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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-28 21:57:11 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-28 21:57:11 +0200 |
| commit | 909489bf9f88d314dc18be930cefa99ec9a4aac7 (patch) | |
| tree | b2080eaceaf79d272a2c4862df76a860e7bf81c3 /arch/x86/kernel/cpu/common.c | |
| parent | Merge tag 'x86-apic-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/... (diff) | |
| parent | x86/asm: Make <asm/asm.h> valid on cross-builds as well (diff) | |
| download | linux-909489bf9f88d314dc18be930cefa99ec9a4aac7.tar.xz linux-909489bf9f88d314dc18be930cefa99ec9a4aac7.zip | |
Merge tag 'x86-asm-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
- Micro-optimize and standardize the do_syscall_64() calling convention
- Make syscall entry flags clearing more conservative
- Clean up syscall table handling
- Clean up & standardize assembly macros, in preparation of FRED
- Misc cleanups and fixes
* tag 'x86-asm-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Make <asm/asm.h> valid on cross-builds as well
x86/regs: Syscall_get_nr() returns -1 for a non-system call
x86/entry: Split PUSH_AND_CLEAR_REGS into two submacros
x86/syscall: Maximize MSR_SYSCALL_MASK
x86/syscall: Unconditionally prototype {ia32,x32}_sys_call_table[]
x86/entry: Reverse arguments to do_syscall_64()
x86/entry: Unify definitions from <asm/calling.h> and <asm/ptrace-abi.h>
x86/asm: Use _ASM_BYTES() in <asm/nops.h>
x86/asm: Add _ASM_BYTES() macro for a .byte ... opcode sequence
x86/asm: Have the __ASM_FORM macros handle commas in arguments
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 212e8bc070da..a99d00393206 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1773,10 +1773,16 @@ void syscall_init(void) wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL); #endif - /* Flags to clear on syscall */ + /* + * Flags to clear on syscall; clear as much as possible + * to minimize user space-kernel interference. + */ wrmsrl(MSR_SYSCALL_MASK, - X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF| - X86_EFLAGS_IOPL|X86_EFLAGS_AC|X86_EFLAGS_NT); + X86_EFLAGS_CF|X86_EFLAGS_PF|X86_EFLAGS_AF| + X86_EFLAGS_ZF|X86_EFLAGS_SF|X86_EFLAGS_TF| + X86_EFLAGS_IF|X86_EFLAGS_DF|X86_EFLAGS_OF| + X86_EFLAGS_IOPL|X86_EFLAGS_NT|X86_EFLAGS_RF| + X86_EFLAGS_AC|X86_EFLAGS_ID); } #else /* CONFIG_X86_64 */ |