Re: Versioning mess proved!!!

[Jack Howarth <howarth at fuse dot net>]

Ulrich,
     I hope I did this right. I changed tA-22.c to

int main(void)
{
   extern void foo (void) __attribute__ ((weak));
   void (*foop) (void) = foo;
   asm volatile ("" : "=r" (foop) : "0" (foop));
   printf ("%p\n", foop);
   if (foop)
         foop();
     return 0;
}

which using 'gcc  -S tA-22.c -L213 -ltB -o tA' created the following in tA

        .file   "tA-22.c"
gcc2_compiled.:
        .section        ".rodata"
        .align 2
.LC0:
        .string "%p\n"
        .section        ".text"
        .align 2
        .globl main
        .type    main,@function
main:
        stwu 1,-48(1)
        mflr 0
        stw 29,36(1)
        stw 30,40(1)
        stw 31,44(1)
        stw 0,52(1)
        mr 31,1
        lis 9,foo@ha
        la 0,foo@l(9)
        stw 0,8(31)
        lwz 9,8(31)
        mr 0,9
        mr 9,0
        stw 9,8(31)
        lis 9,.LC0@ha
        la 3,.LC0@l(9)
        lwz 4,8(31)
        crxor 6,6,6
        bl printf
        lwz 0,8(31)
        cmpwi 0,0,0
        bc 12,2,.L3
        lwz 29,8(31)
        mtlr 29
        blrl
.L3:
        li 3,0
        b .L2
.L2:
        lwz 11,0(1)
        lwz 0,4(11)
        mtlr 0
        lwz 29,-12(11)
        lwz 30,-8(11)
        lwz 31,-4(11)
        mr 1,11
        blr
.Lfe1:
        .size    main,.Lfe1-main
        .weak   foo
        .ident  "GCC: (GNU) 2.95.3 19991030 (prerelease/franzo/20000629)"

This code still segfaults when I run...

LD_LIBRARY_PATH=./22/ LD_BIND_NOW=1 ./tA

    0x10010828
    Segmentation fault (core dumped)


Ulrich Drepper wrote:

> Franz Sirl <Franz.Sirl-kernel@lauterbach.com> writes:
>
> > int main(void)
> > {
> >    extern void foo (void) __attribute__ ((weak));
> >    void (*foop) (void) = foo;
> >    printf ("%p\n", foop);
> >    if (foop)
> >          foop();
> >      return 0;
> > }
>
> What if you change this to
>
>    extern void foo (void) __attribute__ ((weak));
>    void (*foop) (void) = foo;
>    asm volatile ("" : "=r" (foop) : "0" (foop));
>    printf ("%p\n", foop);
>    if (foop)
>          foop();
>      return 0;
>
> (note the asm).  If this fails, please show me the generated asm code.
>
> --
> ---------------.                          ,-.   1325 Chesapeake Terrace
> Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
> Red Hat          `--' drepper at redhat.com   `------------------------

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