linux/arch/x86/kernel
Sebastian Andrzej Siewior bbc55341b9 x86/fpu: Deactivate FPU state after failure during state load
In __fpu__restore_sig(), fpu_fpregs_owner_ctx needs to be reset if the
FPU state was not fully restored. Otherwise the following may happen (on
the same CPU):

  Task A                     Task B               fpu_fpregs_owner_ctx
  *active*                                        A.fpu
  __fpu__restore_sig()
                             ctx switch           load B.fpu
                             *active*             B.fpu
  fpregs_lock()
  copy_user_to_fpregs_zeroing()
    copy_kernel_to_xregs() *modify*
    copy_user_to_xregs() *fails*
  fpregs_unlock()
                            ctx switch            skip loading B.fpu,
                            *active*              B.fpu

In the success case, fpu_fpregs_owner_ctx is set to the current task.

In the failure case, the FPU state might have been modified by loading
the init state.

In this case, fpu_fpregs_owner_ctx needs to be reset in order to ensure
that the FPU state of the following task is loaded from saved state (and
not skipped because it was the previous state).

Reset fpu_fpregs_owner_ctx after a failure during restore occurred, to
ensure that the FPU state for the next task is always loaded.

The problem was debugged-by Yu-cheng Yu <yu-cheng.yu@intel.com>.

 [ bp: Massage commit message. ]

Fixes: 5f409e20b7 ("x86/fpu: Defer FPU state load until return to userspace")
Reported-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191220195906.plk6kpmsrikvbcfn@linutronix.de
2020-01-07 13:44:42 +01:00
..
acpi x86/asm/32: Add ENDs to some functions and relabel with SYM_CODE_* 2019-10-18 11:58:33 +02:00
apic Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 09:52:37 -08:00
cpu x86/mce: Fix possibly incorrect severity calculation on AMD 2019-12-17 09:39:53 +01:00
fpu x86/fpu: Deactivate FPU state after failure during state load 2020-01-07 13:44:42 +01:00
kprobes Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 15:04:47 -08:00
.gitignore
alternative.c x86/alternatives: Teach text_poke_bp() to emulate instructions 2019-11-15 14:07:01 -08:00
amd_gart_64.c dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
amd_nb.c x86/amd_nb: Add PCI device IDs for family 17h, model 70h 2019-09-03 12:47:17 -07:00
apb_timer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
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
asm-offsets_64.c Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-09-17 12:04:39 -07:00
asm-offsets.c x86/paravirt: Make read_cr2() CALLEE_SAVE 2019-07-17 23:17:37 +02:00
audit_64.c
bootflag.c
check.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
cpuid.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 142 2019-05-30 11:25:17 -07:00
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: Align function arguments on opening braces 2019-11-14 18:24:55 +01:00
devicetree.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
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/dumpstack/64: Don't evaluate exception stacks before setup 2019-11-05 00:51:35 +01:00
dumpstack.c x86/dumpstack: Indicate PREEMPT_RT in dumps 2019-07-31 19:03:36 +02:00
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 ftrace: Fix function_graph tracer interaction with BPF trampoline 2019-12-10 13:53:59 -05:00
head32.c x86/boot: Mostly revert commit ae7e1238e6 ("Add ACPI RSDP address to setup_header") 2018-11-20 09:43:10 +01:00
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 Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 10:42:40 -08:00
head_64.S x86/asm/64: Change all ENTRY+END to SYM_CODE_* 2019-10-18 11:58:26 +02:00
hpet.c x86/hpet: Undo the early counter is counting check 2019-07-25 12:21:32 +02:00
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 Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
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/ioperm: Extend IOPL config to control ioperm() as well 2019-11-16 11:24:06 +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: Check for VECTOR_UNUSED directly 2019-08-19 23:19:07 +02:00
irqflags.S x86/asm: Change all ENTRY+ENDPROC to SYM_FUNC_* 2019-10-18 11:58:33 +02:00
irqinit.c x86/irq/32: Handle irq stack allocation failure proper 2019-04-17 15:31:42 +02:00
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/alternatives: Teach text_poke_bp() to emulate instructions 2019-11-15 14:07:01 -08:00
kdebugfs.c x86/boot: Introduce setup_indirect 2019-11-12 16:21:15 +01:00
kexec-bzimage64.c Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
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 x86/kvm: Fix -Wmissing-prototypes warnings 2019-10-25 14:01:14 +02:00
kvmclock.c x86: kvmguest: use TSC clocksource if invariant TSC is exposed 2019-02-20 22:48:52 +01:00
ldt.c x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has() 2019-04-08 12:13:34 +02:00
livepatch.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
machine_kexec_32.c x86/mm: Remove set_pages_x() and set_pages_nx() 2019-09-03 09:26:37 +02:00
machine_kexec_64.c x86/kdump: Remove the backup region handling 2019-11-14 18:24:43 +01:00
Makefile x86/doublefault/32: Rename doublefault.c to doublefault_32.c 2019-11-26 21:53:34 +01:00
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/hotplug: Silence APIC and NMI when CPU is dead 2019-07-25 16:11:59 +02:00
paravirt_patch.c x86/paravirt: Standardize 'insn_buff' variable names 2019-04-29 16:05:49 +02:00
paravirt-spinlocks.c
paravirt.c x86/iopl: Remove legacy IOPL option 2019-11-16 11:24:05 +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/iopl: Remove legacy IOPL option 2019-11-16 11:24:05 +01:00
process_64.c x86/iopl: Remove legacy IOPL option 2019-11-16 11:24:05 +01:00
process.c x86/ioperm: Save an indentation level in tss_update_io_bitmap() 2019-11-30 18:06:56 +01:00
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: Switch to generic vDSO implementation 2019-06-22 21:21:10 +02:00
quirks.c x86/PCI: Remove superfluous returns from void functions 2019-08-20 09:54:36 +02:00
reboot_fixups_32.c
reboot.c x86/apic: Provide and use helper for send_IPI_allbutself() 2019-07-25 16:12:00 +02:00
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/asm: Annotate relocate_kernel_{32,64}.c 2019-10-18 09:53:19 +02:00
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 ACPI updates for 5.5-rc1 2019-11-26 19:25:25 -08:00
signal_compat.c
signal.c x86: use static_cpu_has in uaccess region to avoid instrumentation 2019-07-12 11:05:42 -07:00
smp.c x86/smp: Move smp_function_call implementations into IPI code 2019-07-25 16:12:01 +02:00
smpboot.c Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-09-17 12:04:39 -07:00
stacktrace.c x86/stacktrace: Prevent access_ok() warnings in arch_stack_walk_user() 2019-07-22 10:42:36 +02:00
step.c
sys_x86_64.c
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 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sysfb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tboot.c x86: Use pr_warn instead of pr_warning 2019-10-18 15:00:18 +02:00
time.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 16:59:34 -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/topology: Make DEBUG_HOTPLUG_CPU0 pr_info() more descriptive 2019-04-19 19:42:57 +02:00
trace_clock.c
tracepoint.c x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
traps.c x86/traps: die() instead of panicking on a double fault 2019-11-26 22:00:12 +01:00
tsc_msr.c x86/cpu: Update init data for new Airmont CPU model 2019-09-06 07:30:40 +02:00
tsc_sync.c x86: Use pr_warn instead of pr_warning 2019-10-18 15:00:18 +02:00
tsc.c x86/tsc: Respect tsc command line paraemeter for clocksource_tsc_early 2019-11-05 01:24:56 +01:00
umip.c Merge branches 'x86-cpu-for-linus' and 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 08:58:08 -08:00
unwind_frame.c x86/stackframe/32: Provide consistent pt_regs 2019-06-25 10:23:47 +02:00
unwind_guess.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
unwind_orc.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 16:59:34 -07:00
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 signal: Remove task parameter from force_sig 2019-05-27 09:36:28 -05:00
vmlinux.lds.S x86/vmlinux: Use INT3 instead of NOP for linker fill bytes 2019-11-04 19:10:08 +01:00
vsmp_64.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 346 2019-06-05 17:37:08 +02:00
x86_init.c x86/init: Allow DT configured systems to disable RTC at boot time 2019-11-12 15:46:53 +01:00