On Thu, 17 Sep 2015 23:02:14 +0300 Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> wrote: > 2015-09-17 22:37 GMT+03:00 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>: > > On Thu, 17 Sep 2015 09:17:56 +0800 kbuild test robot <fengguang.wu@xxxxxxxxx> wrote: > > > >> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > >> head: 72714841b705a5b9bccf37ee85a62352bee3a3ef > >> commit: 393f203f5fd54421fddb1e2a263f64d3876eeadb x86_64: kasan: add interceptors for memset/memmove/memcpy functions > >> date: 7 months ago > >> config: i386-randconfig-i0-201537 (attached as .config) > >> reproduce: > >> git checkout 393f203f5fd54421fddb1e2a263f64d3876eeadb > >> # save the attached .config to linux build tree > >> make ARCH=i386 > >> > >> All warnings (new ones prefixed by >>): > >> > >> drivers/firmware/efi/libstub/efi-stub-helper.c: In function 'efi_relocate_kernel': > >> >> drivers/firmware/efi/libstub/efi-stub-helper.c:599:2: warning: implicit declaration of function 'memcpy' [-Wimplicit-function-declaration] > >> memcpy((void *)new_addr, (void *)cur_image_addr, image_size); > > > > I can't reproduce this. > > > > But whatever. I'll do this: > > > > --- a/drivers/firmware/efi/libstub/efi-stub-helper.c~drivers-firmware-efi-libstub-efi-stub-helperc-needs-stringh > > +++ a/drivers/firmware/efi/libstub/efi-stub-helper.c > > @@ -11,6 +11,7 @@ > > */ > > > > #include <linux/efi.h> > > +#include <linux/string.h> > > This won't help. > arch/x86/include/asm/string_32.h has several variants of #define memcpy() > But it doesn't have declaration of memcpy function like: > void memcpy(const void *to, const void *from, size_t len); > Thus '#undef memcpy' causes this warning, and including > <linux/string.h> won't help (It probably already included) Well, I can't tell either way because that warning doesn't come out for me with the provided config. > Patch from KASAN for arm64 series: > http://marc.info/?l=linux-mm&m=144248270719929&w=2 ([PATCH v6 3/6] > x86, efi, kasan: #undef memset/memcpy/memmove per arch.) > should fix this warning, as it moves '#undef memcpy' under #ifdef > X86_64 in arch/x86/include/asm/efi.h hm, that patch was misfiled. We want this for for 4.3-rc. I'll queue it up. I hope it's independent of the rest of that patch series? From: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Subject: x86, efi, kasan: #undef memset/memcpy/memmove per arch In not-instrumented code KASAN replaces instrumented memset/memcpy/memmove with not-instrumented analogues __memset/__memcpy/__memove. However, on x86 the EFI stub is not linked with the kernel. It uses not-instrumented mem*() functions from arch/x86/boot/compressed/string.c So we don't replace them with __mem*() variants in EFI stub. On ARM64 the EFI stub is linked with the kernel, so we should replace mem*() functions with __mem*(), because the EFI stub runs before KASAN sets up early shadow. So let's move these #undef mem* into arch's asm/efi.h which is also included by the EFI stub. Also, this will fix the warning in 32-bit build reported by kbuild test robot: efi-stub-helper.c:599:2: warning: implicit declaration of function 'memcpy' Signed-off-by: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Matt Fleming <matt.fleming@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/efi.h | 12 ++++++++++++ drivers/firmware/efi/libstub/efistub.h | 4 ---- 2 files changed, 12 insertions(+), 4 deletions(-) diff -puN arch/x86/include/asm/efi.h~x86-efi-kasan-undef-memset-memcpy-memmove-per-arch arch/x86/include/asm/efi.h --- a/arch/x86/include/asm/efi.h~x86-efi-kasan-undef-memset-memcpy-memmove-per-arch +++ a/arch/x86/include/asm/efi.h @@ -86,6 +86,18 @@ extern u64 asmlinkage efi_call(void *fp, extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size, u32 type, u64 attribute); +/* + * CONFIG_KASAN may redefine memset to __memset. + * __memset function is present only in kernel binary. + * Since the EFI stub linked into a separate binary it + * doesn't have __memset(). So we should use standard + * memset from arch/x86/boot/compressed/string.c + * The same applies to memcpy and memmove. + */ +#undef memcpy +#undef memset +#undef memmove + #endif /* CONFIG_X86_32 */ extern struct efi_scratch efi_scratch; diff -puN drivers/firmware/efi/libstub/efistub.h~x86-efi-kasan-undef-memset-memcpy-memmove-per-arch drivers/firmware/efi/libstub/efistub.h --- a/drivers/firmware/efi/libstub/efistub.h~x86-efi-kasan-undef-memset-memcpy-memmove-per-arch +++ a/drivers/firmware/efi/libstub/efistub.h @@ -5,10 +5,6 @@ /* error code which can't be mistaken for valid address */ #define EFI_ERROR (~0UL) -#undef memcpy -#undef memset -#undef memmove - void efi_char16_printk(efi_system_table_t *, efi_char16_t *); efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, void *__image, _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . 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