Commit-ID: 1c30fe6cbba6997ae4740bb46910036f8a4a9edb Gitweb: https://git.kernel.org/tip/1c30fe6cbba6997ae4740bb46910036f8a4a9edb Author: Xiaoyao Li <xiaoyao.li@xxxxxxxxxxxxxxx> AuthorDate: Thu, 27 Jun 2019 12:55:25 +0800 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Thu, 27 Jun 2019 09:40:41 +0200 x86/boot: Make gdt 8-byte aligned The segment descriptors are loaded with a implicitly locked instruction, which could trigger the split lock #AC if the variable is not properly aligned and crosses a cache line. Align gdt proper so the descriptors are 8 byte aligned. Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Link: https://lkml.kernel.org/r/20190627045525.105266-1-xiaoyao.li@xxxxxxxxxxxxxxx --- arch/x86/boot/compressed/head_64.S | 1 + 1 file changed, 1 insertion(+) 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
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