Re: unaligned access using bash on glibc 2.5

On Wed, May 02, 2007 at 11:38:51AM +0200, Aurelien Jarno wrote:
> Please find the reduced testcase below. When the value is assigned to
> __libc_errno, the value of r19 has been overrided by the call to free().
> 

And a smaller one:


extern __thread int __libc_errno __attribute__ ((tls_model ("initial-exec")));
extern void free (void *__ptr) __attribute__ ((__nothrow__));

void test(int *p)
{
  free (p);
  __libc_errno = 25;
}

00000000 <test>:
test():
   0:   6b c2 3f d9     stw rp,-14(sp)
   4:   6f c4 00 80     stw,ma r4,40(sp)
   8:   e8 40 00 00     b,l 10 <test+0x10>,rp
                        8: R_PARISC_PCREL17F    free
   c:   6b d3 3f c1     stw r19,-20(sp)
  10:   2a 60 00 00     addil L%0,r19,r1
                        10: R_PARISC_LTOFF_TP21L        __libc_errno
  14:   48 3c 00 00     ldw 0(r1),ret0
                        14: R_PARISC_LTOFF_TP14R        __libc_errno
  18:   34 15 00 32     ldi 19,r21
  1c:   03 60 08 b4     mfctl tr3,r20
  20:   0b 94 0a 14     add,l r20,ret0,r20
  24:   0e 95 12 80     stw r21,0(r20)
  28:   4b c2 3f 59     ldw -54(sp),rp
  2c:   e8 40 c0 00     bv r0(rp)
  30:   4f c4 3f 81     ldw,mb -40(sp),r4



-- 
  .''`.  Aurelien Jarno	            | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   [email protected]         | [email protected]
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