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/[email protected]/ Cc: Suraj Jitindar Singh <[email protected]> Cc: Torsten Duwe <[email protected]> Acked-by: Miroslav Benes <[email protected]> Tested-by: Breno Leitao <[email protected]> Tested-by: Andrea della Porta <[email protected]> Signed-off-by: Song Liu <[email protected]> Acked-by: Will Deacon <[email protected]> --- Changes v4 => v5: 1. Update commit log. v4: https://lore.kernel.org/live-patching/[email protected]/ Changes v3 => v4: 1. Only keep 2/2 from v3, as 1/2 is now included in [3]. 2. Change TIF_PATCH_PENDING from 7 to 13. v3: https://lore.kernel.org/linux-arm-kernel/[email protected]/ Changes v2 => v3: 1. Remove a redundant check for -ENOENT. (Josh Poimboeuf) 2. Add Tested-by and Acked-by on v1. (I forgot to add them in v2.) v2: https://lore.kernel.org/live-patching/[email protected]/ Changes v1 => v2: 1. Rework arch_stack_walk_reliable(). v1: https://lore.kernel.org/live-patching/[email protected]/ --- arch/arm64/Kconfig | 3 +++ arch/arm64/include/asm/thread_info.h | 5 ++++- arch/arm64/kernel/entry-common.c | 4 ++++ 3 files changed, 11 insertions(+), 1 deletion(-) 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); -- 2.47.1
