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98265c17ef
linux/arch/x86/kernel
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Yu-cheng Yu 98265c17ef x86/fpu/xstate: Preserve supervisor states for the slow path in __fpu__restore_sig() 
The signal return code is responsible for taking an XSAVE buffer
present in user memory and loading it into the hardware registers. This
operation only affects user XSAVE state and never affects supervisor
state.

The fast path through this code simply points XRSTOR directly at the
user buffer. However, since user memory is not guaranteed to be always
mapped, this XRSTOR can fail. If it fails, the signal return code falls
back to a slow path which can tolerate page faults.

That slow path copies the xfeatures one by one out of the user buffer
into the task's fpu state area. However, by being in a context where it
can handle page faults, the code can also schedule.

The lazy-fpu-load code would think it has an up-to-date fpstate and
would fail to save the supervisor state when scheduling the task out.
When scheduling back in, it would likely restore stale supervisor state.

To fix that, preserve supervisor state before the slow path.  Modify
copy_user_to_fpregs_zeroing() so that if it fails, fpregs are not zeroed,
and there is no need for fpregs_deactivate() and supervisor states are
preserved.

Move set_thread_flag(TIF_NEED_FPU_LOAD) to the slow path.  Without doing
this, the fast path also needs supervisor states to be saved first.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200512145444.15483-10-yu-cheng.yu@intel.com
2020-05-16 12:09:11 +02:00
..
acpi ACPI, x86/boot: make acpi_nobgrt static 2020-04-08 14:32:03 +02:00
apic x86/apic: Move TSC deadline timer debug printk 2020-05-01 19:15:41 +02:00
cpu A set of fixes for x86 and objtool: 2020-04-19 11:58:32 -07:00
fpu x86/fpu/xstate: Preserve supervisor states for the slow path in __fpu__restore_sig() 2020-05-16 12:09:11 +02:00
kprobes x86/optprobe: Fix OPTPROBE vs UACCESS 2020-03-20 13:06:22 +01:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
alternative.c x86/alternatives: Mark text_poke_loc_init() static 2020-03-25 12:42:35 +01:00
amd_gart_64.c x86/mm: thread pgprot_t through init_memory_mapping() 2020-04-10 15:36:21 -07:00
amd_nb.c x86/amd_nb, char/amd64-agp: Use amd_nb_num() accessor 2020-03-17 10:25:58 +01:00
apb_timer.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
aperture_64.c x86/gart: Exclude GART aperture from kcore 2019-03-23 12:11:49 +01:00
apm_32.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 118 2019-05-24 17:39:02 +02:00
asm-offsets_32.c x86 entry code updates: 2020-03-30 19:14:28 -07:00
asm-offsets_64.c x86/entry: Move max syscall number calculation to syscallhdr.sh 2020-03-21 16:03:21 +01:00
asm-offsets.c efi/x86: Avoid using code32_start 2020-03-08 09:58:17 +01:00
audit_64.c
bootflag.c
check.c
cpuid.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 142 2019-05-30 11:25:17 -07:00
crash_core_32.c x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y 2019-12-23 12:58:41 +01:00
crash_core_64.c x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y 2019-12-23 12:58:41 +01:00
crash_dump_32.c
crash_dump_64.c fs/core/vmcore: Move sev_active() reference to x86 arch code 2019-08-09 22:52:10 +10:00
crash.c x86/crash: Use resource_size() 2020-01-09 14:40:03 +01:00
devicetree.c
doublefault_32.c x86/doublefault/32: Rewrite the x86_32 #DF handler and unify with 64-bit 2019-11-26 22:00:04 +01:00
dumpstack_32.c x86/doublefault/32: Move #DF stack and TSS to cpu_entry_area 2019-11-26 21:53:34 +01:00
dumpstack_64.c x86/unwind: Prevent false warnings for non-current tasks 2020-04-25 12:22:28 +02:00
dumpstack.c x86/kasan: Print original address on #GP 2019-12-31 13:15:38 +01:00
e820.c ACPI updates for 5.5-rc1 2019-11-26 19:25:25 -08:00
early_printk.c efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation 2019-02-04 08:27:30 +01:00
early-quirks.c x86/intel: Disable HPET on Intel Ice Lake platforms 2019-11-29 12:17:58 +01:00
ebda.c
eisa.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 243 2019-06-19 17:09:07 +02:00
espfix_64.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
ftrace_32.S x86/ftrace: Get rid of function_hook 2019-10-25 10:52:22 +02:00
ftrace_64.S New tracing features: 2019-11-27 11:42:01 -08:00
ftrace.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 09:44:15 -08:00
head32.c
head64.c x86/boot/64: Make level2_kernel_pgt pages invalid outside kernel area 2019-10-11 18:38:15 +02:00
head_32.S x86/boot: Remove KEEP_SEGMENTS support 2020-02-22 23:37:37 +01:00
head_64.S x86/asm/64: Change all ENTRY+END to SYM_CODE_* 2019-10-18 11:58:26 +02:00
hpet.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
hw_breakpoint.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
i8237.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
i8253.c x86/timer: Skip PIT initialization on modern chipsets 2019-06-29 11:35:35 +02:00
i8259.c
idt.c Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 11:22:57 -07:00
ima_arch.c EFI updates for v5.7: 2020-02-26 15:21:22 +01:00
io_delay.c x86/io_delay: Define IO_DELAY macros in C instead of Kconfig 2019-05-24 08:46:06 +02:00
ioport.c x86/iopl: Include prototype header for ksys_ioperm() 2020-02-17 16:36:53 +01:00
irq_32.c x86/irq: Move IS_ERR_OR_NULL() check into common do_IRQ() code 2019-08-19 23:19:06 +02:00
irq_64.c x86/irq: Move IS_ERR_OR_NULL() check into common do_IRQ() code 2019-08-19 23:19:06 +02:00
irq_work.c
irq.c x86/irq: Remove useless return value from do_IRQ() 2020-02-27 14:48:40 +01:00
irqflags.S x86/asm: Change all ENTRY+ENDPROC to SYM_FUNC_* 2019-10-18 11:58:33 +02:00
irqinit.c x86: Replace setup_irq() by request_irq() 2020-03-21 15:15:47 +01:00
itmt.c proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
jailhouse.c x86/jailhouse: Only enable platform UARTs if available 2019-10-10 15:43:59 +02:00
jump_label.c x86/jump_label: Move 'inline' keyword placement 2020-03-27 11:05:41 +01:00
kdebugfs.c x86/boot: Introduce setup_indirect 2019-11-12 16:21:15 +01:00
kexec-bzimage64.c efi/x86: Make fw_vendor, config_table and runtime sysfs nodes x86 specific 2020-02-23 21:59:42 +01:00
kgdb.c x86/apic: Provide and use helper for send_IPI_allbutself() 2019-07-25 16:12:00 +02:00
ksysfs.c x86/boot: Introduce setup_indirect 2019-11-12 16:21:15 +01:00
kvm.c KVM: Pre-allocate 1 cpumask variable per cpu for both pv tlb and pv ipis 2020-02-28 10:34:25 +01:00
kvmclock.c x86/vdso: Use generic VDSO clock mode storage 2020-02-17 14:40:23 +01:00
ldt.c x86: Remove unneeded includes 2020-03-21 16:03:25 +01:00
livepatch.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
machine_kexec_32.c x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y 2019-12-23 12:58:41 +01:00
machine_kexec_64.c x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y 2019-12-23 12:58:41 +01:00
Makefile Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2020-04-02 14:49:46 -07:00
mmconf-fam10h_64.c
module.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
mpparse.c x86/boot: Fix memory leak in default_get_smp_config() 2019-07-16 23:13:48 +02:00
msr.c x86/msr: Restrict MSR access when the kernel is locked down 2019-08-19 21:54:16 -07:00
nmi_selftest.c
nmi.c x86: Fix a handful of typos 2020-02-16 20:58:06 +01:00
paravirt_patch.c x86/paravirt: Standardize 'insn_buff' variable names 2019-04-29 16:05:49 +02:00
paravirt-spinlocks.c
paravirt.c x86/ioperm: Add new paravirt function update_io_bitmap() 2020-02-29 12:43:09 +01:00
pci-dma.c dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
pci-iommu_table.c
pci-swiotlb.c dma-mapping: fix filename references 2019-09-03 08:36:30 +02:00
pcspeaker.c
perf_regs.c perf/x86/regs: Check reserved bits 2019-06-24 19:19:24 +02:00
platform-quirks.c
pmem.c
probe_roms.c
process_32.c x86: Remove unneeded includes 2020-03-21 16:03:25 +01:00
process_64.c x86: Remove unneeded includes 2020-03-21 16:03:25 +01:00
process.c x86/fpu/xstate: Define new functions for clearing fpregs and xstates 2020-05-13 13:41:50 +02:00
process.h x86: Use the correct SPDX License Identifier in headers 2019-10-01 20:31:35 +02:00
ptrace.c x86/ptrace: Document FSBASE and GSBASE ABI oddities 2019-11-26 22:00:12 +01:00
pvclock.c x86/vdso: Use generic VDSO clock mode storage 2020-02-17 14:40:23 +01:00
quirks.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
reboot_fixups_32.c
reboot.c x86: Fix a handful of typos 2020-02-16 20:58:06 +01:00
relocate_kernel_32.S x86/asm: Annotate relocate_kernel_{32,64}.c 2019-10-18 09:53:19 +02:00
relocate_kernel_64.S x86/kexec: Make relocate_kernel_64.S objtool clean 2020-03-25 18:28:28 +01:00
resource.c
rtc.c
setup_percpu.c x86: Use pr_warn instead of pr_warning 2019-10-18 15:00:18 +02:00
setup.c mm: hugetlb: optionally allocate gigantic hugepages using cma 2020-04-10 15:36:21 -07:00
signal_compat.c
signal.c x86/fpu/xstate: Define new functions for clearing fpregs and xstates 2020-05-13 13:41:50 +02:00
smp.c x86/smp: Move smp_function_call implementations into IPI code 2019-07-25 16:12:01 +02:00
smpboot.c x86, sched: Move check for CPU type to caller function 2020-04-22 23:10:13 +02:00
stacktrace.c x86 user stack frame reads: switch to explicit __get_user() 2020-02-15 17:26:26 -05:00
step.c
sys_ia32.c x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments 2020-03-21 16:03:24 +01:00
sys_x86_64.c x86: Remove unneeded includes 2020-03-21 16:03:25 +01:00
sysfb_efi.c x86/sysfb_efi: Add quirks for some devices with swapped width and height 2019-07-22 10:47:11 +02:00
sysfb_simplefb.c x86/sysfb: Fix check for bad VRAM size 2020-01-20 10:57:53 +01:00
sysfb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tboot.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
time.c Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-31 11:04:05 -07:00
tls.c x86/tls: Fix possible spectre-v1 in do_get_thread_area() 2019-06-27 23:48:04 +02:00
tls.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
topology.c x86/smp: Replace cpu_up/down() with add/remove_cpu() 2020-03-25 12:59:35 +01:00
trace_clock.c
tracepoint.c
traps.c Support for "split lock" detection: 2020-03-30 19:35:52 -07:00
tsc_msr.c x86 timer updates: 2020-03-30 19:55:39 -07:00
tsc_sync.c x86: Fix a handful of typos 2020-02-16 20:58:06 +01:00
tsc.c Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-31 11:04:05 -07:00
umip.c x86/umip: Make umip_insns static 2020-04-15 11:13:12 +02:00
unwind_frame.c x86/unwind: Prevent false warnings for non-current tasks 2020-04-25 12:22:28 +02:00
unwind_guess.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
unwind_orc.c x86/unwind/orc: Move ORC sorting variables under !CONFIG_MODULES 2020-05-03 13:23:28 +02:00
uprobes.c x86/apic, x86/uprobes: Correct parameter names in kernel-doc comments 2019-10-27 09:00:28 +01:00
verify_cpu.S x86/asm: Annotate local pseudo-functions 2019-10-18 10:04:04 +02:00
vm86_32.c x86: switch save_v86_state() to unsafe_put_user() 2020-03-18 20:36:01 -04:00
vmlinux.lds.S Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-31 10:51:12 -07:00
vsmp_64.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 346 2019-06-05 17:37:08 +02:00
x86_init.c A set of fixes for X86: 2020-02-09 12:11:12 -08:00