void MC_(detect_memory_leaks) ( ThreadId tid, LeakCheckMode mode )
{
Int i;
tl_assert(mode != LC_Off);
// Get the chunks, stop if there were none.
lc_chunks = find_active_chunks(&lc_n_chunks);
if (lc_n_chunks == 0) {
tl_assert(lc_chunks == NULL);
if (VG_(clo_verbosity) >= 1 && !VG_(clo_xml)) {
VG_(UMSG)("All heap blocks were freed -- no leaks are possible.\n");
}
return;
}
// Sort the array so blocks are in ascending order in memory.
VG_(ssort)(lc_chunks, lc_n_chunks, sizeof(VgHashNode*), compare_MC_Chunks);
// Sanity check -- make sure they're in order.
for (i = 0; i < lc_n_chunks-1; i++) {
tl_assert( lc_chunks[i]->data <= lc_chunks[i+1]->data);
}
// Sanity check -- make sure they don't overlap. But do allow exact
// duplicates. If this assertion fails, it may mean that the application
// has done something stupid with VALGRIND_MALLOCLIKE_BLOCK client
// requests, specifically, has made overlapping requests (which are
// nonsensical). Another way to screw up is to use
// VALGRIND_MALLOCLIKE_BLOCK for stack locations; again nonsensical.
for (i = 0; i < lc_n_chunks-1; i++) {
MC_Chunk* ch1 = lc_chunks[i];
MC_Chunk* ch2 = lc_chunks[i+1];
Bool nonsense_overlap = ! (
// Normal case - no overlap.
(ch1->data + ch1->szB <= ch2->data) ||
// Degenerate case: exact duplicates.
(ch1->data == ch2->data && ch1->szB == ch2->szB)
);
if (nonsense_overlap) {
VG_(UMSG)("Block [0x%lx, 0x%lx) overlaps with block [0x%lx, 0x%lx)\n",
ch1->data, (ch1->data + ch1->szB),
ch2->data, (ch2->data + ch2->szB));
}
tl_assert (!nonsense_overlap);
}
// Initialise lc_extras.
lc_extras = VG_(malloc)( "mc.dml.2", lc_n_chunks * sizeof(LC_Extra) );
for (i = 0; i < lc_n_chunks; i++) {
lc_extras[i].state = Unreached;
lc_extras[i].indirect_szB = 0;
}
// Initialise lc_markstack.
lc_markstack = VG_(malloc)( "mc.dml.2", lc_n_chunks * sizeof(Int) );
for (i = 0; i < lc_n_chunks; i++) {
lc_markstack[i] = -1;
}
lc_markstack_top = -1;
// Verbosity.
if (VG_(clo_verbosity) > 0 && !VG_(clo_xml))
VG_(UMSG)( "searching for pointers to %'d not-freed blocks.\n",
lc_n_chunks );
// Scan the memory root-set, pushing onto the mark stack any blocks
// pointed to.
{
Int n_seg_starts;
Addr* seg_starts = VG_(get_segment_starts)( &n_seg_starts );
tl_assert(seg_starts && n_seg_starts > 0);
lc_scanned_szB = 0;
// VG_(am_show_nsegments)( 0, "leakcheck");
for (i = 0; i < n_seg_starts; i++) {
SizeT seg_size;
NSegment const* seg = VG_(am_find_nsegment)( seg_starts[i] );
tl_assert(seg);
if (seg->kind != SkFileC && seg->kind != SkAnonC) continue;
if (!(seg->hasR && seg->hasW)) continue;
if (seg->isCH) continue;
// Don't poke around in device segments as this may cause
// hangs. Exclude /dev/zero just in case someone allocated
// memory by explicitly mapping /dev/zero.
if (seg->kind == SkFileC
&& (VKI_S_ISCHR(seg->mode) || VKI_S_ISBLK(seg->mode))) {
HChar* dev_name = VG_(am_get_filename)( (NSegment*)seg );
if (dev_name && 0 == VG_(strcmp)(dev_name, "/dev/zero")) {
// Don't skip /dev/zero.
} else {
// Skip this device mapping.
continue;
}
}
if (0)
VG_(printf)("ACCEPT %2d %#lx %#lx\n", i, seg->start, seg->end);
// Scan the segment. We use -1 for the clique number, because this
// is a root-set.
seg_size = seg->end - seg->start + 1;
if (VG_(clo_verbosity) > 2) {
VG_(message)(Vg_DebugMsg,
" Scanning root segment: %#lx..%#lx (%lu)\n",
seg->start, seg->end, seg_size);
}
lc_scan_memory(seg->start, seg_size, /*is_prior_definite*/True, -1);
}
}
// Scan GP registers for chunk pointers.
VG_(apply_to_GP_regs)(lc_push_if_a_chunk_ptr_register);
// Process the pushed blocks. After this, every block that is reachable
// from the root-set has been traced.
lc_process_markstack(/*clique*/-1);
if (VG_(clo_verbosity) > 0 && !VG_(clo_xml))
VG_(UMSG)("checked %'lu bytes.\n", lc_scanned_szB);
// Trace all the leaked blocks to determine which are directly leaked and
// which are indirectly leaked. For each Unreached block, push it onto
// the mark stack, and find all the as-yet-Unreached blocks reachable
// from it. These form a clique and are marked IndirectLeak, and their
// size is added to the clique leader's indirect size. If one of the
// found blocks was itself a clique leader (from a previous clique), then
// the cliques are merged.
for (i = 0; i < lc_n_chunks; i++) {
MC_Chunk* ch = lc_chunks[i];
LC_Extra* ex = &(lc_extras[i]);
if (VG_DEBUG_CLIQUE)
VG_(printf)("cliques: %d at %#lx -> Loss state %d\n",
i, ch->data, ex->state);
tl_assert(lc_markstack_top == -1);
if (ex->state == Unreached) {
if (VG_DEBUG_CLIQUE)
VG_(printf)("%d: gathering clique %#lx\n", i, ch->data);
// Push this Unreached block onto the stack and process it.
lc_push(i, ch);
lc_process_markstack(i);
tl_assert(lc_markstack_top == -1);
tl_assert(ex->state == Unreached);
}
}
print_results( tid, ( mode == LC_Full ? True : False ) );
VG_(free) ( lc_chunks );
VG_(free) ( lc_extras );
VG_(free) ( lc_markstack );
}
void MC_(detect_memory_leaks) ( ThreadId tid, LeakCheckMode mode )
{
Int i, j;
tl_assert(mode != LC_Off);
// Get the chunks, stop if there were none.
lc_chunks = find_active_chunks(&lc_n_chunks);
if (lc_n_chunks == 0) {
tl_assert(lc_chunks == NULL);
if (VG_(clo_verbosity) >= 1 && !VG_(clo_xml)) {
VG_(umsg)("All heap blocks were freed -- no leaks are possible\n");
VG_(umsg)("\n");
}
return;
}
// Sort the array so blocks are in ascending order in memory.
VG_(ssort)(lc_chunks, lc_n_chunks, sizeof(VgHashNode*), compare_MC_Chunks);
// Sanity check -- make sure they're in order.
for (i = 0; i < lc_n_chunks-1; i++) {
tl_assert( lc_chunks[i]->data <= lc_chunks[i+1]->data);
}
// Sanity check -- make sure they don't overlap. The one exception is that
// we allow a MALLOCLIKE block to sit entirely within a malloc() block.
// This is for bug 100628. If this occurs, we ignore the malloc() block
// for leak-checking purposes. This is a hack and probably should be done
// better, but at least it's consistent with mempools (which are treated
// like this in find_active_chunks). Mempools have a separate VgHashTable
// for mempool chunks, but if custom-allocated blocks are put in a separate
// table from normal heap blocks it makes free-mismatch checking more
// difficult.
//
// If this check fails, it probably means that the application
// has done something stupid with VALGRIND_MALLOCLIKE_BLOCK client
// requests, eg. has made overlapping requests (which are
// nonsensical), or used VALGRIND_MALLOCLIKE_BLOCK for stack locations;
// again nonsensical.
//
for (i = 0; i < lc_n_chunks-1; i++) {
MC_Chunk* ch1 = lc_chunks[i];
MC_Chunk* ch2 = lc_chunks[i+1];
Addr start1 = ch1->data;
Addr start2 = ch2->data;
Addr end1 = ch1->data + ch1->szB - 1;
Addr end2 = ch2->data + ch2->szB - 1;
Bool isCustom1 = ch1->allockind == MC_AllocCustom;
Bool isCustom2 = ch2->allockind == MC_AllocCustom;
if (end1 < start2) {
// Normal case - no overlap.
// We used to allow exact duplicates, I'm not sure why. --njn
//} else if (start1 == start2 && end1 == end2) {
// Degenerate case: exact duplicates.
} else if (start1 >= start2 && end1 <= end2 && isCustom1 && !isCustom2) {
// Block i is MALLOCLIKE and entirely within block i+1.
// Remove block i+1.
for (j = i+1; j < lc_n_chunks-1; j++) {
lc_chunks[j] = lc_chunks[j+1];
}
lc_n_chunks--;
} else if (start2 >= start1 && end2 <= end1 && isCustom2 && !isCustom1) {
// Block i+1 is MALLOCLIKE and entirely within block i.
// Remove block i.
for (j = i; j < lc_n_chunks-1; j++) {
lc_chunks[j] = lc_chunks[j+1];
}
lc_n_chunks--;
} else {
VG_(umsg)("Block 0x%lx..0x%lx overlaps with block 0x%lx..0x%lx",
start1, end1, start1, end2);
VG_(umsg)("This is usually caused by using VALGRIND_MALLOCLIKE_BLOCK");
VG_(umsg)("in an inappropriate way.");
tl_assert (0);
}
}
// Initialise lc_extras.
lc_extras = VG_(malloc)( "mc.dml.2", lc_n_chunks * sizeof(LC_Extra) );
for (i = 0; i < lc_n_chunks; i++) {
lc_extras[i].state = Unreached;
lc_extras[i].indirect_szB = 0;
}
// Initialise lc_markstack.
lc_markstack = VG_(malloc)( "mc.dml.2", lc_n_chunks * sizeof(Int) );
for (i = 0; i < lc_n_chunks; i++) {
lc_markstack[i] = -1;
}
lc_markstack_top = -1;
// Verbosity.
if (VG_(clo_verbosity) > 1 && !VG_(clo_xml)) {
VG_(umsg)( "Searching for pointers to %'d not-freed blocks\n",
lc_n_chunks );
}
// Scan the memory root-set, pushing onto the mark stack any blocks
// pointed to.
{
Int n_seg_starts;
Addr* seg_starts = VG_(get_segment_starts)( &n_seg_starts );
tl_assert(seg_starts && n_seg_starts > 0);
lc_scanned_szB = 0;
// VG_(am_show_nsegments)( 0, "leakcheck");
for (i = 0; i < n_seg_starts; i++) {
SizeT seg_size;
NSegment const* seg = VG_(am_find_nsegment)( seg_starts[i] );
tl_assert(seg);
if (seg->kind != SkFileC && seg->kind != SkAnonC) continue;
if (!(seg->hasR && seg->hasW)) continue;
if (seg->isCH) continue;
// Don't poke around in device segments as this may cause
// hangs. Exclude /dev/zero just in case someone allocated
// memory by explicitly mapping /dev/zero.
if (seg->kind == SkFileC
&& (VKI_S_ISCHR(seg->mode) || VKI_S_ISBLK(seg->mode))) {
HChar* dev_name = VG_(am_get_filename)( (NSegment*)seg );
if (dev_name && 0 == VG_(strcmp)(dev_name, "/dev/zero")) {
// Don't skip /dev/zero.
} else {
// Skip this device mapping.
continue;
}
}
if (0)
VG_(printf)("ACCEPT %2d %#lx %#lx\n", i, seg->start, seg->end);
// Scan the segment. We use -1 for the clique number, because this
// is a root-set.
seg_size = seg->end - seg->start + 1;
if (VG_(clo_verbosity) > 2) {
VG_(message)(Vg_DebugMsg,
" Scanning root segment: %#lx..%#lx (%lu)\n",
seg->start, seg->end, seg_size);
}
lc_scan_memory(seg->start, seg_size, /*is_prior_definite*/True, -1);
}
}
// Scan GP registers for chunk pointers.
VG_(apply_to_GP_regs)(lc_push_if_a_chunk_ptr_register);
// Process the pushed blocks. After this, every block that is reachable
// from the root-set has been traced.
lc_process_markstack(/*clique*/-1);
if (VG_(clo_verbosity) > 1 && !VG_(clo_xml)) {
VG_(umsg)("Checked %'lu bytes\n", lc_scanned_szB);
VG_(umsg)( "\n" );
}
// Trace all the leaked blocks to determine which are directly leaked and
// which are indirectly leaked. For each Unreached block, push it onto
// the mark stack, and find all the as-yet-Unreached blocks reachable
// from it. These form a clique and are marked IndirectLeak, and their
// size is added to the clique leader's indirect size. If one of the
// found blocks was itself a clique leader (from a previous clique), then
// the cliques are merged.
for (i = 0; i < lc_n_chunks; i++) {
MC_Chunk* ch = lc_chunks[i];
LC_Extra* ex = &(lc_extras[i]);
if (VG_DEBUG_CLIQUE)
VG_(printf)("cliques: %d at %#lx -> Loss state %d\n",
i, ch->data, ex->state);
tl_assert(lc_markstack_top == -1);
if (ex->state == Unreached) {
if (VG_DEBUG_CLIQUE)
VG_(printf)("%d: gathering clique %#lx\n", i, ch->data);
// Push this Unreached block onto the stack and process it.
lc_push(i, ch);
lc_process_markstack(i);
tl_assert(lc_markstack_top == -1);
tl_assert(ex->state == Unreached);
}
}
print_results( tid, ( mode == LC_Full ? True : False ) );
VG_(free) ( lc_chunks );
VG_(free) ( lc_extras );
VG_(free) ( lc_markstack );
}
