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authorSong Liu <song@kernel.org>2025-06-30 10:45:02 -0700
committerCatalin Marinas <catalin.marinas@arm.com>2025-07-01 15:18:53 +0100
commitfd1e0fd71f6552238573efa92fd3e6c324986ee3 (patch)
tree30d1f9e5681ee1d796e673999fd55ab5bebdf088
parent805f13e403cd43bb88790642feef507108af6fc7 (diff)
arm64: Implement HAVE_LIVEPATCH
Allocate a task flag used to represent the patch pending state for the task. When a livepatch is being loaded or unloaded, the livepatch code uses this flag to select the proper version of a being patched kernel functions to use for current task. In arch/arm64/Kconfig, select HAVE_LIVEPATCH and include proper Kconfig. This is largely based on [1] by Suraj Jitindar Singh. [1] https://lore.kernel.org/all/20210604235930.603-1-surajjs@amazon.com/ Cc: Suraj Jitindar Singh <surajjs@amazon.com> Cc: Torsten Duwe <duwe@suse.de> Acked-by: Miroslav Benes <mbenes@suse.cz> Tested-by: Breno Leitao <leitao@debian.org> Tested-by: Andrea della Porta <andrea.porta@suse.com> Signed-off-by: Song Liu <song@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20250630174502.842486-1-song@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/Kconfig3
-rw-r--r--arch/arm64/include/asm/thread_info.h5
-rw-r--r--arch/arm64/kernel/entry-common.c4
3 files changed, 11 insertions, 1 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b7462424aa59..110218542920 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -280,6 +280,7 @@ config ARM64
select USER_STACKTRACE_SUPPORT
select VDSO_GETRANDOM
select HAVE_RELIABLE_STACKTRACE
+ select HAVE_LIVEPATCH
help
ARM 64-bit (AArch64) Linux support.
@@ -2499,3 +2500,5 @@ endmenu # "CPU Power Management"
source "drivers/acpi/Kconfig"
source "arch/arm64/kvm/Kconfig"
+
+source "kernel/livepatch/Kconfig"
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 1269c2487574..f241b8601ebd 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -70,6 +70,7 @@ void arch_setup_new_exec(void);
#define TIF_SYSCALL_TRACEPOINT 10 /* syscall tracepoint for ftrace */
#define TIF_SECCOMP 11 /* syscall secure computing */
#define TIF_SYSCALL_EMU 12 /* syscall emulation active */
+#define TIF_PATCH_PENDING 13 /* pending live patching update */
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_FREEZE 19
#define TIF_RESTORE_SIGMASK 20
@@ -96,6 +97,7 @@ void arch_setup_new_exec(void);
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
+#define _TIF_PATCH_PENDING (1 << TIF_PATCH_PENDING)
#define _TIF_UPROBE (1 << TIF_UPROBE)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#define _TIF_32BIT (1 << TIF_32BIT)
@@ -107,7 +109,8 @@ void arch_setup_new_exec(void);
#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY | \
_TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
_TIF_UPROBE | _TIF_MTE_ASYNC_FAULT | \
- _TIF_NOTIFY_SIGNAL | _TIF_SIGPENDING)
+ _TIF_NOTIFY_SIGNAL | _TIF_SIGPENDING | \
+ _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 7c1970b341b8..a56878d7c733 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);