diff options
| -rw-r--r-- | lib/memdebug.c | 52 |
1 files changed, 49 insertions, 3 deletions
diff --git a/lib/memdebug.c b/lib/memdebug.c index e0c0d2825..9617faf13 100644 --- a/lib/memdebug.c +++ b/lib/memdebug.c @@ -45,6 +45,52 @@ # define assert(x) do { } while (0) #endif +/* + * Until 2011-08-17 libcurl's Memory Tracking feature also performed + * automatic malloc and free filling operations using 0xA5 and 0x13 + * values. Our own preinitialization of dynamically allocated memory + * might be useful when not using third party memory debuggers, but + * on the other hand this would fool memory debuggers into thinking + * that all dynamically allocated memory is properly initialized. + * + * As a default setting, libcurl's Memory Tracking feature no longer + * performs preinitialization of dynamically allocated memory on its + * own. If you know what you are doing, and really want to retain old + * behavior, you can achieve this compiling with preprocessor symbols + * CURL_MT_MALLOC_FILL and CURL_MT_FREE_FILL defined with appropriate + * values. + */ + +#ifdef CURL_MT_MALLOC_FILL +# if (CURL_MT_MALLOC_FILL < 0) || (CURL_MT_MALLOC_FILL > 0xff) +# error "invalid CURL_MT_MALLOC_FILL or out of range" +# endif +#endif + +#ifdef CURL_MT_FREE_FILL +# if (CURL_MT_FREE_FILL < 0) || (CURL_MT_FREE_FILL > 0xff) +# error "invalid CURL_MT_FREE_FILL or out of range" +# endif +#endif + +#if defined(CURL_MT_MALLOC_FILL) && defined(CURL_MT_FREE_FILL) +# if (CURL_MT_MALLOC_FILL == CURL_MT_FREE_FILL) +# error "CURL_MT_MALLOC_FILL same as CURL_MT_FREE_FILL" +# endif +#endif + +#ifdef CURL_MT_MALLOC_FILL +# define mt_malloc_fill(buf,len) memset((buf), CURL_MT_MALLOC_FILL, (len)) +#else +# define mt_malloc_fill(buf,len) +#endif + +#ifdef CURL_MT_FREE_FILL +# define mt_free_fill(buf,len) memset((buf), CURL_MT_FREE_FILL, (len)) +#else +# define mt_free_fill(buf,len) +#endif + struct memdebug { size_t size; union { @@ -141,7 +187,7 @@ void *curl_domalloc(size_t wantedsize, int line, const char *source) mem = (Curl_cmalloc)(size); if(mem) { /* fill memory with junk */ - memset(mem->mem, 0xA5, wantedsize); + mt_malloc_fill(mem->mem, wantedsize); mem->size = wantedsize; } @@ -258,8 +304,8 @@ void curl_dofree(void *ptr, int line, const char *source) # pragma warning(pop) #endif - /* destroy */ - memset(mem->mem, 0x13, mem->size); + /* destroy */ + mt_free_fill(mem->mem, mem->size); /* free for real */ (Curl_cfree)(mem); |