From d15cb3dab1e4f00e29599a4f5e1f6678a530d270 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 8 Mar 2022 16:30:30 +0100 Subject: x86/livepatch: Validate __fentry__ location Currently livepatch assumes __fentry__ lives at func+0, which is most likely untrue with IBT on. Instead make it use ftrace_location() by default which both validates and finds the actual ip if there is any in the same symbol. Suggested-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20220308154318.285971256@infradead.org --- kernel/livepatch/patch.c | 19 ++----------------- 1 file changed, 2 insertions(+), 17 deletions(-) (limited to 'kernel/livepatch/patch.c') diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c index fe316c021d73..c172bf92b576 100644 --- a/kernel/livepatch/patch.c +++ b/kernel/livepatch/patch.c @@ -124,19 +124,6 @@ unlock: ftrace_test_recursion_unlock(bit); } -/* - * Convert a function address into the appropriate ftrace location. - * - * Usually this is just the address of the function, but on some architectures - * it's more complicated so allow them to provide a custom behaviour. - */ -#ifndef klp_get_ftrace_location -static unsigned long klp_get_ftrace_location(unsigned long faddr) -{ - return faddr; -} -#endif - static void klp_unpatch_func(struct klp_func *func) { struct klp_ops *ops; @@ -153,8 +140,7 @@ static void klp_unpatch_func(struct klp_func *func) if (list_is_singular(&ops->func_stack)) { unsigned long ftrace_loc; - ftrace_loc = - klp_get_ftrace_location((unsigned long)func->old_func); + ftrace_loc = ftrace_location((unsigned long)func->old_func); if (WARN_ON(!ftrace_loc)) return; @@ -186,8 +172,7 @@ static int klp_patch_func(struct klp_func *func) if (!ops) { unsigned long ftrace_loc; - ftrace_loc = - klp_get_ftrace_location((unsigned long)func->old_func); + ftrace_loc = ftrace_location((unsigned long)func->old_func); if (!ftrace_loc) { pr_err("failed to find location for function '%s'\n", func->old_name); -- cgit From 5d7c854593a460706dacf8e1b16c9bdcb1c2d7bb Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Mon, 28 Mar 2022 08:26:48 +0200 Subject: livepatch: Remove klp_arch_set_pc() and asm/livepatch.h 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 Acked-by: Petr Mladek Acked-by: Peter Zijlstra (Intel) Acked-by: Miroslav Benes Signed-off-by: Petr Mladek --- 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 (limited to 'kernel/livepatch/patch.c') diff --git a/MAINTAINERS b/MAINTAINERS index 741825cff43c..589c61412e3b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11338,8 +11338,6 @@ 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 -#include +#include #include -#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 752fb182eacb..fb99e3fa034d 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -63,7 +63,6 @@ #include #include #include -#include #include #include 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 #include #include -#include +#include #include #include #include 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 -#include - -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 - * Copyright (C) 2014 SUSE - */ - -#ifndef _ASM_X86_LIVEPATCH_H -#define _ASM_X86_LIVEPATCH_H - -#include -#include - -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 - /* 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); -- cgit