linux_dsm_epyc7002/arch/x86/kernel
Sebastian Andrzej Siewior d9c9ce34ed x86/fpu: Fault-in user stack if copy_fpstate_to_sigframe() fails
In the compacted form, XSAVES may save only the XMM+SSE state but skip
FP (x87 state).

This is denoted by header->xfeatures = 6. The fastpath
(copy_fpregs_to_sigframe()) does that but _also_ initialises the FP
state (cwd to 0x37f, mxcsr as we do, remaining fields to 0).

The slowpath (copy_xstate_to_user()) leaves most of the FP
state untouched. Only mxcsr and mxcsr_flags are set due to
xfeatures_mxcsr_quirk(). Now that XFEATURE_MASK_FP is set
unconditionally, see

  04944b793e ("x86: xsave: set FP, SSE bits in the xsave header in the user sigcontext"),

on return from the signal, random garbage is loaded as the FP state.

Instead of utilizing copy_xstate_to_user(), fault-in the user memory
and retry the fast path. Ideally, the fast path succeeds on the second
attempt but may be retried again if the memory is swapped out due
to memory pressure. If the user memory can not be faulted-in then
get_user_pages() returns an error so we don't loop forever.

Fault in memory via get_user_pages_unlocked() so
copy_fpregs_to_sigframe() succeeds without a fault.

Fixes: 69277c98f5 ("x86/fpu: Always store the registers in copy_fpstate_to_sigframe()")
Reported-by: Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190502171139.mqtegctsg35cir2e@linutronix.de
2019-05-06 09:49:40 +02:00
..
acpi treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
apic treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
cpu x86/pkeys: Add PKRU value to init_fpstate 2019-04-12 20:21:10 +02:00
fpu x86/fpu: Fault-in user stack if copy_fpstate_to_sigframe() fails 2019-05-06 09:49:40 +02:00
kprobes x86/kprobes: Prohibit probing on IRQ handlers directly 2019-02-13 08:16:39 +01:00
.gitignore
alternative.c Merge branch 'x86-alternatives-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-06 08:45:46 -08:00
amd_gart_64.c x86/amd_gart: fix unmapping of non-GART mappings 2019-01-05 08:27:32 +01:00
amd_nb.c x86/amd_nb: Add PCI device IDs for family 17h, model 30h 2018-11-07 21:36:09 +01:00
apb_timer.c
aperture_64.c x86/gart: Exclude GART aperture from kcore 2019-03-23 12:11:49 +01:00
apm_32.c x86/APM: Fix build warning when PROC_FS is not enabled 2018-09-15 10:16:25 +02:00
asm-offsets_32.c x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler 2018-07-20 01:11:36 +02:00
asm-offsets_64.c x86/paravirt: Move the pv_irq_ops under the PARAVIRT_XXL umbrella 2018-09-03 16:50:36 +02:00
asm-offsets.c x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
audit_64.c
bootflag.c
check.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
cpuid.c x86/cpuid: Allow cpuid_read() to schedule 2018-03-27 12:01:48 +02:00
crash_dump_32.c
crash_dump_64.c x86: Fix various typos in comments 2018-12-03 10:49:13 +01:00
crash.c x86/kexec: Fix a kexec_file_load() failure 2019-01-15 12:12:50 +01:00
devicetree.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
doublefault.c
dumpstack_32.c x86/dumpstack: Unify show_regs() 2018-03-08 12:04:59 +01:00
dumpstack_64.c x86/dumpstack: Unify show_regs() 2018-03-08 12:04:59 +01:00
dumpstack.c x86/process: Don't mix user/kernel regs in 64bit __show_regs() 2018-09-06 14:33:12 +02:00
e820.c Merge branch 'akpm' (patches from Andrew) 2019-03-12 10:39:53 -07:00
early_printk.c efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation 2019-02-04 08:27:30 +01:00
early-quirks.c On GEM side: 2018-07-20 12:29:24 +10:00
ebda.c
eisa.c x86/EISA: Don't probe EISA bus for Xen PV guests 2018-09-11 23:36:50 +02:00
espfix_64.c x86/espfix: Document use of _PAGE_GLOBAL 2018-04-09 18:27:33 +02:00
ftrace_32.S x86/retpoline/ftrace: Convert ftrace assembler indirect jumps 2018-01-12 00:14:30 +01:00
ftrace_64.S x86/ftrace: Do not call function graph from dynamic trampolines 2018-12-19 22:43:37 -05:00
ftrace.c The biggest change for this release is in the histogram code. 2019-03-11 17:01:32 -07:00
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: Mostly revert commit ae7e1238e6 ("Add ACPI RSDP address to setup_header") 2018-11-20 09:43:10 +01:00
head_32.S x86/pgtable/32: Allocate 8k page-tables when PTI is enabled 2018-07-20 01:11:41 +02:00
head_64.S xen/pvh: Split CONFIG_XEN_PVH into CONFIG_PVH and CONFIG_XEN_PVH 2018-12-13 13:41:49 -05:00
hpet.c x86/hpet: Prevent potential NULL pointer dereference 2019-03-21 12:24:38 +01:00
hw_breakpoint.c x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return an error 2019-03-22 17:08:17 +01:00
i8237.c x86/i8237: Register device based on FADT legacy boot flag 2018-04-27 16:44:29 +02:00
i8253.c
i8259.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
idt.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
ima_arch.c x86/ima: retry detecting secure boot mode 2018-12-11 07:19:45 -05:00
io_delay.c
ioport.c x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to sys_ioperm() 2018-04-02 20:16:12 +02:00
irq_32.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
irq_64.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
irq_work.c
irq.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
irqflags.S x86/paravirt: Make native_save_fl() extern inline 2018-07-03 10:56:27 +02:00
irqinit.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
itmt.c
jailhouse.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
jump_label.c jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
kdebugfs.c
kexec-bzimage64.c Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-03-10 17:32:04 -07:00
kgdb.c x86/kernel: Mark expected switch-case fall-throughs 2019-01-26 11:19:13 +01:00
ksysfs.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
kvm.c KVM: x86: WARN_ONCE if sending a PV IPI returns a fatal error 2019-01-25 19:11:33 +01:00
kvmclock.c x86: kvmguest: use TSC clocksource if invariant TSC is exposed 2019-02-20 22:48:52 +01:00
ldt.c x86/ldt: Remove unused variable in map_ldt_struct() 2018-11-06 21:35:11 +01:00
livepatch.c
machine_kexec_32.c x86/kexec: Allocate 8k PGDs for PTI 2018-07-30 13:53:48 +02:00
machine_kexec_64.c x86/kdump: Export the SME mask to vmcoreinfo 2019-01-11 16:09:25 +01:00
Makefile jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
mmconf-fam10h_64.c
module.c x86: Add support for 64-bit place relative relocations 2018-09-27 17:56:47 +02:00
mpparse.c x86/mm: Don't leak kernel addresses 2019-03-19 12:10:56 +01:00
msr.c x86: Clean up 'sizeof x' => 'sizeof(x)' 2018-10-29 07:13:28 +01:00
nmi_selftest.c
nmi.c
paravirt_patch_32.c x86/paravirt: Remove unused _paravirt_ident_32 2018-10-30 09:55:31 +01:00
paravirt_patch_64.c x86/paravirt: Remove unused _paravirt_ident_32 2018-10-30 09:55:31 +01:00
paravirt-spinlocks.c x86/paravirt: Use a single ops structure 2018-09-03 16:50:35 +02:00
paravirt.c x86/paravirt: Remove unused _paravirt_ident_32 2018-10-30 09:55:31 +01:00
pci-calgary_64.c x86/calgary: remove the mapping_error dma_map_ops method 2018-12-06 06:56:46 -08:00
pci-dma.c dma-mapping: bypass indirect calls for dma-direct 2018-12-13 21:06:18 +01:00
pci-iommu_table.c x86/iommu: Use NULL instead of 0 2018-08-02 14:33:19 +02:00
pci-swiotlb.c dma-direct: merge swiotlb_dma_ops into the dma_direct code 2018-12-13 21:06:17 +01:00
pcspeaker.c x86/platform/pcspeaker: Use PTR_ERR_OR_ZERO() to fix ptr_ret.cocci warning 2018-07-24 09:46:42 +02:00
perf_regs.c perf/x86: Store user space frame-pointer value on a sample 2018-05-25 08:11:12 +02:00
platform-quirks.c x86/i8237: Register device based on FADT legacy boot flag 2018-04-27 16:44:29 +02:00
pmem.c
probe_roms.c
process_32.c x86/fpu: Defer FPU state load until return to userspace 2019-04-12 19:34:47 +02:00
process_64.c x86/fpu: Defer FPU state load until return to userspace 2019-04-12 19:34:47 +02:00
process.c x86/fpu: Defer FPU state load until return to userspace 2019-04-12 19:34:47 +02:00
process.h x86/speculation: Change misspelled STIPB to STIBP 2018-12-06 11:49:15 +01:00
ptrace.c x86/fsgsbase/64: Fix the base write helper functions 2018-12-18 14:26:09 +01:00
pvclock.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
quirks.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
reboot_fixups_32.c
reboot.c x86/apic: Fix restoring boot IRQ mode in reboot and kexec/kdump 2018-02-17 11:47:45 +01:00
relocate_kernel_32.S
relocate_kernel_64.S x86/kexec: Make kexec (mostly) work in 5-level paging mode 2018-01-31 08:39:40 +01:00
resource.c
rtc.c x86: Convert x86_platform_ops to timespec64 2018-05-19 14:03:14 +02:00
setup_percpu.c memblock: drop memblock_alloc_*_nopanic() variants 2019-03-12 10:04:02 -07:00
setup.c Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-01-05 13:25:58 -08:00
signal_compat.c signal: Add TRAP_UNK si_code for undiagnosted trap exceptions 2018-04-25 10:40:56 -05:00
signal.c x86/fpu: Remove fpu->initialized 2019-04-10 15:42:40 +02:00
smp.c x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d 2018-08-05 09:53:13 +02:00
smpboot.c Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-07 16:36:57 -08:00
stacktrace.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
step.c
sys_x86_64.c x86/compat: Adjust in_compat_syscall() to generic code under !COMPAT 2018-11-01 12:59:25 +01:00
sysfb_efi.c x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
sysfb_simplefb.c
sysfb.c
tboot.c iommu/vtd: Cleanup dma_remapping.h header 2018-11-12 14:22:56 +01:00
tce_64.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
time.c Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 19:07:25 +01:00
tls.c
tls.h
topology.c x86/xen: Disable CPU0 hotplug for Xen PV 2018-09-12 21:15:02 +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/fpu: Use a feature number instead of mask in two more helpers 2019-04-10 18:20:27 +02:00
tsc_msr.c x86/cpu: Sanitize FAM6_ATOM naming 2018-10-02 10:14:32 +02:00
tsc_sync.c
tsc.c x86/tsc: Make calibration refinement more robust 2018-11-06 21:53:15 +01:00
umip.c signal/x86: Use force_sig_fault where appropriate 2018-09-21 15:30:54 +02:00
unwind_frame.c x86/unwind: Handle NULL pointer calls better in frame unwinder 2019-03-06 23:03:26 +01:00
unwind_guess.c
unwind_orc.c x86/unwind: Add hardcoded ORC entry for NULL 2019-03-06 23:03:26 +01:00
uprobes.c x86/kernel: Mark expected switch-case fall-throughs 2019-01-26 11:19:13 +01:00
verify_cpu.S
vm86_32.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
vmlinux.lds.S x86/build: Use the single-argument OUTPUT_FORMAT() linker script command 2019-01-16 12:21:53 +01:00
vsmp_64.c x86/vsmp: Remove dependency on pv_irq_ops 2018-11-06 21:35:11 +01:00
x86_init.c x86/acpi, x86/boot: Take RSDP address for boot params if available 2018-10-10 10:44:22 +02:00