linux-kernel - [PATCH v2 1/4] x86/acpi/suspend: Remove indirect jump

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <20260203175821.511847-2-brgerst@gmail.com>
Date: Tue,  3 Feb 2026 12:58:18 -0500
From: Brian Gerst <brgerst@...il.com>
To: linux-kernel@...r.kernel.org,
	x86@...nel.org
Cc: Ingo Molnar <mingo@...nel.org>,
	"H . Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Borislav Petkov <bp@...en8.de>,
	Ard Biesheuvel <ardb@...nel.org>,
	"Rafael J . Wysocki" <rafael@...nel.org>,
	Len Brown <lenb@...nel.org>,
	Pavel Machek <pavel@...nel.org>,
	Brian Gerst <brgerst@...il.com>
Subject: [PATCH v2 1/4] x86/acpi/suspend: Remove indirect jump

wakeup_long64() is called from common_startup_64() via initial_code, so
it is already running on the normal virtual mapping.  There is no need
to use an indirect jump since it is not switching mappings.

Signed-off-by: Brian Gerst <brgerst@...il.com>
---
 arch/x86/kernel/acpi/wakeup_64.S | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S
index 04f561f75e99..3d56610f0108 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/arch/x86/kernel/acpi/wakeup_64.S
@@ -41,10 +41,9 @@ SYM_FUNC_START(wakeup_long64)
 	movq	saved_rsi(%rip), %rsi
 	movq	saved_rbp(%rip), %rbp
 
-	movq	saved_rip(%rip), %rax
-	ANNOTATE_RETPOLINE_SAFE
-	jmp	*%rax
+	jmp	.Lresume_point
 SYM_FUNC_END(wakeup_long64)
+STACK_FRAME_NON_STANDARD wakeup_long64
 
 SYM_FUNC_START(do_suspend_lowlevel)
 	FRAME_BEGIN
@@ -71,8 +70,6 @@ SYM_FUNC_START(do_suspend_lowlevel)
 	pushfq
 	popq	pt_regs_flags(%rax)
 
-	movq	$.Lresume_point, saved_rip(%rip)
-
 	movq	%rsp, saved_rsp(%rip)
 	movq	%rbp, saved_rbp(%rip)
 	movq	%rbx, saved_rbx(%rip)
@@ -84,11 +81,8 @@ SYM_FUNC_START(do_suspend_lowlevel)
 	xorl	%eax, %eax
 	call	x86_acpi_enter_sleep_state
 	/* in case something went wrong, restore the machine status and go on */
-	jmp	.Lresume_point
 
-	.align 4
 .Lresume_point:
-	ANNOTATE_NOENDBR
 	/* We don't restore %rax, it must be 0 anyway */
 	movq	$saved_context, %rax
 	movq	saved_context_cr4(%rax), %rbx
@@ -139,7 +133,6 @@ saved_rsi:		.quad	0
 saved_rdi:		.quad	0
 saved_rbx:		.quad	0
 
-saved_rip:		.quad	0
 saved_rsp:		.quad	0
 
 SYM_DATA(saved_magic,	.quad	0)
-- 
2.52.0