From c7858bf16c0b2cc62f475f31e6df28c3a68da1d6 Mon Sep 17 00:00:00 2001 From: Michal Marek Date: Tue, 3 Jan 2017 13:49:42 +0100 Subject: [PATCH] asm-prototypes: Clear any CPP defines before declaring the functions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The asm-prototypes.h file is used to provide dummy function declarations for genksyms, when processing asm files with EXPORT_SYMBOL. Make sure that any architecture defines get out of our way. x86 currently has an issue with memcpy on 64bit with CONFIG_KMEMCHECK=y and with memset/__memset on 32bit: $ cat init/test.c #include $ make -s init/test.o In file included from ./arch/x86/include/asm/string.h:4:0, from ./include/linux/string.h:18, from ./include/linux/bitmap.h:8, from ./include/linux/cpumask.h:11, from ./arch/x86/include/asm/cpumask.h:4, from ./arch/x86/include/asm/msr.h:10, from ./arch/x86/include/asm/processor.h:20, from ./arch/x86/include/asm/cpufeature.h:4, from ./arch/x86/include/asm/thread_info.h:52, from ./include/linux/thread_info.h:25, from ./arch/x86/include/asm/preempt.h:6, from ./include/linux/preempt.h:59, from ./include/linux/spinlock.h:50, from ./include/linux/seqlock.h:35, from ./include/linux/time.h:5, from ./include/uapi/linux/timex.h:56, from ./include/linux/timex.h:56, from ./include/linux/sched.h:19, from ./include/linux/uaccess.h:4, from ./arch/x86/include/asm/asm-prototypes.h:2, from init/test.c:1: ./arch/x86/include/asm/string_64.h:52:47: error: expected declaration specifiers or ‘...’ before ‘(’ token #define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len)) ./include/asm-generic/asm-prototypes.h:6:14: note: in expansion of macro ‘memcpy’ extern void *memcpy(void *, const void *, __kernel_size_t); ^ ... During real build, this manifests itself by genksyms segfaulting. Fixes: 334bb7738764 ("x86/kbuild: enable modversions for symbols exported from asm") Reported-and-tested-by: Borislav Petkov Cc: Adam Borowski Signed-off-by: Michal Marek --- include/asm-generic/asm-prototypes.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/include/asm-generic/asm-prototypes.h b/include/asm-generic/asm-prototypes.h index df13637e4017..939869c772b1 100644 --- a/include/asm-generic/asm-prototypes.h +++ b/include/asm-generic/asm-prototypes.h @@ -1,7 +1,13 @@ #include +#undef __memset extern void *__memset(void *, int, __kernel_size_t); +#undef __memcpy extern void *__memcpy(void *, const void *, __kernel_size_t); +#undef __memmove extern void *__memmove(void *, const void *, __kernel_size_t); +#undef memset extern void *memset(void *, int, __kernel_size_t); +#undef memcpy extern void *memcpy(void *, const void *, __kernel_size_t); +#undef memmove extern void *memmove(void *, const void *, __kernel_size_t); -- GitLab