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

Sohil Mehta posted 5 patches 1 month ago
[PATCH v3 2/5] x86/traps: Consolidate user fixups in the #GP handler
Posted by Sohil Mehta 1 month ago
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@intel.com>
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
---
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
[tip: x86/cpu] x86/traps: Consolidate user fixups in the #GP handler
Posted by tip-bot2 for Sohil Mehta 2 weeks, 6 days ago
The following commit has been merged into the x86/cpu branch of tip:

Commit-ID:     4e57fdd11083d5cd44febc4b6613777291ec936e
Gitweb:        https://git.kernel.org/tip/4e57fdd11083d5cd44febc4b6613777291ec936e
Author:        Sohil Mehta <sohil.mehta@intel.com>
AuthorDate:    Mon, 09 Mar 2026 11:10:26 -07:00
Committer:     Dave Hansen <dave.hansen@linux.intel.com>
CommitterDate: Thu, 19 Mar 2026 15:11:13 -07:00

x86/traps: Consolidate user fixups in the #GP handler

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@intel.com>
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Link: https://patch.msgid.link/20260309181029.398498-3-sohil.mehta@intel.com
---
 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 4dbff8e..614a281 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 d432f38..3ce99cb 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;