Fix 341539 VG_(describe_addr) should not describe address as belonging to client
segment if it is past the heap end
Describes specifically an address that is in the brk data segment
or in the 'reduced' (after brk reduction) section of the brk data segment.
Based on a patch from Ivo Raisr.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14833 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/NEWS b/NEWS
index f3704fe..4597a70 100644
--- a/NEWS
+++ b/NEWS
@@ -18,8 +18,8 @@
* ==================== OTHER CHANGES ====================
* Address description logic (used by memcheck and helgrind)
- now describes anonymous or file mmap-ed segments and
- shared memory segments.
+ now describes addressed in anonymous segments, file mmap-ed
+ segments, shared memory segments and the brk data segment.
* Option --error-markers=<begin>,<end> can be used to mark
the begin/end of errors in textual output mode, to facilitate
@@ -94,6 +94,8 @@
340856 disInstr(arm64): unhandled instruction 0x1E634C45 (fcsel)
340922 arm64: unhandled getgroups/setgroups syscalls
341238 Recognize GCC5/DWARFv5 DW_LANG constants (Go, C11, C++11, C++14)
+341539 VG_(describe_addr) should not describe address as belonging to client
+ segment if it is past the heap end
341789 aarch64: shmat fails with valgrind on ARMv8
342063 wrong format specifier for test mcblocklistsearch in gdbserver_tests
n-i-bz Provide implementations of certain compiler builtins to support
diff --git a/coregrind/m_addrinfo.c b/coregrind/m_addrinfo.c
index 533b620..290f279 100644
--- a/coregrind/m_addrinfo.c
+++ b/coregrind/m_addrinfo.c
@@ -30,6 +30,7 @@
*/
#include "pub_core_basics.h"
+#include "pub_core_clientstate.h"
#include "pub_core_libcassert.h"
#include "pub_core_libcbase.h"
#include "pub_core_libcprint.h"
@@ -263,6 +264,27 @@
/* Try to find a segment belonging to the client. */
{
const NSegment *seg = VG_(am_find_nsegment) (a);
+
+ /* Special case to detect the brk data segment. */
+ if (seg != NULL
+ && seg->kind == SkAnonC
+ && VG_(brk_limit) >= seg->start
+ && VG_(brk_limit) <= seg->end+1) {
+ /* Address a is in a Anon Client segment which contains
+ VG_(brk_limit). So, this segment is the brk data segment
+ as initimg-linux.c:setup_client_dataseg maps an anonymous
+ segment followed by a reservation, with one reservation
+ page that will never be used by syswrap-generic.c:do_brk,
+ when increasing VG_(brk_limit).
+ So, the brk data segment will never be merged with the
+ next segment, and so an address in that area will
+ either be in the brk data segment, or in the unmapped
+ part of the brk data segment reservation. */
+ ai->tag = Addr_BrkSegment;
+ ai->Addr.BrkSegment.brk_limit = VG_(brk_limit);
+ return;
+ }
+
if (seg != NULL
&& (seg->kind == SkAnonC
|| seg->kind == SkFileC
@@ -328,6 +350,9 @@
VG_(free)(ai->Addr.SectKind.objname);
break;
+ case Addr_BrkSegment:
+ break;
+
case Addr_SegmentKind:
VG_(free)(ai->Addr.SegmentKind.filename);
break;
@@ -586,6 +611,26 @@
}
break;
+ case Addr_BrkSegment:
+ if (a < ai->Addr.BrkSegment.brk_limit)
+ VG_(emit)( "%sAddress 0x%llx is in the brk data segment"
+ " 0x%llx-0x%llx%s\n",
+ xpre,
+ (ULong)a,
+ (ULong)VG_(brk_base),
+ (ULong)ai->Addr.BrkSegment.brk_limit - 1,
+ xpost );
+ else
+ VG_(emit)( "%sAddress 0x%llx is %lu bytes after "
+ "the brk data segment limit"
+ " 0x%llx%s\n",
+ xpre,
+ (ULong)a,
+ a - ai->Addr.BrkSegment.brk_limit,
+ (ULong)ai->Addr.BrkSegment.brk_limit,
+ xpost );
+ break;
+
case Addr_SegmentKind:
VG_(emit)( "%sAddress 0x%llx is in "
"a %s%s%s %s%s%pS segment%s\n",
diff --git a/include/pub_tool_addrinfo.h b/include/pub_tool_addrinfo.h
index b8fc634..3b1c45f 100644
--- a/include/pub_tool_addrinfo.h
+++ b/include/pub_tool_addrinfo.h
@@ -72,6 +72,7 @@
Addr_DataSym, // in a global data sym
Addr_Variable, // variable described by the debug info
Addr_SectKind, // Section from a mmap-ed object file
+ Addr_BrkSegment, // address in brk data segment
Addr_SegmentKind // Client segment (mapped memory)
}
AddrTag;
@@ -174,6 +175,15 @@
VgSectKind kind;
} SectKind;
+ // Described address is or was in the brk data segment.
+ // brk_limit is the limit that was in force
+ // at the time address was described.
+ // If address is >= brk_limit, it means address is in a zone
+ // of the data segment that was shrinked.
+ struct {
+ Addr brk_limit; // limit in force when address was described.
+ } BrkSegment;
+
struct {
SegKind segkind; // SkAnonC, SkFileC or SkShmC.
HChar *filename; // NULL if segkind != SkFileC
diff --git a/memcheck/tests/dw4.c b/memcheck/tests/dw4.c
index 38c2421..574f97c 100644
--- a/memcheck/tests/dw4.c
+++ b/memcheck/tests/dw4.c
@@ -19,11 +19,11 @@
#include "memcheck/memcheck.h"
/* Cause memcheck to complain about the address "a" and so to print
- its best guess as to what "a" actually is. a must be
- addressible. */
-
+ its best guess as to what "a" actually is.*/
void croak ( void* aV )
{
+ if(VALGRIND_CHECK_MEM_IS_ADDRESSABLE(aV,1) != 0)
+ return;
char* a = (char*)aV;
char* undefp = malloc(1);
char saved = *a;
@@ -82,5 +82,15 @@
croak( q);
unlink(filename);
+ /* Describe memory in or past the heap end. */
+ void *addr = sbrk(0);
+ croak(addr); // in the first brk page, after brk_limit
+ sbrk(4 * 1024); // increase brk segment
+ croak(addr); // Now, must be inside.
+ addr = (void *) ((char*)addr + 2 * 1024);
+ croak(addr); // Must still be inside.
+ sbrk(-3*1024);
+ croak(addr); // Must now be after.
+
return 0;
}
diff --git a/memcheck/tests/dw4.stderr.exp b/memcheck/tests/dw4.stderr.exp
index 605d9bd..e396a43 100644
--- a/memcheck/tests/dw4.stderr.exp
+++ b/memcheck/tests/dw4.stderr.exp
@@ -27,3 +27,23 @@
by 0x........: main (dw4.c:82)
Address 0x........ is in a rw- mapped file valgrind-dw4-test.PID segment
+Uninitialised byte(s) found during client check request
+ at 0x........: croak (dw4.c:32)
+ by 0x........: main (dw4.c:87)
+ Address 0x........ is 0 bytes after the brk data segment limit 0x........
+
+Uninitialised byte(s) found during client check request
+ at 0x........: croak (dw4.c:32)
+ by 0x........: main (dw4.c:89)
+ Address 0x........ is in the brk data segment 0x........-0x........
+
+Uninitialised byte(s) found during client check request
+ at 0x........: croak (dw4.c:32)
+ by 0x........: main (dw4.c:91)
+ Address 0x........ is in the brk data segment 0x........-0x........
+
+Unaddressable byte(s) found during client check request
+ at 0x........: croak (dw4.c:25)
+ by 0x........: main (dw4.c:93)
+ Address 0x........ is 1024 bytes after the brk data segment limit 0x........
+
