The following commit has been merged into the core/entry branch of tip:
Commit-ID: 89d163dd9dacb028773244dba0a2c86f3a6b74b7
Gitweb: https://git.kernel.org/tip/89d163dd9dacb028773244dba0a2c86f3a6b74b7
Author: Thomas Gleixner <tglx@kernel.org>
AuthorDate: Tue, 07 Jul 2026 21:05:58 +02:00
Committer: Thomas Gleixner <tglx@kernel.org>
CommitterDate: Sun, 12 Jul 2026 12:38:00 +02:00
powerpc: Move stack randomization after syscall_enter_from_user_mode()
add_random_kstack_offset() is invoked before syscall_enter_from_user_mode()
establishes state. That's wrong because add_random_kstack_offset() calls
into instrumentable code.
Move it after syscall_enter_from_user_mode() to ensure that state is
correctly established.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.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/20260707190253.718191130@kernel.org
---
arch/powerpc/kernel/syscall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index a9da2af..ee07b2e 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -19,8 +19,8 @@ notrace long system_call_exception(struct pt_regs *regs, unsigned long r0)
long ret;
syscall_fn f;
- add_random_kstack_offset();
r0 = syscall_enter_from_user_mode(regs, r0);
+ add_random_kstack_offset();
if (unlikely(r0 >= NR_syscalls)) {
if (unlikely(trap_is_unsupported_scv(regs))) {