diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2023-11-09 21:09:56 +0100 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-12-13 13:35:38 +0100 |
| commit | 7d28365a06af74cee015a448d32ab6e98cd05cfb (patch) | |
| tree | 70fb5cad9cec88a0c061ecaa66f30fc2e9b0cec9 /arch/x86 | |
| parent | x86/docs: Remove reference to syscall trampoline in PTI (diff) | |
| download | linux-7d28365a06af74cee015a448d32ab6e98cd05cfb.tar.xz linux-7d28365a06af74cee015a448d32ab6e98cd05cfb.zip | |
x86/head_64: Use TESTB instead of TESTL in secondary_startup_64_no_verify()
There is no need to use TESTL when checking the least-significant bit
with a TEST instruction. Use TESTB, which is three bytes shorter:
f6 05 00 00 00 00 01 testb $0x1,0x0(%rip)
vs:
f7 05 00 00 00 00 01 testl $0x1,0x0(%rip)
00 00 00
for the same effect.
No functional changes intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231109201032.4439-1-ubizjak@gmail.com
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/head_64.S | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 086a2c3aaaa0..1f79d809305d 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -182,7 +182,7 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) /* Enable PAE mode, PSE, PGE and LA57 */ orl $(X86_CR4_PAE | X86_CR4_PSE | X86_CR4_PGE), %ecx #ifdef CONFIG_X86_5LEVEL - testl $1, __pgtable_l5_enabled(%rip) + testb $1, __pgtable_l5_enabled(%rip) jz 1f orl $X86_CR4_LA57, %ecx 1: |