The following commit has been merged into the x86/asm branch of tip:
Commit-ID: 6829f19810e96903d7b532145c3d1701b4d9a0f6
Gitweb: https://git.kernel.org/tip/6829f19810e96903d7b532145c3d1701b4d9a0f6
Author: Uros Bizjak <ubizjak@gmail.com>
AuthorDate: Mon, 30 Mar 2026 10:59:22 +02:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Tue, 31 Mar 2026 09:50:10 +02:00
x86/process/32: Use correct type for 'gs' variable in __show_regs() to avoid zero-extension
Change the type of 'gs' variable in __show_regs() from
'unsigned short' to 'unsigned int'. This prevents unwanted
zero-extension when storing the 16-bit segment register
into a wider general purpose register.
The code improves from:
50: 8c ee mov %gs,%esi
52: 0f b7 f6 movzwl %si,%esi
...
be: 89 74 24 14 mov %esi,0x14(%esp)
to:
50: 8c ef mov %gs,%edi
...
bb: 89 7c 24 14 mov %edi,0x14(%esp)
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://patch.msgid.link/20260330085938.67985-3-ubizjak@gmail.com
---
arch/x86/kernel/process_32.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 3ef15c2..168dabf 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -61,7 +61,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode mode,
{
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
unsigned long d0, d1, d2, d3, d6, d7;
- unsigned short gs;
+ unsigned int gs;
savesegment(gs, gs);