[Bug string/27828] New: memmove doesn't work with tagged address

[Bug string/27828] New: memmove doesn't work with tagged address

[hjl.tools at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27828

            Bug ID: 27828
           Summary: memmove doesn't work with tagged address
           Product: glibc
           Version: 2.34
            Status: NEW
          Severity: normal
          Priority: P2
         Component: string
          Assignee: unassigned at sourceware dot org
          Reporter: hjl.tools at gmail dot com
                CC: carlos at redhat dot com, fweimer at redhat dot com
  Target Milestone: ---

string/memmove.c has

rettype
inhibit_loop_to_libcall
MEMMOVE (a1const void *a1, a2const void *a2, size_t len)
{
  unsigned long int dstp = (long int) dest;
  unsigned long int srcp = (long int) src;

  /* This test makes the forward copying code be used whenever possible.
     Reduces the working set.  */
  if (dstp - srcp >= len)       /* *Unsigned* compare!  */
      ^^^^^^^^^^^^  This doesn't work with tagged address.
    {
      ...
    }

Processor specific memmove may have the same issue.

sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:

247 L(start_movsb):
248         mov     %RDX_LP, %RCX_LP
249         cmp     %RSI_LP, %RDI_LP
            ^^^^^^^^^^^^^^^^^^^^^^^^ This has the same issue.
250         jb      1f

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[Bug string/27828] memmove doesn't work with tagged address

[hjl.tools at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27828

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |OBSOLETE

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> ---
Overlapping pointers should have the same tag.

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