From e1478d8eaf27704db17a44dee4c53696ed01fc9c Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 15 Feb 2022 13:41:04 +0100 Subject: asm-generic: Refactor dereference_[kernel]_function_descriptor() dereference_function_descriptor() and dereference_kernel_function_descriptor() are identical on the three architectures implementing them. Make them common and put them out-of-line in kernel/extable.c which is one of the users and has similar type of functions. Signed-off-by: Christophe Leroy Reviewed-by: Kees Cook Reviewed-by: Arnd Bergmann Acked-by: Helge Deller Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/449db09b2eba57f4ab05f80102a67d8675bc8bcd.1644928018.git.christophe.leroy@csgroup.eu --- arch/ia64/include/asm/sections.h | 19 ------------------- arch/parisc/include/asm/sections.h | 9 --------- arch/parisc/kernel/process.c | 21 --------------------- arch/powerpc/include/asm/sections.h | 23 ----------------------- include/asm-generic/sections.h | 2 ++ kernel/extable.c | 23 ++++++++++++++++++++++- 6 files changed, 24 insertions(+), 73 deletions(-) diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h index 3abe0562b01a..8e0875cf6071 100644 --- a/arch/ia64/include/asm/sections.h +++ b/arch/ia64/include/asm/sections.h @@ -30,23 +30,4 @@ extern char __start_gate_brl_fsys_bubble_down_patchlist[], __end_gate_brl_fsys_b extern char __start_unwind[], __end_unwind[]; extern char __start_ivt_text[], __end_ivt_text[]; -#undef dereference_function_descriptor -static inline void *dereference_function_descriptor(void *ptr) -{ - struct fdesc *desc = ptr; - void *p; - - if (!get_kernel_nofault(p, (void *)&desc->addr)) - ptr = p; - return ptr; -} - -#undef dereference_kernel_function_descriptor -static inline void *dereference_kernel_function_descriptor(void *ptr) -{ - if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd) - return ptr; - return dereference_function_descriptor(ptr); -} - #endif /* _ASM_IA64_SECTIONS_H */ diff --git a/arch/parisc/include/asm/sections.h b/arch/parisc/include/asm/sections.h index ace1d4047a0b..33df42b5cc6d 100644 --- a/arch/parisc/include/asm/sections.h +++ b/arch/parisc/include/asm/sections.h @@ -12,13 +12,4 @@ typedef Elf64_Fdesc func_desc_t; extern char __alt_instructions[], __alt_instructions_end[]; -#ifdef CONFIG_64BIT - -#undef dereference_function_descriptor -void *dereference_function_descriptor(void *); - -#undef dereference_kernel_function_descriptor -void *dereference_kernel_function_descriptor(void *); -#endif - #endif diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c index ea3d83b6fb62..2030c77592d3 100644 --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -263,27 +263,6 @@ __get_wchan(struct task_struct *p) return 0; } -#ifdef CONFIG_64BIT -void *dereference_function_descriptor(void *ptr) -{ - Elf64_Fdesc *desc = ptr; - void *p; - - if (!get_kernel_nofault(p, (void *)&desc->addr)) - ptr = p; - return ptr; -} - -void *dereference_kernel_function_descriptor(void *ptr) -{ - if (ptr < (void *)__start_opd || - ptr >= (void *)__end_opd) - return ptr; - - return dereference_function_descriptor(ptr); -} -#endif - static inline unsigned long brk_rnd(void) { return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h index fddfb3937868..8be2c491c733 100644 --- a/arch/powerpc/include/asm/sections.h +++ b/arch/powerpc/include/asm/sections.h @@ -58,29 +58,6 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end) (unsigned long)_stext < end; } -#ifdef PPC64_ELF_ABI_v1 - -#undef dereference_function_descriptor -static inline void *dereference_function_descriptor(void *ptr) -{ - struct func_desc *desc = ptr; - void *p; - - if (!get_kernel_nofault(p, (void *)&desc->addr)) - ptr = p; - return ptr; -} - -#undef dereference_kernel_function_descriptor -static inline void *dereference_kernel_function_descriptor(void *ptr) -{ - if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd) - return ptr; - - return dereference_function_descriptor(ptr); -} -#endif /* PPC64_ELF_ABI_v1 */ - #endif #endif /* __KERNEL__ */ diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h index bbf97502470c..d0f7bdd2fdf2 100644 --- a/include/asm-generic/sections.h +++ b/include/asm-generic/sections.h @@ -60,6 +60,8 @@ extern __visible const void __nosave_begin, __nosave_end; /* Function descriptor handling (if any). Override in asm/sections.h */ #ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS +void *dereference_function_descriptor(void *ptr); +void *dereference_kernel_function_descriptor(void *ptr); #else #define dereference_function_descriptor(p) ((void *)(p)) #define dereference_kernel_function_descriptor(p) ((void *)(p)) diff --git a/kernel/extable.c b/kernel/extable.c index b6f330f0fe74..394c39b86e38 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -3,6 +3,7 @@ Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM. */ +#include #include #include #include @@ -132,12 +133,32 @@ out: } /* - * On some architectures (PPC64, IA64) function pointers + * On some architectures (PPC64, IA64, PARISC) function pointers * are actually only tokens to some data that then holds the * real function address. As a result, to find if a function * pointer is part of the kernel text, we need to do some * special dereferencing first. */ +#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS +void *dereference_function_descriptor(void *ptr) +{ + func_desc_t *desc = ptr; + void *p; + + if (!get_kernel_nofault(p, (void *)&desc->addr)) + ptr = p; + return ptr; +} + +void *dereference_kernel_function_descriptor(void *ptr) +{ + if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd) + return ptr; + + return dereference_function_descriptor(ptr); +} +#endif + int func_ptr_is_kernel_text(void *ptr) { unsigned long addr; -- cgit