Suresh Siddha 870568b390 x86, fpu: fix CONFIG_PREEMPT=y corruption of application's FPU stack ... Jürgen Mell reported an FPU state corruption bug under CONFIG_PREEMPT, and bisected it to commit v2.6.19-1363-gacc2076, "i386: add sleazy FPU optimization". Add tsk_used_math() checks to prevent calling math_state_restore() which can sleep in the case of !tsk_used_math(). This prevents making a blocking call in __switch_to(). Apparently "fpu_counter > 5" check is not enough, as in some signal handling and fork/exec scenarios, fpu_counter > 5 and !tsk_used_math() is possible. It's a side effect though. This is the failing scenario: process 'A' in save_i387_ia32() just after clear_used_math() Got an interrupt and pre-empted out. At the next context switch to process 'A' again, kernel tries to restore the math state proactively and sees a fpu_counter > 0 and !tsk_used_math() This results in init_fpu() during the __switch_to()'s math_state_restore() And resulting in fpu corruption which will be saved/restored (save_i387_fxsave and restore_i387_fxsave) during the remaining part of the signal handling after the context switch. Bisected-by: Jürgen Mell <j.mell@t-online.de> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Jürgen Mell <j.mell@t-online.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org		2008-06-04 16:21:24 +02:00
..
acpi	x86: fix APIC warning on 32bit v2	2008-06-04 13:11:46 +02:00
cpu	[CPUFREQ] Crusoe: longrun cpufreq module reports false min freq	2008-05-19 18:17:28 -04:00
.gitignore	.gitignore update for x86 arch	2007-10-17 21:19:04 +02:00
alternative.c	x86: harden kernel code patching	2008-04-25 19:54:07 +02:00
aperture_64.c	x86: clean up aperture_64.c	2008-04-17 17:41:19 +02:00
apic_32.c	x86: cleanup div_sc() usage	2008-04-26 17:35:47 +02:00
apic_64.c	x86: don't read maxlvt before checking if APIC is mapped	2008-05-23 14:08:06 +02:00
apm_32.c	Merge branches 'release', 'acpica', 'bugzilla-10224', 'bugzilla-9772', 'bugzilla-9916', 'ec', 'eeepc', 'idle', 'misc', 'pm-legacy', 'sysfs-links-2.6.26', 'thermal', 'thinkpad' and 'video' into release	2008-04-30 13:58:00 -04:00
asm-offsets_32.c	x86: use kbuild.h	2008-04-29 08:06:29 -07:00
asm-offsets_64.c	x86: use kbuild.h	2008-04-29 08:06:29 -07:00
asm-offsets.c
audit_64.c
bootflag.c	x86: coding style cleanup for kernel/bootflag.c	2008-01-30 13:32:31 +01:00
bugs_64.c	x86: don't use large pages to map the first 2/4MB of memory	2008-04-17 17:41:30 +02:00
cpuid.c	PM: Remove destroy_suspended_device()	2008-04-19 19:10:28 -07:00
crash_dump_32.c	kmap leak fix for x86_32 kdump	2007-10-19 11:53:33 -07:00
crash_dump_64.c
crash.c	x86: allow machine_crash_shutdown to be replaced	2008-04-27 12:00:29 +03:00
doublefault_32.c	x86: unify tss_struct	2008-01-30 13:31:31 +01:00
ds.c	x86: debug Store - call kfree if only we really need it	2008-04-17 17:41:34 +02:00
e820_32.c	x86: rename find_max_pfn() to propagate_e820_map()	2008-04-19 19:19:55 +02:00
e820_64.c	bootprotocol: cleanup	2008-04-29 13:45:24 +02:00
early_printk.c	x86: coding style fixes to x86/kernel/early_printk.c	2008-04-17 17:40:51 +02:00
early-quirks.c	x86: fix section mismatch warning in early-quirks.c	2008-01-30 13:33:37 +01:00
efi_32.c	x86: sparse error in efi_32.c	2008-02-19 16:18:28 +01:00
efi_64.c	x86: EFI_PAGE_SHIFT fix	2008-04-19 19:19:54 +02:00
efi_stub_32.S
efi_stub_64.S	x86: EFI runtime service support	2008-01-30 13:31:19 +01:00
efi.c	x86: EFI_PAGE_SHIFT fix	2008-04-19 19:19:54 +02:00
entry_32.S	xen: fold xen_sysexit into xen_iret	2008-04-24 23:57:33 +02:00
entry_64.S	x86: ptrace vs -ENOSYS	2008-04-17 17:41:13 +02:00
genapic_64.c	fix: x86: support for new UV apic	2008-04-30 23:15:34 +02:00
genapic_flat_64.c	x86: use cpumask_of_cpu()	2008-04-17 17:41:36 +02:00
genx2apic_uv_x.c	x86: UV startup of slave cpus	2008-04-19 19:19:58 +02:00
geode_32.c	x86: GEODE: cache results from geode_has_vsa2() and uninline	2008-05-08 15:43:50 +02:00
head32.c	x86: introduce kernel/head32.c	2008-04-17 17:40:49 +02:00
head64.c	x86, boot: add linked list of struct setup_data	2008-04-26 21:34:42 +02:00
head_32.S	x86: fix early-BUG message	2008-04-30 23:15:34 +02:00
head_64.S	x86: move suspend wakeup code to C	2008-04-17 17:41:37 +02:00
hpet.c	hpet: fix	2008-04-30 23:15:34 +02:00
i386_ksyms_32.c	Generic semaphore implementation	2008-04-17 10:42:34 -04:00
i387.c	x86: fix broken math-emu with lazy allocation of fpu area	2008-06-04 13:11:46 +02:00
i8237.c	Driver core: change sysdev classes to use dynamic kobject names	2008-01-24 20:40:40 -08:00
i8253.c	x86: cleanup div_sc() usage	2008-04-26 17:35:47 +02:00
i8259_32.c	x86: i8259A: remove redundant irq_descinitialization	2008-02-19 16:18:34 +01:00
i8259_64.c	x86: provide a native_init_IRQ function on 64-bit	2008-01-30 13:33:19 +01:00
init_task.c	[PATCH] take init_files to fs/file.c	2008-05-16 17:22:20 -04:00
io_apic_32.c	x86: Fix 32-bit MSI-X allocation leakage	2008-04-28 10:49:17 -07:00
io_apic_64.c	x86: section mismatch fixes, #3	2008-04-26 17:35:48 +02:00
io_delay.c	x86: add dmi quirk for io_delay	2008-03-26 22:23:40 +01:00
ioport.c	x86: refactor ioport unification	2008-01-30 13:33:10 +01:00
ipi.c	x86: create ipi.c	2008-04-17 17:40:56 +02:00
irq_32.c	proper __do_softirq() prototype	2008-04-29 08:06:02 -07:00
irq_64.c	x86: rename the struct pt_regs members for 32/64-bit consistency	2008-01-30 13:30:56 +01:00
k8.c
kdebugfs.c	x86, boot: export linked list of struct setup_data via debugfs	2008-04-26 21:34:42 +02:00
kgdb.c	x86: KGDB build fix	2008-04-19 19:19:54 +02:00
kprobes.c	x86: replace most VM86 flags with flags from processor-flags.h	2008-04-17 17:41:33 +02:00
kvm.c	x86: KVM guest: hypercall batching	2008-04-27 12:00:28 +03:00
kvmclock.c	namespacecheck: automated fixes	2008-05-23 14:08:06 +02:00
ldt.c	x86: cleanup - eliminate numbers in LDT allocation code	2008-02-04 16:48:03 +01:00
machine_kexec_32.c	vmcoreinfo: fix the configuration dependencies	2008-02-07 08:42:25 -08:00
machine_kexec_64.c	vmcoreinfo: add the symbol "phys_base"	2008-04-02 15:28:19 -07:00
Makefile	pcspkr: fix dependancies	2008-05-07 12:42:03 +02:00
mca_32.c	x86: coding style fixes to arch/x86/kernel/mca_32.c	2008-04-17 17:40:49 +02:00
mfgpt_32.c	x86: geode: MSR cleanup	2008-04-28 08:58:35 -07:00
microcode.c	x86: use new set_cpus_allowed_ptr function	2008-04-19 19:44:58 +02:00
mmconf-fam10h_64.c	x86: add pci=check_enable_amd_mmconf and dmi check	2008-04-26 23:41:04 +02:00
module_32.c
module_64.c
mpparse.c	x86: es7000 build fix	2008-05-04 20:04:45 +02:00
msr.c	PM: Remove destroy_suspended_device()	2008-04-19 19:10:28 -07:00
nmi_32.c	ftrace: add notrace annotations for NMI routines	2008-04-19 19:19:55 +02:00
nmi_64.c	ftrace: add notrace annotations for NMI routines	2008-04-19 19:19:55 +02:00
numaq_32.c	x86: convert TSC disabling to generic cpuid disable bitmap	2008-01-30 13:33:20 +01:00
olpc.c	x86: olpc: add One Laptop Per Child architecture support	2008-04-29 08:06:07 -07:00
paravirt_patch_32.c	x86: move patching code to arch-specific file.	2008-01-30 13:32:10 +01:00
paravirt_patch_64.c	x86: add stringify header	2008-01-30 13:33:19 +01:00
paravirt.c	x86: add pud_alloc for 4-level pagetables	2008-04-24 23:57:31 +02:00
pci-calgary_64.c	x86: remove duplicate get_bios_ebda() from rio.h	2008-04-26 17:35:47 +02:00
pci-dma.c	x86/pci: fix broken ISA DMA	2008-05-12 21:27:50 +02:00
pci-gart_64.c	suspend-vs-iommu: prevent suspend if we could not resume	2008-06-04 13:11:47 +02:00
pci-nommu.c	x86: unify pci-nommu	2008-04-19 19:19:57 +02:00
pci-swiotlb_64.c	x86: dma-ops on highmem fix	2008-04-19 19:19:56 +02:00
pcspeaker.c
pmtimer_64.c	x86: move pmtmr related declarations	2008-01-30 13:30:18 +01:00
process_32.c	x86, fpu: fix CONFIG_PREEMPT=y corruption of application's FPU stack	2008-06-04 16:21:24 +02:00
process_64.c	x86, fpu: fix CONFIG_PREEMPT=y corruption of application's FPU stack	2008-06-04 16:21:24 +02:00
process.c	x86: disable mwait for AMD family 10H/11H CPUs	2008-05-17 22:57:20 +02:00
ptrace.c	x86: user_regset_view table fix for ia32 on 64-bit	2008-05-13 19:40:20 +02:00
quirks.c	x86: hpet clock enable quirk on nVidia nForce 430	2008-03-21 17:06:15 +01:00
reboot_fixups_32.c	x86: add the RDC machine specific reboot fixup	2008-01-30 13:33:36 +01:00
reboot.c	x86: remove dell reboot dmi quirk board name match	2008-05-04 20:04:45 +02:00
relocate_kernel_32.S	x86: relocate_kernel - use predefined macroses for page attributes	2008-04-17 17:41:29 +02:00
relocate_kernel_64.S	x86: relocate_kernel - use predefined macroses for page attributes	2008-04-17 17:41:29 +02:00
rtc.c	x86: fix cmos read and write to not use inb_p and outb_p	2008-04-17 17:40:47 +02:00
scx200_32.c	x86: fix sparse warning in kernel/scx200_32.c	2008-01-31 22:05:45 +01:00
setup64.c	x86: fix exec mappings comments	2008-04-19 19:19:55 +02:00
setup_32.c	x86: restrict keyboard io ports reservation to make ipmi driver work	2008-05-10 19:31:45 +02:00
setup_64.c	x86: early_init_centaur(): use set_cpu_cap()	2008-05-13 19:37:38 +02:00
setup.c	x86: [VOYAGER] fix duplicate phys_cpu_present_map symbol	2008-05-12 21:27:51 +02:00
sigframe.h	x86: move struct definitions to unifed sigframe.h	2008-04-17 17:40:46 +02:00
signal_32.c	signals: x86 TS_RESTORE_SIGMASK	2008-04-30 08:29:37 -07:00
signal_64.c	signals: x86 TS_RESTORE_SIGMASK	2008-04-30 08:29:37 -07:00
smp.c	x86: fix app crashes after SMP resume	2008-05-13 19:36:12 +02:00
smpboot.c	x86: disable preemption in native_smp_prepare_cpus	2008-06-04 13:11:46 +02:00
smpcommon_32.c	x86: create smpcommon.c	2008-04-17 17:40:55 +02:00
smpcommon.c	x86: create smpcommon.c	2008-04-17 17:40:55 +02:00
srat_32.c	x86: replace remaining __FUNCTION__ occurances	2008-04-17 17:40:57 +02:00
stacktrace.c	x86: don't save unreliable stack trace entries	2008-02-26 12:55:58 +01:00
step.c	x86: prevent unconditional writes to DebugCtl MSR	2008-04-17 17:40:58 +02:00
summit_32.c	x86: use get_bios_ebda()	2008-04-26 17:35:47 +02:00
sys_i386_32.c	unified (weak) sys_pipe implementation	2008-05-03 13:50:33 -07:00
sys_x86_64.c	unified (weak) sys_pipe implementation	2008-05-03 13:50:33 -07:00
syscall_64.c	x86: coding style fixes to arch/x86/kernel/syscall_64.c	2008-04-17 17:40:48 +02:00
syscall_table_32.S	timerfd: wire the new timerfd API to the x86 family	2008-02-05 09:44:07 -08:00
tce_64.c	x86: Create clflush() inline, remove hardcoded wbinvd	2007-10-17 20:16:12 +02:00
test_nx.c	x86: Explicitly include required header files.	2008-04-17 17:41:15 +02:00
test_rodata.c	x86: include proper prototypes for rodata_test	2008-02-14 23:30:20 +01:00
time_32.c	proper extern for late_time_init	2008-04-29 08:06:03 -07:00
time_64.c	time: fix typo in comments	2008-02-08 09:22:29 -08:00
tlb_32.c	x86: create tlb files	2008-04-17 17:40:56 +02:00
tlb_64.c	x86: use cpumask function for present, possible, and online cpus	2008-04-26 17:35:47 +02:00
tls.c	asmlinkage_protect replaces prevent_tail_call	2008-04-10 17:28:26 -07:00
tls.h	x86: x86 user_regset TLS	2008-01-30 13:31:52 +01:00
topology.c	x86: fix section mismatch warning in topology.c:arch_register_cpu	2008-02-19 16:18:30 +01:00
trampoline_32.S	x86: trampoline_32.S - switch to .cpuinit.data	2008-04-26 17:35:47 +02:00
trampoline_64.S	x86: move suspend wakeup code to C	2008-04-17 17:41:37 +02:00
trampoline.c	x86: standalone trampoline code	2008-04-17 17:41:37 +02:00
traps_32.c	i386: fix signal type for iret exception	2008-04-26 17:35:46 +02:00
traps_64.c	x86, fpu: lazy allocation of FPU area - v5	2008-04-19 19:19:55 +02:00
tsc_32.c	x86: disable TSC for sched_clock() when calibration failed	2008-05-23 14:08:06 +02:00
tsc_64.c	x86: fix setup of cyc2ns in tsc_64.c	2008-05-23 14:08:06 +02:00
tsc_sync.c	x86: add warning to check_tsc_warp()	2008-01-30 13:33:24 +01:00
verify_cpu_64.S
vm86_32.c	x86: replace most VM86 flags with flags from processor-flags.h	2008-04-17 17:41:33 +02:00
vmi_32.c	x86: unify KERNEL_PGD_PTRS	2008-04-24 23:57:31 +02:00
vmiclock_32.c	x86: isolate PIC/PIT in/out calls	2008-01-30 13:33:14 +01:00
vmlinux_32.lds.S	x86: use ELF section to list CPU vendor specific code	2008-04-17 17:40:47 +02:00
vmlinux_64.lds.S	x86_64 vDSO: use initdata	2008-04-28 13:49:35 -07:00
vmlinux.lds.S
vsmp_64.c	x86: fix warning in "x86: clean up vSMP detection"	2008-04-29 13:45:24 +02:00
vsyscall_64.c	"make namespacecheck" fixes	2008-04-24 23:15:44 +02:00
x8664_ksyms_64.c	x86: fix csum_partial() export	2008-05-13 19:38:47 +02:00