linux/arch/x86/kernel
H. Peter Anvin (Intel) 6de4ac1d03 x86/syscall: Maximize MSR_SYSCALL_MASK
It is better to clear as many flags as possible when we do a system
call entry, as opposed to the other way around. The fewer flags we
keep, the lesser the possible interference between the kernel and user
space.

The flags changed are:

 - CF, PF, AF, ZF, SF, OF: these are arithmetic flags which affect
   branches, possibly speculatively. They should be cleared for the same
   reasons we now clear all GPRs on entry.

 - RF: suppresses a code breakpoint on the subsequent instruction. It is
   probably impossible to enter the kernel with RF set, but if it is
   somehow not, it would break a kernel debugger setting a breakpoint on
   the entry point. Either way, user space should not be able to control
   kernel behavior here.

 - ID: this flag has no direct effect (it is a scratch bit only.)
   However, there is no reason to retain the user space value in the
   kernel, and the standard should be to clear unless needed, not the
   other way around.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210510185316.3307264-5-hpa@zytor.com
2021-05-12 10:49:15 +02:00
..
acpi Trivial cleanups and fixes all over the place. 2021-04-26 09:25:47 -07:00
apic A single commit to make the vector allocation code more resilent against an 2021-04-26 10:00:38 -07:00
cpu x86/syscall: Maximize MSR_SYSCALL_MASK 2021-05-12 10:49:15 +02:00
fpu x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
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 The x86 MM changes in this cycle were: 2021-04-29 11:41:43 -07:00
amd_gart_64.c
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
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
crash_dump_64.c
devicetree.c
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: Fix various typos in comments 2021-03-18 15:31:53 +01:00
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 x86/entry: Unify definitions from <asm/calling.h> and <asm/ptrace-abi.h> 2021-05-12 10:49:13 +02:00
hpet.c
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 ARM: 2021-05-01 10:14:08 -07:00
kvmclock.c First big cleanup to the paravirt infra to use alternatives and thus 2021-04-26 09:01:29 -07:00
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/paravirt: Have only one paravirt patch function 2021-03-11 20:11:09 +01:00
mmconf-fam10h_64.c
module.c x86/build: Treat R_386_PLT32 relocation as R_386_PC32 2021-01-28 12:24:06 +01:00
mpparse.c
msr.c x86/MSR: Filter MSR writes through X86_IOC_WRMSR_REGS ioctl too 2021-01-27 19:06:47 +01:00
nmi.c KVM/VMX: Invoke NMI non-IST entry instead of IST entry 2021-05-05 22:54:10 +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
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/process: setup io_threads more like normal user space threads 2021-05-05 17:47:41 -06:00
process.h
process_32.c
process_64.c x86/irq: Sanitize irq stack tracking 2021-02-10 23:34:13 +01:00
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
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 - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
setup_percpu.c x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
sev-es-shared.c x86/sev-es: Replace open-coded hlt-loops with sev_es_terminate() 2021-03-18 23:04:12 +01:00
sev-es.c - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
sev_verify_cbit.S
signal.c Merge branch 'linus' into x86/cleanups, to resolve conflict 2021-03-21 22:16:08 +01:00
signal_compat.c signal: Introduce TRAP_PERF si_code and si_perf to siginfo 2021-04-16 16:32:41 +02:00
smp.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
smpboot.c x86/smpboot: Remove duplicate includes 2021-05-05 21:50:13 +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 - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
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
vsmp_64.c
x86_init.c