Commit fd1e0fd7 authored by Song Liu's avatar Song Liu Committed by Catalin Marinas
Browse files

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: default avatarMiroslav Benes <mbenes@suse.cz>
Tested-by: default avatarBreno Leitao <leitao@debian.org>
Tested-by: default avatarAndrea della Porta <andrea.porta@suse.com>
Signed-off-by: default avatarSong Liu <song@kernel.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250630174502.842486-1-song@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 805f13e4

arch/arm64/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -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"

arch/arm64/include/asm/thread_info.h

+4 −1
Original line number Diff line number Diff line
@@ -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 | \

arch/arm64/kernel/entry-common.c

+4 −0
Original line number Diff line number Diff line
@@ -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);