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Date: Sun, 21 Mar 2010 09:00:44 -0400
From: Brian Gerst <brgerst@...il.com>
To: hpa@...or.com
Cc: x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/4] 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@...il.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
--
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