arch/x86/entry/syscall_32.c | 19 +++++-------------- arch/x86/entry/syscall_64.c | 3 +-- arch/x86/include/asm/entry-common.h | 1 - 3 files changed, 6 insertions(+), 17 deletions(-)
The following commit has been merged into the core/entry branch of tip:
Commit-ID: 9d311796e2ce75b3aaded2719a01d7e248c3a24f
Gitweb: https://git.kernel.org/tip/9d311796e2ce75b3aaded2719a01d7e248c3a24f
Author: Thomas Gleixner <tglx@kernel.org>
AuthorDate: Tue, 07 Jul 2026 21:06:27 +02:00
Committer: Thomas Gleixner <tglx@kernel.org>
CommitterDate: Sun, 12 Jul 2026 12:38:01 +02:00
x86/syscall: Use [syscall_]enter_from_user_mode_randomize_stack()
These functions integrate the stack randomization.
syscall_enter_from_user_mode_randomize_stack() has the advantage that the
randomization happens early right after enter_from_user_mode().
In both cases also the overhead of get/put_cpu_var() in
add_random_kstack_offset() is avoided.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Reviewed-by: Radu Rendec <radu@rendec.net>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Link: https://patch.msgid.link/20260707190254.079478122@kernel.org
---
arch/x86/entry/syscall_32.c | 19 +++++--------------
arch/x86/entry/syscall_64.c | 3 +--
arch/x86/include/asm/entry-common.h | 1 -
3 files changed, 6 insertions(+), 17 deletions(-)
diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 31b9492..2b13f1c 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -142,10 +142,9 @@ __visible noinstr void do_int80_emulation(struct pt_regs *regs)
* int80_is_external() below which calls into the APIC driver.
* Identical for soft and external interrupts.
*/
- enter_from_user_mode(regs);
+ enter_from_user_mode_randomize_stack(regs);
instrumentation_begin();
- add_random_kstack_offset();
/* Validate that this is a soft interrupt to the extent possible */
if (unlikely(int80_is_external()))
@@ -210,11 +209,9 @@ DEFINE_FREDENTRY_RAW(int80_emulation)
{
int nr;
- enter_from_user_mode(regs);
+ enter_from_user_mode_randomize_stack(regs);
instrumentation_begin();
- add_random_kstack_offset();
-
/*
* FRED pushed 0 into regs::orig_ax and regs::ax contains the
* syscall number.
@@ -252,10 +249,10 @@ __visible noinstr void do_int80_syscall_32(struct pt_regs *regs)
* orig_ax, the int return value truncates it. This matches
* the semantics of syscall_get_nr().
*/
- nr = syscall_enter_from_user_mode(regs, nr);
+ nr = syscall_enter_from_user_mode_randomize_stack(regs, nr);
+
instrumentation_begin();
- add_random_kstack_offset();
do_syscall_32_irqs_on(regs, nr);
instrumentation_end();
@@ -268,15 +265,9 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs)
int nr = syscall_32_enter(regs);
int res;
- /*
- * This cannot use syscall_enter_from_user_mode() as it has to
- * fetch EBP before invoking any of the syscall entry work
- * functions.
- */
- enter_from_user_mode(regs);
+ enter_from_user_mode_randomize_stack(regs);
instrumentation_begin();
- add_random_kstack_offset();
local_irq_enable();
/* Fetch EBP from where the vDSO stashed it. */
if (IS_ENABLED(CONFIG_X86_64)) {
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 71f0325..0acd7e9 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -86,10 +86,9 @@ static __always_inline bool do_syscall_x32(struct pt_regs *regs, int nr)
/* Returns true to return using SYSRET, or false to use IRET */
__visible noinstr bool do_syscall_64(struct pt_regs *regs, int nr)
{
- nr = syscall_enter_from_user_mode(regs, nr);
+ nr = syscall_enter_from_user_mode_randomize_stack(regs, nr);
instrumentation_begin();
- add_random_kstack_offset();
if (!do_syscall_x64(regs, nr) && !do_syscall_x32(regs, nr) && nr != -1) {
/* Invalid system call, but still a system call. */
diff --git a/arch/x86/include/asm/entry-common.h b/arch/x86/include/asm/entry-common.h
index eca24b5..3fed46b 100644
--- a/arch/x86/include/asm/entry-common.h
+++ b/arch/x86/include/asm/entry-common.h
@@ -2,7 +2,6 @@
#ifndef _ASM_X86_ENTRY_COMMON_H
#define _ASM_X86_ENTRY_COMMON_H
-#include <linux/randomize_kstack.h>
#include <linux/user-return-notifier.h>
#include <asm/nospec-branch.h>© 2016 - 2026 Red Hat, Inc.