Introduce leak detection code for MALLOC_STATS

src/lib/libc/stdlib/malloc.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: malloc.c,v 1.131 2011/05/08 07:08:13 otto Exp $	*/
+/*	$OpenBSD: malloc.c,v 1.132 2011/05/12 09:29:30 otto Exp $	*/
 /*
  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
  *
@@ -43,6 +43,7 @@
 #include <unistd.h>
 
 #ifdef MALLOC_STATS
+#include <sys/tree.h>
 #include <fcntl.h>
 #endif
 
@@ -94,6 +95,9 @@
 struct region_info {
 	void *p;		/* page; low bits used to mark chunks */
 	uintptr_t size;		/* size for pages, or chunk_info pointer */
+#ifdef MALLOC_STATS
+	void *f;		/* where allocated from */
+#endif
 };
 
 LIST_HEAD(chunk_head, chunk_info);
@@ -125,9 +129,11 @@ struct dir_info {
 	size_t cheap_reallocs;
 #define STATS_INC(x) ((x)++)
 #define STATS_ZERO(x) ((x) = 0)
+#define STATS_SETF(x,y) ((x)->f = (y))
 #else
 #define STATS_INC(x)	/* nothing */
 #define STATS_ZERO(x)	/* nothing */
+#define STATS_SETF(x,y)	/* nothing */
 #endif /* MALLOC_STATS */
 	u_int32_t canary2;
 };
@@ -195,6 +201,9 @@ extern char	*__progname;
 #ifdef MALLOC_STATS
 void malloc_dump(int);
 static void malloc_exit(void);
+#define CALLER	__builtin_return_address(0)
+#else
+#define CALLER	NULL
 #endif
 
 /* low bits of r->p determine size: 0 means >= page size and p->size holding
@@ -696,7 +705,7 @@ alloc_chunk_info(struct dir_info *d)
 }
 
 static int
-insert(struct dir_info *d, void *p, size_t sz)
+insert(struct dir_info *d, void *p, size_t sz, void *f)
 {
 	size_t index;
 	size_t mask;
@@ -717,6 +726,9 @@ insert(struct dir_info *d, void *p, size_t sz)
 	}
 	d->r[index].p = p;
 	d->r[index].size = sz;
+#ifdef MALLOC_STATS
+	d->r[index].f = f;
+#endif
 	d->regions_free--;
 	return 0;
 }
@@ -839,7 +851,7 @@ omalloc_make_chunks(struct dir_info *d, int bits)
 	if ((uintptr_t)pp & bits)
 		wrterror("pp & bits", pp);
 
-	insert(d, (void *)((uintptr_t)pp | bits), (uintptr_t)bp);
+	insert(d, (void *)((uintptr_t)pp | bits), (uintptr_t)bp, NULL);
 	return bp;
 }
 
@@ -848,7 +860,7 @@ omalloc_make_chunks(struct dir_info *d, int bits)
  * Allocate a chunk
  */
 static void *
-malloc_bytes(struct dir_info *d, size_t size)
+malloc_bytes(struct dir_info *d, size_t size, void *f)
 {
 	int		i, j;
 	size_t		k;
@@ -908,6 +920,12 @@ malloc_bytes(struct dir_info *d, size_t size)
 			i = 0;
 	}
 	d->chunk_start += i + 1;
+#ifdef MALLOC_STATS
+	if (i == 0) {
+		struct region_info *r = find(d, bp->page);
+		r->f = f;
+	}
+#endif
 
 	*lp ^= u;
 
@@ -980,7 +998,7 @@ free_bytes(struct dir_info *d, struct region_info *r, void *ptr)
 
 
 static void *
-omalloc(size_t sz, int zero_fill)
+omalloc(size_t sz, int zero_fill, void *f)
 {
 	void *p;
 	size_t psz;
@@ -997,7 +1015,7 @@ omalloc(size_t sz, int zero_fill)
 			errno = ENOMEM;
 			return NULL;
 		}
-		if (insert(g_pool, p, sz)) {
+		if (insert(g_pool, p, sz, f)) {
 			unmap(g_pool, p, psz);
 			errno = ENOMEM;
 			return NULL;
@@ -1034,7 +1052,7 @@ omalloc(size_t sz, int zero_fill)
 
 	} else {
 		/* takes care of SOME_JUNK */
-		p = malloc_bytes(g_pool, sz);
+		p = malloc_bytes(g_pool, sz, f);
 		if (zero_fill && p != NULL && sz > 0)
 			memset(p, 0, sz);
 	}
@@ -1090,7 +1108,7 @@ malloc(size_t size)
 		malloc_recurse();
 		return NULL;
 	}
-	r = omalloc(size, mopts.malloc_zero);
+	r = omalloc(size, mopts.malloc_zero, CALLER);
 	malloc_active--;
 	_MALLOC_UNLOCK();
 	if (r == NULL && mopts.malloc_xmalloc) {
@@ -1198,14 +1216,14 @@ free(void *ptr)
 
 
 static void *
-orealloc(void *p, size_t newsz)
+orealloc(void *p, size_t newsz, void *f)
 {
 	struct region_info *r;
 	size_t oldsz, goldsz, gnewsz;
 	void *q;
 
 	if (p == NULL)
-		return omalloc(newsz, 0);
+		return omalloc(newsz, 0, f);
 
 	r = find(g_pool, p);
 	if (r == NULL) {
@@ -1245,6 +1263,7 @@ orealloc(void *p, size_t newsz)
 						memset(q, SOME_JUNK,
 						    rnewsz - roldsz);
 					r->size = newsz;
+					STATS_SETF(r, f);
 					STATS_INC(g_pool->cheap_reallocs);
 					return p;
 				} else if (q != MAP_FAILED)
@@ -1263,29 +1282,34 @@ orealloc(void *p, size_t newsz)
 			}
 			unmap(g_pool, (char *)p + rnewsz, roldsz - rnewsz);
 			r->size = gnewsz;
+			STATS_SETF(r, f);
 			return p;
 		} else {
 			if (newsz > oldsz && mopts.malloc_junk)
 				memset((char *)p + newsz, SOME_JUNK,
 				    rnewsz - mopts.malloc_guard - newsz);
 			r->size = gnewsz;
+			STATS_SETF(r, f);
 			return p;
 		}
 	}
 	if (newsz <= oldsz && newsz > oldsz / 2 && !mopts.malloc_realloc) {
 		if (mopts.malloc_junk && newsz > 0)
 			memset((char *)p + newsz, SOME_JUNK, oldsz - newsz);
+		STATS_SETF(r, f);
 		return p;
 	} else if (newsz != oldsz || mopts.malloc_realloc) {
-		q = omalloc(newsz, 0);
+		q = omalloc(newsz, 0, f);
 		if (q == NULL)
 			return NULL;
 		if (newsz != 0 && oldsz != 0)
 			memcpy(q, p, oldsz < newsz ? oldsz : newsz);
 		ofree(p);
 		return q;
-	} else
+	} else {
+		STATS_SETF(r, f);
 		return p;
+	}
 }
 
 void *
@@ -1304,7 +1328,7 @@ realloc(void *ptr, size_t size)
 		malloc_recurse();
 		return NULL;
 	}
-	r = orealloc(ptr, size);
+	r = orealloc(ptr, size, CALLER);
   
 	malloc_active--;
 	_MALLOC_UNLOCK();
@@ -1347,7 +1371,7 @@ calloc(size_t nmemb, size_t size)
 	}
 
 	size *= nmemb;
-	r = omalloc(size, 1);
+	r = omalloc(size, 1, CALLER);
   
 	malloc_active--;
 	_MALLOC_UNLOCK();
@@ -1386,17 +1410,110 @@ posix_memalign(void **memptr, size_t alignment, size_t size)
 }
 
 #ifdef MALLOC_STATS
+
+struct malloc_leak {
+	void (*f)();
+	size_t total_size;
+	int count;
+};
+
+struct leaknode {
+	RB_ENTRY(leaknode) entry;
+	struct malloc_leak d;
+};
+
+static int
+leakcmp(struct leaknode *e1, struct leaknode *e2)
+{
+	return e1->d.f < e2->d.f ? -1 : e1->d.f > e2->d.f;
+}
+
+static RB_HEAD(leaktree, leaknode) leakhead;
+RB_GENERATE_STATIC(leaktree, leaknode, entry, leakcmp)
+
+static void
+putleakinfo(void *f, size_t sz, int cnt)
+{
+	struct leaknode key, *p;
+	static struct leaknode *page;
+	static int used;
+
+	if (cnt == 0)
+		return;
+
+	key.d.f = f;
+	p = RB_FIND(leaktree, &leakhead, &key);
+	if (p == NULL) {
+		if (page == NULL ||
+		    used >= MALLOC_PAGESIZE / sizeof(struct leaknode)) {
+			page = MMAP(MALLOC_PAGESIZE);
+			if (page == MAP_FAILED)
+				return;
+			used = 0;
+		}
+		p = &page[used++];
+		p->d.f = f;
+		p->d.total_size = sz * cnt;
+		p->d.count = cnt;
+		RB_INSERT(leaktree, &leakhead, p);
+	} else {
+		p->d.total_size += sz * cnt;
+		p->d.count += cnt;
+	}
+}
+
+static struct malloc_leak *malloc_leaks;
+
+static void
+dump_leaks(int fd)
+{
+	struct leaknode *p;
+	char buf[64];
+	int i = 0;
+
+	snprintf(buf, sizeof(buf), "Leak report\n");
+	write(fd, buf, strlen(buf));
+	snprintf(buf, sizeof(buf), "           f     sum      #    avg\n");
+	write(fd, buf, strlen(buf));
+	/* XXX only one page of summary */
+	if (malloc_leaks == NULL)
+		malloc_leaks = MMAP(MALLOC_PAGESIZE);
+	if (malloc_leaks != MAP_FAILED)
+		memset(malloc_leaks, 0, MALLOC_PAGESIZE);
+	RB_FOREACH(p, leaktree, &leakhead) {
+		snprintf(buf, sizeof(buf), "%12p %7zu %6u %6zu\n", p->d.f,
+		    p->d.total_size, p->d.count, p->d.total_size / p->d.count);
+		write(fd, buf, strlen(buf));
+		if (malloc_leaks == MAP_FAILED ||
+		    i >= MALLOC_PAGESIZE / sizeof(struct malloc_leak))
+			continue;
+		malloc_leaks[i].f = p->d.f;
+		malloc_leaks[i].total_size = p->d.total_size;
+		malloc_leaks[i].count = p->d.count;
+		i++;
+	}
+}
+
 static void
-dump_chunk(int fd, struct chunk_info *p, int fromfreelist)
+dump_chunk(int fd, struct chunk_info *p, void *f, int fromfreelist)
 {
 	char buf[64];
 
 	while (p != NULL) {
-		snprintf(buf, sizeof(buf), "chunk %d %d/%d %p\n", p->size,
-		    p->free, p->total, p->page);
+		snprintf(buf, sizeof(buf), "chunk %12p %12p %4d %d/%d\n",
+		    p->page, ((p->bits[0] & 1) ? NULL : f),
+		    p->size, p->free, p->total);
 		write(fd, buf, strlen(buf));
-		if (!fromfreelist)
+		if (!fromfreelist) {
+			if (p->bits[0] & 1) 
+				putleakinfo(NULL, p->size, p->total - p->free);
+			else {
+				putleakinfo(f, p->size, 1);
+				putleakinfo(NULL, p->size,
+				    p->total - p->free - 1);
+			}
 			break;
+		}
 		p = LIST_NEXT(p, entries);
 		if (p != NULL) {
 			snprintf(buf, sizeof(buf), "    ");
@@ -1418,7 +1535,7 @@ dump_free_chunk_info(int fd, struct dir_info *d)
 		if (p != NULL) {
 			snprintf(buf, sizeof(buf), "%2d) ", i);
 			write(fd, buf, strlen(buf));
-			dump_chunk(fd, p, 1);
+			dump_chunk(fd, p, NULL, 1);
 		}
 	}
 
@@ -1472,35 +1589,58 @@ malloc_dump1(int fd, struct dir_info *d)
 	write(fd, buf, strlen(buf));
 	snprintf(buf, sizeof(buf), "Regions slots free %zu\n", d->regions_free);
 	write(fd, buf, strlen(buf));
+	dump_free_chunk_info(fd, d);
+	dump_free_page_info(fd, d);
+	snprintf(buf, sizeof(buf),
+	    "slot)  hash d  type         page            f size [free/n]\n");
+	write(fd, buf, strlen(buf));
 	for (i = 0; i < d->regions_total; i++) {
 		if (d->r[i].p != NULL) {
 			size_t h = hash(d->r[i].p) &
 			    (d->regions_total - 1);
-			snprintf(buf, sizeof(buf), "%4zx) #%zx %zd ",
+			snprintf(buf, sizeof(buf), "%4zx) #%4zx %zd ",
 			    i, h, h - i);
 			write(fd, buf, strlen(buf));
 			REALSIZE(realsize, &d->r[i]);
 			if (realsize > MALLOC_MAXCHUNK) {
+				putleakinfo(d->r[i].f, realsize, 1);
 				snprintf(buf, sizeof(buf),
-				    "%p: %zu\n", d->r[i].p, realsize);
+				    "pages %12p %12p %zu\n", d->r[i].p, 
+				    d->r[i].f, realsize);
 				write(fd, buf, strlen(buf));
 			} else
 				dump_chunk(fd,
-				    (struct chunk_info *)d->r[i].size, 0);
+				    (struct chunk_info *)d->r[i].size, 
+				    d->r[i].f, 0);
 		}
 	}
-	dump_free_chunk_info(fd, d);
-	dump_free_page_info(fd, d);
 	snprintf(buf, sizeof(buf), "In use %zu\n", malloc_used);
 	write(fd, buf, strlen(buf));
 	snprintf(buf, sizeof(buf), "Guarded %zu\n", malloc_guarded);
 	write(fd, buf, strlen(buf));
+	dump_leaks(fd);
+	write(fd, "\n", 1);
 }
 
-
 void
 malloc_dump(int fd)
 {
+	int i;
+	void *p;
+	struct region_info *r;
+
+	for (i = 0; i <= MALLOC_DELAYED_CHUNKS; i++) {
+		p = g_pool->delayed_chunks[i];
+		if (p == NULL)
+			continue;
+		r = find(g_pool, p);
+		if (r == NULL) 
+			wrterror("bogus pointer in malloc_dump", p);
+		free_bytes(g_pool, r, p);
+		g_pool->delayed_chunks[i] = NULL;
+	}
+	/* XXX leak when run multiple times */
+	RB_INIT(&leakhead);
 	malloc_dump1(fd, g_pool);
 }