linux/arch/x86/kernel
Dave Hansen 9782a712eb x86/fpu: Add PKRU storage outside of task XSAVE buffer
PKRU is currently partly XSAVE-managed and partly not. It has space
in the task XSAVE buffer and is context-switched by XSAVE/XRSTOR.
However, it is switched more eagerly than FPU because there may be a
need for PKRU to be up-to-date for things like copy_to/from_user() since
PKRU affects user-permission memory accesses, not just accesses from
userspace itself.

This leaves PKRU in a very odd position. XSAVE brings very little value
to the table for how Linux uses PKRU except for signal related XSTATE
handling.

Prepare to move PKRU away from being XSAVE-managed. Allocate space in
the thread_struct for it and save/restore it in the context-switch path
separately from the XSAVE-managed features. task->thread_struct.pkru
is only valid when the task is scheduled out. For the current task the
authoritative source is the hardware, i.e. it has to be retrieved via
rdpkru().

Leave the XSAVE code in place for now to ensure bisectability.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210623121456.399107624@linutronix.de
2021-06-23 19:37:45 +02:00
..
acpi Trivial cleanups and fixes all over the place. 2021-04-26 09:25:47 -07:00
apic x86/apic: Mark _all_ legacy interrupts when IO/APIC is missing 2021-05-29 11:41:14 +02:00
cpu x86/cpu: Write the default PKRU value when enabling PKE 2021-06-23 19:14:54 +02:00
fpu x86/fpu: Dont restore PKRU in fpregs_restore_userspace() 2021-06-23 19:33:32 +02:00
kprobes - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
.gitignore
alternative.c x86/alternative: Optimize single-byte NOPs at an arbitrary position 2021-06-03 16:33:09 +02:00
amd_gart_64.c dma-mapping: split <linux/dma-mapping.h> 2020-10-06 07:07:03 +02:00
amd_nb.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
aperture_64.c
apm_32.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
asm-offsets.c x86/paravirt: Switch iret pvops to ALTERNATIVE 2021-03-11 19:58:54 +01:00
asm-offsets_32.c x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
asm-offsets_64.c x86/xen: Drop USERGS_SYSRET64 paravirt call 2021-02-10 12:32:07 +01:00
audit_64.c
bootflag.c
check.c
cpuid.c smp: Cleanup smp_call_function*() 2020-11-24 16:47:49 +01:00
crash.c Devicetree updates for v5.13: 2021-04-28 15:50:24 -07:00
crash_core_32.c
crash_core_64.c
crash_dump_32.c x86/crashdump/32: Simplify copy_oldmem_page() 2020-11-24 14:42:09 +01:00
crash_dump_64.c
devicetree.c x86/devicetree: Fix the ioapic interrupt type table 2020-10-28 20:26:24 +01:00
doublefault_32.c x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
dumpstack.c - Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in the end 2020-12-14 13:45:26 -08:00
dumpstack_32.c
dumpstack_64.c x86/irq/64: Adjust the per CPU irq stack pointer by 8 2021-02-10 23:34:14 +01:00
e820.c Power management updates for 5.13-rc1 2021-04-26 15:10:25 -07:00
early-quirks.c x86/gpu: Add Alderlake-S stolen memory support 2021-01-26 06:55:09 -08:00
early_printk.c
ebda.c
eisa.c
espfix_64.c
ftrace.c x86: Remove dynamic NOP selection 2021-03-15 16:24:59 +01:00
ftrace_32.S
ftrace_64.S x86/ftrace: Support objtool vmlinux.o validation in ftrace_64.S 2021-01-26 11:33:02 -06:00
head32.c
head64.c x86/sev-es: Rename sev-es.{ch} to sev.{ch} 2021-05-10 07:40:27 +02:00
head_32.S x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
head_64.S - Fix the vmlinux size check on 64-bit along with adding useful clarifications on the topic 2020-12-14 13:54:50 -08:00
hpet.c x86/hpet: Use irq_find_matching_fwspec() to find remapping irqdomain 2020-10-28 20:26:28 +01:00
hw_breakpoint.c x86/debug: Prevent data breakpoints on cpu_dr7 2021-02-05 20:13:12 +01:00
i8237.c
i8253.c
i8259.c
idt.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
io_delay.c
ioport.c
irq.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
irq_32.c softirq: Move do_softirq_own_stack() to generic asm header 2021-02-10 23:34:16 +01:00
irq_64.c x86/softirq/64: Inline do_softirq_own_stack() 2021-02-10 23:34:17 +01:00
irq_work.c
irqflags.S x86/pv: Rework arch_local_irq_restore() to not use popf 2021-02-10 12:36:45 +01:00
irqinit.c
itmt.c
jailhouse.c
jump_label.c x86: Remove dynamic NOP selection 2021-03-15 16:24:59 +01:00
kdebugfs.c
kexec-bzimage64.c x86: Use ELF fields defined in 'struct kimage' 2021-03-08 12:06:29 -07:00
kgdb.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
ksysfs.c
kvm.c x86/kvm: Unify kvm_pv_guest_cpu_reboot() with kvm_guest_cpu_offline() 2021-05-07 06:06:11 -04:00
kvmclock.c x86/kvm: Disable all PV features on crash 2021-05-07 06:06:10 -04:00
ldt.c x86/ldt: Use tlb_gather_mmu_fullmm() when freeing LDT page-tables 2021-01-29 20:02:29 +01:00
machine_kexec_32.c
machine_kexec_64.c Devicetree updates for v5.13: 2021-04-28 15:50:24 -07:00
Makefile x86/sev-es: Rename sev-es.{ch} to sev.{ch} 2021-05-10 07:40:27 +02:00
mmconf-fam10h_64.c x86/msr: Rename MSR_K8_SYSCFG to MSR_AMD64_SYSCFG 2021-05-10 07:51:38 +02:00
module.c x86/build: Treat R_386_PLT32 relocation as R_386_PC32 2021-01-28 12:24:06 +01:00
mpparse.c Surgery of the MSI interrupt handling to prepare the support of upcoming 2020-10-12 11:40:41 -07:00
msr.c x86/MSR: Filter MSR writes through X86_IOC_WRMSR_REGS ioctl too 2021-01-27 19:06:47 +01:00
nmi.c x86/sev-es: Rename sev-es.{ch} to sev.{ch} 2021-05-10 07:40:27 +02:00
nmi_selftest.c
paravirt-spinlocks.c x86/paravirt: Add new features for paravirt patching 2021-03-11 19:51:49 +01:00
paravirt.c The x86 MM changes in this cycle were: 2021-04-29 11:41:43 -07:00
pci-dma.c dma-mapping: move dma-debug.h to kernel/dma/ 2020-10-06 07:07:05 +02:00
pci-iommu_table.c x86: Remove definition of DEBUG 2021-01-15 08:23:10 +01:00
pci-swiotlb.c
pcspeaker.c
perf_regs.c - Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in the end 2020-12-14 13:45:26 -08:00
platform-quirks.c
pmem.c
probe_roms.c
process.c x86/fpu: Add PKRU storage outside of task XSAVE buffer 2021-06-23 19:37:45 +02:00
process.h
process_32.c
process_64.c x86/fpu: Add PKRU storage outside of task XSAVE buffer 2021-06-23 19:37:45 +02:00
ptrace.c x86/ptrace: Clean up PTRACE_GETREGS/PTRACE_PUTREGS regset selection 2021-02-04 12:33:15 +01:00
pvclock.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
quirks.c x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() 2020-10-06 11:18:04 +02:00
reboot.c x86: 2021-02-21 13:31:43 -08:00
reboot_fixups_32.c
relocate_kernel_32.S x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
relocate_kernel_64.S x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
resource.c
rtc.c
setup.c x86/setup: Always reserve the first 1M of RAM 2021-06-03 19:57:55 +02:00
setup_percpu.c x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
sev-shared.c x86/sev-es: Invalidate the GHCB after completing VMGEXIT 2021-05-18 07:06:29 +02:00
sev.c x86/sev-es: Use __put_user()/__get_user() for data accesses 2021-05-19 18:45:37 +02:00
sev_verify_cbit.S x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path 2020-10-29 18:06:52 +01:00
signal.c x86/signal: Detect and prevent an alternate signal stack overflow 2021-05-19 12:40:30 +02:00
signal_compat.c signal: Deliver all of the siginfo perf data in _perf 2021-05-18 16:20:54 -05:00
smp.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
smpboot.c x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations 2021-05-13 12:10:24 +02:00
stacktrace.c stacktrace: Move documentation for arch_stack_walk_reliable() to header 2021-03-10 15:52:31 +01:00
static_call.c x86: Remove dynamic NOP selection 2021-03-15 16:24:59 +01:00
step.c entry: Ensure trap after single-step on system call return 2021-02-06 00:21:42 +01:00
sys_ia32.c
sys_x86_64.c x86/mm: Refine mmap syscall implementation 2021-01-05 19:07:42 +01:00
sysfb.c
sysfb_efi.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
sysfb_simplefb.c
tboot.c x86/boot/tboot: Avoid Wstringop-overread-warning 2021-03-23 00:16:13 +01:00
time.c
tls.c x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
tls.h
topology.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
trace_clock.c
tracepoint.c
traps.c x86/fpu: Rename and sanitize fpu__save/copy() 2021-06-23 18:55:56 +02:00
tsc.c Trivial cleanups and fixes all over the place. 2021-04-26 09:25:47 -07:00
tsc_msr.c
tsc_sync.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
umip.c - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
unwind_frame.c
unwind_guess.c
unwind_orc.c x86/unwind/orc: Silence warnings caused by missing ORC data 2021-03-06 13:09:45 +01:00
uprobes.c x86/uprobes: Convert to insn_decode() 2021-03-15 12:05:03 +01:00
verify_cpu.S
vm86_32.c x86/vm86/32: Remove VM86_SCREEN_BITMAP support 2021-01-21 20:08:53 +01:00
vmlinux.lds.S x86/build: Fix vmlinux size check on 64-bit 2020-10-29 21:54:35 +01:00
vsmp_64.c
x86_init.c x86/apic: Support 15 bits of APIC ID in MSI where available 2020-10-28 20:26:29 +01:00