From 70d7d357578245f1993fd2d3ccd26088bcd38941 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 2 Dec 2008 20:16:03 +0100 Subject: x86: fix broken flushing in GART nofullflush path Impact: remove stale IOTLB entries In the non-default nofullflush case the GART is only flushed when next_bit wraps around. But it can happen that an unmap operation unmaps memory which is behind the current next_bit location. If these addresses are reused it may result in stale GART IO/TLB entries. Fix this by setting the GART next_bit always behind an unmapped location. Signed-off-by: Joerg Roedel Signed-off-by: Ingo Molnar --- arch/x86/kernel/pci-gart_64.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c index a42b02b4df68..ba7ad83e20a8 100644 --- a/arch/x86/kernel/pci-gart_64.c +++ b/arch/x86/kernel/pci-gart_64.c @@ -123,6 +123,8 @@ static void free_iommu(unsigned long offset, int size) spin_lock_irqsave(&iommu_bitmap_lock, flags); iommu_area_free(iommu_gart_bitmap, offset, size); + if (offset >= next_bit) + next_bit = offset + size; spin_unlock_irqrestore(&iommu_bitmap_lock, flags); } -- cgit v1.2.3 From f91ba190648be4ff127d6aaf3993ac19d66dc2c2 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 25 Nov 2008 12:56:12 +0100 Subject: AMD IOMMU: set device table entry for aliased devices In some rare cases a request can arrive an IOMMU with its originial requestor id even it is aliased. Handle this by setting the device table entry to the same protection domain for the original and the aliased requestor id. Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index e4899e0e8787..a232e5a85d48 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -858,6 +858,9 @@ static int get_device_resources(struct device *dev, print_devid(_bdf, 1); } + if (domain_for_device(_bdf) == NULL) + set_device_domain(*iommu, *domain, _bdf); + return 1; } -- cgit v1.2.3 From 09ee17eb8ea89514c13980c4010bdbbaea8630c2 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Wed, 3 Dec 2008 12:19:27 +0100 Subject: AMD IOMMU: fix possible race while accessing iommu->need_sync The access to the iommu->need_sync member needs to be protected by the iommu->lock. Otherwise this is a possible race condition. Fix it with this patch. Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index a232e5a85d48..5662e226b0c9 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -187,6 +187,8 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd) spin_lock_irqsave(&iommu->lock, flags); ret = __iommu_queue_command(iommu, cmd); + if (!ret) + iommu->need_sync = 1; spin_unlock_irqrestore(&iommu->lock, flags); return ret; @@ -210,10 +212,13 @@ static int iommu_completion_wait(struct amd_iommu *iommu) cmd.data[0] = CMD_COMPL_WAIT_INT_MASK; CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT); - iommu->need_sync = 0; - spin_lock_irqsave(&iommu->lock, flags); + if (!iommu->need_sync) + goto out; + + iommu->need_sync = 0; + ret = __iommu_queue_command(iommu, &cmd); if (ret) @@ -254,8 +259,6 @@ static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid) ret = iommu_queue_command(iommu, &cmd); - iommu->need_sync = 1; - return ret; } @@ -281,8 +284,6 @@ static int iommu_queue_inv_iommu_pages(struct amd_iommu *iommu, ret = iommu_queue_command(iommu, &cmd); - iommu->need_sync = 1; - return ret; } @@ -762,8 +763,6 @@ static void set_device_domain(struct amd_iommu *iommu, write_unlock_irqrestore(&amd_iommu_devtable_lock, flags); iommu_queue_inv_dev_entry(iommu, devid); - - iommu->need_sync = 1; } /***************************************************************************** @@ -1034,8 +1033,7 @@ static dma_addr_t map_single(struct device *dev, phys_addr_t paddr, if (addr == bad_dma_address) goto out; - if (unlikely(iommu->need_sync)) - iommu_completion_wait(iommu); + iommu_completion_wait(iommu); out: spin_unlock_irqrestore(&domain->lock, flags); @@ -1063,8 +1061,7 @@ static void unmap_single(struct device *dev, dma_addr_t dma_addr, __unmap_single(iommu, domain->priv, dma_addr, size, dir); - if (unlikely(iommu->need_sync)) - iommu_completion_wait(iommu); + iommu_completion_wait(iommu); spin_unlock_irqrestore(&domain->lock, flags); } @@ -1130,8 +1127,7 @@ static int map_sg(struct device *dev, struct scatterlist *sglist, goto unmap; } - if (unlikely(iommu->need_sync)) - iommu_completion_wait(iommu); + iommu_completion_wait(iommu); out: spin_unlock_irqrestore(&domain->lock, flags); @@ -1176,8 +1172,7 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist, s->dma_address = s->dma_length = 0; } - if (unlikely(iommu->need_sync)) - iommu_completion_wait(iommu); + iommu_completion_wait(iommu); spin_unlock_irqrestore(&domain->lock, flags); } @@ -1228,8 +1223,7 @@ static void *alloc_coherent(struct device *dev, size_t size, goto out; } - if (unlikely(iommu->need_sync)) - iommu_completion_wait(iommu); + iommu_completion_wait(iommu); out: spin_unlock_irqrestore(&domain->lock, flags); @@ -1260,8 +1254,7 @@ static void free_coherent(struct device *dev, size_t size, __unmap_single(iommu, domain->priv, dma_addr, size, DMA_BIDIRECTIONAL); - if (unlikely(iommu->need_sync)) - iommu_completion_wait(iommu); + iommu_completion_wait(iommu); spin_unlock_irqrestore(&domain->lock, flags); -- cgit v1.2.3 From 9adc13867ec5fe0cd35434f92954d90e42381f0b Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 4 Dec 2008 13:33:35 +0100 Subject: x86: fix early panic with boot option "nosmp" Impact: fix boot crash with numcpus=0 on certain systems Fix early exception in __get_smp_config with nosmp. Bail out early when there is no MP table. Reported-by: Wu Fengguang Signed-off-by: Andi Kleen Tested-by: Wu Fengguang Signed-off-by: Ingo Molnar --- arch/x86/kernel/mpparse.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c index f98f4e1dba09..0f4c1fd5a1f4 100644 --- a/arch/x86/kernel/mpparse.c +++ b/arch/x86/kernel/mpparse.c @@ -604,6 +604,9 @@ static void __init __get_smp_config(unsigned int early) printk(KERN_INFO "Using ACPI for processor (LAPIC) " "configuration information\n"); + if (!mpf) + return; + printk(KERN_INFO "Intel MultiProcessor Specification v1.%d\n", mpf->mpf_specification); #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32) -- cgit v1.2.3 From bb9d4ff80bc032d7961815c2ff5eaf458ae3adff Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 4 Dec 2008 15:59:48 +0100 Subject: AMD IOMMU: fix iommu_map_page function Impact: bugfix in iommu_map_page function Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 5662e226b0c9..67970a8c2ee9 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -344,7 +344,7 @@ static int iommu_map(struct protection_domain *dom, u64 __pte, *pte, *page; bus_addr = PAGE_ALIGN(bus_addr); - phys_addr = PAGE_ALIGN(bus_addr); + phys_addr = PAGE_ALIGN(phys_addr); /* only support 512GB address spaces for now */ if (bus_addr > IOMMU_MAP_SIZE_L3 || !(prot & IOMMU_PROT_MASK)) -- cgit v1.2.3 From 3cc3d84bffbd93bdb671ac7961b12cd98fbb9266 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 4 Dec 2008 16:44:31 +0100 Subject: AMD IOMMU: fix loop counter in free_pagetable function Impact: bugfix Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 67970a8c2ee9..0637e65ca0c7 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -600,7 +600,7 @@ static void dma_ops_free_pagetable(struct dma_ops_domain *dma_dom) continue; p2 = IOMMU_PTE_PAGE(p1[i]); - for (j = 0; j < 512; ++i) { + for (j = 0; j < 512; ++j) { if (!IOMMU_PTE_PRESENT(p2[j])) continue; p3 = IOMMU_PTE_PAGE(p2[j]); -- cgit v1.2.3 From 24f811603e8ef4b9173f47fa263230168e237128 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 8 Dec 2008 14:25:39 +0100 Subject: AMD IOMMU: fix typo in comment Impact: cleanup Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 0637e65ca0c7..2fde073b6be6 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -922,8 +922,8 @@ static void dma_ops_domain_unmap(struct amd_iommu *iommu, /* * This function contains common code for mapping of a physically - * contiguous memory region into DMA address space. It is uses by all - * mapping functions provided by this IOMMU driver. + * contiguous memory region into DMA address space. It is used by all + * mapping functions provided with this IOMMU driver. * Must be called with the domain lock held. */ static dma_addr_t __map_single(struct device *dev, -- cgit v1.2.3 From 8ad909c4c1b91bd35ba6a2af5e7ab3fc8d9fe283 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 8 Dec 2008 14:37:20 +0100 Subject: AMD IOMMU: fix WARN_ON in dma_ops unmap path Impact: minor fix Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 2fde073b6be6..3133a0ea09ff 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -910,7 +910,7 @@ static void dma_ops_domain_unmap(struct amd_iommu *iommu, if (address >= dom->aperture_size) return; - WARN_ON(address & 0xfffULL || address > dom->aperture_size); + WARN_ON(address & ~PAGE_MASK || address >= dom->aperture_size); pte = dom->pte_pages[IOMMU_PTE_L1_INDEX(address)]; pte += IOMMU_PTE_L0_INDEX(address); -- cgit v1.2.3 From b8d9905d025d80a2357e8ce4704fde2923f6a1bd Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 8 Dec 2008 14:40:26 +0100 Subject: AMD IOMMU: __unmap_single: check for bad_dma_address instead of 0 Impact: minor fix Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 3133a0ea09ff..a7b6dec6fc3f 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -983,7 +983,8 @@ static void __unmap_single(struct amd_iommu *iommu, dma_addr_t i, start; unsigned int pages; - if ((dma_addr == 0) || (dma_addr + size > dma_dom->aperture_size)) + if ((dma_addr == bad_dma_address) || + (dma_addr + size > dma_dom->aperture_size)) return; pages = iommu_num_pages(dma_addr, size, PAGE_SIZE); -- cgit v1.2.3 From 087052b02f42b50316c6e4d7f2d8dfba3de6fc2e Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 17 Oct 2008 16:09:57 +0200 Subject: x86: fix default_spin_lock_flags() prototype MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit these warnings: arch/x86/kernel/paravirt-spinlocks.c: In function ‘default_spin_lock_flags’: arch/x86/kernel/paravirt-spinlocks.c:12: warning: passing argument 1 of ‘__raw_spin_lock’ from incompatible pointer type arch/x86/kernel/paravirt-spinlocks.c: At top level: arch/x86/kernel/paravirt-spinlocks.c:11: warning: ‘default_spin_lock_flags’ defined but not used showed that the prototype of default_spin_lock_flags() was confused about what type spinlocks have. the proper type on UP is raw_spinlock_t. Signed-off-by: Ingo Molnar --- arch/x86/kernel/paravirt-spinlocks.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 0e9f1982b1dd..95777b0faa73 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -7,7 +7,8 @@ #include -static void default_spin_lock_flags(struct raw_spinlock *lock, unsigned long flags) +static inline void +default_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags) { __raw_spin_lock(lock); } -- cgit v1.2.3 From ae8d04e2ecbb233926860e9ce145eac19c7835dc Mon Sep 17 00:00:00 2001 From: Zachary Amsden Date: Sat, 13 Dec 2008 12:36:58 -0800 Subject: x86 Fix VMI crash on boot in 2.6.28-rc8 VMI initialiation can relocate the fixmap, causing early_ioremap to malfunction if it is initialized before the relocation. To fix this, VMI activation is split into two phases; the detection, which must happen before setting up ioremap, and the activation, which must happen after parsing early boot parameters. This fixes a crash on boot when VMI is enabled under VMware. Signed-off-by: Zachary Amsden Signed-off-by: Linus Torvalds --- arch/x86/kernel/setup.c | 12 +++++------- arch/x86/kernel/smpboot.c | 2 -- arch/x86/kernel/vmi_32.c | 16 +++++++++++----- 3 files changed, 16 insertions(+), 14 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 9d5674f7b6cc..bdec76e55594 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -794,6 +794,9 @@ void __init setup_arch(char **cmdline_p) printk(KERN_INFO "Command line: %s\n", boot_command_line); #endif + /* VMI may relocate the fixmap; do this before touching ioremap area */ + vmi_init(); + early_cpu_init(); early_ioremap_init(); @@ -880,13 +883,8 @@ void __init setup_arch(char **cmdline_p) check_efer(); #endif -#if defined(CONFIG_VMI) && defined(CONFIG_X86_32) - /* - * Must be before kernel pagetables are setup - * or fixmap area is touched. - */ - vmi_init(); -#endif + /* Must be before kernel pagetables are setup */ + vmi_activate(); /* after early param, so could get panic from serial */ reserve_early_setup_data(); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 7b1093397319..f71f96fc9e62 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -294,9 +294,7 @@ static void __cpuinit start_secondary(void *unused) * fragile that we want to limit the things done here to the * most necessary things. */ -#ifdef CONFIG_VMI vmi_bringup(); -#endif cpu_init(); preempt_disable(); smp_callin(); diff --git a/arch/x86/kernel/vmi_32.c b/arch/x86/kernel/vmi_32.c index 8b6c393ab9fd..22fd6577156a 100644 --- a/arch/x86/kernel/vmi_32.c +++ b/arch/x86/kernel/vmi_32.c @@ -960,8 +960,6 @@ static inline int __init activate_vmi(void) void __init vmi_init(void) { - unsigned long flags; - if (!vmi_rom) probe_vmi_rom(); else @@ -973,13 +971,21 @@ void __init vmi_init(void) reserve_top_address(-vmi_rom->virtual_top); - local_irq_save(flags); - activate_vmi(); - #ifdef CONFIG_X86_IO_APIC /* This is virtual hardware; timer routing is wired correctly */ no_timer_check = 1; #endif +} + +void vmi_activate(void) +{ + unsigned long flags; + + if (!vmi_rom) + return; + + local_irq_save(flags); + activate_vmi(); local_irq_restore(flags & X86_EFLAGS_IF); } -- cgit v1.2.3 From adf77bac052bb5bf0722b2ce2af9fefc5b2d2a71 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 22 Dec 2008 17:56:05 -0800 Subject: x86: prioritize the FPU traps for the error code In the case of multiple FPU errors, prioritize the error codes, instead of returning __SI_FAULT, which ends up pushing a 0 as the error code to userspace, a POSIX violation. For i386, we will simply return if there are no errors at all; for x86-64 this is probably a "can't happen" (and the code should be unified), but for this patch, return __SI_FAULT|SI_KERNEL if this ever happens. Signed-off-by: H. Peter Anvin --- arch/x86/kernel/traps.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 04d242ab0161..c320c29255c2 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -664,7 +664,7 @@ void math_error(void __user *ip) { struct task_struct *task; siginfo_t info; - unsigned short cwd, swd; + unsigned short cwd, swd, err; /* * Save the info for the exception handler and clear the error. @@ -675,7 +675,6 @@ void math_error(void __user *ip) task->thread.error_code = 0; info.si_signo = SIGFPE; info.si_errno = 0; - info.si_code = __SI_FAULT; info.si_addr = ip; /* * (~cwd & swd) will mask out exceptions that are not set to unmasked @@ -689,34 +688,31 @@ void math_error(void __user *ip) */ cwd = get_fpu_cwd(task); swd = get_fpu_swd(task); - switch (swd & ~cwd & 0x3f) { - case 0x000: /* No unmasked exception */ -#ifdef CONFIG_X86_32 + + err = swd & ~cwd & 0x3f; + +#if CONFIG_X86_32 + if (!err) return; #endif - default: /* Multiple exceptions */ - break; - case 0x001: /* Invalid Op */ + + if (err & 0x001) { /* Invalid op */ /* * swd & 0x240 == 0x040: Stack Underflow * swd & 0x240 == 0x240: Stack Overflow * User must clear the SF bit (0x40) if set */ info.si_code = FPE_FLTINV; - break; - case 0x002: /* Denormalize */ - case 0x010: /* Underflow */ - info.si_code = FPE_FLTUND; - break; - case 0x004: /* Zero Divide */ + } else if (err & 0x004) { /* Divide by Zero */ info.si_code = FPE_FLTDIV; - break; - case 0x008: /* Overflow */ + } else if (err & 0x008) { /* Overflow */ info.si_code = FPE_FLTOVF; - break; - case 0x020: /* Precision */ + } else if (err & 0x012) { /* Denormal, Underflow */ + info.si_code = FPE_FLTUND; + } else if (err & 0x020) { /* Precision */ info.si_code = FPE_FLTRES; - break; + } else { + info.si_code = __SI_FAULT|SI_KERNEL; /* WTF? */ } force_sig_info(SIGFPE, &info, task); } -- cgit v1.2.3 From 1fcccb008be12ea823aaa392758e1e41fb82de9a Mon Sep 17 00:00:00 2001 From: Jaswinder Singh Date: Tue, 23 Dec 2008 21:50:11 +0530 Subject: x86: traps.c replace #if CONFIG_X86_32 with #ifdef CONFIG_X86_32 Impact: cleanup, avoid warning on X86_64 Fixes this warning on X86_64: CC arch/x86/kernel/traps.o arch/x86/kernel/traps.c:695:5: warning: "CONFIG_X86_32" is not defined Signed-off-by: Jaswinder Singh Signed-off-by: Ingo Molnar --- arch/x86/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index c320c29255c2..f37cee75ab58 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -691,7 +691,7 @@ void math_error(void __user *ip) err = swd & ~cwd & 0x3f; -#if CONFIG_X86_32 +#ifdef CONFIG_X86_32 if (!err) return; #endif -- cgit v1.2.3 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') diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index f37cee75ab58..f5a640ba04bc 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