linux-kernel - [tip: x86/entry] x86/fred: Fix 64bit identifier in fred

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <176038995604.709179.16080488698468273330.tip-bot2@tip-bot2>
Date: Mon, 13 Oct 2025 21:12:36 -0000
From: "tip-bot2 for Andrew Cooper" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Andrew Cooper <andrew.cooper3@...rix.com>,
 Dave Hansen <dave.hansen@...ux.intel.com>, "Xin Li (Intel)" <xin@...or.com>,
 "H. Peter Anvin (Intel)" <hpa@...or.com>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: x86/entry] x86/fred: Fix 64bit identifier in fred_ss

The following commit has been merged into the x86/entry branch of tip:

Commit-ID:     4ab13be5ed12f4954d1f46cc6298e1adb2d6681b
Gitweb:        https://git.kernel.org/tip/4ab13be5ed12f4954d1f46cc6298e1adb2d6681b
Author:        Andrew Cooper <andrew.cooper3@...rix.com>
AuthorDate:    Wed, 03 Sep 2025 00:01:17 +01:00
Committer:     Dave Hansen <dave.hansen@...ux.intel.com>
CommitterDate: Mon, 13 Oct 2025 14:05:42 -07:00

x86/fred: Fix 64bit identifier in fred_ss

FRED can only be enabled in Long Mode.  This is the 64bit mode (as opposed to
compatibility mode) identifier, rather than being something hard-wired at 1.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@...rix.com>
Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com>
Reviewed-by: Xin Li (Intel) <xin@...or.com>
Reviewed-by: H. Peter Anvin (Intel) <hpa@...or.com>
Acked-by: H. Peter Anvin (Intel) <hpa@...or.com>
---
 arch/x86/entry/entry_fred.c   | 4 ++--
 arch/x86/include/asm/fred.h   | 2 +-
 arch/x86/include/asm/ptrace.h | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c
index f004a4d..94e626c 100644
--- a/arch/x86/entry/entry_fred.c
+++ b/arch/x86/entry/entry_fred.c
@@ -78,13 +78,13 @@ static noinstr void fred_intx(struct pt_regs *regs)
 static __always_inline void fred_other(struct pt_regs *regs)
 {
 	/* The compiler can fold these conditions into a single test */
-	if (likely(regs->fred_ss.vector == FRED_SYSCALL && regs->fred_ss.lm)) {
+	if (likely(regs->fred_ss.vector == FRED_SYSCALL && regs->fred_ss.l)) {
 		regs->orig_ax = regs->ax;
 		regs->ax = -ENOSYS;
 		do_syscall_64(regs, regs->orig_ax);
 		return;
 	} else if (ia32_enabled() &&
-		   likely(regs->fred_ss.vector == FRED_SYSENTER && !regs->fred_ss.lm)) {
+		   likely(regs->fred_ss.vector == FRED_SYSENTER && !regs->fred_ss.l)) {
 		regs->orig_ax = regs->ax;
 		regs->ax = -ENOSYS;
 		do_fast_syscall_32(regs);
diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h
index 12b34d5..2bb6567 100644
--- a/arch/x86/include/asm/fred.h
+++ b/arch/x86/include/asm/fred.h
@@ -79,7 +79,7 @@ static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int 
 		.type   = type,
 		.vector = vector,
 		.nmi    = type == EVENT_TYPE_NMI,
-		.lm     = 1,
+		.l      = 1,
 	};
 
 	asm_fred_entry_from_kvm(ss);
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 50f7546..37370c3 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -84,8 +84,8 @@ struct fred_ss {
 			:  4,
 		/* Event was incident to enclave execution */
 		enclave	:  1,
-		/* CPU was in long mode */
-		lm	:  1,
+		/* CPU was in 64-bit mode */
+		l	:  1,
 		/*
 		 * Nested exception during FRED delivery, not set
 		 * for #DF.