WSL2-Linux-Kernel/arch/x86/kernel
yu-cheng yu 394db20ca2 x86/fpu: Disable AVX when eagerfpu is off
When "eagerfpu=off" is given as a command-line input, the kernel
should disable AVX support.

The Task Switched bit used for lazy context switching does not
support AVX. If AVX is enabled without eagerfpu context
switching, one task's AVX state could become corrupted or leak
to other tasks. This is a bug and has bad security implications.

This only affects systems that have AVX/AVX2/AVX512 and this
issue will be found only when one actually uses AVX/AVX2/AVX512
_AND_ does eagerfpu=off.

Reference: Intel Software Developer's Manual Vol. 3A

Sec. 2.5 Control Registers:
TS Task Switched bit (bit 3 of CR0) -- Allows the saving of the
x87 FPU/ MMX/SSE/SSE2/SSE3/SSSE3/SSE4 context on a task switch
to be delayed until an x87 FPU/MMX/SSE/SSE2/SSE3/SSSE3/SSE4
instruction is actually executed by the new task.

Sec. 13.4.1 Using the TS Flag to Control the Saving of the X87
FPU and SSE State
When the TS flag is set, the processor monitors the instruction
stream for x87 FPU, MMX, SSE instructions. When the processor
detects one of these instructions, it raises a
device-not-available exeception (#NM) prior to executing the
instruction.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: yu-cheng yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/1452119094-7252-5-git-send-email-yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-12 11:51:21 +01:00
..
acpi x86, ACPI: Handle apic/x2apic entries in MADT in correct order 2015-10-15 01:31:06 +02:00
apic Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-01-11 15:37:06 -08:00
cpu Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-01-11 17:16:01 -08:00
fpu x86/fpu: Disable AVX when eagerfpu is off 2016-01-12 11:51:21 +01:00
kprobes Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-14 14:37:47 -07:00
.gitignore
Makefile kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
alternative.c x86/alternatives: Make optimize_nops() interrupt safe and synced 2015-09-03 21:27:47 +02:00
amd_gart_64.c
amd_nb.c x86/gart: Check for GART support before accessing GART registers 2015-05-06 11:15:53 +02:00
apb_timer.c x86/asm/tsc: Rename native_read_tsc() to rdtsc() 2015-07-06 15:23:28 +02:00
aperture_64.c x86/gart: Check for GART support before accessing GART registers 2015-05-06 11:15:53 +02:00
apm_32.c apm32: Fix cputime == jiffies assumption 2015-07-29 15:44:58 +02:00
asm-offsets.c x86/paravirt: Remove the unused irq_enable_sysexit pv op 2015-11-23 10:48:16 +01:00
asm-offsets_32.c x86: Remove unused TI_cpu 2015-05-05 20:48:02 +02:00
asm-offsets_64.c x86/entry, x86/paravirt: Remove the unused usergs_sysret32 PV op 2015-11-23 10:48:16 +01:00
audit_64.c x86: hook up execveat system call 2014-12-13 12:42:51 -08:00
bootflag.c x86: don't use module_init for non-modular core bootflag code 2015-06-16 14:12:34 -04:00
check.c Linux 4.2-rc8 2015-08-25 09:59:19 +02:00
cpuid.c x86: Drop bogus __ref / __refdata annotations 2015-07-20 18:57:20 +02:00
crash.c perf, x86: Stop Intel PT before kdump starts 2015-11-23 09:58:26 +01:00
crash_dump_32.c
crash_dump_64.c
devicetree.c Replace module_init with equivalent device_initcall in non modules. 2015-07-02 10:30:48 -07:00
doublefault.c
dumpstack.c Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-13 13:23:34 -07:00
dumpstack_32.c Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-13 13:23:34 -07:00
dumpstack_64.c x86/kernel: Use kstack_end() in dumpstack_64.c 2015-02-23 18:37:13 +01:00
e820.c x86/e820: Deinline e820_type_to_string, save 126 bytes 2015-09-30 21:54:40 +02:00
early-quirks.c timers/x86/hpet: Type adjustments 2015-10-21 11:17:32 +02:00
early_printk.c x86/early_printk: Set __iomem address space for IO 2015-10-13 21:45:56 +02:00
espfix_64.c Merge branch 'x86/urgent' into x86/asm, before applying dependent patches 2015-07-31 10:23:35 +02:00
ftrace.c ftrace: Calculate the correct dyn_ftrace number to report to the userspace 2015-10-22 15:44:24 -04:00
head.c
head32.c x86: Store a per-cpu shadow copy of CR4 2015-02-04 12:10:42 +01:00
head64.c x86/kasan: Fix KASAN shadow region page tables 2015-07-06 14:53:13 +02:00
head_32.S x86/microcode: Merge the early microcode loader 2015-10-21 11:22:12 +02:00
head_64.S x86/cpu: Call verify_cpu() after having entered long mode too 2015-11-07 10:45:02 +01:00
hpet.c timers/x86/hpet: Type adjustments 2015-10-21 11:17:32 +02:00
hw_breakpoint.c x86/cpufeature: Remove unused and seldomly used cpu_has_xx macros 2015-12-19 11:49:55 +01:00
i386_ksyms_32.c preempt: Use preempt_schedule_context() as the official tracing preemption point 2015-06-07 15:57:42 +02:00
i8237.c
i8253.c clockevents/drivers/i8253: Migrate to new 'set-state' interface 2015-08-10 11:40:30 +02:00
i8259.c x86/irq: Probe for PIC presence before allocating descs for legacy IRQs 2015-11-07 10:37:37 +01:00
io_delay.c
ioport.c x86/asm/entry: Rename 'init_tss' to 'cpu_tss' 2015-03-06 08:32:58 +01:00
irq.c Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 15:20:51 -07:00
irq_32.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
irq_64.c x86/irq: Drop unlikely before IS_ERR_OR_NULL 2015-10-01 11:08:56 +02:00
irq_work.c treewide: Remove old email address 2015-11-23 09:44:58 +01:00
irqinit.c x86/irq: Store irq descriptor in vector array 2015-08-06 00:14:59 +02:00
jump_label.c jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP} 2015-08-03 11:34:12 +02:00
kdebugfs.c
kexec-bzimage64.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2015-09-08 12:41:25 -07:00
kgdb.c x86/kgdb: Replace bool_int_array[NR_CPUS] with bitmap 2015-09-28 10:13:31 +02:00
ksysfs.c
kvm.c The bulk of the changes here is for x86. And for once it's not 2015-06-24 09:36:49 -07:00
kvmclock.c x86/vdso: Remove pvclock fixmap machinery 2015-12-11 08:56:03 +01:00
ldt.c x86/ldt: Fix small LDT allocation for Xen 2015-09-14 12:10:50 +02:00
livepatch.c livepatch: Fix crash with !CONFIG_DEBUG_SET_MODULE_RONX 2015-11-06 11:10:03 +01:00
machine_kexec_32.c x86, irq: Move IOAPIC related declarations from hw_irq.h into io_apic.h 2014-12-16 14:08:17 +01:00
machine_kexec_64.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching 2015-06-23 14:07:26 -07:00
mcount_64.S x86/ftrace: Add comment on static function tracing 2015-11-19 11:07:49 +01:00
mmconf-fam10h_64.c
module.c x86/mm/KASLR: Propagate KASLR status to kernel proper 2015-04-03 15:26:15 +02:00
mpparse.c x86: Cleanup irq_domain ops 2015-04-24 15:36:55 +02:00
msr.c
nmi.c x86/nmi: Save regs in crash dump on external NMI 2015-12-19 11:07:01 +01:00
nmi_selftest.c
paravirt-spinlocks.c locking/pvqspinlock: Rename QUEUED_SPINLOCK to QUEUED_SPINLOCKS 2015-05-11 09:52:09 +02:00
paravirt.c Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-01-11 16:26:03 -08:00
paravirt_patch_32.c x86/paravirt: Remove the unused irq_enable_sysexit pv op 2015-11-23 10:48:16 +01:00
paravirt_patch_64.c x86/entry, x86/paravirt: Remove the unused usergs_sysret32 PV op 2015-11-23 10:48:16 +01:00
pci-calgary_64.c x86/platform/calgary: Constify cal_chipset_ops structures 2015-11-29 08:50:58 +01:00
pci-dma.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
pci-iommu_table.c
pci-nommu.c
pci-swiotlb.c x86/mm/64: Enable SWIOTLB if system has SRAT memory regions above MAX_DMA32_PFN 2015-12-06 12:46:31 +01:00
pcspeaker.c
perf_regs.c perf/x86/64: Report regs_user->ax too in get_regs_user() 2015-04-11 13:08:53 +02:00
pmem.c libnvdimm, e820: skip module loading when no type-12 2015-11-30 09:10:33 -08:00
probe_roms.c
process.c x86/vm86: Set thread.vm86 to NULL on fork/clone 2015-10-31 09:50:25 +01:00
process_32.c sched/core, sched/x86: Kill thread_info::saved_preempt_count 2015-10-06 17:08:18 +02:00
process_64.c x86/LDT: Print the real LDT base address 2015-12-29 12:34:38 +01:00
ptrace.c arch/x86/kernel/ptrace.c: Remove unused arg_offs_table 2015-12-29 11:35:34 +01:00
pvclock.c x86/vdso: Remove pvclock fixmap machinery 2015-12-11 08:56:03 +01:00
quirks.c timers/x86/hpet: Type adjustments 2015-10-21 11:17:32 +02:00
reboot.c x86/nmi: Save regs in crash dump on external NMI 2015-12-19 11:07:01 +01:00
reboot_fixups_32.c
relocate_kernel_32.S x86/asm: Optimize unnecessarily wide TEST instructions 2015-03-07 11:12:43 +01:00
relocate_kernel_64.S x86/asm: Replace "MOVQ $imm, %reg" with MOVL 2015-04-01 13:17:39 +02:00
resource.c
rtc.c x86/paravirt: Prevent rtc_cmos platform device init on PV guests 2015-12-19 21:35:13 +01:00
setup.c Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-01-11 17:16:01 -08:00
setup_percpu.c
signal.c x86/signal: Fix restart_syscall number for x32 tasks 2015-12-05 18:52:14 +01:00
signal_compat.c x86/compat: Move copy_siginfo_*_user32() to signal_compat.c 2015-07-06 15:28:55 +02:00
smp.c x86/smp: Remove single IPI wrapper 2015-11-05 13:07:54 +01:00
smpboot.c x86/cpufeature: Remove unused and seldomly used cpu_has_xx macros 2015-12-19 11:49:55 +01:00
stacktrace.c
step.c Merge branch 'x86/urgent' into x86/asm to fix up conflicts and to pick up fixes 2015-08-18 09:39:47 +02:00
sys_x86_64.c x86/mm: Improve AMD Bulldozer ASLR workaround 2015-03-31 10:01:17 +02:00
sysfb.c
sysfb_efi.c
sysfb_simplefb.c
tboot.c
tce_64.c
test_nx.c
test_rodata.c treewide: Fix typo in printk messages 2015-03-06 23:05:39 +01:00
time.c x86/asm/entry: Change all 'user_mode_vm()' calls to 'user_mode()' 2015-03-23 11:14:17 +01:00
tls.c x86, tls: Interpret an all-zero struct user_desc as "no segment" 2015-01-22 21:45:07 +01:00
tls.h
topology.c x86: Drop bogus __ref / __refdata annotations 2015-07-20 18:57:20 +02:00
trace_clock.c x86/asm/tsc: Add rdtsc_ordered() and use it in trivial call sites 2015-07-06 15:23:29 +02:00
tracepoint.c
traps.c x86/fpu/mpx: Rework MPX 'xstate' types 2015-09-14 12:22:00 +02:00
tsc.c x86/tsc: Remove unused tsc_pre_init() hook 2015-11-19 11:03:13 +01:00
tsc_msr.c
tsc_sync.c x86/asm/tsc/sync: Use rdtsc_ordered() in check_tsc_warp() and drop extra barriers 2015-07-06 15:23:29 +02:00
uprobes.c uprobes/x86: Make arch_uretprobe_is_alive(RP_CHECK_CALL) more clever 2015-07-31 10:38:06 +02:00
verify_cpu.S x86/cpu: Call verify_cpu() after having entered long mode too 2015-11-07 10:45:02 +01:00
vm86_32.c x86/cpufeature: Remove unused and seldomly used cpu_has_xx macros 2015-12-19 11:49:55 +01:00
vmlinux.lds.S kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
vsmp_64.c x86: replace __init_or_module with __init in non-modular vsmp_64.c 2015-06-16 14:12:41 -04:00
x86_init.c x86/tsc: Remove unused tsc_pre_init() hook 2015-11-19 11:03:13 +01:00
x8664_ksyms_64.c preempt: Use preempt_schedule_context() as the official tracing preemption point 2015-06-07 15:57:42 +02:00