From a73ad3331fdbf4191cf99b83ea9ac7082b6757ba Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Thu, 25 Dec 2008 10:39:01 -0800 Subject: x86: unify the implementation of FPU traps On 32 bits, we may suffer IRQ 13, or supposedly we might have a buggy implementation which gives spurious trap 16. We did not check for this on 64 bits, but there is no reason we can't make the code the same in both cases. Furthermore, this is presumably rare, so do the spurious check last, instead of first. Signed-off-by: H. Peter Anvin --- arch/x86/kernel/traps.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'arch/x86/kernel/traps.c') diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index f37cee75ab5..f5a640ba04b 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -689,12 +689,7 @@ void math_error(void __user *ip) cwd = get_fpu_cwd(task); swd = get_fpu_swd(task); - err = swd & ~cwd & 0x3f; - -#ifdef CONFIG_X86_32 - if (!err) - return; -#endif + err = swd & ~cwd; if (err & 0x001) { /* Invalid op */ /* @@ -712,7 +707,9 @@ void math_error(void __user *ip) } else if (err & 0x020) { /* Precision */ info.si_code = FPE_FLTRES; } else { - info.si_code = __SI_FAULT|SI_KERNEL; /* WTF? */ + /* If we're using IRQ 13, or supposedly even some trap 16 + implementations, it's possible we get a spurious trap... */ + return; /* Spurious trap, no error */ } force_sig_info(SIGFPE, &info, task); } -- cgit v1.2.3 From bd8b96dfc216eebc72950a6c40da8d3eca8667df Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 26 Dec 2008 09:20:22 +0100 Subject: x86: clean up comment style in arch/x86/kernel/traps.c Impact: cleanup Signed-off-by: Ingo Molnar --- arch/x86/kernel/traps.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) (limited to 'arch/x86/kernel/traps.c') diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index f5a640ba04b..dbfb8028992 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -292,8 +292,10 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) tsk->thread.error_code = error_code; tsk->thread.trap_no = 8; - /* This is always a kernel trap and never fixable (and thus must - never return). */ + /* + * This is always a kernel trap and never fixable (and thus must + * never return). + */ for (;;) die(str, regs, error_code); } @@ -524,9 +526,11 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) } #ifdef CONFIG_X86_64 -/* Help handler running on IST stack to switch back to user stack - for scheduling or signal handling. The actual stack switch is done in - entry.S */ +/* + * Help handler running on IST stack to switch back to user stack + * for scheduling or signal handling. The actual stack switch is done in + * entry.S + */ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) { struct pt_regs *regs = eregs; @@ -536,8 +540,10 @@ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) /* Exception from user space */ else if (user_mode(eregs)) regs = task_pt_regs(current); - /* Exception from kernel and interrupts are enabled. Move to - kernel process stack. */ + /* + * Exception from kernel and interrupts are enabled. Move to + * kernel process stack. + */ else if (eregs->flags & X86_EFLAGS_IF) regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs)); if (eregs != regs) @@ -707,8 +713,10 @@ void math_error(void __user *ip) } else if (err & 0x020) { /* Precision */ info.si_code = FPE_FLTRES; } else { - /* If we're using IRQ 13, or supposedly even some trap 16 - implementations, it's possible we get a spurious trap... */ + /* + * If we're using IRQ 13, or supposedly even some trap 16 + * implementations, it's possible we get a spurious trap... + */ return; /* Spurious trap, no error */ } force_sig_info(SIGFPE, &info, task); -- cgit v1.2.3