[PATCH 7/8] arm64: Define TIF_PATCH_PENDING for livepatch

Weinan Liu
2025-01-27T21:33:42Z

From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>

- Define TIF_PATCH_PENDING in arch/arm64/include/asm/thread_info.h
for livepatch.

- Check TIF_PATCH_PENDING in do_notify_resume() to patch the
current task for livepatch.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
Signed-off-by: Weinan Liu <wnliu@google.com>
---
arch/arm64/include/asm/thread_info.h | 4 +++-
arch/arm64/kernel/entry-common.c | 4 ++++
2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 1114c1c3300a..3810c2f3914e 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -64,6 +64,7 @@ void arch_setup_new_exec(void);
#define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */
#define TIF_MTE_ASYNC_FAULT 5 /* MTE Asynchronous Tag Check Fault */
#define TIF_NOTIFY_SIGNAL 6 /* signal notifications exist */
+#define TIF_PATCH_PENDING 7 /* pending live patching update */
#define TIF_SYSCALL_TRACE 8 /* syscall trace active */
#define TIF_SYSCALL_AUDIT 9 /* syscall auditing */
#define TIF_SYSCALL_TRACEPOINT 10 /* syscall tracepoint for ftrace */
@@ -99,11 +100,12 @@ void arch_setup_new_exec(void);
#define _TIF_MTE_ASYNC_FAULT (1 << TIF_MTE_ASYNC_FAULT)
#define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL)
#define _TIF_TSC_SIGSEGV (1 << TIF_TSC_SIGSEGV)
+#define _TIF_PATCH_PENDING (1 << TIF_PATCH_PENDING)

#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
_TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
_TIF_UPROBE | _TIF_MTE_ASYNC_FAULT | \
- _TIF_NOTIFY_SIGNAL)
+ _TIF_NOTIFY_SIGNAL | _TIF_PATCH_PENDING)

#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index b260ddc4d3e9..b537af333b42 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -8,6 +8,7 @@
#include <linux/context_tracking.h>
#include <linux/kasan.h>
#include <linux/linkage.h>
+#include <linux/livepatch.h>
#include <linux/lockdep.h>
#include <linux/ptrace.h>
#include <linux/resume_user_mode.h>
@@ -144,6 +145,9 @@ static void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags)
(void __user *)NULL, current);
}

+ if (thread_flags & _TIF_PATCH_PENDING)
+ klp_update_patch_state(current);
+
if (thread_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
do_signal(regs);

--
2.48.1.262.g85cc9f2d1e-goog