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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-13 13:36:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-13 13:36:07 -0700 |
| commit | 029f56db6ac248769f2c260bfaf3c3c0e23e904c (patch) | |
| tree | 78c03b03258c0ac5d7b9546acc2ba14e87e277fd /arch/x86/kernel | |
| parent | 7cd4ecd9177b94af783b8e21de7c65b41a871342 (diff) | |
| parent | aa5cacdc29d76a005cbbee018a47faa6e724dd2d (diff) | |
Merge tag 'x86_asm_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Borislav Petkov:
"Two asm wrapper fixes:
- Use XORL instead of XORQ to avoid a REX prefix and save some bytes
in the .fixup section, by Uros Bizjak.
- Replace __force_order dummy variable with a memory clobber to fix
LLVM requiring a definition for former and to prevent memory
accesses from still being cached/reordered, by Arvind Sankar"
* tag 'x86_asm_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Replace __force_order with a memory clobber
x86/uaccess: Use XORL %0,%0 in __get_user_asm()
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 7824fc62c7cd..c51158914ea2 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -360,7 +360,7 @@ void native_write_cr0(unsigned long val) unsigned long bits_missing = 0; set_register: - asm volatile("mov %0,%%cr0": "+r" (val), "+m" (__force_order)); + asm volatile("mov %0,%%cr0": "+r" (val) : : "memory"); if (static_branch_likely(&cr_pinning)) { if (unlikely((val & X86_CR0_WP) != X86_CR0_WP)) { @@ -379,7 +379,7 @@ void native_write_cr4(unsigned long val) unsigned long bits_changed = 0; set_register: - asm volatile("mov %0,%%cr4": "+r" (val), "+m" (cr4_pinned_bits)); + asm volatile("mov %0,%%cr4": "+r" (val) : : "memory"); if (static_branch_likely(&cr_pinning)) { if (unlikely((val & cr4_pinned_mask) != cr4_pinned_bits)) { |