diff options
Diffstat (limited to 'mysys/safemalloc.c')
| -rw-r--r-- | mysys/safemalloc.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/mysys/safemalloc.c b/mysys/safemalloc.c new file mode 100644 index 00000000..e2d59f8e --- /dev/null +++ b/mysys/safemalloc.c @@ -0,0 +1,404 @@ +/* Copyright (C) 2000 MySQL AB, 2011 Monty Program Ab + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +/******************************************************************** + memory debugger + based on safemalloc, memory sub-system, written by Bjorn Benson +********************************************************************/ + + +#include "mysys_priv.h" +#include <my_stacktrace.h> /* my_addr_resolve */ + +#if HAVE_EXECINFO_H +#include <execinfo.h> +#endif + +/* + this can be set to 1 if we leak memory and know it + (to disable memory leak tests on exit) +*/ +int sf_leaking_memory= 0; + +#ifdef SAFEMALLOC + +/* this mutex protects all sf_* variables, and nothing else*/ +static pthread_mutex_t sf_mutex; +static int init_done= 0; + +#ifndef SF_REMEMBER_FRAMES +#define SF_REMEMBER_FRAMES 8 +#endif + +/* ignore the first two frames (sf_malloc itself, and my_malloc) */ +#define SF_FRAMES_SKIP 2 + +/* + Structure that stores information of an allocated memory block + The data is at &struct_adr+sizeof(struct irem) + Note that sizeof(struct st_irem) % sizeof(double) == 0 +*/ +struct st_irem +{ + struct st_irem *next; /* Linked list of structures */ + struct st_irem *prev; /* Other link */ + size_t datasize; /* Size requested */ +#if SIZEOF_SIZE_T == 4 + size_t pad; /* Compensate 32bit datasize */ +#endif +#ifdef HAVE_BACKTRACE + void *frame[SF_REMEMBER_FRAMES]; /* call stack */ +#endif + uint32 flags; /* Flags passed to malloc */ + my_thread_id thread_id; /* Which thread did the allocation */ + uint32 marker; /* Underrun marker value */ +}; + +static int sf_malloc_count= 0; /* Number of allocated chunks */ + +static void *sf_min_adress= (void*) (intptr)~0ULL, + *sf_max_adress= 0; + +static struct st_irem *sf_malloc_root = 0; + +#define MAGICSTART 0x14235296 /* A magic value for underrun key */ + +#define MAGICEND0 0x68 /* Magic values for overrun keys */ +#define MAGICEND1 0x34 /* " */ +#define MAGICEND2 0x7A /* " */ +#define MAGICEND3 0x15 /* " */ + +static int bad_ptr(const char *where, void *ptr); +static void free_memory(void *ptr); +static void sf_terminate(); + +/* Setup default call to get a thread id for the memory */ + +my_thread_id default_sf_malloc_dbug_id(void) +{ + return my_thread_dbug_id(); +} + +my_thread_id (*sf_malloc_dbug_id)(void)= default_sf_malloc_dbug_id; + + +/** + allocates memory +*/ + +void *sf_malloc(size_t size, myf my_flags) +{ + struct st_irem *irem; + uchar *data; + + /* + this style of initialization looks like race conditon prone, + but it is safe under the assumption that a program does + at least one malloc() while still being single threaded. + */ + if (!init_done) + { + pthread_mutex_init(&sf_mutex, NULL); + atexit(sf_terminate); + init_done= 1; + } + + if (size > SIZE_T_MAX - 1024L*1024L*16L) /* Wrong call */ + return 0; + + if (!(irem= (struct st_irem *) malloc (sizeof(struct st_irem) + size + 4))) + return 0; + + /* we guarantee the alignment */ + compile_time_assert(sizeof(struct st_irem) % sizeof(double) == 0); + + /* Fill up the structure */ + data= (uchar*) (irem + 1); + irem->datasize= size; + irem->prev= 0; + irem->flags= my_flags; + irem->marker= MAGICSTART; + irem->thread_id= sf_malloc_dbug_id(); + data[size + 0]= MAGICEND0; + data[size + 1]= MAGICEND1; + data[size + 2]= MAGICEND2; + data[size + 3]= MAGICEND3; + +#ifdef HAVE_BACKTRACE + { + void *frame[SF_REMEMBER_FRAMES + SF_FRAMES_SKIP]; + int frames= backtrace(frame, array_elements(frame)); + if (frames < SF_FRAMES_SKIP) + frames= 0; + else + { + frames-= SF_FRAMES_SKIP; + memcpy(irem->frame, frame + SF_FRAMES_SKIP, sizeof(void*)*frames); + } + if (frames < SF_REMEMBER_FRAMES) + irem->frame[frames]= 0; + } +#endif + + pthread_mutex_lock(&sf_mutex); + + /* Add this structure to the linked list */ + if ((irem->next= sf_malloc_root)) + sf_malloc_root->prev= irem; + sf_malloc_root= irem; + + /* Keep the statistics */ + sf_malloc_count++; + set_if_smaller(sf_min_adress, (void*)data); + set_if_bigger(sf_max_adress, (void*)data); + + pthread_mutex_unlock(&sf_mutex); + + TRASH_ALLOC(data, size); + return data; +} + +void *sf_realloc(void *ptr, size_t size, myf my_flags) +{ + char *data; + + if (!ptr) + return sf_malloc(size, my_flags); + + if (bad_ptr("Reallocating", ptr)) + return 0; + + if ((data= sf_malloc(size, my_flags))) + { + struct st_irem *irem= (struct st_irem *)ptr - 1; + set_if_smaller(size, irem->datasize); + memcpy(data, ptr, size); + free_memory(ptr); + } + return data; +} + +void sf_free(void *ptr) +{ + if (!ptr || bad_ptr("Freeing", ptr)) + return; + + free_memory(ptr); +} + +/** + Return size of memory block and if block is thread specific + + sf_malloc_usable_size() + @param ptr Pointer to malloced block + @param flags We will store 1 here if block is marked as MY_THREAD_SPECIFIC + otherwise 0 + + @return Size of block +*/ + +size_t sf_malloc_usable_size(void *ptr, my_bool *is_thread_specific) +{ + struct st_irem *irem= (struct st_irem *)ptr - 1; + DBUG_ENTER("sf_malloc_usable_size"); + *is_thread_specific= MY_TEST(irem->flags & MY_THREAD_SPECIFIC); + DBUG_PRINT("exit", ("size: %lu flags: %lu", (ulong) irem->datasize, + (ulong)irem->flags)); + DBUG_RETURN(irem->datasize); +} + +#ifdef HAVE_BACKTRACE +static void print_stack(void **frame) +{ + const char *err; + int i; + + if ((err= my_addr_resolve_init())) + { + fprintf(stderr, "(my_addr_resolve failure: %s)\n", err); + return; + } + + for (i=0; i < SF_REMEMBER_FRAMES && frame[i]; i++) + { + my_addr_loc loc; + if (i) + fprintf(stderr, ", "); + + if (my_addr_resolve(frame[i], &loc)) + fprintf(stderr, "%p", frame[i]); + else + fprintf(stderr, "%s:%u", loc.file, loc.line); + } + fprintf(stderr, "\n"); +} +#else +#define print_stack(X) fprintf(stderr, "???\n") +#endif + +static void free_memory(void *ptr) +{ + struct st_irem *irem= (struct st_irem *)ptr - 1; + + if ((irem->flags & MY_THREAD_SPECIFIC) && irem->thread_id && + irem->thread_id != sf_malloc_dbug_id()) + { + fprintf(stderr, "Warning: %4lu bytes freed by T@%lu, allocated by T@%lu at ", + (ulong) irem->datasize, + (ulong) sf_malloc_dbug_id(), (ulong) irem->thread_id); + print_stack(irem->frame); + } + + pthread_mutex_lock(&sf_mutex); + /* Remove this structure from the linked list */ + if (irem->prev) + irem->prev->next= irem->next; + else + sf_malloc_root= irem->next; + + if (irem->next) + irem->next->prev= irem->prev; + + /* Handle the statistics */ + sf_malloc_count--; + pthread_mutex_unlock(&sf_mutex); + + /* only trash the data and magic values, but keep the stack trace */ + TRASH_FREE((uchar*)(irem + 1) - 4, irem->datasize + 8); + free(irem); + return; +} + +static void warn(const char *format,...) +{ + va_list args; + DBUG_PRINT("error", ("%s", format)); + va_start(args,format); + vfprintf(stderr, format, args); + fflush(stderr); + va_end(args); + +#ifdef HAVE_BACKTRACE + { + void *frame[SF_REMEMBER_FRAMES + SF_FRAMES_SKIP]; + int frames= backtrace(frame, array_elements(frame)); + fprintf(stderr, " at "); + if (frames < SF_REMEMBER_FRAMES + SF_FRAMES_SKIP) + frame[frames]= 0; + print_stack(frame + SF_FRAMES_SKIP); + } +#endif +} + +static int bad_ptr(const char *where, void *ptr) +{ + struct st_irem *irem= (struct st_irem *)ptr - 1; + const uchar *magicend; + + if (((intptr) ptr) % sizeof(double)) + { + warn("Error: %s wrong aligned pointer", where); + return 1; + } + if (ptr < sf_min_adress || ptr > sf_max_adress) + { + warn("Error: %s pointer out of range", where); + return 1; + } + if (irem->marker != MAGICSTART) + { + DBUG_PRINT("error",("Unallocated data or underrun buffer %p", ptr)); + warn("Error: %s unallocated data or underrun buffer %p", where, ptr); + return 1; + } + + magicend= (uchar*)ptr + irem->datasize; + if (magicend[0] != MAGICEND0 || + magicend[1] != MAGICEND1 || + magicend[2] != MAGICEND2 || + magicend[3] != MAGICEND3) + { + DBUG_PRINT("error",("Overrun buffer %p", ptr)); + warn("Error: %s overrun buffer %p", where, ptr); + fprintf(stderr, "Allocated at "); + print_stack(irem->frame); + return 1; + } + + return 0; +} + +/* check all allocated memory list for consistency */ +int sf_sanity() +{ + struct st_irem *irem; + int flag= 0; + int count= 0; + + pthread_mutex_lock(&sf_mutex); + count= sf_malloc_count; + for (irem= sf_malloc_root; irem && count > 0; count--, irem= irem->next) + flag+= bad_ptr("Safemalloc", irem + 1); + pthread_mutex_unlock(&sf_mutex); + if (count || irem) + { + warn("Error: Safemalloc link list destroyed"); + return 1; + } + return 0; +} + +/** + report on all the memory pieces that have not been free'd + + @param id Id of thread to report. 0 if all +*/ + +void sf_report_leaked_memory(my_thread_id id) +{ + size_t total= 0; + struct st_irem *irem; + + sf_sanity(); + + /* Report on all the memory that was allocated but not free'd */ + + for (irem= sf_malloc_root; irem; irem= irem->next) + { + if (!id || (irem->thread_id == id && irem->flags & MY_THREAD_SPECIFIC)) + { + my_thread_id tid = irem->thread_id && irem->flags & MY_THREAD_SPECIFIC ? + irem->thread_id : 0; + fprintf(stderr, "Warning: %4lu bytes lost at %p, allocated by T@%llu at ", + (ulong) irem->datasize, (char*) (irem + 1), tid); + print_stack(irem->frame); + total+= irem->datasize; + } + } + if (total) + fprintf(stderr, "Memory lost: %lu bytes in %d chunks\n", + (ulong) total, sf_malloc_count); + return; +} + +static void sf_terminate() +{ + if (!sf_leaking_memory) + sf_report_leaked_memory(0); + + pthread_mutex_destroy(&sf_mutex); +} + +#endif |