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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-10 10:09:22 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-10 10:09:22 -0800 |
| commit | 25f8c7785e254779fbd2127c4eced81811e8e421 (patch) | |
| tree | 3b377bd739e5a7d94a2bb50398387a2322028d51 /arch/x86/lib | |
| parent | 308319e990ae95b2a752fa0a1730f88598ca0dc7 (diff) | |
| parent | 244122b4d2e5221e6abd6e21d6a58170104db781 (diff) | |
| download | linux-25f8c7785e254779fbd2127c4eced81811e8e421.tar.bz2 | |
Merge tag 'x86_cpu_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpuid updates from Borislav Petkov:
- Enable the short string copies for CPUs which support them, in
copy_user_enhanced_fast_string()
- Avoid writing MSR_CSTAR on Intel due to TDX guests raising a #VE trap
* tag 'x86_cpu_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/lib: Add fast-short-rep-movs check to copy_user_enhanced_fast_string()
x86/cpu: Don't write CSTAR MSR on Intel CPUs
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/copy_user_64.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index 2797e630b9b1..1c429f0489dd 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -200,8 +200,8 @@ EXPORT_SYMBOL(copy_user_generic_string) */ SYM_FUNC_START(copy_user_enhanced_fast_string) ASM_STAC - cmpl $64,%edx - jb .L_copy_short_string /* less then 64 bytes, avoid the costly 'rep' */ + /* CPUs without FSRM should avoid rep movsb for short copies */ + ALTERNATIVE "cmpl $64, %edx; jb .L_copy_short_string", "", X86_FEATURE_FSRM movl %edx,%ecx 1: rep movsb |