[PATCH v3 2/5] x86/traps: Consolidate user fixups in the #GP handler

From: Sohil Mehta

Date: Mon Mar 09 2026 - 14:16:46 EST


Move the UMIP exception fixup under the common "if (user_mode(regs))"
condition where the rest of user mode fixups reside. Also, move the UMIP
feature check into its fixup function to keep the calling code
consistent and clean.

No functional change intended.

Suggested-by: Dave Hansen <dave.hansen@xxxxxxxxx>
Signed-off-by: Sohil Mehta <sohil.mehta@xxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Reviewed-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx>
---
v3:
- Pickup review and tested-by tags.

v2:
- No change
---
arch/x86/kernel/traps.c | 8 +++-----
arch/x86/kernel/umip.c | 3 +++
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 4dbff8ef9b1c..614a281bd419 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -921,11 +921,6 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)

cond_local_irq_enable(regs);

- if (static_cpu_has(X86_FEATURE_UMIP)) {
- if (user_mode(regs) && fixup_umip_exception(regs))
- goto exit;
- }
-
if (v8086_mode(regs)) {
local_irq_enable();
handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
@@ -940,6 +935,9 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)
if (fixup_vdso_exception(regs, X86_TRAP_GP, error_code, 0))
goto exit;

+ if (fixup_umip_exception(regs))
+ goto exit;
+
gp_user_force_sig_segv(regs, X86_TRAP_GP, error_code, desc);
goto exit;
}
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index d432f3824f0c..3ce99cbcf187 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -354,6 +354,9 @@ bool fixup_umip_exception(struct pt_regs *regs)
void __user *uaddr;
struct insn insn;

+ if (!cpu_feature_enabled(X86_FEATURE_UMIP))
+ return false;
+
if (!regs)
return false;

--
2.43.0