Fix memory corruption when trying to get "core show locks".

Review https://reviewboard.asterisk.org/r/2580/ tried to fix the mismatch
in memory pools but had a math error determining the buffer size and
didn't address other similar memory pool mismatches.

* Effectively reverted the previous patch to go in the same direction as
trunk for the returned memory pool of ast_bt_get_symbols().

* Fixed memory leak in ast_bt_get_symbols() when BETTER_BACKTRACES is
defined.

* Fixed some formatting in ast_bt_get_symbols().

* Fixed sig_pri.c freeing memory allocated by libpri when MALLOC_DEBUG is
enabled.

* Fixed __dump_backtrace() freeing memory from ast_bt_get_symbols() when
MALLOC_DEBUG is enabled.

* Moved __dump_backtrace() because of compile issues with the utils
directory.

(closes issue ASTERISK-22221)
Reported by: Matt Jordan

Review: https://reviewboard.asterisk.org/r/2778/
........

Merged revisions 397525 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 397528 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@397570 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/sig_pri.c

@@ -9430,7 +9430,7 @@ void sig_pri_cli_show_span(int fd, int *dchannels, struct sig_pri_span *pri)
 			info_str = pri_dump_info_str(pri->pri);
 			if (info_str) {
 				ast_cli(fd, "%s", info_str);
-				free(info_str);
+				ast_std_free(info_str);
 			}
 #else
 			pri_dump_info(pri->pri);

include/asterisk/astmm.h

@@ -54,6 +54,12 @@ extern "C" {
 #undef vasprintf
 #undef free
 
+void *ast_std_malloc(size_t size);
+void *ast_std_calloc(size_t nmemb, size_t size);
+void *ast_std_realloc(void *ptr, size_t size);
+void ast_std_free(void *ptr);
+void ast_free_ptr(void *ptr);
+
 void *__ast_calloc(size_t nmemb, size_t size, const char *file, int lineno, const char *func);
 void *__ast_calloc_cache(size_t nmemb, size_t size, const char *file, int lineno, const char *func);
 void *__ast_malloc(size_t size, const char *file, int lineno, const char *func);

include/asterisk/backtrace.h

@@ -87,7 +87,7 @@ void *__ast_bt_destroy(struct ast_bt *bt);
  * \param addresses A list of addresses, such as the ->addresses structure element of struct ast_bt.
  * \param num_frames Number of addresses in the addresses list
  * \retval NULL Unable to allocate memory
- * \return List of strings. This should be freed with a single call to free.
+ * \return List of strings. Free the entire list with a single ast_std_free call.
  * \since 1.6.2.16
  */
 char **__ast_bt_get_symbols(void **addresses, size_t num_frames);

include/asterisk/lock.h

@@ -290,22 +290,6 @@ void ast_remove_lock_info(void *lock_addr);
 #endif /* HAVE_BKTR */
 #endif /* !defined(LOW_MEMORY) */
 
-#ifdef HAVE_BKTR
-static inline void __dump_backtrace(struct ast_bt *bt, int canlog)
-{
-	char **strings;
-
-	ssize_t i;
-
-	strings = backtrace_symbols(bt->addresses, bt->num_frames);
-
-	for (i = 0; i < bt->num_frames; i++)
-		__ast_mutex_logger("%s\n", strings[i]);
-
-	free(strings);
-}
-#endif
-
 /*!
  * \brief log info for the current lock with ast_log().
  *

include/asterisk/utils.h

@@ -465,24 +465,20 @@ long int ast_random(void);
  */
 #define ast_random_double() (((double)ast_random()) / RAND_MAX)
 
+#ifndef __AST_DEBUG_MALLOC
+#define ast_std_malloc malloc
+#define ast_std_calloc calloc
+#define ast_std_realloc realloc
+#define ast_std_free free
+
 /*!
  * \brief free() wrapper
  *
  * ast_free_ptr should be used when a function pointer for free() needs to be passed
  * as the argument to a function. Otherwise, astmm will cause seg faults.
  */
-#ifdef __AST_DEBUG_MALLOC
-static void ast_free_ptr(void *ptr) attribute_unused;
-static void ast_free_ptr(void *ptr)
-{
-	ast_free(ptr);
-}
-#else
 #define ast_free free
 #define ast_free_ptr ast_free
-#endif
-
-#ifndef __AST_DEBUG_MALLOC
 
 /*
  * This buffer is in static memory. We never intend to read it,

main/astmm.c

@@ -158,6 +158,31 @@ AST_MUTEX_DEFINE_STATIC_NOTRACKING(reglock);
 		}                                    \
 	} while (0)
 
+void *ast_std_malloc(size_t size)
+{
+	return malloc(size);
+}
+
+void *ast_std_calloc(size_t nmemb, size_t size)
+{
+	return calloc(nmemb, size);
+}
+
+void *ast_std_realloc(void *ptr, size_t size)
+{
+	return realloc(ptr, size);
+}
+
+void ast_std_free(void *ptr)
+{
+	free(ptr);
+}
+
+void ast_free_ptr(void *ptr)
+{
+	ast_free(ptr);
+}
+
 static void print_backtrace(struct ast_bt *bt)
 {
 	int i = 0;
@@ -172,11 +197,10 @@ static void print_backtrace(struct ast_bt *bt)
 		for (i = 3; i < bt->num_frames - 2; i++) {
 			astmm_log("#%d: [%p] %s\n", i - 3, bt->addresses[i], strings[i]);
 		}
-		free(strings);
+		ast_std_free(strings);
 	}
 }
 
-
 /*!
  * \internal
  *
@@ -343,9 +367,7 @@ static void region_free(struct ast_freed_regions *freed, struct ast_region *reg)
 
 	if (old) {
 		region_data_check(old);
-		if (old->bt) {
+		old->bt = ast_bt_destroy(old->bt);
-			old->bt = ast_bt_destroy(old->bt);
-		}
 		free(old);
 	}
 }

main/astobj2.c

@@ -132,7 +132,7 @@ void ao2_bt(void)
 	for(i = 0; i < c; i++) {
 		ast_verbose("%d: %p %s\n", i, addresses[i], strings[i]);
 	}
-	free(strings);
+	ast_std_free(strings);
 }
 #endif
 

main/backtrace.c

@@ -40,17 +40,10 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$");
 #include <bfd.h>
 #endif
 
-/* Undefine the overrides for memory allocation. astmm.c uses these functions
- * as well.
- */
-#undef calloc
-#undef malloc
-#undef free
-#undef realloc
-
 struct ast_bt *__ast_bt_create(void)
 {
-	struct ast_bt *bt = calloc(1, sizeof(*bt));
+	struct ast_bt *bt = ast_std_calloc(1, sizeof(*bt));
+
 	if (!bt) {
 		return NULL;
 	}
@@ -69,15 +62,15 @@ int __ast_bt_get_addresses(struct ast_bt *bt)
 
 void *__ast_bt_destroy(struct ast_bt *bt)
 {
-	if (bt->alloced) {
+	if (bt && bt->alloced) {
-		free(bt);
+		ast_std_free(bt);
 	}
 	return NULL;
 }
 
 char **__ast_bt_get_symbols(void **addresses, size_t num_frames)
 {
-	char **strings = NULL;
+	char **strings;
 #if defined(BETTER_BACKTRACES)
 	int stackfr;
 	bfd *bfdobj;           /* bfd.h */
@@ -97,9 +90,12 @@ char **__ast_bt_get_symbols(void **addresses, size_t num_frames)
 
 #if defined(BETTER_BACKTRACES)
 	strings_size = num_frames * sizeof(*strings);
-	eachlen = calloc(num_frames, sizeof(*eachlen));
 
-	if (!(strings = calloc(num_frames, sizeof(*strings)))) {
+	eachlen = ast_std_calloc(num_frames, sizeof(*eachlen));
+	strings = ast_std_calloc(num_frames, sizeof(*strings));
+	if (!eachlen || !strings) {
+		ast_std_free(eachlen);
+		ast_std_free(strings);
 		return NULL;
 	}
 
@@ -114,6 +110,7 @@ char **__ast_bt_get_symbols(void **addresses, size_t num_frames)
 
 		if (strcmp(dli.dli_fname, "asterisk") == 0) {
 			char asteriskpath[256];
+
 			if (!(dli.dli_fname = ast_utils_which("asterisk", asteriskpath, sizeof(asteriskpath)))) {
 				/* This will fail to find symbols */
 				dli.dli_fname = "asterisk";
@@ -121,22 +118,22 @@ char **__ast_bt_get_symbols(void **addresses, size_t num_frames)
 		}
 
 		lastslash = strrchr(dli.dli_fname, '/');
-		if (	(bfdobj = bfd_openr(dli.dli_fname, NULL)) &&
+		if ((bfdobj = bfd_openr(dli.dli_fname, NULL)) &&
-				bfd_check_format(bfdobj, bfd_object) &&
+			bfd_check_format(bfdobj, bfd_object) &&
-				(allocsize = bfd_get_symtab_upper_bound(bfdobj)) > 0 &&
+			(allocsize = bfd_get_symtab_upper_bound(bfdobj)) > 0 &&
-				(syms = malloc(allocsize)) &&
+			(syms = ast_std_malloc(allocsize)) &&
-				(symbolcount = bfd_canonicalize_symtab(bfdobj, syms))) {
+			(symbolcount = bfd_canonicalize_symtab(bfdobj, syms))) {
 
 			if (bfdobj->flags & DYNAMIC) {
 				offset = addresses[stackfr] - dli.dli_fbase;
 			} else {
-				offset = addresses[stackfr] - (void *)0;
+				offset = addresses[stackfr] - (void *) 0;
 			}
 
 			for (section = bfdobj->sections; section; section = section->next) {
-				if (	!bfd_get_section_flags(bfdobj, section) & SEC_ALLOC ||
+				if (!bfd_get_section_flags(bfdobj, section) & SEC_ALLOC ||
-						section->vma > offset ||
+					section->vma > offset ||
-						section->size + section->vma < offset) {
+					section->size + section->vma < offset) {
 					continue;
 				}
 
@@ -151,7 +148,9 @@ char **__ast_bt_get_symbols(void **addresses, size_t num_frames)
 				found++;
 				if ((lastslash = strrchr(file, '/'))) {
 					const char *prevslash;
-					for (prevslash = lastslash - 1; *prevslash != '/' && prevslash >= file; prevslash--);
+
+					for (prevslash = lastslash - 1; *prevslash != '/' && prevslash >= file; prevslash--) {
+					}
 					if (prevslash >= file) {
 						lastslash = prevslash;
 					}
@@ -173,7 +172,7 @@ char **__ast_bt_get_symbols(void **addresses, size_t num_frames)
 		}
 		if (bfdobj) {
 			bfd_close(bfdobj);
-			free(syms);
+			ast_std_free(syms);
 		}
 
 		/* Default output, if we cannot find the information within BFD */
@@ -193,27 +192,31 @@ char **__ast_bt_get_symbols(void **addresses, size_t num_frames)
 
 		if (!ast_strlen_zero(msg)) {
 			char **tmp;
-			eachlen[stackfr] = strlen(msg);
+
-			if (!(tmp = realloc(strings, strings_size + eachlen[stackfr] + 1))) {
+			eachlen[stackfr] = strlen(msg) + 1;
-				free(strings);
+			if (!(tmp = ast_std_realloc(strings, strings_size + eachlen[stackfr]))) {
+				ast_std_free(strings);
 				strings = NULL;
 				break; /* out of stack frame iteration */
 			}
 			strings = tmp;
 			strings[stackfr] = (char *) strings + strings_size;
-			ast_copy_string(strings[stackfr], msg, eachlen[stackfr] + 1);
+			strcpy(strings[stackfr], msg);/* Safe since we just allocated the room. */
-			strings_size += eachlen[stackfr] + 1;
+			strings_size += eachlen[stackfr];
 		}
 	}
 
 	if (strings) {
-		/* Recalculate the offset pointers */
+		/* Recalculate the offset pointers because of the reallocs. */
 		strings[0] = (char *) strings + num_frames * sizeof(*strings);
 		for (stackfr = 1; stackfr < num_frames; stackfr++) {
-			strings[stackfr] = strings[stackfr - 1] + eachlen[stackfr - 1] + 1;
+			strings[stackfr] = strings[stackfr - 1] + eachlen[stackfr - 1];
 		}
 	}
+	ast_std_free(eachlen);
+
 #else /* !defined(BETTER_BACKTRACES) */
+
 	strings = backtrace_symbols(addresses, num_frames);
 #endif /* defined(BETTER_BACKTRACES) */
 	return strings;

main/lock.c

@@ -29,6 +29,7 @@
 
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
+#include "asterisk/utils.h"
 #include "asterisk/lock.h"
 
 /* Allow direct use of pthread_mutex_* / pthread_cond_* */
@@ -45,6 +46,22 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #undef pthread_cond_wait
 #undef pthread_cond_timedwait
 
+#if defined(DEBUG_THREADS) && defined(HAVE_BKTR)
+static void __dump_backtrace(struct ast_bt *bt, int canlog)
+{
+	char **strings;
+	ssize_t i;
+
+	strings = backtrace_symbols(bt->addresses, bt->num_frames);
+
+	for (i = 0; i < bt->num_frames; i++) {
+		__ast_mutex_logger("%s\n", strings[i]);
+	}
+
+	ast_std_free(strings);
+}
+#endif	/* defined(DEBUG_THREADS) && defined(HAVE_BKTR) */
+
 int __ast_pthread_mutex_init(int tracking, const char *filename, int lineno, const char *func,
 						const char *mutex_name, ast_mutex_t *t)
 {

main/logger.c

@@ -1587,9 +1587,7 @@ void ast_log_backtrace(void)
 			ast_debug(1, "#%d: [%p] %s\n", i - 3, bt->addresses[i], strings[i]);
 		}
 
-		/* MALLOC_DEBUG will erroneously report an error here, unless we undef the macro. */
+		ast_std_free(strings);
-#undef free
-		free(strings);
 	} else {
 		ast_debug(1, "Could not allocate memory for backtrace\n");
 	}

main/utils.c

@@ -862,9 +862,8 @@ static void append_backtrace_information(struct ast_str **str, struct ast_bt *bt
 		for (frame_iterator = 0; frame_iterator < num_frames; ++frame_iterator) {
 			ast_str_append(str, 0, "\t%s\n", symbols[frame_iterator]);
 		}
-/* Prevent MALLOC_DEBUG from complaining */
+
-#undef free
+		ast_std_free(symbols);
-		free(symbols);
 	} else {
 		ast_str_append(str, 0, "\tCouldn't retrieve backtrace symbols\n");
 	}