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    Subject[patch 1/1] x86_64: make string func definition work as intended
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    From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
    CC: Andi Kleen <ak@suse.de>

    In include/asm-x86_64/string.h there are such comments:

    /* Use C out of line version for memcmp */
    #define memcmp __builtin_memcmp
    int memcmp(const void * cs,const void * ct,size_t count);

    This would mean that if the compiler does not decide to use __builtin_memcmp,
    it emits a call to memcmp to be satisfied by the C out-of-line version in
    lib/string.c. What happens is that after preprocessing, in lib/string.i you
    may find the definition of "__builtin_strcmp".

    Actually, by accident, in the object you will find the definition of
    strcmp and such (maybe a trick intended to redirect calls to __builtin_memcmp
    to the default memcmp when the definition is not expanded); however, this
    particular case is not a documented feature as far as I can see.

    Also, the EXPORT_SYMBOL does not work, so it's duplicated in the arch.

    I simply added some #undef to lib/string.c and removed the (now duplicated)
    exports in x86-64 and UML/x86_64 subarchs (the second ones are introduced by
    another patch I just posted for -mm).

    I agree this can be a bit kludgy, so if you want add another solution.

    Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
    ---

    linux-2.6.12-paolo/arch/um/sys-x86_64/ksyms.c | 3 ---
    linux-2.6.12-paolo/arch/x86_64/kernel/x8664_ksyms.c | 13 -------------
    linux-2.6.12-paolo/lib/string.c | 4 ++++
    3 files changed, 4 insertions(+), 16 deletions(-)

    diff -puN include/asm-x86_64/string.h~x86_64-string-func include/asm-x86_64/string.h
    diff -puN lib/string.c~x86_64-string-func lib/string.c
    --- linux-2.6.12/lib/string.c~x86_64-string-func 2005-05-01 20:45:29.000000000 +0200
    +++ linux-2.6.12-paolo/lib/string.c 2005-05-01 20:45:29.000000000 +0200
    @@ -65,6 +65,7 @@ EXPORT_SYMBOL(strnicmp);
    * @dest: Where to copy the string to
    * @src: Where to copy the string from
    */
    +#undef strcpy
    char * strcpy(char * dest,const char *src)
    {
    char *tmp = dest;
    @@ -132,6 +133,7 @@ EXPORT_SYMBOL(strlcpy);
    * @dest: The string to be appended to
    * @src: The string to append to it
    */
    +#undef strcat
    char * strcat(char * dest, const char * src)
    {
    char *tmp = dest;
    @@ -209,6 +211,7 @@ EXPORT_SYMBOL(strlcat);
    * @cs: One string
    * @ct: Another string
    */
    +#undef strcmp
    int strcmp(const char * cs,const char * ct)
    {
    register signed char __res;
    @@ -514,6 +517,7 @@ EXPORT_SYMBOL(memmove);
    * @ct: Another area of memory
    * @count: The size of the area.
    */
    +#undef memcmp
    int memcmp(const void * cs,const void * ct,size_t count)
    {
    const unsigned char *su1, *su2;
    diff -puN arch/x86_64/kernel/x8664_ksyms.c~x86_64-string-func arch/x86_64/kernel/x8664_ksyms.c
    --- linux-2.6.12/arch/x86_64/kernel/x8664_ksyms.c~x86_64-string-func 2005-05-01 20:45:29.000000000 +0200
    +++ linux-2.6.12-paolo/arch/x86_64/kernel/x8664_ksyms.c 2005-05-01 20:45:29.000000000 +0200
    @@ -139,35 +139,23 @@ EXPORT_SYMBOL_GPL(unset_nmi_callback);
    #undef memmove
    #undef memchr
    #undef strlen
    -#undef strcpy
    #undef strncmp
    #undef strncpy
    #undef strchr
    -#undef strcmp
    -#undef strcpy
    -#undef strcat
    -#undef memcmp

    extern void * memset(void *,int,__kernel_size_t);
    extern size_t strlen(const char *);
    extern void * memmove(void * dest,const void *src,size_t count);
    -extern char * strcpy(char * dest,const char *src);
    -extern int strcmp(const char * cs,const char * ct);
    extern void *memchr(const void *s, int c, size_t n);
    extern void * memcpy(void *,const void *,__kernel_size_t);
    extern void * __memcpy(void *,const void *,__kernel_size_t);
    -extern char * strcat(char *, const char *);
    -extern int memcmp(const void * cs,const void * ct,size_t count);

    EXPORT_SYMBOL(memset);
    EXPORT_SYMBOL(strlen);
    EXPORT_SYMBOL(memmove);
    -EXPORT_SYMBOL(strcpy);
    EXPORT_SYMBOL(strncmp);
    EXPORT_SYMBOL(strncpy);
    EXPORT_SYMBOL(strchr);
    -EXPORT_SYMBOL(strcmp);
    -EXPORT_SYMBOL(strcat);
    EXPORT_SYMBOL(strncat);
    EXPORT_SYMBOL(memchr);
    EXPORT_SYMBOL(strrchr);
    @@ -175,7 +163,6 @@ EXPORT_SYMBOL(strnlen);
    EXPORT_SYMBOL(memscan);
    EXPORT_SYMBOL(memcpy);
    EXPORT_SYMBOL(__memcpy);
    -EXPORT_SYMBOL(memcmp);

    #ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM
    /* prototypes are wrong, these are assembly with custom calling functions */
    diff -puN arch/um/sys-x86_64/ksyms.c~x86_64-string-func arch/um/sys-x86_64/ksyms.c
    --- linux-2.6.12/arch/um/sys-x86_64/ksyms.c~x86_64-string-func 2005-05-01 20:45:29.000000000 +0200
    +++ linux-2.6.12-paolo/arch/um/sys-x86_64/ksyms.c 2005-05-01 20:45:29.000000000 +0200
    @@ -14,9 +14,6 @@ EXPORT_SYMBOL(__up_wakeup);

    /*XXX: we need them because they would be exported by x86_64 */
    EXPORT_SYMBOL(__memcpy);
    -EXPORT_SYMBOL(strcmp);
    -EXPORT_SYMBOL(strcat);
    -EXPORT_SYMBOL(strcpy);

    /* Networking helper routines. */
    /*EXPORT_SYMBOL(csum_partial_copy_from);
    _
    -
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