[PATCH] livepatch: Remove klp_arch_set_pc() and asm/livepatch.h

Christophe Leroy
2022-03-28T06:27:17Z

All three versions of klp_arch_set_pc() do exactly the same: they
call ftrace_instruction_pointer_set().

Call ftrace_instruction_pointer_set() directly and remove
klp_arch_set_pc().

As klp_arch_set_pc() was the only thing remaining in asm/livepatch.h
on x86 and s390, remove asm/livepatch.h

livepatch.h remains on powerpc but its content is exclusively used
by powerpc specific code.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
MAINTAINERS | 2 --
arch/powerpc/include/asm/livepatch.h | 10 +---------
arch/powerpc/kernel/irq.c | 1 -
arch/powerpc/kernel/setup_64.c | 2 +-
arch/s390/include/asm/livepatch.h | 22 ----------------------
arch/x86/include/asm/livepatch.h | 20 --------------------
include/linux/livepatch.h | 2 --
kernel/livepatch/patch.c | 2 +-
8 files changed, 3 insertions(+), 58 deletions(-)
delete mode 100644 arch/s390/include/asm/livepatch.h
delete mode 100644 arch/x86/include/asm/livepatch.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 1ef8327aef1f..cb5f0d4a8fcc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11253,8 +11253,6 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching.g
F: Documentation/ABI/testing/sysfs-kernel-livepatch
F: Documentation/livepatch/
F: arch/powerpc/include/asm/livepatch.h
-F: arch/s390/include/asm/livepatch.h
-F: arch/x86/include/asm/livepatch.h
F: include/linux/livepatch.h
F: kernel/livepatch/
F: lib/livepatch/
diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index 1c60094ea0cd..d044a1fd4f44 100644
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -7,17 +7,9 @@
#ifndef _ASM_POWERPC_LIVEPATCH_H
#define _ASM_POWERPC_LIVEPATCH_H

-#include <linux/module.h>
-#include <linux/ftrace.h>
+#include <linux/sched.h>
#include <linux/sched/task_stack.h>

-#ifdef CONFIG_LIVEPATCH
-static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
-{
- ftrace_instruction_pointer_set(fregs, ip);
-}
-#endif /* CONFIG_LIVEPATCH */
-
#ifdef CONFIG_LIVEPATCH_64
static inline void klp_init_thread_info(struct task_struct *p)
{
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 1c4715a03cd1..8c20226bcc11 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -64,7 +64,6 @@
#include <asm/machdep.h>
#include <asm/udbg.h>
#include <asm/smp.h>
-#include <asm/livepatch.h>
#include <asm/hw_irq.h>
#include <asm/softirq_stack.h>

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index e547066a06aa..2c1e9a5ac6ca 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -59,7 +59,7 @@
#include <asm/udbg.h>
#include <asm/kexec.h>
#include <asm/code-patching.h>
-#include <asm/livepatch.h>
+#include <asm/ftrace.h>
#include <asm/opal.h>
#include <asm/cputhreads.h>
#include <asm/hw_irq.h>
diff --git a/arch/s390/include/asm/livepatch.h b/arch/s390/include/asm/livepatch.h
deleted file mode 100644
index 5209f223331a..000000000000
--- a/arch/s390/include/asm/livepatch.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
-/*
- * livepatch.h - s390-specific Kernel Live Patching Core
- *
- * Copyright (c) 2013-2015 SUSE
- * Authors: Jiri Kosina
- * Vojtech Pavlik
- * Jiri Slaby
- */
-
-#ifndef ASM_LIVEPATCH_H
-#define ASM_LIVEPATCH_H
-
-#include <linux/ftrace.h>
-#include <asm/ptrace.h>
-
-static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
-{
- ftrace_instruction_pointer_set(fregs, ip);
-}
-
-#endif
diff --git a/arch/x86/include/asm/livepatch.h b/arch/x86/include/asm/livepatch.h
deleted file mode 100644
index 7c5cc6660e4b..000000000000
--- a/arch/x86/include/asm/livepatch.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * livepatch.h - x86-specific Kernel Live Patching Core
- *
- * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
- * Copyright (C) 2014 SUSE
- */
-
-#ifndef _ASM_X86_LIVEPATCH_H
-#define _ASM_X86_LIVEPATCH_H
-
-#include <asm/setup.h>
-#include <linux/ftrace.h>
-
-static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
-{
- ftrace_instruction_pointer_set(fregs, ip);
-}
-
-#endif /* _ASM_X86_LIVEPATCH_H */
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 2614247a9781..293e29960c6e 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -16,8 +16,6 @@

#if IS_ENABLED(CONFIG_LIVEPATCH)

-#include <asm/livepatch.h>
-
/* task patch states */
#define KLP_UNDEFINED -1
#define KLP_UNPATCHED 0
diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c
index c172bf92b576..4c4f5a776d80 100644
--- a/kernel/livepatch/patch.c
+++ b/kernel/livepatch/patch.c
@@ -118,7 +118,7 @@ static void notrace klp_ftrace_handler(unsigned long ip,
if (func->nop)
goto unlock;

- klp_arch_set_pc(fregs, (unsigned long)func->new_func);
+ ftrace_instruction_pointer_set(fregs, (unsigned long)func->new_func);

unlock:
ftrace_test_recursion_unlock(bit);
--
2.35.1