cwd/swd vs. mxcsr).  This also fixes
the discrepency introduced by commit adf77bac, which fixed FPU
but not SIMD.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/include/asm/traps.h |    2 +-
 arch/x86/kernel/irqinit.c    |    2 +-
 arch/x86/kernel/traps.c      |  100 +++++++++++++----------------------------
 3 files changed, 34 insertions(+), 70 deletions(-)

diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 4da91ad..f66cda5 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -79,7 +79,7 @@ static inline int get_si_code(unsigned long condition)
 
 extern int panic_on_unrecovered_nmi;
 
-void math_error(void __user *);
+void math_error(struct pt_regs *, int, int);
 void math_emulate(struct math_emu_info *);
 #ifndef CONFIG_X86_32
 asmlinkage void smp_thermal_interrupt(void);
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index d593222..1867351 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -61,7 +61,7 @@ static irqreturn_t math_error_irq(int cpl, void *dev_id)
 	outb(0, 0xF0);
 	if (ignore_fpu_irq || !boot_cpu_data.hard_math)
 		return IRQ_NONE;
-	math_error((void __user *)get_irq_regs()->ip);
+	math_error(get_irq_regs(), 0, 16);
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index bb4a7b3..495dd5d 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -592,36 +592,48 @@ static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
  * the correct behaviour even in the presence of the asynchronous
  * IRQ13 behaviour
  */
-void math_error(void __user *ip)
+void math_error(struct pt_regs *regs, int error_code, int trapnr)
 {
 	struct task_struct *task;
 	siginfo_t info;
-	unsigned short cwd, swd, err;
+	unsigned short err;
 
 	/*
 	 * Save the info for the exception handler and clear the error.
 	 */
 	task = current;
 	save_init_fpu(task);
-	task->thread.trap_no = 16;
-	task->thread.error_code = 0;
+	task->thread.trap_no = trapnr;
+	task->thread.error_code = error_code;
 	info.si_signo = SIGFPE;
 	info.si_errno = 0;
-	info.si_addr = ip;
-	/*
-	 * (~cwd & swd) will mask out exceptions that are not set to unmasked
-	 * status.  0x3f is the exception bits in these regs, 0x200 is the
-	 * C1 reg you need in case of a stack fault, 0x040 is the stack
-	 * fault bit.  We should only be taking one exception at a time,
-	 * so if this combination doesn't produce any single exception,
-	 * then we have a bad program that isn't synchronizing its FPU usage
-	 * and it will suffer the consequences since we won't be able to
-	 * fully reproduce the context of the exception
-	 */
-	cwd = get_fpu_cwd(task);
-	swd = get_fpu_swd(task);
+	info.si_addr = (void __user *)regs->ip;
+	if (trapnr == 16) {
+		unsigned short cwd, swd;
+		/*
+		 * (~cwd & swd) will mask out exceptions that are not set to unmasked
+		 * status.  0x3f is the exception bits in these regs, 0x200 is the
+		 * C1 reg you need in case of a stack fault, 0x040 is the stack
+		 * fault bit.  We should only be taking one exception at a time,
+		 * so if this combination doesn't produce any single exception,
+		 * then we have a bad program that isn't synchronizing its FPU usage
+		 * and it will suffer the consequences since we won't be able to
+		 * fully reproduce the context of the exception
+		 */
+		cwd = get_fpu_cwd(task);
+		swd = get_fpu_swd(task);
 
-	err = swd & ~cwd;
+		err = swd & ~cwd;
+	} else {
+		/*
+		 * The SIMD FPU exceptions are handled a little differently, as there
+		 * is only a single status/control register.  Thus, to determine which
+		 * unmasked exception was caught we must mask the exception mask bits
+		 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
+		 */
+		unsigned short mxcsr = get_fpu_mxcsr(task);
+		err = ~(mxcsr >> 7) & mxcsr;
+	}
 
 	if (err & 0x001) {	/* Invalid op */
 		/*
@@ -660,55 +672,7 @@ dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 		return;
 #endif
 
-	math_error((void __user *)regs->ip);
-}
-
-static void simd_math_error(void __user *ip)
-{
-	struct task_struct *task;
-	siginfo_t info;
-	unsigned short mxcsr;
-
-	/*
-	 * Save the info for the exception handler and clear the error.
-	 */
-	task = current;
-	save_init_fpu(task);
-	task->thread.trap_no = 19;
-	task->thread.error_code = 0;
-	info.si_signo = SIGFPE;
-	info.si_errno = 0;
-	info.si_code = __SI_FAULT;
-	info.si_addr = ip;
-	/*
-	 * The SIMD FPU exceptions are handled a little differently, as there
-	 * is only a single status/control register.  Thus, to determine which
-	 * unmasked exception was caught we must mask the exception mask bits
-	 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
-	 */
-	mxcsr = get_fpu_mxcsr(task);
-	switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
-	case 0x000:
-	default:
-		break;
-	case 0x001: /* Invalid Op */
-		info.si_code = FPE_FLTINV;
-		break;
-	case 0x002: /* Denormalize */
-	case 0x010: /* Underflow */
-		info.si_code = FPE_FLTUND;
-		break;
-	case 0x004: /* Zero Divide */
-		info.si_code = FPE_FLTDIV;
-		break;
-	case 0x008: /* Overflow */
-		info.si_code = FPE_FLTOVF;
-		break;
-	case 0x020: /* Precision */
-		info.si_code = FPE_FLTRES;
-		break;
-	}
-	force_sig_info(SIGFPE, &info, task);
+	math_error(regs, error_code, 16);
 }
 
 dotraplinkage void
@@ -724,7 +688,7 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 		return;
 #endif
 
-	simd_math_error((void __user *)regs->ip);
+	math_error(regs, error_code, 19);
 }
 
 dotraplinkage void
-- 
1.6.6.1

[tip:x86/fpu] x86: Merge simd_math_error() into math_error()

[tip-bot for Brian Gerst]

Commit-ID:  9b6dba9e0798325dab427b9d60c61630ccc39b28
Gitweb:     http://git.kernel.org/tip/9b6dba9e0798325dab427b9d60c61630ccc39b28
Author:     Brian Gerst <brgerst@gmail.com>
AuthorDate: Sun, 21 Mar 2010 09:00:44 -0400
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Mon, 3 May 2010 13:39:29 -0700

x86: Merge simd_math_error() into math_error()

The only difference between FPU and SIMD exceptions is where the
status bits are read from (cwd/swd vs. mxcsr).  This also fixes
the discrepency introduced by commit adf77bac, which fixed FPU
but not SIMD.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1269176446-2489-3-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/include/asm/traps.h |    2 +-
 arch/x86/kernel/irqinit.c    |    2 +-
 arch/x86/kernel/traps.c      |  100 +++++++++++++----------------------------
 3 files changed, 34 insertions(+), 70 deletions(-)

diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 4da91ad..f66cda5 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -79,7 +79,7 @@ static inline int get_si_code(unsigned long condition)
 
 extern int panic_on_unrecovered_nmi;
 
-void math_error(void __user *);
+void math_error(struct pt_regs *, int, int);
 void math_emulate(struct math_emu_info *);
 #ifndef CONFIG_X86_32
 asmlinkage void smp_thermal_interrupt(void);
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index 0ed2d30..990ae7c 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -60,7 +60,7 @@ static irqreturn_t math_error_irq(int cpl, void *dev_id)
 	outb(0, 0xF0);
 	if (ignore_fpu_irq || !boot_cpu_data.hard_math)
 		return IRQ_NONE;
-	math_error((void __user *)get_irq_regs()->ip);
+	math_error(get_irq_regs(), 0, 16);
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index a16c9df..a472992 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -595,36 +595,48 @@ static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
  * the correct behaviour even in the presence of the asynchronous
  * IRQ13 behaviour
  */
-void math_error(void __user *ip)
+void math_error(struct pt_regs *regs, int error_code, int trapnr)
 {
 	struct task_struct *task;
 	siginfo_t info;
-	unsigned short cwd, swd, err;
+	unsigned short err;
 
 	/*
 	 * Save the info for the exception handler and clear the error.
 	 */
 	task = current;
 	save_init_fpu(task);
-	task->thread.trap_no = 16;
-	task->thread.error_code = 0;
+	task->thread.trap_no = trapnr;
+	task->thread.error_code = error_code;
 	info.si_signo = SIGFPE;
 	info.si_errno = 0;
-	info.si_addr = ip;
-	/*
-	 * (~cwd & swd) will mask out exceptions that are not set to unmasked
-	 * status.  0x3f is the exception bits in these regs, 0x200 is the
-	 * C1 reg you need in case of a stack fault, 0x040 is the stack
-	 * fault bit.  We should only be taking one exception at a time,
-	 * so if this combination doesn't produce any single exception,
-	 * then we have a bad program that isn't synchronizing its FPU usage
-	 * and it will suffer the consequences since we won't be able to
-	 * fully reproduce the context of the exception
-	 */
-	cwd = get_fpu_cwd(task);
-	swd = get_fpu_swd(task);
+	info.si_addr = (void __user *)regs->ip;
+	if (trapnr == 16) {
+		unsigned short cwd, swd;
+		/*
+		 * (~cwd & swd) will mask out exceptions that are not set to unmasked
+		 * status.  0x3f is the exception bits in these regs, 0x200 is the
+		 * C1 reg you need in case of a stack fault, 0x040 is the stack
+		 * fault bit.  We should only be taking one exception at a time,
+		 * so if this combination doesn't produce any single exception,
+		 * then we have a bad program that isn't synchronizing its FPU usage
+		 * and it will suffer the consequences since we won't be able to
+		 * fully reproduce the context of the exception
+		 */
+		cwd = get_fpu_cwd(task);
+		swd = get_fpu_swd(task);
 
-	err = swd & ~cwd;
+		err = swd & ~cwd;
+	} else {
+		/*
+		 * The SIMD FPU exceptions are handled a little differently, as there
+		 * is only a single status/control register.  Thus, to determine which
+		 * unmasked exception was caught we must mask the exception mask bits
+		 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
+		 */
+		unsigned short mxcsr = get_fpu_mxcsr(task);
+		err = ~(mxcsr >> 7) & mxcsr;
+	}
 
 	if (err & 0x001) {	/* Invalid op */
 		/*
@@ -663,55 +675,7 @@ dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 		return;
 #endif
 
-	math_error((void __user *)regs->ip);
-}
-
-static void simd_math_error(void __user *ip)
-{
-	struct task_struct *task;
-	siginfo_t info;
-	unsigned short mxcsr;
-
-	/*
-	 * Save the info for the exception handler and clear the error.
-	 */
-	task = current;
-	save_init_fpu(task);
-	task->thread.trap_no = 19;
-	task->thread.error_code = 0;
-	info.si_signo = SIGFPE;
-	info.si_errno = 0;
-	info.si_code = __SI_FAULT;
-	info.si_addr = ip;
-	/*
-	 * The SIMD FPU exceptions are handled a little differently, as there
-	 * is only a single status/control register.  Thus, to determine which
-	 * unmasked exception was caught we must mask the exception mask bits
-	 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
-	 */
-	mxcsr = get_fpu_mxcsr(task);
-	switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
-	case 0x000:
-	default:
-		break;
-	case 0x001: /* Invalid Op */
-		info.si_code = FPE_FLTINV;
-		break;
-	case 0x002: /* Denormalize */
-	case 0x010: /* Underflow */
-		info.si_code = FPE_FLTUND;
-		break;
-	case 0x004: /* Zero Divide */
-		info.si_code = FPE_FLTDIV;
-		break;
-	case 0x008: /* Overflow */
-		info.si_code = FPE_FLTOVF;
-		break;
-	case 0x020: /* Precision */
-		info.si_code = FPE_FLTRES;
-		break;
-	}
-	force_sig_info(SIGFPE, &info, task);
+	math_error(regs, error_code, 16);
 }
 
 dotraplinkage void
@@ -727,7 +691,7 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 		return;
 #endif
 
-	simd_math_error((void __user *)regs->ip);
+	math_error(regs, error_code, 19);
 }
 
 dotraplinkage void

[PATCH 3/4] x86: Merge kernel_math_error() into math_error()

[Brian Gerst]

Clean up the kernel exception handling and make it more similar to
the other traps.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/kernel/traps.c |   44 ++++++++++++++++----------------------------
 1 files changed, 16 insertions(+), 28 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 495dd5d..d53a443 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -573,20 +573,6 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
 	return;
 }
 
-#ifdef CONFIG_X86_64
-static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
-{
-	if (fixup_exception(regs))
-		return 1;
-
-	notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
-	/* Illegal floating point operation in the kernel */
-	current->thread.trap_no = trapnr;
-	die(str, regs, 0);
-	return 0;
-}
-#endif
-
 /*
  * Note that we play around with the 'TS' bit in an attempt to get
  * the correct behaviour even in the presence of the asynchronous
@@ -594,14 +580,28 @@ static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
  */
 void math_error(struct pt_regs *regs, int error_code, int trapnr)
 {
-	struct task_struct *task;
+	struct task_struct *task = current;
 	siginfo_t info;
 	unsigned short err;
+	char *str = (trapnr == 16) ? "fpu exception" : "simd exception";
+
+	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP)
+		return;
+	conditional_sti(regs);
+
+	if (!user_mode_vm(regs))
+	{
+		if (!fixup_exception(regs)) {
+			task->thread.error_code = error_code;
+			task->thread.trap_no = trapnr;
+			die(str, regs, error_code);
+		}
+		return;
+	}
 
 	/*
 	 * Save the info for the exception handler and clear the error.
 	 */
-	task = current;
 	save_init_fpu(task);
 	task->thread.trap_no = trapnr;
 	task->thread.error_code = error_code;
@@ -662,14 +662,8 @@ void math_error(struct pt_regs *regs, int error_code, int trapnr)
 
 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 {
-	conditional_sti(regs);
-
 #ifdef CONFIG_X86_32
 	ignore_fpu_irq = 1;
-#else
-	if (!user_mode(regs) &&
-	    kernel_math_error(regs, "kernel x87 math error", 16))
-		return;
 #endif
 
 	math_error(regs, error_code, 16);
@@ -678,14 +672,8 @@ dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 dotraplinkage void
 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 {
-	conditional_sti(regs);
-
 #ifdef CONFIG_X86_32
 	ignore_fpu_irq = 1;
-#else
-	if (!user_mode(regs) &&
-			kernel_math_error(regs, "kernel simd math error", 19))
-		return;
 #endif
 
 	math_error(regs, error_code, 19);
-- 
1.6.6.1

[tip:x86/fpu] x86: Merge kernel_math_error() into math_error()

[tip-bot for Brian Gerst]

Commit-ID:  e2e75c915de045f0785387dc32f55e92fab0614c
Gitweb:     http://git.kernel.org/tip/e2e75c915de045f0785387dc32f55e92fab0614c
Author:     Brian Gerst <brgerst@gmail.com>
AuthorDate: Sun, 21 Mar 2010 09:00:45 -0400
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Mon, 3 May 2010 13:39:31 -0700

x86: Merge kernel_math_error() into math_error()

Clean up the kernel exception handling and make it more similar to
the other traps.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1269176446-2489-4-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/kernel/traps.c |   44 ++++++++++++++++----------------------------
 1 files changed, 16 insertions(+), 28 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index a472992..53ba86f 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -576,20 +576,6 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
 	return;
 }
 
-#ifdef CONFIG_X86_64
-static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
-{
-	if (fixup_exception(regs))
-		return 1;
-
-	notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
-	/* Illegal floating point operation in the kernel */
-	current->thread.trap_no = trapnr;
-	die(str, regs, 0);
-	return 0;
-}
-#endif
-
 /*
  * Note that we play around with the 'TS' bit in an attempt to get
  * the correct behaviour even in the presence of the asynchronous
@@ -597,14 +583,28 @@ static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
  */
 void math_error(struct pt_regs *regs, int error_code, int trapnr)
 {
-	struct task_struct *task;
+	struct task_struct *task = current;
 	siginfo_t info;
 	unsigned short err;
+	char *str = (trapnr == 16) ? "fpu exception" : "simd exception";
+
+	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP)
+		return;
+	conditional_sti(regs);
+
+	if (!user_mode_vm(regs))
+	{
+		if (!fixup_exception(regs)) {
+			task->thread.error_code = error_code;
+			task->thread.trap_no = trapnr;
+			die(str, regs, error_code);
+		}
+		return;
+	}
 
 	/*
 	 * Save the info for the exception handler and clear the error.
 	 */
-	task = current;
 	save_init_fpu(task);
 	task->thread.trap_no = trapnr;
 	task->thread.error_code = error_code;
@@ -665,14 +665,8 @@ void math_error(struct pt_regs *regs, int error_code, int trapnr)
 
 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 {
-	conditional_sti(regs);
-
 #ifdef CONFIG_X86_32
 	ignore_fpu_irq = 1;
-#else
-	if (!user_mode(regs) &&
-	    kernel_math_error(regs, "kernel x87 math error", 16))
-		return;
 #endif
 
 	math_error(regs, error_code, 16);
@@ -681,14 +675,8 @@ dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 dotraplinkage void
 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 {
-	conditional_sti(regs);
-
 #ifdef CONFIG_X86_32
 	ignore_fpu_irq = 1;
-#else
-	if (!user_mode(regs) &&
-			kernel_math_error(regs, "kernel simd math error", 19))
-		return;
 #endif
 
 	math_error(regs, error_code, 19);

[PATCH 4/4] x86-32: Don't set ignore_fpu_irq in simd exception

[Brian Gerst]

Any processor that supports simd will have an internal fpu, and the
irq13 handler will not be enabled.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/kernel/traps.c |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index d53a443..3e271ed 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -672,10 +672,6 @@ dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 dotraplinkage void
 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 {
-#ifdef CONFIG_X86_32
-	ignore_fpu_irq = 1;
-#endif
-
 	math_error(regs, error_code, 19);
 }
 
-- 
1.6.6.1

[tip:x86/fpu] x86-32: Don't set ignore_fpu_irq in simd exception

[tip-bot for Brian Gerst]

Commit-ID:  250825008f1f94887bc039e9227a8adfb5ba366e
Gitweb:     http://git.kernel.org/tip/250825008f1f94887bc039e9227a8adfb5ba366e
Author:     Brian Gerst <brgerst@gmail.com>
AuthorDate: Sun, 21 Mar 2010 09:00:46 -0400
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Mon, 3 May 2010 13:39:32 -0700

x86-32: Don't set ignore_fpu_irq in simd exception

Any processor that supports simd will have an internal fpu, and the
irq13 handler will not be enabled.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1269176446-2489-5-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/kernel/traps.c |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 53ba86f..00516e1 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -675,10 +675,6 @@ dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 dotraplinkage void
 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 {
-#ifdef CONFIG_X86_32
-	ignore_fpu_irq = 1;
-#endif
-
 	math_error(regs, error_code, 19);
 }