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Subject[PATCH] x86/boot/compressed/64: Do not truncate gdt address
Before going to 32-bit trampoline we need to load GDT to make sure that
we have the table with 32-bit code segment.

The load was implemented incorrectly and the table address is truncated
to 32-bit. It causes problems if gdt is above 4G.

Reported-and-tested-by: Andrei Vagin <>
Fixes: b4b56015ed1c ("x86/boot/compressed/64: Handle 5-level paging boot if kernel is above 4G")
Signed-off-by: Kirill A. Shutemov <>
arch/x86/boot/compressed/head_64.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 70b30f2bc9e0..99a0e7993252 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -332,7 +332,7 @@ ENTRY(startup_64)

/* Make sure we have GDT with 32-bit code segment */
leaq gdt(%rip), %rax
- movl %eax, gdt64+2(%rip)
+ movq %rax, gdt64+2(%rip)
lgdt gdt64(%rip)

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