From: Mark Wielaard <mark@klomp.org>
Date: Tue, 7 Jul 2015 13:01:40 +0000 (+0000)
Subject: 349941 di_notify_mmap might create wrong start/size DebugInfoMapping
X-Git-Tag: svn/VALGRIND_3_11_0~247
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c814eb6b3551e6fc8b2c9d569f745e62432f57bc;p=thirdparty%2Fvalgrind.git

349941 di_notify_mmap might create wrong start/size DebugInfoMapping

Use seg->start instead of a as DebugInfoMapping avma. Normally seg->start
equals a. But when it is not then the size of the map might extend beyond
the segment (and not actually cover the start of the segment). When another
ELF file is them mapped right after this then it triggers an overlap purge
of the DebugInfo. In the case the mapping was for libc or ld.so this then
removes all intercepts causing "bad things".

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15398
---

diff --git a/NEWS b/NEWS
index 48fe21c82a..035de411e0 100644
--- a/NEWS
+++ b/NEWS
@@ -250,6 +250,7 @@ where XXXXXX is the bug number as listed below.
 349626  Implemented additional Xen hypercalls
 349874  Fix typos in source code
 349828  memcpy intercepts memmove causing src/dst overlap error (ppc64 ld.so)
+349941  di_notify_mmap might create wrong start/size DebugInfoMapping
 n-i-bz  Provide implementations of certain compiler builtins to support
         compilers who may not provide those
 n-i-bz  Old STABS code is still being compiled, but never used. Remove it.
diff --git a/coregrind/m_debuginfo/debuginfo.c b/coregrind/m_debuginfo/debuginfo.c
index 8f2178e204..b69c1c8129 100644
--- a/coregrind/m_debuginfo/debuginfo.c
+++ b/coregrind/m_debuginfo/debuginfo.c
@@ -1038,7 +1038,7 @@ ULong VG_(di_notify_mmap)( Addr a, Bool allow_SkFileV, Int use_fd )
 
    /* Note the details about the mapping. */
    DebugInfoMapping map;
-   map.avma = a;
+   map.avma = seg->start;
    map.size = seg->end + 1 - seg->start;
    map.foff = seg->offset;
    map.rx   = is_rx_map;