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authorXiaoyao Li <xiaoyao.li@linux.intel.com>2019-06-27 06:55:25 +0200
committerIngo Molnar <mingo@kernel.org>2019-06-27 10:56:11 +0200
commit2238246ff8d533a5f2327d1f953375876d8a013c (patch)
treee3b64cc4f0c0979b156aeb489e24c1d98d51fddc /arch
parentx86/kexec: Add the ACPI NVS region to the ident map (diff)
downloadlinux-2238246ff8d533a5f2327d1f953375876d8a013c.tar.xz
linux-2238246ff8d533a5f2327d1f953375876d8a013c.zip
x86/boot: Make the GDT 8-byte aligned
The segment descriptors are loaded with an implicitly LOCK-ed instruction, which could trigger the split lock #AC exception if the variable is not properly aligned and crosses a cache line. Align the GDT properly so the descriptors are all 8 byte aligned. Signed-off-by: Xiaoyao Li <xiaoyao.li@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Link: https://lkml.kernel.org/r/20190627045525.105266-1-xiaoyao.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/boot/compressed/head_64.S1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index fafb75c6c592..6233ae35d0d9 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -659,6 +659,7 @@ no_longmode:
gdt64:
.word gdt_end - gdt
.quad 0
+ .balign 8
gdt:
.word gdt_end - gdt
.long gdt