2019-03-04 05:27:06

by Daniel Axtens

[permalink] [raw]
Subject: Re: [PATCH v9 02/11] powerpc: prepare string/mem functions for KASAN

Hi Christophe,
> diff --git a/arch/powerpc/include/asm/kasan.h b/arch/powerpc/include/asm/kasan.h
> new file mode 100644
> index 000000000000..c3161b8fc017
> --- /dev/null
> +++ b/arch/powerpc/include/asm/kasan.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __ASM_KASAN_H
> +#define __ASM_KASAN_H
> +
> +#ifdef CONFIG_KASAN
> +#define _GLOBAL_KASAN(fn) .weak fn ; _GLOBAL(__##fn) ; _GLOBAL(fn)
> +#define _GLOBAL_TOC_KASAN(fn) .weak fn ; _GLOBAL_TOC(__##fn) ; _GLOBAL_TOC(fn)
> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(__##fn) ; EXPORT_SYMBOL(fn)

I'm having some trouble with this. I get warnings like this:

WARNING: EXPORT symbol "__memcpy" [vmlinux] version generation failed, symbol will not be versioned.

It seems to be related to the export line, as if I swap the exports to
do fn before __##fn I get:

WARNING: EXPORT symbol "memset" [vmlinux] version generation failed, symbol will not be versioned.

I have narrowed this down to combining 2 EXPORT_SYMBOL()s on one line.
This works - no warning:

EXPORT_SYMBOL(memset)
EXPORT_SYMBOL(__memset)

This throws a warning:

EXPORT_SYMBOL(memset) ; EXPORT_SYMBOL(__memset)

I notice in looking at the diff of preprocessed source we end up
invoking an asm macro that doesn't seem to have a full final argument, I
wonder if that's relevant...

-___EXPORT_SYMBOL __memset, __memset, ; ___EXPORT_SYMBOL memset, memset,
+___EXPORT_SYMBOL __memset, __memset,
+___EXPORT_SYMBOL memset, memset,

I also notice that nowhere else in the source do people have multiple
EXPORT_SYMBOLs on the same line, and other arches seem to just
unconditionally export both symbols on multiple lines.

I have no idea how this works for you - maybe it's affected by something 32bit.

How would you feel about this approach instead? I'm not tied to any of
the names or anything.

diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index e0637730a8e7..7b6a91b448dd 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -214,6 +214,9 @@ name: \

#define DOTSYM(a) a

+#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
+ .weak weakname ; .set weakname, strongname ;
+
#else

#define XGLUE(a,b) a##b
@@ -236,6 +239,10 @@ GLUE(.,name):

#define DOTSYM(a) GLUE(.,a)

+#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
+ .weak weakname ; .set weakname, strongname ; \
+ .weak DOTSYM(weakname) ; .set DOTSYM(weakname), DOTSYM(strongname) ;
+
#endif

#else /* 32-bit */
@@ -251,6 +258,9 @@ GLUE(.,name):

#define _GLOBAL_TOC(name) _GLOBAL(name)

+#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
+ .weak weakname ; .set weakname, strongname ;
+
#endif

/*
--- a/arch/powerpc/lib/mem_64.S
+++ b/arch/powerpc/lib/mem_64.S
@@ -33,7 +33,8 @@ EXPORT_SYMBOL(__memset32)
EXPORT_SYMBOL(__memset64)
#endif

-_GLOBAL_KASAN(memset)
+PROVIDE_WEAK_ALIAS(__memset,memset)
+_GLOBAL(__memset)
neg r0,r3
rlwimi r4,r4,8,16,23
andi. r0,r0,7 /* # bytes to be 8-byte aligned */
@@ -98,9 +99,11 @@ _GLOBAL_KASAN(memset)
10: bflr 31
stb r4,0(r6)
blr
-EXPORT_SYMBOL_KASAN(memset)
+EXPORT_SYMBOL(memset)
+EXPORT_SYMBOL(__memset)

-_GLOBAL_TOC_KASAN(memmove)
+PROVIDE_WEAK_ALIAS(__memmove,memove)
+_GLOBAL_TOC(__memmove)
cmplw 0,r3,r4
bgt backwards_memcpy
b memcpy
@@ -141,4 +144,5 @@ _GLOBAL(backwards_memcpy)
beq 2b
mtctr r7
b 1b
-EXPORT_SYMBOL_KASAN(memmove)
+EXPORT_SYMBOL(memmove)
+EXPORT_SYMBOL(__memmove)
diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
index 862b515b8868..7c1b09556cad 100644
--- a/arch/powerpc/lib/memcpy_64.S
+++ b/arch/powerpc/lib/memcpy_64.S
@@ -19,7 +19,8 @@
#endif

.align 7
-_GLOBAL_TOC_KASAN(memcpy)
+PROVIDE_WEAK_ALIAS(__memcpy,memcpy)
+_GLOBAL_TOC(__memcpy)
BEGIN_FTR_SECTION
#ifdef __LITTLE_ENDIAN__
cmpdi cr7,r5,0
@@ -230,4 +231,5 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
blr
#endif
-EXPORT_SYMBOL_KASAN(memcpy)
+EXPORT_SYMBOL(__memcpy)
+EXPORT_SYMBOL(memcpy)


Regards,
Daniel


> +#else
> +#define _GLOBAL_KASAN(fn) _GLOBAL(fn)
> +#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(fn)
> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(fn)
> +#endif
> +
> +#endif
> diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h
> index 1647de15a31e..9bf6dffb4090 100644
> --- a/arch/powerpc/include/asm/string.h
> +++ b/arch/powerpc/include/asm/string.h
> @@ -4,14 +4,17 @@
>
> #ifdef __KERNEL__
>
> +#ifndef CONFIG_KASAN
> #define __HAVE_ARCH_STRNCPY
> #define __HAVE_ARCH_STRNCMP
> +#define __HAVE_ARCH_MEMCHR
> +#define __HAVE_ARCH_MEMCMP
> +#define __HAVE_ARCH_MEMSET16
> +#endif
> +
> #define __HAVE_ARCH_MEMSET
> #define __HAVE_ARCH_MEMCPY
> #define __HAVE_ARCH_MEMMOVE
> -#define __HAVE_ARCH_MEMCMP
> -#define __HAVE_ARCH_MEMCHR
> -#define __HAVE_ARCH_MEMSET16
> #define __HAVE_ARCH_MEMCPY_FLUSHCACHE
>
> extern char * strcpy(char *,const char *);
> @@ -27,7 +30,27 @@ extern int memcmp(const void *,const void *,__kernel_size_t);
> extern void * memchr(const void *,int,__kernel_size_t);
> extern void * memcpy_flushcache(void *,const void *,__kernel_size_t);
>
> +void *__memset(void *s, int c, __kernel_size_t count);
> +void *__memcpy(void *to, const void *from, __kernel_size_t n);
> +void *__memmove(void *to, const void *from, __kernel_size_t n);
> +
> +#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
> +/*
> + * For files that are not instrumented (e.g. mm/slub.c) we
> + * should use not instrumented version of mem* functions.
> + */
> +#define memcpy(dst, src, len) __memcpy(dst, src, len)
> +#define memmove(dst, src, len) __memmove(dst, src, len)
> +#define memset(s, c, n) __memset(s, c, n)
> +
> +#ifndef __NO_FORTIFY
> +#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
> +#endif
> +
> +#endif
> +
> #ifdef CONFIG_PPC64
> +#ifndef CONFIG_KASAN
> #define __HAVE_ARCH_MEMSET32
> #define __HAVE_ARCH_MEMSET64
>
> @@ -49,8 +72,11 @@ static inline void *memset64(uint64_t *p, uint64_t v, __kernel_size_t n)
> {
> return __memset64(p, v, n * 8);
> }
> +#endif
> #else
> +#ifndef CONFIG_KASAN
> #define __HAVE_ARCH_STRLEN
> +#endif
>
> extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
> #endif
> diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh
> index 667df97d2595..181fd10008ef 100644
> --- a/arch/powerpc/kernel/prom_init_check.sh
> +++ b/arch/powerpc/kernel/prom_init_check.sh
> @@ -16,8 +16,16 @@
> # If you really need to reference something from prom_init.o add
> # it to the list below:
>
> +grep "^CONFIG_KASAN=y$" .config >/dev/null
> +if [ $? -eq 0 ]
> +then
> + MEM_FUNCS="__memcpy __memset"
> +else
> + MEM_FUNCS="memcpy memset"
> +fi
> +
> WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
> -_end enter_prom memcpy memset reloc_offset __secondary_hold
> +_end enter_prom $MEM_FUNCS reloc_offset __secondary_hold
> __secondary_hold_acknowledge __secondary_hold_spinloop __start
> strcmp strcpy strlcpy strlen strncmp strstr kstrtobool logo_linux_clut224
> reloc_got2 kernstart_addr memstart_addr linux_banner _stext
> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
> index 79396e184bca..47a4de434c22 100644
> --- a/arch/powerpc/lib/Makefile
> +++ b/arch/powerpc/lib/Makefile
> @@ -8,9 +8,14 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
> CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
> CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
>
> -obj-y += string.o alloc.o code-patching.o feature-fixups.o
> +obj-y += alloc.o code-patching.o feature-fixups.o
>
> -obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o strlen_32.o
> +ifndef CONFIG_KASAN
> +obj-y += string.o memcmp_$(BITS).o
> +obj-$(CONFIG_PPC32) += strlen_32.o
> +endif
> +
> +obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o
>
> obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
>
> @@ -34,7 +39,7 @@ obj64-$(CONFIG_KPROBES_SANITY_TEST) += test_emulate_step.o \
> test_emulate_step_exec_instr.o
>
> obj-y += checksum_$(BITS).o checksum_wrappers.o \
> - string_$(BITS).o memcmp_$(BITS).o
> + string_$(BITS).o
>
> obj-y += sstep.o ldstfp.o quad.o
> obj64-y += quad.o
> diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
> index ba66846fe973..fc4fa7246200 100644
> --- a/arch/powerpc/lib/copy_32.S
> +++ b/arch/powerpc/lib/copy_32.S
> @@ -14,6 +14,7 @@
> #include <asm/ppc_asm.h>
> #include <asm/export.h>
> #include <asm/code-patching-asm.h>
> +#include <asm/kasan.h>
>
> #define COPY_16_BYTES \
> lwz r7,4(r4); \
> @@ -68,6 +69,7 @@ CACHELINE_BYTES = L1_CACHE_BYTES
> LG_CACHELINE_BYTES = L1_CACHE_SHIFT
> CACHELINE_MASK = (L1_CACHE_BYTES-1)
>
> +#ifndef CONFIG_KASAN
> _GLOBAL(memset16)
> rlwinm. r0 ,r5, 31, 1, 31
> addi r6, r3, -4
> @@ -81,6 +83,7 @@ _GLOBAL(memset16)
> sth r4, 4(r6)
> blr
> EXPORT_SYMBOL(memset16)
> +#endif
>
> /*
> * Use dcbz on the complete cache lines in the destination
> @@ -91,7 +94,7 @@ EXPORT_SYMBOL(memset16)
> * We therefore skip the optimised bloc that uses dcbz. This jump is
> * replaced by a nop once cache is active. This is done in machine_init()
> */
> -_GLOBAL(memset)
> +_GLOBAL_KASAN(memset)
> cmplwi 0,r5,4
> blt 7f
>
> @@ -150,7 +153,7 @@ _GLOBAL(memset)
> 9: stbu r4,1(r6)
> bdnz 9b
> blr
> -EXPORT_SYMBOL(memset)
> +EXPORT_SYMBOL_KASAN(memset)
>
> /*
> * This version uses dcbz on the complete cache lines in the
> @@ -163,12 +166,12 @@ EXPORT_SYMBOL(memset)
> * We therefore jump to generic_memcpy which doesn't use dcbz. This jump is
> * replaced by a nop once cache is active. This is done in machine_init()
> */
> -_GLOBAL(memmove)
> +_GLOBAL_KASAN(memmove)
> cmplw 0,r3,r4
> bgt backwards_memcpy
> /* fall through */
>
> -_GLOBAL(memcpy)
> +_GLOBAL_KASAN(memcpy)
> 1: b generic_memcpy
> patch_site 1b, patch__memcpy_nocache
>
> @@ -242,8 +245,8 @@ _GLOBAL(memcpy)
> stbu r0,1(r6)
> bdnz 40b
> 65: blr
> -EXPORT_SYMBOL(memcpy)
> -EXPORT_SYMBOL(memmove)
> +EXPORT_SYMBOL_KASAN(memcpy)
> +EXPORT_SYMBOL_KASAN(memmove)
>
> generic_memcpy:
> srwi. r7,r5,3
> diff --git a/arch/powerpc/lib/mem_64.S b/arch/powerpc/lib/mem_64.S
> index 3c3be02f33b7..7cd6cf6822a2 100644
> --- a/arch/powerpc/lib/mem_64.S
> +++ b/arch/powerpc/lib/mem_64.S
> @@ -12,7 +12,9 @@
> #include <asm/errno.h>
> #include <asm/ppc_asm.h>
> #include <asm/export.h>
> +#include <asm/kasan.h>
>
> +#ifndef CONFIG_KASAN
> _GLOBAL(__memset16)
> rlwimi r4,r4,16,0,15
> /* fall through */
> @@ -29,8 +31,9 @@ _GLOBAL(__memset64)
> EXPORT_SYMBOL(__memset16)
> EXPORT_SYMBOL(__memset32)
> EXPORT_SYMBOL(__memset64)
> +#endif
>
> -_GLOBAL(memset)
> +_GLOBAL_KASAN(memset)
> neg r0,r3
> rlwimi r4,r4,8,16,23
> andi. r0,r0,7 /* # bytes to be 8-byte aligned */
> @@ -95,9 +98,9 @@ _GLOBAL(memset)
> 10: bflr 31
> stb r4,0(r6)
> blr
> -EXPORT_SYMBOL(memset)
> +EXPORT_SYMBOL_KASAN(memset)
>
> -_GLOBAL_TOC(memmove)
> +_GLOBAL_TOC_KASAN(memmove)
> cmplw 0,r3,r4
> bgt backwards_memcpy
> b memcpy
> @@ -138,4 +141,4 @@ _GLOBAL(backwards_memcpy)
> beq 2b
> mtctr r7
> b 1b
> -EXPORT_SYMBOL(memmove)
> +EXPORT_SYMBOL_KASAN(memmove)
> diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
> index 273ea67e60a1..862b515b8868 100644
> --- a/arch/powerpc/lib/memcpy_64.S
> +++ b/arch/powerpc/lib/memcpy_64.S
> @@ -11,6 +11,7 @@
> #include <asm/export.h>
> #include <asm/asm-compat.h>
> #include <asm/feature-fixups.h>
> +#include <asm/kasan.h>
>
> #ifndef SELFTEST_CASE
> /* For big-endian, 0 == most CPUs, 1 == POWER6, 2 == Cell */
> @@ -18,7 +19,7 @@
> #endif
>
> .align 7
> -_GLOBAL_TOC(memcpy)
> +_GLOBAL_TOC_KASAN(memcpy)
> BEGIN_FTR_SECTION
> #ifdef __LITTLE_ENDIAN__
> cmpdi cr7,r5,0
> @@ -229,4 +230,4 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
> 4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
> blr
> #endif
> -EXPORT_SYMBOL(memcpy)
> +EXPORT_SYMBOL_KASAN(memcpy)
> --
> 2.13.3


2019-03-06 21:56:40

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH v9 02/11] powerpc: prepare string/mem functions for KASAN



Le 04/03/2019 à 06:26, Daniel Axtens a écrit :
> Hi Christophe,
>> diff --git a/arch/powerpc/include/asm/kasan.h b/arch/powerpc/include/asm/kasan.h
>> new file mode 100644
>> index 000000000000..c3161b8fc017
>> --- /dev/null
>> +++ b/arch/powerpc/include/asm/kasan.h
>> @@ -0,0 +1,15 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef __ASM_KASAN_H
>> +#define __ASM_KASAN_H
>> +
>> +#ifdef CONFIG_KASAN
>> +#define _GLOBAL_KASAN(fn) .weak fn ; _GLOBAL(__##fn) ; _GLOBAL(fn)
>> +#define _GLOBAL_TOC_KASAN(fn) .weak fn ; _GLOBAL_TOC(__##fn) ; _GLOBAL_TOC(fn)
>> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(__##fn) ; EXPORT_SYMBOL(fn)
>
> I'm having some trouble with this. I get warnings like this:

I don't have such problem, neither with ppc32 nor with ppc64e_defconfig.

What config are you using ?

Another (unrelated) question I have:
On the initial arm64 implementation (39d114ddc682 arm64: add KASAN
support) they made KASAN implementation depend on SPARSEMEM_VMEMMAP
(allthough they later removed that dependency with commit e17d8025f07e
arm64/mm/kasan: don't use vmemmap_populate() to initialize shadow)

So I'm wondering why on your side, KASAN depends on !SPARSEMEM_VMEMMAP

Thanks
Christophe

>
> WARNING: EXPORT symbol "__memcpy" [vmlinux] version generation failed, symbol will not be versioned.
>
> It seems to be related to the export line, as if I swap the exports to
> do fn before __##fn I get:
>
> WARNING: EXPORT symbol "memset" [vmlinux] version generation failed, symbol will not be versioned.
>
> I have narrowed this down to combining 2 EXPORT_SYMBOL()s on one line.
> This works - no warning:
>
> EXPORT_SYMBOL(memset)
> EXPORT_SYMBOL(__memset)
>
> This throws a warning:
>
> EXPORT_SYMBOL(memset) ; EXPORT_SYMBOL(__memset)
>
> I notice in looking at the diff of preprocessed source we end up
> invoking an asm macro that doesn't seem to have a full final argument, I
> wonder if that's relevant...
>
> -___EXPORT_SYMBOL __memset, __memset, ; ___EXPORT_SYMBOL memset, memset,
> +___EXPORT_SYMBOL __memset, __memset,
> +___EXPORT_SYMBOL memset, memset,
>
> I also notice that nowhere else in the source do people have multiple
> EXPORT_SYMBOLs on the same line, and other arches seem to just
> unconditionally export both symbols on multiple lines.
>
> I have no idea how this works for you - maybe it's affected by something 32bit.
>
> How would you feel about this approach instead? I'm not tied to any of
> the names or anything.
>
> diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
> index e0637730a8e7..7b6a91b448dd 100644
> --- a/arch/powerpc/include/asm/ppc_asm.h
> +++ b/arch/powerpc/include/asm/ppc_asm.h
> @@ -214,6 +214,9 @@ name: \
>
> #define DOTSYM(a) a
>
> +#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
> + .weak weakname ; .set weakname, strongname ;
> +
> #else
>
> #define XGLUE(a,b) a##b
> @@ -236,6 +239,10 @@ GLUE(.,name):
>
> #define DOTSYM(a) GLUE(.,a)
>
> +#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
> + .weak weakname ; .set weakname, strongname ; \
> + .weak DOTSYM(weakname) ; .set DOTSYM(weakname), DOTSYM(strongname) ;
> +
> #endif
>
> #else /* 32-bit */
> @@ -251,6 +258,9 @@ GLUE(.,name):
>
> #define _GLOBAL_TOC(name) _GLOBAL(name)
>
> +#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
> + .weak weakname ; .set weakname, strongname ;
> +
> #endif
>
> /*
> --- a/arch/powerpc/lib/mem_64.S
> +++ b/arch/powerpc/lib/mem_64.S
> @@ -33,7 +33,8 @@ EXPORT_SYMBOL(__memset32)
> EXPORT_SYMBOL(__memset64)
> #endif
>
> -_GLOBAL_KASAN(memset)
> +PROVIDE_WEAK_ALIAS(__memset,memset)
> +_GLOBAL(__memset)
> neg r0,r3
> rlwimi r4,r4,8,16,23
> andi. r0,r0,7 /* # bytes to be 8-byte aligned */
> @@ -98,9 +99,11 @@ _GLOBAL_KASAN(memset)
> 10: bflr 31
> stb r4,0(r6)
> blr
> -EXPORT_SYMBOL_KASAN(memset)
> +EXPORT_SYMBOL(memset)
> +EXPORT_SYMBOL(__memset)
>
> -_GLOBAL_TOC_KASAN(memmove)
> +PROVIDE_WEAK_ALIAS(__memmove,memove)
> +_GLOBAL_TOC(__memmove)
> cmplw 0,r3,r4
> bgt backwards_memcpy
> b memcpy
> @@ -141,4 +144,5 @@ _GLOBAL(backwards_memcpy)
> beq 2b
> mtctr r7
> b 1b
> -EXPORT_SYMBOL_KASAN(memmove)
> +EXPORT_SYMBOL(memmove)
> +EXPORT_SYMBOL(__memmove)
> diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
> index 862b515b8868..7c1b09556cad 100644
> --- a/arch/powerpc/lib/memcpy_64.S
> +++ b/arch/powerpc/lib/memcpy_64.S
> @@ -19,7 +19,8 @@
> #endif
>
> .align 7
> -_GLOBAL_TOC_KASAN(memcpy)
> +PROVIDE_WEAK_ALIAS(__memcpy,memcpy)
> +_GLOBAL_TOC(__memcpy)
> BEGIN_FTR_SECTION
> #ifdef __LITTLE_ENDIAN__
> cmpdi cr7,r5,0
> @@ -230,4 +231,5 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
> 4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
> blr
> #endif
> -EXPORT_SYMBOL_KASAN(memcpy)
> +EXPORT_SYMBOL(__memcpy)
> +EXPORT_SYMBOL(memcpy)
>
>
> Regards,
> Daniel
>
>
>> +#else
>> +#define _GLOBAL_KASAN(fn) _GLOBAL(fn)
>> +#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(fn)
>> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(fn)
>> +#endif
>> +
>> +#endif
>> diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h
>> index 1647de15a31e..9bf6dffb4090 100644
>> --- a/arch/powerpc/include/asm/string.h
>> +++ b/arch/powerpc/include/asm/string.h
>> @@ -4,14 +4,17 @@
>>
>> #ifdef __KERNEL__
>>
>> +#ifndef CONFIG_KASAN
>> #define __HAVE_ARCH_STRNCPY
>> #define __HAVE_ARCH_STRNCMP
>> +#define __HAVE_ARCH_MEMCHR
>> +#define __HAVE_ARCH_MEMCMP
>> +#define __HAVE_ARCH_MEMSET16
>> +#endif
>> +
>> #define __HAVE_ARCH_MEMSET
>> #define __HAVE_ARCH_MEMCPY
>> #define __HAVE_ARCH_MEMMOVE
>> -#define __HAVE_ARCH_MEMCMP
>> -#define __HAVE_ARCH_MEMCHR
>> -#define __HAVE_ARCH_MEMSET16
>> #define __HAVE_ARCH_MEMCPY_FLUSHCACHE
>>
>> extern char * strcpy(char *,const char *);
>> @@ -27,7 +30,27 @@ extern int memcmp(const void *,const void *,__kernel_size_t);
>> extern void * memchr(const void *,int,__kernel_size_t);
>> extern void * memcpy_flushcache(void *,const void *,__kernel_size_t);
>>
>> +void *__memset(void *s, int c, __kernel_size_t count);
>> +void *__memcpy(void *to, const void *from, __kernel_size_t n);
>> +void *__memmove(void *to, const void *from, __kernel_size_t n);
>> +
>> +#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
>> +/*
>> + * For files that are not instrumented (e.g. mm/slub.c) we
>> + * should use not instrumented version of mem* functions.
>> + */
>> +#define memcpy(dst, src, len) __memcpy(dst, src, len)
>> +#define memmove(dst, src, len) __memmove(dst, src, len)
>> +#define memset(s, c, n) __memset(s, c, n)
>> +
>> +#ifndef __NO_FORTIFY
>> +#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
>> +#endif
>> +
>> +#endif
>> +
>> #ifdef CONFIG_PPC64
>> +#ifndef CONFIG_KASAN
>> #define __HAVE_ARCH_MEMSET32
>> #define __HAVE_ARCH_MEMSET64
>>
>> @@ -49,8 +72,11 @@ static inline void *memset64(uint64_t *p, uint64_t v, __kernel_size_t n)
>> {
>> return __memset64(p, v, n * 8);
>> }
>> +#endif
>> #else
>> +#ifndef CONFIG_KASAN
>> #define __HAVE_ARCH_STRLEN
>> +#endif
>>
>> extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
>> #endif
>> diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh
>> index 667df97d2595..181fd10008ef 100644
>> --- a/arch/powerpc/kernel/prom_init_check.sh
>> +++ b/arch/powerpc/kernel/prom_init_check.sh
>> @@ -16,8 +16,16 @@
>> # If you really need to reference something from prom_init.o add
>> # it to the list below:
>>
>> +grep "^CONFIG_KASAN=y$" .config >/dev/null
>> +if [ $? -eq 0 ]
>> +then
>> + MEM_FUNCS="__memcpy __memset"
>> +else
>> + MEM_FUNCS="memcpy memset"
>> +fi
>> +
>> WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
>> -_end enter_prom memcpy memset reloc_offset __secondary_hold
>> +_end enter_prom $MEM_FUNCS reloc_offset __secondary_hold
>> __secondary_hold_acknowledge __secondary_hold_spinloop __start
>> strcmp strcpy strlcpy strlen strncmp strstr kstrtobool logo_linux_clut224
>> reloc_got2 kernstart_addr memstart_addr linux_banner _stext
>> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
>> index 79396e184bca..47a4de434c22 100644
>> --- a/arch/powerpc/lib/Makefile
>> +++ b/arch/powerpc/lib/Makefile
>> @@ -8,9 +8,14 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
>> CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
>> CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
>>
>> -obj-y += string.o alloc.o code-patching.o feature-fixups.o
>> +obj-y += alloc.o code-patching.o feature-fixups.o
>>
>> -obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o strlen_32.o
>> +ifndef CONFIG_KASAN
>> +obj-y += string.o memcmp_$(BITS).o
>> +obj-$(CONFIG_PPC32) += strlen_32.o
>> +endif
>> +
>> +obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o
>>
>> obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
>>
>> @@ -34,7 +39,7 @@ obj64-$(CONFIG_KPROBES_SANITY_TEST) += test_emulate_step.o \
>> test_emulate_step_exec_instr.o
>>
>> obj-y += checksum_$(BITS).o checksum_wrappers.o \
>> - string_$(BITS).o memcmp_$(BITS).o
>> + string_$(BITS).o
>>
>> obj-y += sstep.o ldstfp.o quad.o
>> obj64-y += quad.o
>> diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
>> index ba66846fe973..fc4fa7246200 100644
>> --- a/arch/powerpc/lib/copy_32.S
>> +++ b/arch/powerpc/lib/copy_32.S
>> @@ -14,6 +14,7 @@
>> #include <asm/ppc_asm.h>
>> #include <asm/export.h>
>> #include <asm/code-patching-asm.h>
>> +#include <asm/kasan.h>
>>
>> #define COPY_16_BYTES \
>> lwz r7,4(r4); \
>> @@ -68,6 +69,7 @@ CACHELINE_BYTES = L1_CACHE_BYTES
>> LG_CACHELINE_BYTES = L1_CACHE_SHIFT
>> CACHELINE_MASK = (L1_CACHE_BYTES-1)
>>
>> +#ifndef CONFIG_KASAN
>> _GLOBAL(memset16)
>> rlwinm. r0 ,r5, 31, 1, 31
>> addi r6, r3, -4
>> @@ -81,6 +83,7 @@ _GLOBAL(memset16)
>> sth r4, 4(r6)
>> blr
>> EXPORT_SYMBOL(memset16)
>> +#endif
>>
>> /*
>> * Use dcbz on the complete cache lines in the destination
>> @@ -91,7 +94,7 @@ EXPORT_SYMBOL(memset16)
>> * We therefore skip the optimised bloc that uses dcbz. This jump is
>> * replaced by a nop once cache is active. This is done in machine_init()
>> */
>> -_GLOBAL(memset)
>> +_GLOBAL_KASAN(memset)
>> cmplwi 0,r5,4
>> blt 7f
>>
>> @@ -150,7 +153,7 @@ _GLOBAL(memset)
>> 9: stbu r4,1(r6)
>> bdnz 9b
>> blr
>> -EXPORT_SYMBOL(memset)
>> +EXPORT_SYMBOL_KASAN(memset)
>>
>> /*
>> * This version uses dcbz on the complete cache lines in the
>> @@ -163,12 +166,12 @@ EXPORT_SYMBOL(memset)
>> * We therefore jump to generic_memcpy which doesn't use dcbz. This jump is
>> * replaced by a nop once cache is active. This is done in machine_init()
>> */
>> -_GLOBAL(memmove)
>> +_GLOBAL_KASAN(memmove)
>> cmplw 0,r3,r4
>> bgt backwards_memcpy
>> /* fall through */
>>
>> -_GLOBAL(memcpy)
>> +_GLOBAL_KASAN(memcpy)
>> 1: b generic_memcpy
>> patch_site 1b, patch__memcpy_nocache
>>
>> @@ -242,8 +245,8 @@ _GLOBAL(memcpy)
>> stbu r0,1(r6)
>> bdnz 40b
>> 65: blr
>> -EXPORT_SYMBOL(memcpy)
>> -EXPORT_SYMBOL(memmove)
>> +EXPORT_SYMBOL_KASAN(memcpy)
>> +EXPORT_SYMBOL_KASAN(memmove)
>>
>> generic_memcpy:
>> srwi. r7,r5,3
>> diff --git a/arch/powerpc/lib/mem_64.S b/arch/powerpc/lib/mem_64.S
>> index 3c3be02f33b7..7cd6cf6822a2 100644
>> --- a/arch/powerpc/lib/mem_64.S
>> +++ b/arch/powerpc/lib/mem_64.S
>> @@ -12,7 +12,9 @@
>> #include <asm/errno.h>
>> #include <asm/ppc_asm.h>
>> #include <asm/export.h>
>> +#include <asm/kasan.h>
>>
>> +#ifndef CONFIG_KASAN
>> _GLOBAL(__memset16)
>> rlwimi r4,r4,16,0,15
>> /* fall through */
>> @@ -29,8 +31,9 @@ _GLOBAL(__memset64)
>> EXPORT_SYMBOL(__memset16)
>> EXPORT_SYMBOL(__memset32)
>> EXPORT_SYMBOL(__memset64)
>> +#endif
>>
>> -_GLOBAL(memset)
>> +_GLOBAL_KASAN(memset)
>> neg r0,r3
>> rlwimi r4,r4,8,16,23
>> andi. r0,r0,7 /* # bytes to be 8-byte aligned */
>> @@ -95,9 +98,9 @@ _GLOBAL(memset)
>> 10: bflr 31
>> stb r4,0(r6)
>> blr
>> -EXPORT_SYMBOL(memset)
>> +EXPORT_SYMBOL_KASAN(memset)
>>
>> -_GLOBAL_TOC(memmove)
>> +_GLOBAL_TOC_KASAN(memmove)
>> cmplw 0,r3,r4
>> bgt backwards_memcpy
>> b memcpy
>> @@ -138,4 +141,4 @@ _GLOBAL(backwards_memcpy)
>> beq 2b
>> mtctr r7
>> b 1b
>> -EXPORT_SYMBOL(memmove)
>> +EXPORT_SYMBOL_KASAN(memmove)
>> diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
>> index 273ea67e60a1..862b515b8868 100644
>> --- a/arch/powerpc/lib/memcpy_64.S
>> +++ b/arch/powerpc/lib/memcpy_64.S
>> @@ -11,6 +11,7 @@
>> #include <asm/export.h>
>> #include <asm/asm-compat.h>
>> #include <asm/feature-fixups.h>
>> +#include <asm/kasan.h>
>>
>> #ifndef SELFTEST_CASE
>> /* For big-endian, 0 == most CPUs, 1 == POWER6, 2 == Cell */
>> @@ -18,7 +19,7 @@
>> #endif
>>
>> .align 7
>> -_GLOBAL_TOC(memcpy)
>> +_GLOBAL_TOC_KASAN(memcpy)
>> BEGIN_FTR_SECTION
>> #ifdef __LITTLE_ENDIAN__
>> cmpdi cr7,r5,0
>> @@ -229,4 +230,4 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
>> 4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
>> blr
>> #endif
>> -EXPORT_SYMBOL(memcpy)
>> +EXPORT_SYMBOL_KASAN(memcpy)
>> --
>> 2.13.3

2019-03-07 06:20:13

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH v9 02/11] powerpc: prepare string/mem functions for KASAN

Hi Daniel,

On 03/04/2019 05:26 AM, Daniel Axtens wrote:
> Hi Christophe,
>> diff --git a/arch/powerpc/include/asm/kasan.h b/arch/powerpc/include/asm/kasan.h
>> new file mode 100644
>> index 000000000000..c3161b8fc017
>> --- /dev/null
>> +++ b/arch/powerpc/include/asm/kasan.h
>> @@ -0,0 +1,15 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef __ASM_KASAN_H
>> +#define __ASM_KASAN_H
>> +
>> +#ifdef CONFIG_KASAN
>> +#define _GLOBAL_KASAN(fn) .weak fn ; _GLOBAL(__##fn) ; _GLOBAL(fn)
>> +#define _GLOBAL_TOC_KASAN(fn) .weak fn ; _GLOBAL_TOC(__##fn) ; _GLOBAL_TOC(fn)
>> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(__##fn) ; EXPORT_SYMBOL(fn)
>
> I'm having some trouble with this. I get warnings like this:
>
> WARNING: EXPORT symbol "__memcpy" [vmlinux] version generation failed, symbol will not be versioned.

I don't have this problem, neither with my PPC32 defconfigs nor with
ppc64e_defconfig - SPARSEMEM_VMEMMAP + KASAN
Using GCC 8.1

I've been looking into it in more details and can't understand the need
for a weak symbol. A weak symbol is to allow it's optional replacement
by other code. But here KASAN replaces it inconditionally, so I see no
point for a weak symbol here.

Regarding the export of the functions, I believe that when the functions
are defined in KASAN, they should be exported by KASAN and not by the
arch. But such a change is out of scope for now. So lets have a double
export for now, one day we will drop it.

Regarding export of __memcpy() etc..., there is at least the LKDTM
module which inhibits KASAN, so it really needs to be exported.

What about the patch below ?

Christophe

diff --git a/arch/powerpc/include/asm/kasan.h
b/arch/powerpc/include/asm/kasan.h
new file mode 100644
index 000000000000..2c179a39d4ba
--- /dev/null
+++ b/arch/powerpc/include/asm/kasan.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_KASAN_H
+#define __ASM_KASAN_H
+
+#ifdef CONFIG_KASAN
+#define _GLOBAL_KASAN(fn) _GLOBAL(__##fn)
+#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(__##fn)
+#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(__##fn)
+#else
+#define _GLOBAL_KASAN(fn) _GLOBAL(fn)
+#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(fn)
+#define EXPORT_SYMBOL_KASAN(fn)
+#endif
+
+#endif
diff --git a/arch/powerpc/include/asm/string.h
b/arch/powerpc/include/asm/string.h
index 1647de15a31e..9bf6dffb4090 100644
--- a/arch/powerpc/include/asm/string.h
+++ b/arch/powerpc/include/asm/string.h
@@ -4,14 +4,17 @@

#ifdef __KERNEL__

+#ifndef CONFIG_KASAN
#define __HAVE_ARCH_STRNCPY
#define __HAVE_ARCH_STRNCMP
+#define __HAVE_ARCH_MEMCHR
+#define __HAVE_ARCH_MEMCMP
+#define __HAVE_ARCH_MEMSET16
+#endif
+
#define __HAVE_ARCH_MEMSET
#define __HAVE_ARCH_MEMCPY
#define __HAVE_ARCH_MEMMOVE
-#define __HAVE_ARCH_MEMCMP
-#define __HAVE_ARCH_MEMCHR
-#define __HAVE_ARCH_MEMSET16
#define __HAVE_ARCH_MEMCPY_FLUSHCACHE

extern char * strcpy(char *,const char *);
@@ -27,7 +30,27 @@ extern int memcmp(const void *,const void
*,__kernel_size_t);
extern void * memchr(const void *,int,__kernel_size_t);
extern void * memcpy_flushcache(void *,const void *,__kernel_size_t);

+void *__memset(void *s, int c, __kernel_size_t count);
+void *__memcpy(void *to, const void *from, __kernel_size_t n);
+void *__memmove(void *to, const void *from, __kernel_size_t n);
+
+#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
+/*
+ * For files that are not instrumented (e.g. mm/slub.c) we
+ * should use not instrumented version of mem* functions.
+ */
+#define memcpy(dst, src, len) __memcpy(dst, src, len)
+#define memmove(dst, src, len) __memmove(dst, src, len)
+#define memset(s, c, n) __memset(s, c, n)
+
+#ifndef __NO_FORTIFY
+#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
+#endif
+
+#endif
+
#ifdef CONFIG_PPC64
+#ifndef CONFIG_KASAN
#define __HAVE_ARCH_MEMSET32
#define __HAVE_ARCH_MEMSET64

@@ -49,8 +72,11 @@ static inline void *memset64(uint64_t *p, uint64_t v,
__kernel_size_t n)
{
return __memset64(p, v, n * 8);
}
+#endif
#else
+#ifndef CONFIG_KASAN
#define __HAVE_ARCH_STRLEN
+#endif

extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
#endif
diff --git a/arch/powerpc/kernel/prom_init_check.sh
b/arch/powerpc/kernel/prom_init_check.sh
index 667df97d2595..181fd10008ef 100644
--- a/arch/powerpc/kernel/prom_init_check.sh
+++ b/arch/powerpc/kernel/prom_init_check.sh
@@ -16,8 +16,16 @@
# If you really need to reference something from prom_init.o add
# it to the list below:

+grep "^CONFIG_KASAN=y$" .config >/dev/null
+if [ $? -eq 0 ]
+then
+ MEM_FUNCS="__memcpy __memset"
+else
+ MEM_FUNCS="memcpy memset"
+fi
+
WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
-_end enter_prom memcpy memset reloc_offset __secondary_hold
+_end enter_prom $MEM_FUNCS reloc_offset __secondary_hold
__secondary_hold_acknowledge __secondary_hold_spinloop __start
strcmp strcpy strlcpy strlen strncmp strstr kstrtobool logo_linux_clut224
reloc_got2 kernstart_addr memstart_addr linux_banner _stext
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 79396e184bca..47a4de434c22 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -8,9 +8,14 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)

-obj-y += string.o alloc.o code-patching.o feature-fixups.o
+obj-y += alloc.o code-patching.o feature-fixups.o

-obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o strlen_32.o
+ifndef CONFIG_KASAN
+obj-y += string.o memcmp_$(BITS).o
+obj-$(CONFIG_PPC32) += strlen_32.o
+endif
+
+obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o

obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o

@@ -34,7 +39,7 @@ obj64-$(CONFIG_KPROBES_SANITY_TEST) +=
test_emulate_step.o \
test_emulate_step_exec_instr.o

obj-y += checksum_$(BITS).o checksum_wrappers.o \
- string_$(BITS).o memcmp_$(BITS).o
+ string_$(BITS).o

obj-y += sstep.o ldstfp.o quad.o
obj64-y += quad.o
diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
index ba66846fe973..d5642481fb98 100644
--- a/arch/powerpc/lib/copy_32.S
+++ b/arch/powerpc/lib/copy_32.S
@@ -14,6 +14,7 @@
#include <asm/ppc_asm.h>
#include <asm/export.h>
#include <asm/code-patching-asm.h>
+#include <asm/kasan.h>

#define COPY_16_BYTES \
lwz r7,4(r4); \
@@ -68,6 +69,7 @@ CACHELINE_BYTES = L1_CACHE_BYTES
LG_CACHELINE_BYTES = L1_CACHE_SHIFT
CACHELINE_MASK = (L1_CACHE_BYTES-1)

+#ifndef CONFIG_KASAN
_GLOBAL(memset16)
rlwinm. r0 ,r5, 31, 1, 31
addi r6, r3, -4
@@ -81,6 +83,7 @@ _GLOBAL(memset16)
sth r4, 4(r6)
blr
EXPORT_SYMBOL(memset16)
+#endif

/*
* Use dcbz on the complete cache lines in the destination
@@ -91,7 +94,7 @@ EXPORT_SYMBOL(memset16)
* We therefore skip the optimised bloc that uses dcbz. This jump is
* replaced by a nop once cache is active. This is done in machine_init()
*/
-_GLOBAL(memset)
+_GLOBAL_KASAN(memset)
cmplwi 0,r5,4
blt 7f

@@ -151,6 +154,7 @@ _GLOBAL(memset)
bdnz 9b
blr
EXPORT_SYMBOL(memset)
+EXPORT_SYMBOL_KASAN(memset)

/*
* This version uses dcbz on the complete cache lines in the
@@ -163,12 +167,12 @@ EXPORT_SYMBOL(memset)
* We therefore jump to generic_memcpy which doesn't use dcbz. This
jump is
* replaced by a nop once cache is active. This is done in machine_init()
*/
-_GLOBAL(memmove)
+_GLOBAL_KASAN(memmove)
cmplw 0,r3,r4
bgt backwards_memcpy
/* fall through */

-_GLOBAL(memcpy)
+_GLOBAL_KASAN(memcpy)
1: b generic_memcpy
patch_site 1b, patch__memcpy_nocache

@@ -244,6 +248,8 @@ _GLOBAL(memcpy)
65: blr
EXPORT_SYMBOL(memcpy)
EXPORT_SYMBOL(memmove)
+EXPORT_SYMBOL_KASAN(memcpy)
+EXPORT_SYMBOL_KASAN(memmove)

generic_memcpy:
srwi. r7,r5,3
diff --git a/arch/powerpc/lib/mem_64.S b/arch/powerpc/lib/mem_64.S
index 3c3be02f33b7..7f6bd031c306 100644
--- a/arch/powerpc/lib/mem_64.S
+++ b/arch/powerpc/lib/mem_64.S
@@ -12,7 +12,9 @@
#include <asm/errno.h>
#include <asm/ppc_asm.h>
#include <asm/export.h>
+#include <asm/kasan.h>

+#ifndef CONFIG_KASAN
_GLOBAL(__memset16)
rlwimi r4,r4,16,0,15
/* fall through */
@@ -29,8 +31,9 @@ _GLOBAL(__memset64)
EXPORT_SYMBOL(__memset16)
EXPORT_SYMBOL(__memset32)
EXPORT_SYMBOL(__memset64)
+#endif

-_GLOBAL(memset)
+_GLOBAL_KASAN(memset)
neg r0,r3
rlwimi r4,r4,8,16,23
andi. r0,r0,7 /* # bytes to be 8-byte aligned */
@@ -96,8 +99,9 @@ _GLOBAL(memset)
stb r4,0(r6)
blr
EXPORT_SYMBOL(memset)
+EXPORT_SYMBOL_KASAN(memset)

-_GLOBAL_TOC(memmove)
+_GLOBAL_TOC_KASAN(memmove)
cmplw 0,r3,r4
bgt backwards_memcpy
b memcpy
@@ -139,3 +143,4 @@ _GLOBAL(backwards_memcpy)
mtctr r7
b 1b
EXPORT_SYMBOL(memmove)
+EXPORT_SYMBOL_KASAN(memmove)
diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
index 273ea67e60a1..25c3772c1dfb 100644
--- a/arch/powerpc/lib/memcpy_64.S
+++ b/arch/powerpc/lib/memcpy_64.S
@@ -11,6 +11,7 @@
#include <asm/export.h>
#include <asm/asm-compat.h>
#include <asm/feature-fixups.h>
+#include <asm/kasan.h>

#ifndef SELFTEST_CASE
/* For big-endian, 0 == most CPUs, 1 == POWER6, 2 == Cell */
@@ -18,7 +19,7 @@
#endif

.align 7
-_GLOBAL_TOC(memcpy)
+_GLOBAL_TOC_KASAN(memcpy)
BEGIN_FTR_SECTION
#ifdef __LITTLE_ENDIAN__
cmpdi cr7,r5,0
@@ -230,3 +231,4 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
blr
#endif
EXPORT_SYMBOL(memcpy)
+EXPORT_SYMBOL_KASAN(memcpy)


>
> It seems to be related to the export line, as if I swap the exports to
> do fn before __##fn I get:
>
> WARNING: EXPORT symbol "memset" [vmlinux] version generation failed, symbol will not be versioned.
>
> I have narrowed this down to combining 2 EXPORT_SYMBOL()s on one line.
> This works - no warning:
>
> EXPORT_SYMBOL(memset)
> EXPORT_SYMBOL(__memset)
>
> This throws a warning:
>
> EXPORT_SYMBOL(memset) ; EXPORT_SYMBOL(__memset)
>
> I notice in looking at the diff of preprocessed source we end up
> invoking an asm macro that doesn't seem to have a full final argument, I
> wonder if that's relevant...
>
> -___EXPORT_SYMBOL __memset, __memset, ; ___EXPORT_SYMBOL memset, memset,
> +___EXPORT_SYMBOL __memset, __memset,
> +___EXPORT_SYMBOL memset, memset,
>
> I also notice that nowhere else in the source do people have multiple
> EXPORT_SYMBOLs on the same line, and other arches seem to just
> unconditionally export both symbols on multiple lines.
>
> I have no idea how this works for you - maybe it's affected by something 32bit.
>
> How would you feel about this approach instead? I'm not tied to any of
> the names or anything.
>
> diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
> index e0637730a8e7..7b6a91b448dd 100644
> --- a/arch/powerpc/include/asm/ppc_asm.h
> +++ b/arch/powerpc/include/asm/ppc_asm.h
> @@ -214,6 +214,9 @@ name: \
>
> #define DOTSYM(a) a
>
> +#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
> + .weak weakname ; .set weakname, strongname ;
> +
> #else
>
> #define XGLUE(a,b) a##b
> @@ -236,6 +239,10 @@ GLUE(.,name):
>
> #define DOTSYM(a) GLUE(.,a)
>
> +#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
> + .weak weakname ; .set weakname, strongname ; \
> + .weak DOTSYM(weakname) ; .set DOTSYM(weakname), DOTSYM(strongname) ;
> +
> #endif
>
> #else /* 32-bit */
> @@ -251,6 +258,9 @@ GLUE(.,name):
>
> #define _GLOBAL_TOC(name) _GLOBAL(name)
>
> +#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
> + .weak weakname ; .set weakname, strongname ;
> +
> #endif
>
> /*
> --- a/arch/powerpc/lib/mem_64.S
> +++ b/arch/powerpc/lib/mem_64.S
> @@ -33,7 +33,8 @@ EXPORT_SYMBOL(__memset32)
> EXPORT_SYMBOL(__memset64)
> #endif
>
> -_GLOBAL_KASAN(memset)
> +PROVIDE_WEAK_ALIAS(__memset,memset)
> +_GLOBAL(__memset)
> neg r0,r3
> rlwimi r4,r4,8,16,23
> andi. r0,r0,7 /* # bytes to be 8-byte aligned */
> @@ -98,9 +99,11 @@ _GLOBAL_KASAN(memset)
> 10: bflr 31
> stb r4,0(r6)
> blr
> -EXPORT_SYMBOL_KASAN(memset)
> +EXPORT_SYMBOL(memset)
> +EXPORT_SYMBOL(__memset)
>
> -_GLOBAL_TOC_KASAN(memmove)
> +PROVIDE_WEAK_ALIAS(__memmove,memove)
> +_GLOBAL_TOC(__memmove)
> cmplw 0,r3,r4
> bgt backwards_memcpy
> b memcpy
> @@ -141,4 +144,5 @@ _GLOBAL(backwards_memcpy)
> beq 2b
> mtctr r7
> b 1b
> -EXPORT_SYMBOL_KASAN(memmove)
> +EXPORT_SYMBOL(memmove)
> +EXPORT_SYMBOL(__memmove)
> diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
> index 862b515b8868..7c1b09556cad 100644
> --- a/arch/powerpc/lib/memcpy_64.S
> +++ b/arch/powerpc/lib/memcpy_64.S
> @@ -19,7 +19,8 @@
> #endif
>
> .align 7
> -_GLOBAL_TOC_KASAN(memcpy)
> +PROVIDE_WEAK_ALIAS(__memcpy,memcpy)
> +_GLOBAL_TOC(__memcpy)
> BEGIN_FTR_SECTION
> #ifdef __LITTLE_ENDIAN__
> cmpdi cr7,r5,0
> @@ -230,4 +231,5 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
> 4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
> blr
> #endif
> -EXPORT_SYMBOL_KASAN(memcpy)
> +EXPORT_SYMBOL(__memcpy)
> +EXPORT_SYMBOL(memcpy)
>
>
> Regards,
> Daniel
>
>
>> +#else
>> +#define _GLOBAL_KASAN(fn) _GLOBAL(fn)
>> +#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(fn)
>> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(fn)
>> +#endif
>> +
>> +#endif
>> diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h
>> index 1647de15a31e..9bf6dffb4090 100644
>> --- a/arch/powerpc/include/asm/string.h
>> +++ b/arch/powerpc/include/asm/string.h
>> @@ -4,14 +4,17 @@
>>
>> #ifdef __KERNEL__
>>
>> +#ifndef CONFIG_KASAN
>> #define __HAVE_ARCH_STRNCPY
>> #define __HAVE_ARCH_STRNCMP
>> +#define __HAVE_ARCH_MEMCHR
>> +#define __HAVE_ARCH_MEMCMP
>> +#define __HAVE_ARCH_MEMSET16
>> +#endif
>> +
>> #define __HAVE_ARCH_MEMSET
>> #define __HAVE_ARCH_MEMCPY
>> #define __HAVE_ARCH_MEMMOVE
>> -#define __HAVE_ARCH_MEMCMP
>> -#define __HAVE_ARCH_MEMCHR
>> -#define __HAVE_ARCH_MEMSET16
>> #define __HAVE_ARCH_MEMCPY_FLUSHCACHE
>>
>> extern char * strcpy(char *,const char *);
>> @@ -27,7 +30,27 @@ extern int memcmp(const void *,const void *,__kernel_size_t);
>> extern void * memchr(const void *,int,__kernel_size_t);
>> extern void * memcpy_flushcache(void *,const void *,__kernel_size_t);
>>
>> +void *__memset(void *s, int c, __kernel_size_t count);
>> +void *__memcpy(void *to, const void *from, __kernel_size_t n);
>> +void *__memmove(void *to, const void *from, __kernel_size_t n);
>> +
>> +#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
>> +/*
>> + * For files that are not instrumented (e.g. mm/slub.c) we
>> + * should use not instrumented version of mem* functions.
>> + */
>> +#define memcpy(dst, src, len) __memcpy(dst, src, len)
>> +#define memmove(dst, src, len) __memmove(dst, src, len)
>> +#define memset(s, c, n) __memset(s, c, n)
>> +
>> +#ifndef __NO_FORTIFY
>> +#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
>> +#endif
>> +
>> +#endif
>> +
>> #ifdef CONFIG_PPC64
>> +#ifndef CONFIG_KASAN
>> #define __HAVE_ARCH_MEMSET32
>> #define __HAVE_ARCH_MEMSET64
>>
>> @@ -49,8 +72,11 @@ static inline void *memset64(uint64_t *p, uint64_t v, __kernel_size_t n)
>> {
>> return __memset64(p, v, n * 8);
>> }
>> +#endif
>> #else
>> +#ifndef CONFIG_KASAN
>> #define __HAVE_ARCH_STRLEN
>> +#endif
>>
>> extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
>> #endif
>> diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh
>> index 667df97d2595..181fd10008ef 100644
>> --- a/arch/powerpc/kernel/prom_init_check.sh
>> +++ b/arch/powerpc/kernel/prom_init_check.sh
>> @@ -16,8 +16,16 @@
>> # If you really need to reference something from prom_init.o add
>> # it to the list below:
>>
>> +grep "^CONFIG_KASAN=y$" .config >/dev/null
>> +if [ $? -eq 0 ]
>> +then
>> + MEM_FUNCS="__memcpy __memset"
>> +else
>> + MEM_FUNCS="memcpy memset"
>> +fi
>> +
>> WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
>> -_end enter_prom memcpy memset reloc_offset __secondary_hold
>> +_end enter_prom $MEM_FUNCS reloc_offset __secondary_hold
>> __secondary_hold_acknowledge __secondary_hold_spinloop __start
>> strcmp strcpy strlcpy strlen strncmp strstr kstrtobool logo_linux_clut224
>> reloc_got2 kernstart_addr memstart_addr linux_banner _stext
>> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
>> index 79396e184bca..47a4de434c22 100644
>> --- a/arch/powerpc/lib/Makefile
>> +++ b/arch/powerpc/lib/Makefile
>> @@ -8,9 +8,14 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
>> CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
>> CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
>>
>> -obj-y += string.o alloc.o code-patching.o feature-fixups.o
>> +obj-y += alloc.o code-patching.o feature-fixups.o
>>
>> -obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o strlen_32.o
>> +ifndef CONFIG_KASAN
>> +obj-y += string.o memcmp_$(BITS).o
>> +obj-$(CONFIG_PPC32) += strlen_32.o
>> +endif
>> +
>> +obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o
>>
>> obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
>>
>> @@ -34,7 +39,7 @@ obj64-$(CONFIG_KPROBES_SANITY_TEST) += test_emulate_step.o \
>> test_emulate_step_exec_instr.o
>>
>> obj-y += checksum_$(BITS).o checksum_wrappers.o \
>> - string_$(BITS).o memcmp_$(BITS).o
>> + string_$(BITS).o
>>
>> obj-y += sstep.o ldstfp.o quad.o
>> obj64-y += quad.o
>> diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
>> index ba66846fe973..fc4fa7246200 100644
>> --- a/arch/powerpc/lib/copy_32.S
>> +++ b/arch/powerpc/lib/copy_32.S
>> @@ -14,6 +14,7 @@
>> #include <asm/ppc_asm.h>
>> #include <asm/export.h>
>> #include <asm/code-patching-asm.h>
>> +#include <asm/kasan.h>
>>
>> #define COPY_16_BYTES \
>> lwz r7,4(r4); \
>> @@ -68,6 +69,7 @@ CACHELINE_BYTES = L1_CACHE_BYTES
>> LG_CACHELINE_BYTES = L1_CACHE_SHIFT
>> CACHELINE_MASK = (L1_CACHE_BYTES-1)
>>
>> +#ifndef CONFIG_KASAN
>> _GLOBAL(memset16)
>> rlwinm. r0 ,r5, 31, 1, 31
>> addi r6, r3, -4
>> @@ -81,6 +83,7 @@ _GLOBAL(memset16)
>> sth r4, 4(r6)
>> blr
>> EXPORT_SYMBOL(memset16)
>> +#endif
>>
>> /*
>> * Use dcbz on the complete cache lines in the destination
>> @@ -91,7 +94,7 @@ EXPORT_SYMBOL(memset16)
>> * We therefore skip the optimised bloc that uses dcbz. This jump is
>> * replaced by a nop once cache is active. This is done in machine_init()
>> */
>> -_GLOBAL(memset)
>> +_GLOBAL_KASAN(memset)
>> cmplwi 0,r5,4
>> blt 7f
>>
>> @@ -150,7 +153,7 @@ _GLOBAL(memset)
>> 9: stbu r4,1(r6)
>> bdnz 9b
>> blr
>> -EXPORT_SYMBOL(memset)
>> +EXPORT_SYMBOL_KASAN(memset)
>>
>> /*
>> * This version uses dcbz on the complete cache lines in the
>> @@ -163,12 +166,12 @@ EXPORT_SYMBOL(memset)
>> * We therefore jump to generic_memcpy which doesn't use dcbz. This jump is
>> * replaced by a nop once cache is active. This is done in machine_init()
>> */
>> -_GLOBAL(memmove)
>> +_GLOBAL_KASAN(memmove)
>> cmplw 0,r3,r4
>> bgt backwards_memcpy
>> /* fall through */
>>
>> -_GLOBAL(memcpy)
>> +_GLOBAL_KASAN(memcpy)
>> 1: b generic_memcpy
>> patch_site 1b, patch__memcpy_nocache
>>
>> @@ -242,8 +245,8 @@ _GLOBAL(memcpy)
>> stbu r0,1(r6)
>> bdnz 40b
>> 65: blr
>> -EXPORT_SYMBOL(memcpy)
>> -EXPORT_SYMBOL(memmove)
>> +EXPORT_SYMBOL_KASAN(memcpy)
>> +EXPORT_SYMBOL_KASAN(memmove)
>>
>> generic_memcpy:
>> srwi. r7,r5,3
>> diff --git a/arch/powerpc/lib/mem_64.S b/arch/powerpc/lib/mem_64.S
>> index 3c3be02f33b7..7cd6cf6822a2 100644
>> --- a/arch/powerpc/lib/mem_64.S
>> +++ b/arch/powerpc/lib/mem_64.S
>> @@ -12,7 +12,9 @@
>> #include <asm/errno.h>
>> #include <asm/ppc_asm.h>
>> #include <asm/export.h>
>> +#include <asm/kasan.h>
>>
>> +#ifndef CONFIG_KASAN
>> _GLOBAL(__memset16)
>> rlwimi r4,r4,16,0,15
>> /* fall through */
>> @@ -29,8 +31,9 @@ _GLOBAL(__memset64)
>> EXPORT_SYMBOL(__memset16)
>> EXPORT_SYMBOL(__memset32)
>> EXPORT_SYMBOL(__memset64)
>> +#endif
>>
>> -_GLOBAL(memset)
>> +_GLOBAL_KASAN(memset)
>> neg r0,r3
>> rlwimi r4,r4,8,16,23
>> andi. r0,r0,7 /* # bytes to be 8-byte aligned */
>> @@ -95,9 +98,9 @@ _GLOBAL(memset)
>> 10: bflr 31
>> stb r4,0(r6)
>> blr
>> -EXPORT_SYMBOL(memset)
>> +EXPORT_SYMBOL_KASAN(memset)
>>
>> -_GLOBAL_TOC(memmove)
>> +_GLOBAL_TOC_KASAN(memmove)
>> cmplw 0,r3,r4
>> bgt backwards_memcpy
>> b memcpy
>> @@ -138,4 +141,4 @@ _GLOBAL(backwards_memcpy)
>> beq 2b
>> mtctr r7
>> b 1b
>> -EXPORT_SYMBOL(memmove)
>> +EXPORT_SYMBOL_KASAN(memmove)
>> diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
>> index 273ea67e60a1..862b515b8868 100644
>> --- a/arch/powerpc/lib/memcpy_64.S
>> +++ b/arch/powerpc/lib/memcpy_64.S
>> @@ -11,6 +11,7 @@
>> #include <asm/export.h>
>> #include <asm/asm-compat.h>
>> #include <asm/feature-fixups.h>
>> +#include <asm/kasan.h>
>>
>> #ifndef SELFTEST_CASE
>> /* For big-endian, 0 == most CPUs, 1 == POWER6, 2 == Cell */
>> @@ -18,7 +19,7 @@
>> #endif
>>
>> .align 7
>> -_GLOBAL_TOC(memcpy)
>> +_GLOBAL_TOC_KASAN(memcpy)
>> BEGIN_FTR_SECTION
>> #ifdef __LITTLE_ENDIAN__
>> cmpdi cr7,r5,0
>> @@ -229,4 +230,4 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
>> 4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
>> blr
>> #endif
>> -EXPORT_SYMBOL(memcpy)
>> +EXPORT_SYMBOL_KASAN(memcpy)
>> --
>> 2.13.3

2019-03-08 03:45:51

by Daniel Axtens

[permalink] [raw]
Subject: Re: [PATCH v9 02/11] powerpc: prepare string/mem functions for KASAN

Christophe Leroy <[email protected]> writes:

> Le 04/03/2019 à 06:26, Daniel Axtens a écrit :
>> Hi Christophe,
>>> diff --git a/arch/powerpc/include/asm/kasan.h b/arch/powerpc/include/asm/kasan.h
>>> new file mode 100644
>>> index 000000000000..c3161b8fc017
>>> --- /dev/null
>>> +++ b/arch/powerpc/include/asm/kasan.h
>>> @@ -0,0 +1,15 @@
>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>> +#ifndef __ASM_KASAN_H
>>> +#define __ASM_KASAN_H
>>> +
>>> +#ifdef CONFIG_KASAN
>>> +#define _GLOBAL_KASAN(fn) .weak fn ; _GLOBAL(__##fn) ; _GLOBAL(fn)
>>> +#define _GLOBAL_TOC_KASAN(fn) .weak fn ; _GLOBAL_TOC(__##fn) ; _GLOBAL_TOC(fn)
>>> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(__##fn) ; EXPORT_SYMBOL(fn)
>>
>> I'm having some trouble with this. I get warnings like this:
>
> I don't have such problem, neither with ppc32 nor with ppc64e_defconfig.
>

Fascinating, I'll dig into that more.

> What config are you using ?

Attached, it's based on the one provided with the SDK for the T4240RDB.

> Another (unrelated) question I have:
> On the initial arm64 implementation (39d114ddc682 arm64: add KASAN
> support) they made KASAN implementation depend on SPARSEMEM_VMEMMAP
> (allthough they later removed that dependency with commit e17d8025f07e
> arm64/mm/kasan: don't use vmemmap_populate() to initialize shadow)
>
> So I'm wondering why on your side, KASAN depends on !SPARSEMEM_VMEMMAP

I use the vmemmap area as the shadow region for kasan, in a way that
takes absolutely no account of any other use. It's very possible that I
could instead do something similar to what arm64 used to do - I think
one of the previous ppc64 approaches did something similar too.

Regards,
Daniel


Attachments:
.config (84.15 kB)

2019-03-08 04:50:36

by Daniel Axtens

[permalink] [raw]
Subject: Re: [PATCH v9 02/11] powerpc: prepare string/mem functions for KASAN

>>> +#ifdef CONFIG_KASAN
>>> +#define _GLOBAL_KASAN(fn) .weak fn ; _GLOBAL(__##fn) ; _GLOBAL(fn)
>>> +#define _GLOBAL_TOC_KASAN(fn) .weak fn ; _GLOBAL_TOC(__##fn) ; _GLOBAL_TOC(fn)
>>> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(__##fn) ; EXPORT_SYMBOL(fn)
>>
>> I'm having some trouble with this. I get warnings like this:
>>
>> WARNING: EXPORT symbol "__memcpy" [vmlinux] version generation failed, symbol will not be versioned.
>
> I don't have this problem, neither with my PPC32 defconfigs nor with
> ppc64e_defconfig - SPARSEMEM_VMEMMAP + KASAN
> Using GCC 8.1
>
> I've been looking into it in more details and can't understand the need
> for a weak symbol. A weak symbol is to allow it's optional replacement
> by other code. But here KASAN replaces it inconditionally, so I see no
> point for a weak symbol here.

If you don't make it weak, and kasan and arch code will export it as
a regular symbol, and you will end up with a clash like this:

powerpc64-linux-gnu-ld: mm/kasan/common.o: in function `.memset':
(.text+0x210): multiple definition of `.memset'; arch/powerpc/lib/mem_64.o:(.text+0x0): first defined here
powerpc64-linux-gnu-ld: mm/kasan/common.o:(.opd+0x78): multiple definition of `memset'; arch/powerpc/lib/mem_64.o:(.opd+0x0): first defined here

But your patch doesn't do that, so don't worry :)

> Regarding the export of the functions, I believe that when the functions
> are defined in KASAN, they should be exported by KASAN and not by the
> arch. But such a change is out of scope for now. So lets have a double
> export for now, one day we will drop it.
>
> Regarding export of __memcpy() etc..., there is at least the LKDTM
> module which inhibits KASAN, so it really needs to be exported.
>
> What about the patch below ?

Yes, that works for me. After de-mangling it I have used it to replace
your patch 2 v9.

Thanks for bearing with me.

Regards,
Daniel

>
> Christophe
>
> diff --git a/arch/powerpc/include/asm/kasan.h
> b/arch/powerpc/include/asm/kasan.h
> new file mode 100644
> index 000000000000..2c179a39d4ba
> --- /dev/null
> +++ b/arch/powerpc/include/asm/kasan.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __ASM_KASAN_H
> +#define __ASM_KASAN_H
> +
> +#ifdef CONFIG_KASAN
> +#define _GLOBAL_KASAN(fn) _GLOBAL(__##fn)
> +#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(__##fn)
> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(__##fn)
> +#else
> +#define _GLOBAL_KASAN(fn) _GLOBAL(fn)
> +#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(fn)
> +#define EXPORT_SYMBOL_KASAN(fn)
> +#endif
> +
> +#endif
> diff --git a/arch/powerpc/include/asm/string.h
> b/arch/powerpc/include/asm/string.h
> index 1647de15a31e..9bf6dffb4090 100644
> --- a/arch/powerpc/include/asm/string.h
> +++ b/arch/powerpc/include/asm/string.h
> @@ -4,14 +4,17 @@
>
> #ifdef __KERNEL__
>
> +#ifndef CONFIG_KASAN
> #define __HAVE_ARCH_STRNCPY
> #define __HAVE_ARCH_STRNCMP
> +#define __HAVE_ARCH_MEMCHR
> +#define __HAVE_ARCH_MEMCMP
> +#define __HAVE_ARCH_MEMSET16
> +#endif
> +
> #define __HAVE_ARCH_MEMSET
> #define __HAVE_ARCH_MEMCPY
> #define __HAVE_ARCH_MEMMOVE
> -#define __HAVE_ARCH_MEMCMP
> -#define __HAVE_ARCH_MEMCHR
> -#define __HAVE_ARCH_MEMSET16
> #define __HAVE_ARCH_MEMCPY_FLUSHCACHE
>
> extern char * strcpy(char *,const char *);
> @@ -27,7 +30,27 @@ extern int memcmp(const void *,const void
> *,__kernel_size_t);
> extern void * memchr(const void *,int,__kernel_size_t);
> extern void * memcpy_flushcache(void *,const void *,__kernel_size_t);
>
> +void *__memset(void *s, int c, __kernel_size_t count);
> +void *__memcpy(void *to, const void *from, __kernel_size_t n);
> +void *__memmove(void *to, const void *from, __kernel_size_t n);
> +
> +#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
> +/*
> + * For files that are not instrumented (e.g. mm/slub.c) we
> + * should use not instrumented version of mem* functions.
> + */
> +#define memcpy(dst, src, len) __memcpy(dst, src, len)
> +#define memmove(dst, src, len) __memmove(dst, src, len)
> +#define memset(s, c, n) __memset(s, c, n)
> +
> +#ifndef __NO_FORTIFY
> +#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
> +#endif
> +
> +#endif
> +
> #ifdef CONFIG_PPC64
> +#ifndef CONFIG_KASAN
> #define __HAVE_ARCH_MEMSET32
> #define __HAVE_ARCH_MEMSET64
>
> @@ -49,8 +72,11 @@ static inline void *memset64(uint64_t *p, uint64_t v,
> __kernel_size_t n)
> {
> return __memset64(p, v, n * 8);
> }
> +#endif
> #else
> +#ifndef CONFIG_KASAN
> #define __HAVE_ARCH_STRLEN
> +#endif
>
> extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
> #endif
> diff --git a/arch/powerpc/kernel/prom_init_check.sh
> b/arch/powerpc/kernel/prom_init_check.sh
> index 667df97d2595..181fd10008ef 100644
> --- a/arch/powerpc/kernel/prom_init_check.sh
> +++ b/arch/powerpc/kernel/prom_init_check.sh
> @@ -16,8 +16,16 @@
> # If you really need to reference something from prom_init.o add
> # it to the list below:
>
> +grep "^CONFIG_KASAN=y$" .config >/dev/null
> +if [ $? -eq 0 ]
> +then
> + MEM_FUNCS="__memcpy __memset"
> +else
> + MEM_FUNCS="memcpy memset"
> +fi
> +
> WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
> -_end enter_prom memcpy memset reloc_offset __secondary_hold
> +_end enter_prom $MEM_FUNCS reloc_offset __secondary_hold
> __secondary_hold_acknowledge __secondary_hold_spinloop __start
> strcmp strcpy strlcpy strlen strncmp strstr kstrtobool logo_linux_clut224
> reloc_got2 kernstart_addr memstart_addr linux_banner _stext
> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
> index 79396e184bca..47a4de434c22 100644
> --- a/arch/powerpc/lib/Makefile
> +++ b/arch/powerpc/lib/Makefile
> @@ -8,9 +8,14 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
> CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
> CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
>
> -obj-y += string.o alloc.o code-patching.o feature-fixups.o
> +obj-y += alloc.o code-patching.o feature-fixups.o
>
> -obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o strlen_32.o
> +ifndef CONFIG_KASAN
> +obj-y += string.o memcmp_$(BITS).o
> +obj-$(CONFIG_PPC32) += strlen_32.o
> +endif
> +
> +obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o
>
> obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
>
> @@ -34,7 +39,7 @@ obj64-$(CONFIG_KPROBES_SANITY_TEST) +=
> test_emulate_step.o \
> test_emulate_step_exec_instr.o
>
> obj-y += checksum_$(BITS).o checksum_wrappers.o \
> - string_$(BITS).o memcmp_$(BITS).o
> + string_$(BITS).o
>
> obj-y += sstep.o ldstfp.o quad.o
> obj64-y += quad.o
> diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
> index ba66846fe973..d5642481fb98 100644
> --- a/arch/powerpc/lib/copy_32.S
> +++ b/arch/powerpc/lib/copy_32.S
> @@ -14,6 +14,7 @@
> #include <asm/ppc_asm.h>
> #include <asm/export.h>
> #include <asm/code-patching-asm.h>
> +#include <asm/kasan.h>
>
> #define COPY_16_BYTES \
> lwz r7,4(r4); \
> @@ -68,6 +69,7 @@ CACHELINE_BYTES = L1_CACHE_BYTES
> LG_CACHELINE_BYTES = L1_CACHE_SHIFT
> CACHELINE_MASK = (L1_CACHE_BYTES-1)
>
> +#ifndef CONFIG_KASAN
> _GLOBAL(memset16)
> rlwinm. r0 ,r5, 31, 1, 31
> addi r6, r3, -4
> @@ -81,6 +83,7 @@ _GLOBAL(memset16)
> sth r4, 4(r6)
> blr
> EXPORT_SYMBOL(memset16)
> +#endif
>
> /*
> * Use dcbz on the complete cache lines in the destination
> @@ -91,7 +94,7 @@ EXPORT_SYMBOL(memset16)
> * We therefore skip the optimised bloc that uses dcbz. This jump is
> * replaced by a nop once cache is active. This is done in machine_init()
> */
> -_GLOBAL(memset)
> +_GLOBAL_KASAN(memset)
> cmplwi 0,r5,4
> blt 7f
>
> @@ -151,6 +154,7 @@ _GLOBAL(memset)
> bdnz 9b
> blr
> EXPORT_SYMBOL(memset)
> +EXPORT_SYMBOL_KASAN(memset)
>
> /*
> * This version uses dcbz on the complete cache lines in the
> @@ -163,12 +167,12 @@ EXPORT_SYMBOL(memset)
> * We therefore jump to generic_memcpy which doesn't use dcbz. This
> jump is
> * replaced by a nop once cache is active. This is done in machine_init()
> */
> -_GLOBAL(memmove)
> +_GLOBAL_KASAN(memmove)
> cmplw 0,r3,r4
> bgt backwards_memcpy
> /* fall through */
>
> -_GLOBAL(memcpy)
> +_GLOBAL_KASAN(memcpy)
> 1: b generic_memcpy
> patch_site 1b, patch__memcpy_nocache
>
> @@ -244,6 +248,8 @@ _GLOBAL(memcpy)
> 65: blr
> EXPORT_SYMBOL(memcpy)
> EXPORT_SYMBOL(memmove)
> +EXPORT_SYMBOL_KASAN(memcpy)
> +EXPORT_SYMBOL_KASAN(memmove)
>
> generic_memcpy:
> srwi. r7,r5,3
> diff --git a/arch/powerpc/lib/mem_64.S b/arch/powerpc/lib/mem_64.S
> index 3c3be02f33b7..7f6bd031c306 100644
> --- a/arch/powerpc/lib/mem_64.S
> +++ b/arch/powerpc/lib/mem_64.S
> @@ -12,7 +12,9 @@
> #include <asm/errno.h>
> #include <asm/ppc_asm.h>
> #include <asm/export.h>
> +#include <asm/kasan.h>
>
> +#ifndef CONFIG_KASAN
> _GLOBAL(__memset16)
> rlwimi r4,r4,16,0,15
> /* fall through */
> @@ -29,8 +31,9 @@ _GLOBAL(__memset64)
> EXPORT_SYMBOL(__memset16)
> EXPORT_SYMBOL(__memset32)
> EXPORT_SYMBOL(__memset64)
> +#endif
>
> -_GLOBAL(memset)
> +_GLOBAL_KASAN(memset)
> neg r0,r3
> rlwimi r4,r4,8,16,23
> andi. r0,r0,7 /* # bytes to be 8-byte aligned */
> @@ -96,8 +99,9 @@ _GLOBAL(memset)
> stb r4,0(r6)
> blr
> EXPORT_SYMBOL(memset)
> +EXPORT_SYMBOL_KASAN(memset)
>
> -_GLOBAL_TOC(memmove)
> +_GLOBAL_TOC_KASAN(memmove)
> cmplw 0,r3,r4
> bgt backwards_memcpy
> b memcpy
> @@ -139,3 +143,4 @@ _GLOBAL(backwards_memcpy)
> mtctr r7
> b 1b
> EXPORT_SYMBOL(memmove)
> +EXPORT_SYMBOL_KASAN(memmove)
> diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
> index 273ea67e60a1..25c3772c1dfb 100644
> --- a/arch/powerpc/lib/memcpy_64.S
> +++ b/arch/powerpc/lib/memcpy_64.S
> @@ -11,6 +11,7 @@
> #include <asm/export.h>
> #include <asm/asm-compat.h>
> #include <asm/feature-fixups.h>
> +#include <asm/kasan.h>
>
> #ifndef SELFTEST_CASE
> /* For big-endian, 0 == most CPUs, 1 == POWER6, 2 == Cell */
> @@ -18,7 +19,7 @@
> #endif
>
> .align 7
> -_GLOBAL_TOC(memcpy)
> +_GLOBAL_TOC_KASAN(memcpy)
> BEGIN_FTR_SECTION
> #ifdef __LITTLE_ENDIAN__
> cmpdi cr7,r5,0
> @@ -230,3 +231,4 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
> blr
> #endif
> EXPORT_SYMBOL(memcpy)
> +EXPORT_SYMBOL_KASAN(memcpy)
>
>
>>
>> It seems to be related to the export line, as if I swap the exports to
>> do fn before __##fn I get:
>>
>> WARNING: EXPORT symbol "memset" [vmlinux] version generation failed, symbol will not be versioned.
>>
>> I have narrowed this down to combining 2 EXPORT_SYMBOL()s on one line.
>> This works - no warning:
>>
>> EXPORT_SYMBOL(memset)
>> EXPORT_SYMBOL(__memset)
>>
>> This throws a warning:
>>
>> EXPORT_SYMBOL(memset) ; EXPORT_SYMBOL(__memset)
>>
>> I notice in looking at the diff of preprocessed source we end up
>> invoking an asm macro that doesn't seem to have a full final argument, I
>> wonder if that's relevant...
>>
>> -___EXPORT_SYMBOL __memset, __memset, ; ___EXPORT_SYMBOL memset, memset,
>> +___EXPORT_SYMBOL __memset, __memset,
>> +___EXPORT_SYMBOL memset, memset,
>>
>> I also notice that nowhere else in the source do people have multiple
>> EXPORT_SYMBOLs on the same line, and other arches seem to just
>> unconditionally export both symbols on multiple lines.
>>
>> I have no idea how this works for you - maybe it's affected by something 32bit.
>>
>> How would you feel about this approach instead? I'm not tied to any of
>> the names or anything.
>>
>> diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
>> index e0637730a8e7..7b6a91b448dd 100644
>> --- a/arch/powerpc/include/asm/ppc_asm.h
>> +++ b/arch/powerpc/include/asm/ppc_asm.h
>> @@ -214,6 +214,9 @@ name: \
>>
>> #define DOTSYM(a) a
>>
>> +#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
>> + .weak weakname ; .set weakname, strongname ;
>> +
>> #else
>>
>> #define XGLUE(a,b) a##b
>> @@ -236,6 +239,10 @@ GLUE(.,name):
>>
>> #define DOTSYM(a) GLUE(.,a)
>>
>> +#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
>> + .weak weakname ; .set weakname, strongname ; \
>> + .weak DOTSYM(weakname) ; .set DOTSYM(weakname), DOTSYM(strongname) ;
>> +
>> #endif
>>
>> #else /* 32-bit */
>> @@ -251,6 +258,9 @@ GLUE(.,name):
>>
>> #define _GLOBAL_TOC(name) _GLOBAL(name)
>>
>> +#define PROVIDE_WEAK_ALIAS(strongname, weakname) \
>> + .weak weakname ; .set weakname, strongname ;
>> +
>> #endif
>>
>> /*
>> --- a/arch/powerpc/lib/mem_64.S
>> +++ b/arch/powerpc/lib/mem_64.S
>> @@ -33,7 +33,8 @@ EXPORT_SYMBOL(__memset32)
>> EXPORT_SYMBOL(__memset64)
>> #endif
>>
>> -_GLOBAL_KASAN(memset)
>> +PROVIDE_WEAK_ALIAS(__memset,memset)
>> +_GLOBAL(__memset)
>> neg r0,r3
>> rlwimi r4,r4,8,16,23
>> andi. r0,r0,7 /* # bytes to be 8-byte aligned */
>> @@ -98,9 +99,11 @@ _GLOBAL_KASAN(memset)
>> 10: bflr 31
>> stb r4,0(r6)
>> blr
>> -EXPORT_SYMBOL_KASAN(memset)
>> +EXPORT_SYMBOL(memset)
>> +EXPORT_SYMBOL(__memset)
>>
>> -_GLOBAL_TOC_KASAN(memmove)
>> +PROVIDE_WEAK_ALIAS(__memmove,memove)
>> +_GLOBAL_TOC(__memmove)
>> cmplw 0,r3,r4
>> bgt backwards_memcpy
>> b memcpy
>> @@ -141,4 +144,5 @@ _GLOBAL(backwards_memcpy)
>> beq 2b
>> mtctr r7
>> b 1b
>> -EXPORT_SYMBOL_KASAN(memmove)
>> +EXPORT_SYMBOL(memmove)
>> +EXPORT_SYMBOL(__memmove)
>> diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
>> index 862b515b8868..7c1b09556cad 100644
>> --- a/arch/powerpc/lib/memcpy_64.S
>> +++ b/arch/powerpc/lib/memcpy_64.S
>> @@ -19,7 +19,8 @@
>> #endif
>>
>> .align 7
>> -_GLOBAL_TOC_KASAN(memcpy)
>> +PROVIDE_WEAK_ALIAS(__memcpy,memcpy)
>> +_GLOBAL_TOC(__memcpy)
>> BEGIN_FTR_SECTION
>> #ifdef __LITTLE_ENDIAN__
>> cmpdi cr7,r5,0
>> @@ -230,4 +231,5 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
>> 4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
>> blr
>> #endif
>> -EXPORT_SYMBOL_KASAN(memcpy)
>> +EXPORT_SYMBOL(__memcpy)
>> +EXPORT_SYMBOL(memcpy)
>>
>>
>> Regards,
>> Daniel
>>
>>
>>> +#else
>>> +#define _GLOBAL_KASAN(fn) _GLOBAL(fn)
>>> +#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(fn)
>>> +#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(fn)
>>> +#endif
>>> +
>>> +#endif
>>> diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h
>>> index 1647de15a31e..9bf6dffb4090 100644
>>> --- a/arch/powerpc/include/asm/string.h
>>> +++ b/arch/powerpc/include/asm/string.h
>>> @@ -4,14 +4,17 @@
>>>
>>> #ifdef __KERNEL__
>>>
>>> +#ifndef CONFIG_KASAN
>>> #define __HAVE_ARCH_STRNCPY
>>> #define __HAVE_ARCH_STRNCMP
>>> +#define __HAVE_ARCH_MEMCHR
>>> +#define __HAVE_ARCH_MEMCMP
>>> +#define __HAVE_ARCH_MEMSET16
>>> +#endif
>>> +
>>> #define __HAVE_ARCH_MEMSET
>>> #define __HAVE_ARCH_MEMCPY
>>> #define __HAVE_ARCH_MEMMOVE
>>> -#define __HAVE_ARCH_MEMCMP
>>> -#define __HAVE_ARCH_MEMCHR
>>> -#define __HAVE_ARCH_MEMSET16
>>> #define __HAVE_ARCH_MEMCPY_FLUSHCACHE
>>>
>>> extern char * strcpy(char *,const char *);
>>> @@ -27,7 +30,27 @@ extern int memcmp(const void *,const void *,__kernel_size_t);
>>> extern void * memchr(const void *,int,__kernel_size_t);
>>> extern void * memcpy_flushcache(void *,const void *,__kernel_size_t);
>>>
>>> +void *__memset(void *s, int c, __kernel_size_t count);
>>> +void *__memcpy(void *to, const void *from, __kernel_size_t n);
>>> +void *__memmove(void *to, const void *from, __kernel_size_t n);
>>> +
>>> +#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
>>> +/*
>>> + * For files that are not instrumented (e.g. mm/slub.c) we
>>> + * should use not instrumented version of mem* functions.
>>> + */
>>> +#define memcpy(dst, src, len) __memcpy(dst, src, len)
>>> +#define memmove(dst, src, len) __memmove(dst, src, len)
>>> +#define memset(s, c, n) __memset(s, c, n)
>>> +
>>> +#ifndef __NO_FORTIFY
>>> +#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
>>> +#endif
>>> +
>>> +#endif
>>> +
>>> #ifdef CONFIG_PPC64
>>> +#ifndef CONFIG_KASAN
>>> #define __HAVE_ARCH_MEMSET32
>>> #define __HAVE_ARCH_MEMSET64
>>>
>>> @@ -49,8 +72,11 @@ static inline void *memset64(uint64_t *p, uint64_t v, __kernel_size_t n)
>>> {
>>> return __memset64(p, v, n * 8);
>>> }
>>> +#endif
>>> #else
>>> +#ifndef CONFIG_KASAN
>>> #define __HAVE_ARCH_STRLEN
>>> +#endif
>>>
>>> extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
>>> #endif
>>> diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh
>>> index 667df97d2595..181fd10008ef 100644
>>> --- a/arch/powerpc/kernel/prom_init_check.sh
>>> +++ b/arch/powerpc/kernel/prom_init_check.sh
>>> @@ -16,8 +16,16 @@
>>> # If you really need to reference something from prom_init.o add
>>> # it to the list below:
>>>
>>> +grep "^CONFIG_KASAN=y$" .config >/dev/null
>>> +if [ $? -eq 0 ]
>>> +then
>>> + MEM_FUNCS="__memcpy __memset"
>>> +else
>>> + MEM_FUNCS="memcpy memset"
>>> +fi
>>> +
>>> WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
>>> -_end enter_prom memcpy memset reloc_offset __secondary_hold
>>> +_end enter_prom $MEM_FUNCS reloc_offset __secondary_hold
>>> __secondary_hold_acknowledge __secondary_hold_spinloop __start
>>> strcmp strcpy strlcpy strlen strncmp strstr kstrtobool logo_linux_clut224
>>> reloc_got2 kernstart_addr memstart_addr linux_banner _stext
>>> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
>>> index 79396e184bca..47a4de434c22 100644
>>> --- a/arch/powerpc/lib/Makefile
>>> +++ b/arch/powerpc/lib/Makefile
>>> @@ -8,9 +8,14 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
>>> CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
>>> CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
>>>
>>> -obj-y += string.o alloc.o code-patching.o feature-fixups.o
>>> +obj-y += alloc.o code-patching.o feature-fixups.o
>>>
>>> -obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o strlen_32.o
>>> +ifndef CONFIG_KASAN
>>> +obj-y += string.o memcmp_$(BITS).o
>>> +obj-$(CONFIG_PPC32) += strlen_32.o
>>> +endif
>>> +
>>> +obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o
>>>
>>> obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
>>>
>>> @@ -34,7 +39,7 @@ obj64-$(CONFIG_KPROBES_SANITY_TEST) += test_emulate_step.o \
>>> test_emulate_step_exec_instr.o
>>>
>>> obj-y += checksum_$(BITS).o checksum_wrappers.o \
>>> - string_$(BITS).o memcmp_$(BITS).o
>>> + string_$(BITS).o
>>>
>>> obj-y += sstep.o ldstfp.o quad.o
>>> obj64-y += quad.o
>>> diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
>>> index ba66846fe973..fc4fa7246200 100644
>>> --- a/arch/powerpc/lib/copy_32.S
>>> +++ b/arch/powerpc/lib/copy_32.S
>>> @@ -14,6 +14,7 @@
>>> #include <asm/ppc_asm.h>
>>> #include <asm/export.h>
>>> #include <asm/code-patching-asm.h>
>>> +#include <asm/kasan.h>
>>>
>>> #define COPY_16_BYTES \
>>> lwz r7,4(r4); \
>>> @@ -68,6 +69,7 @@ CACHELINE_BYTES = L1_CACHE_BYTES
>>> LG_CACHELINE_BYTES = L1_CACHE_SHIFT
>>> CACHELINE_MASK = (L1_CACHE_BYTES-1)
>>>
>>> +#ifndef CONFIG_KASAN
>>> _GLOBAL(memset16)
>>> rlwinm. r0 ,r5, 31, 1, 31
>>> addi r6, r3, -4
>>> @@ -81,6 +83,7 @@ _GLOBAL(memset16)
>>> sth r4, 4(r6)
>>> blr
>>> EXPORT_SYMBOL(memset16)
>>> +#endif
>>>
>>> /*
>>> * Use dcbz on the complete cache lines in the destination
>>> @@ -91,7 +94,7 @@ EXPORT_SYMBOL(memset16)
>>> * We therefore skip the optimised bloc that uses dcbz. This jump is
>>> * replaced by a nop once cache is active. This is done in machine_init()
>>> */
>>> -_GLOBAL(memset)
>>> +_GLOBAL_KASAN(memset)
>>> cmplwi 0,r5,4
>>> blt 7f
>>>
>>> @@ -150,7 +153,7 @@ _GLOBAL(memset)
>>> 9: stbu r4,1(r6)
>>> bdnz 9b
>>> blr
>>> -EXPORT_SYMBOL(memset)
>>> +EXPORT_SYMBOL_KASAN(memset)
>>>
>>> /*
>>> * This version uses dcbz on the complete cache lines in the
>>> @@ -163,12 +166,12 @@ EXPORT_SYMBOL(memset)
>>> * We therefore jump to generic_memcpy which doesn't use dcbz. This jump is
>>> * replaced by a nop once cache is active. This is done in machine_init()
>>> */
>>> -_GLOBAL(memmove)
>>> +_GLOBAL_KASAN(memmove)
>>> cmplw 0,r3,r4
>>> bgt backwards_memcpy
>>> /* fall through */
>>>
>>> -_GLOBAL(memcpy)
>>> +_GLOBAL_KASAN(memcpy)
>>> 1: b generic_memcpy
>>> patch_site 1b, patch__memcpy_nocache
>>>
>>> @@ -242,8 +245,8 @@ _GLOBAL(memcpy)
>>> stbu r0,1(r6)
>>> bdnz 40b
>>> 65: blr
>>> -EXPORT_SYMBOL(memcpy)
>>> -EXPORT_SYMBOL(memmove)
>>> +EXPORT_SYMBOL_KASAN(memcpy)
>>> +EXPORT_SYMBOL_KASAN(memmove)
>>>
>>> generic_memcpy:
>>> srwi. r7,r5,3
>>> diff --git a/arch/powerpc/lib/mem_64.S b/arch/powerpc/lib/mem_64.S
>>> index 3c3be02f33b7..7cd6cf6822a2 100644
>>> --- a/arch/powerpc/lib/mem_64.S
>>> +++ b/arch/powerpc/lib/mem_64.S
>>> @@ -12,7 +12,9 @@
>>> #include <asm/errno.h>
>>> #include <asm/ppc_asm.h>
>>> #include <asm/export.h>
>>> +#include <asm/kasan.h>
>>>
>>> +#ifndef CONFIG_KASAN
>>> _GLOBAL(__memset16)
>>> rlwimi r4,r4,16,0,15
>>> /* fall through */
>>> @@ -29,8 +31,9 @@ _GLOBAL(__memset64)
>>> EXPORT_SYMBOL(__memset16)
>>> EXPORT_SYMBOL(__memset32)
>>> EXPORT_SYMBOL(__memset64)
>>> +#endif
>>>
>>> -_GLOBAL(memset)
>>> +_GLOBAL_KASAN(memset)
>>> neg r0,r3
>>> rlwimi r4,r4,8,16,23
>>> andi. r0,r0,7 /* # bytes to be 8-byte aligned */
>>> @@ -95,9 +98,9 @@ _GLOBAL(memset)
>>> 10: bflr 31
>>> stb r4,0(r6)
>>> blr
>>> -EXPORT_SYMBOL(memset)
>>> +EXPORT_SYMBOL_KASAN(memset)
>>>
>>> -_GLOBAL_TOC(memmove)
>>> +_GLOBAL_TOC_KASAN(memmove)
>>> cmplw 0,r3,r4
>>> bgt backwards_memcpy
>>> b memcpy
>>> @@ -138,4 +141,4 @@ _GLOBAL(backwards_memcpy)
>>> beq 2b
>>> mtctr r7
>>> b 1b
>>> -EXPORT_SYMBOL(memmove)
>>> +EXPORT_SYMBOL_KASAN(memmove)
>>> diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
>>> index 273ea67e60a1..862b515b8868 100644
>>> --- a/arch/powerpc/lib/memcpy_64.S
>>> +++ b/arch/powerpc/lib/memcpy_64.S
>>> @@ -11,6 +11,7 @@
>>> #include <asm/export.h>
>>> #include <asm/asm-compat.h>
>>> #include <asm/feature-fixups.h>
>>> +#include <asm/kasan.h>
>>>
>>> #ifndef SELFTEST_CASE
>>> /* For big-endian, 0 == most CPUs, 1 == POWER6, 2 == Cell */
>>> @@ -18,7 +19,7 @@
>>> #endif
>>>
>>> .align 7
>>> -_GLOBAL_TOC(memcpy)
>>> +_GLOBAL_TOC_KASAN(memcpy)
>>> BEGIN_FTR_SECTION
>>> #ifdef __LITTLE_ENDIAN__
>>> cmpdi cr7,r5,0
>>> @@ -229,4 +230,4 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
>>> 4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
>>> blr
>>> #endif
>>> -EXPORT_SYMBOL(memcpy)
>>> +EXPORT_SYMBOL_KASAN(memcpy)
>>> --
>>> 2.13.3