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00f06127ce

Stefan Eissing

2025-12-10

SUCCESS Duration: 206s

Subject

memdebug: fix realloc logging

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

lib/memdebug.c +65 -23

lib/memdebug.c+65 -23

@@ -71,6 +71,29 @@ static bool dbg_mutex_init = 0;
	static curl_mutex_t dbg_mutex;
	#endif

+	static bool curl_dbg_lock(void)
+	{
+	#if defined(USE_THREADS_POSIX) \|\| defined(USE_THREADS_WIN32)
+	if(dbg_mutex_init) {
+	Curl_mutex_acquire(&dbg_mutex);
+	return TRUE;
+	}
+	#endif
+	return FALSE;
+	}
+
+	static void curl_dbg_unlock(bool was_locked)
+	{
+	#if defined(USE_THREADS_POSIX) \|\| defined(USE_THREADS_WIN32)
+	if(was_locked)
+	Curl_mutex_release(&dbg_mutex);
+	#else
+	(void)was_locked;
+	#endif
+	}
+
+	static void curl_dbg_log_locked(const char *format, ...) CURL_PRINTF(1, 2);
+
	/* LeakSantizier (LSAN) calls _exit() instead of exit() when a leak is detected
	on exit so the logfile must be closed explicitly or data could be lost.
	Though _exit() does not call atexit handlers such as this, LSAN's call to
@@ -295,6 +318,7 @@ void curl_dbg_realloc(void ptr, size_t wantedsize,
	int line, const char *source)
	{
	struct memdebug *mem = NULL;
+	bool was_locked;

	size_t size = sizeof(struct memdebug) + wantedsize;

@@ -303,6 +327,10 @@ void curl_dbg_realloc(void ptr, size_t wantedsize,
	if(countcheck("realloc", line, source))
	return NULL;

+	/* need to realloc under lock, as we get out-of-order log
+	* entries otherwise, since another thread might alloc the
+	* memory released by realloc() before otherwise would log it. */
+	was_locked = curl_dbg_lock();
	#ifdef __INTEL_COMPILER
	# pragma warning(push)
	# pragma warning(disable:1684)
@@ -318,10 +346,11 @@ void curl_dbg_realloc(void ptr, size_t wantedsize,

	mem = (Curl_crealloc)(mem, size);
	if(source)
-	curl_dbg_log("MEM %s:%d realloc(%p, %zu) = %p\n",
-	source, line, (void *)ptr, wantedsize,
-	mem ? (void )mem->mem : (void )0);
+	curl_dbg_log_locked("MEM %s:%d realloc(%p, %zu) = %p\n",
+	source, line, (void *)ptr, wantedsize,
+	mem ? (void )mem->mem : (void )0);

+	curl_dbg_unlock(was_locked);
	if(mem) {
	mem->size = wantedsize;
	return mem->mem;
@@ -522,29 +551,18 @@ int curl_dbg_fclose(FILE file, int line, const char source)
	return res;
	}

-	/* this does the writing to the memory tracking log file */
-	void curl_dbg_log(const char *format, ...)
+	static void curl_dbg_vlog(const char * const fmt,
+	va_list ap) CURL_PRINTF(1, 0);
+
+	static void curl_dbg_vlog(const char * const fmt, va_list ap)
	{
	char buf[1024];
-	size_t nchars;
-	va_list ap;
-
-	if(!curl_dbg_logfile)
-	return;
-
-	va_start(ap, format);
-	nchars = curl_mvsnprintf(buf, sizeof(buf), format, ap);
-	va_end(ap);
+	size_t nchars = curl_mvsnprintf(buf, sizeof(buf), fmt, ap);

	if(nchars > (int)sizeof(buf) - 1)
	nchars = (int)sizeof(buf) - 1;

	if(nchars > 0) {
-	#if defined(USE_THREADS_POSIX) \|\| defined(USE_THREADS_WIN32)
-	bool lock_mutex = dbg_mutex_init;
-	if(lock_mutex)
-	Curl_mutex_acquire(&dbg_mutex);
-	#endif
	if(sizeof(membuf) - nchars < memwidx) {
	/* flush */
	fwrite(membuf, 1, memwidx, curl_dbg_logfile);
@@ -557,11 +575,35 @@ void curl_dbg_log(const char *format, ...)
	}
	memcpy(&membuf[memwidx], buf, nchars);
	memwidx += nchars;
-	#if defined(USE_THREADS_POSIX) \|\| defined(USE_THREADS_WIN32)
-	if(lock_mutex)
-	Curl_mutex_release(&dbg_mutex);
-	#endif
	}
	}

+	static void curl_dbg_log_locked(const char *format, ...)
+	{
+	va_list ap;
+
+	if(!curl_dbg_logfile)
+	return;
+
+	va_start(ap, format);
+	curl_dbg_vlog(format, ap);
+	va_end(ap);
+	}
+
+	/* this does the writing to the memory tracking log file */
+	void curl_dbg_log(const char *format, ...)
+	{
+	bool was_locked;
+	va_list ap;
+
+	if(!curl_dbg_logfile)
+	return;
+
+	was_locked = curl_dbg_lock();
+	va_start(ap, format);
+	curl_dbg_vlog(format, ap);
+	va_end(ap);
+	curl_dbg_unlock(was_locked);
+	}
+
	#endif /* CURLDEBUG */