NEWS

Snapshot 20030716 (16 July 2003)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

20030716 is a snapshot of our current CVS head (development) branch.
This is the branch which will become valgrind-2.0.  It contains
significant enhancements over the 1.9.X branch.

Despite this being a snapshot of the CVS head, it is believed to be
quite stable -- at least as stable as 1.9.6 or 1.0.4, if not more so
-- and therefore suitable for widespread use.  Please let us know asap
if it causes problems for you.

Two reasons for releasing a snapshot now are:

- It's been a while since 1.9.6, and this snapshot fixes
  various problems that 1.9.6 has with threaded programs 
  on glibc-2.3.X based systems.

- So as to make available improvements in the 2.0 line.

Major changes in 20030716, as compared to 1.9.6:

- More fixes to threading support on glibc-2.3.1 and 2.3.2-based
  systems (SuSE 8.2, Red Hat 9).  If you have had problems
  with inconsistent/illogical behaviour of errno, h_errno or the DNS
  resolver functions in threaded programs, 20030716 should improve
  matters.  This snapshot seems stable enough to run OpenOffice.org
  1.1rc on Red Hat 7.3, SuSE 8.2 and Red Hat 9, and that's a big
  threaded app if ever I saw one.

- Automatic generation of suppression records; you no longer
  need to write them by hand.  Use --gen-suppressions=yes.

- strcpy/memcpy/etc check their arguments for overlaps, when
  running with the Memcheck or Addrcheck skins.

- malloc_usable_size() is now supported.

- new client requests:
    - VALGRIND_COUNT_ERRORS, VALGRIND_COUNT_LEAKS: 
      useful with regression testing
    - VALGRIND_NON_SIMD_CALL[0123]: for running arbitrary functions 
      on real CPU (use with caution!)

- The GDB attach mechanism is more flexible.  Allow the GDB to
  be run to be specified by --gdb-path=/path/to/gdb, and specify
  which file descriptor V will read its input from with
  --input-fd=<number>.

- Cachegrind gives more accurate results (wasn't tracking instructions in
  malloc() and friends previously, is now).

- Complete support for the MMX instruction set.

- Partial support for the SSE and SSE2 instruction sets.  Work for this
  is ongoing.  About half the SSE/SSE2 instructions are done, so
  some SSE based programs may work.  Currently you need to specify
  --skin=addrcheck.  Basically not suitable for real use yet.

- Significant speedups (10%-20%) for standard memory checking.

- Fix assertion failure in pthread_once().

- Fix this:
    valgrind: vg_intercept.c:598 (vgAllRoadsLeadToRome_select): 
              Assertion `ms_end >= ms_now' failed.

- Implement pthread_mutexattr_setpshared.

- Understand Pentium 4 branch hints.  Also implemented a couple more
  obscure x86 instructions.

- Lots of other minor bug fixes.

- We have a decent regression test system, for the first time.
  This doesn't help you directly, but it does make it a lot easier
  for us to track the quality of the system, especially across
  multiple linux distributions.  

  You can run the regression tests with 'make regtest' after 'make
  install' completes.  On SuSE 8.2 and Red Hat 9 I get this:
 
     == 84 tests, 0 stderr failures, 0 stdout failures ==

  On Red Hat 8, I get this:

     == 84 tests, 2 stderr failures, 1 stdout failure ==
     corecheck/tests/res_search               (stdout)
     memcheck/tests/sigaltstack               (stderr)

  sigaltstack is probably harmless.  res_search doesn't work
  on R H 8 even running natively, so I'm not too worried.   

  On Red Hat 7.3, a glibc-2.2.5 system, I get these harmless failures:

     == 84 tests, 2 stderr failures, 1 stdout failure ==
     corecheck/tests/pth_atfork1              (stdout)
     corecheck/tests/pth_atfork1              (stderr)
     memcheck/tests/sigaltstack               (stderr)

  You need to run on a PII system, at least, since some tests
  contain P6-specific instructions, and the test machine needs
  access to the internet so that corecheck/tests/res_search
  (a test that the DNS resolver works) can function.

As ever, thanks for the vast amount of feedback :) and bug reports :(
We may not answer all messages, but we do at least look at all of
them, and tend to fix the most frequently reported bugs.



Version 1.9.6 (7 May 2003 or thereabouts)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Major changes in 1.9.6:

- Improved threading support for glibc >= 2.3.2 (SuSE 8.2,
  RedHat 9, to name but two ...)  It turned out that 1.9.5
  had problems with threading support on glibc >= 2.3.2,
  usually manifested by threaded programs deadlocking in system calls,
  or running unbelievably slowly.  Hopefully these are fixed now.  1.9.6
  is the first valgrind which gives reasonable support for
  glibc-2.3.2.  Also fixed a 2.3.2 problem with pthread_atfork().

- Majorly expanded FAQ.txt.  We've added workarounds for all
  common problems for which a workaround is known.

Minor changes in 1.9.6:

- Fix identification of the main thread's stack.  Incorrect
  identification of it was causing some on-stack addresses to not get
  identified as such.  This only affected the usefulness of some error
  messages; the correctness of the checks made is unchanged.

- Support for kernels >= 2.5.68.

- Dummy implementations of __libc_current_sigrtmin, 
  __libc_current_sigrtmax and __libc_allocate_rtsig, hopefully
  good enough to keep alive programs which previously died for lack of
  them.

- Fix bug in the VALGRIND_DISCARD_TRANSLATIONS client request.

- Fix bug in the DWARF2 debug line info loader, when instructions 
  following each other have source lines far from each other 
  (e.g. with inlined functions).

- Debug info reading: read symbols from both "symtab" and "dynsym"
  sections, rather than merely from the one that comes last in the
  file.

- New syscall support: prctl(), creat(), lookup_dcookie().

- When checking calls to accept(), recvfrom(), getsocketopt(),
  don't complain if buffer values are NULL.

- Try and avoid assertion failures in
  mash_LD_PRELOAD_and_LD_LIBRARY_PATH.

- Minor bug fixes in cg_annotate.



Version 1.9.5 (7 April 2003)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It occurs to me that it would be helpful for valgrind users to record
in the source distribution the changes in each release.  So I now
attempt to mend my errant ways :-)  Changes in this and future releases
will be documented in the NEWS file in the source distribution.

Major changes in 1.9.5:

- (Critical bug fix): Fix a bug in the FPU simulation.  This was
  causing some floating point conditional tests not to work right.
  Several people reported this.  If you had floating point code which
  didn't work right on 1.9.1 to 1.9.4, it's worth trying 1.9.5.

- Partial support for Red Hat 9.  RH9 uses the new Native Posix 
  Threads Library (NPTL), instead of the older LinuxThreads.  
  This potentially causes problems with V which will take some
  time to correct.  In the meantime we have partially worked around
  this, and so 1.9.5 works on RH9.  Threaded programs still work,
  but they may deadlock, because some system calls (accept, read,
  write, etc) which should be nonblocking, in fact do block.  This
  is a known bug which we are looking into.

  If you can, your best bet (unfortunately) is to avoid using 
  1.9.5 on a Red Hat 9 system, or on any NPTL-based distribution.
  If your glibc is 2.3.1 or earlier, you're almost certainly OK.

Minor changes in 1.9.5:

- Added some #errors to valgrind.h to ensure people don't include
  it accidentally in their sources.  This is a change from 1.0.X
  which was never properly documented.  The right thing to include
  is now memcheck.h.  Some people reported problems and strange
  behaviour when (incorrectly) including valgrind.h in code with 
  1.9.1 -- 1.9.4.  This is no longer possible.

- Add some __extension__ bits and pieces so that gcc configured
  for valgrind-checking compiles even with -Werror.  If you
  don't understand this, ignore it.  Of interest to gcc developers
  only.

- Removed a pointless check which caused problems interworking 
  with Clearcase.  V would complain about shared objects whose
  names did not end ".so", and refuse to run.  This is now fixed.
  In fact it was fixed in 1.9.4 but not documented.

- Fixed a bug causing an assertion failure of "waiters == 1"
  somewhere in vg_scheduler.c, when running large threaded apps,
  notably MySQL.

- Add support for the munlock system call (124).

Some comments about future releases:

1.9.5 is, we hope, the most stable Valgrind so far.  It pretty much
supersedes the 1.0.X branch.  If you are a valgrind packager, please
consider making 1.9.5 available to your users.  You can regard the
1.0.X branch as obsolete: 1.9.5 is stable and vastly superior.  There
are no plans at all for further releases of the 1.0.X branch.

If you want a leading-edge valgrind, consider building the cvs head
(from SourceForge), or getting a snapshot of it.  Current cool stuff
going in includes MMX support (done); SSE/SSE2 support (in progress),
a significant (10-20%) performance improvement (done), and the usual
large collection of minor changes.  Hopefully we will be able to
improve our NPTL support, but no promises.