Finalise distro docs for 3.3.0.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7287 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/README_PACKAGERS b/README_PACKAGERS
index 5d0e976..519d147 100644
--- a/README_PACKAGERS
+++ b/README_PACKAGERS
@@ -1,9 +1,34 @@
 
+These notes were significantly updated on 6 Dec 2007 for the Valgrind
+3.3.0 release.
+
 Greetings, packaging person!  This information is aimed at people
 building binary distributions of Valgrind.
 
-Thanks for taking the time and effort to make a binary distribution
-of Valgrind.  The following notes may save you some trouble.
+Thanks for taking the time and effort to make a binary distribution of
+Valgrind.  The following notes may save you some trouble.
+
+
+-- Do not ship your Linux distro with a completely stripped
+   /lib/ld.so.  At least leave the debugging symbol names on -- line
+   number info isn't necessary.  If you don't want to leave symbols on
+   ld.so, alternatively you can have your distro install ld.so's
+   debuginfo package by default, or make ld.so.debuginfo be a
+   requirement of your Valgrind RPM/DEB/whatever.
+
+   Reason for this is that Valgrind's Memcheck tool needs to intercept
+   calls to, and provide replacements for, some symbols in ld.so at
+   startup (most importantly strlen).  If it cannot do that, Memcheck
+   shows a large number of false positives due to the highly optimised
+   strlen (etc) routines in ld.so.  This has caused some trouble in
+   the past.  As of version 3.3.0, on some targets (ppc32-linux,
+   ppc64-linux), Memcheck will simply stop at startup (and print an
+   error message) if such symbols are not present, because it is
+   infeasible to continue.
+
+   It's not like this is going to cost you much space.  We only need
+   the symbols for ld.so (a few K at most).  Not the debug info and
+   not any debuginfo or extra symbols for any other libraries.
 
 
 -- (Unfortunate but true) When you configure to build with the 
@@ -16,9 +41,10 @@
    So you can't build a relocatable RPM / whatever from Valgrind.
 
 
--- Don't strip the debug info off stage2 or libpthread.so.
-   Valgrind will still work if you do, but it will generate less
-   helpful error messages.  Here's an example:
+-- Don't strip the debug info off lib/valgrind/$platform/vgpreload*.so
+   in the installation tree.  Either Valgrind won't work at all, or it
+   will still work if you do, but will generate less helpful error
+   messages.  Here's an example:
 
    Mismatched free() / delete / delete []
       at 0x40043249: free (vg_clientfuncs.c:171)
@@ -32,15 +58,15 @@
       by 0x4C21788F: OLEFilter::convert(QCString const &) (olefilter.cc:272)
 
    This tells you that some memory allocated with new[] was freed with
-   free().  If stage2 was stripped the message would look like this:
+   free().
 
    Mismatched free() / delete / delete []
-      at 0x40043249: (inside stage2)
+      at 0x40043249: (inside vgpreload_memcheck.so)
       by 0x4102BB4E: QGArray::~QGArray(void) (tools/qgarray.cpp:149)
       by 0x4C261C41: PptDoc::~PptDoc(void) (include/qmemarray.h:60)
       by 0x4C261F0E: PptXml::~PptXml(void) (pptxml.cc:44)
       Address 0x4BB292A8 is 0 bytes inside a block of size 64 alloc'd
-      at 0x4004318C: (inside stage2)
+      at 0x4004318C: (inside vgpreload_memcheck.so)
       by 0x4C21BC15: KLaola::readSBStream(int) const (klaola.cc:314)
       by 0x4C21C155: KLaola::stream(KLaola::OLENode const *) (klaola.cc:416)
       by 0x4C21788F: OLEFilter::convert(QCString const &) (olefilter.cc:272)
@@ -51,15 +77,22 @@
    from valgrind.
 
 
--- Please test the final installation works by running it on
-   something huge.  I suggest checking that it can start and
-   exit successfully both Mozilla-1.0 and OpenOffice.org 1.0.
-   I use these as test programs, and I know they fairly thoroughly
-   exercise Valgrind.  The command lines to use are:
+-- Don't strip symbols from lib/valgrind/$platform/{cachegrind,
+   callgrind,exp-drd,exp-omega,helgrind,lackey,massif,memcheck,none}
+   in the installation tree.  Doing so will likely cause problems.
+   Removing the line number info is probably OK, although that has not
+   been tested by the Valgrind developers.
 
-   valgrind -v --trace-children=yes --workaround-gcc296-bugs=yes mozilla
 
-   valgrind -v --trace-children=yes --workaround-gcc296-bugs=yes soffice
+-- Please test the final installation works by running it on something
+   huge.  I suggest checking that it can start and exit successfully
+   both Firefox-2.0.0.X and OpenOffice.org 2.3.X.  I use these as test
+   programs, and I know they fairly thoroughly exercise Valgrind.  The
+   command lines to use are:
+
+   valgrind -v --trace-children=yes mozilla
+
+   valgrind -v --trace-children=yes soffice
 
 
 If you find any more hints/tips for packaging, please report