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mariadb/mysys/safemalloc.c
monty@mysql.com/narttu.mysql.fi 088e2395f1 WL#3817: Simplify string / memory area types and make things more consistent (first part) 
The following type conversions was done:

- Changed byte to uchar
- Changed gptr to uchar*
- Change my_string to char *
- Change my_size_t to size_t
- Change size_s to size_t

Removed declaration of byte, gptr, my_string, my_size_t and size_s. 

Following function parameter changes was done:
- All string functions in mysys/strings was changed to use size_t
  instead of uint for string lengths.
- All read()/write() functions changed to use size_t (including vio).
- All protocoll functions changed to use size_t instead of uint
- Functions that used a pointer to a string length was changed to use size_t*
- Changed malloc(), free() and related functions from using gptr to use void *
  as this requires fewer casts in the code and is more in line with how the
  standard functions work.
- Added extra length argument to dirname_part() to return the length of the
  created string.
- Changed (at least) following functions to take uchar* as argument:
  - db_dump()
  - my_net_write()
  - net_write_command()
  - net_store_data()
  - DBUG_DUMP()
  - decimal2bin() & bin2decimal()
- Changed my_compress() and my_uncompress() to use size_t. Changed one
  argument to my_uncompress() from a pointer to a value as we only return
  one value (makes function easier to use).
- Changed type of 'pack_data' argument to packfrm() to avoid casts.
- Changed in readfrm() and writefrom(), ha_discover and handler::discover()
  the type for argument 'frmdata' to uchar** to avoid casts.
- Changed most Field functions to use uchar* instead of char* (reduced a lot of
  casts).
- Changed field->val_xxx(xxx, new_ptr) to take const pointers.

Other changes:
- Removed a lot of not needed casts
- Added a few new cast required by other changes
- Added some cast to my_multi_malloc() arguments for safety (as string lengths
  needs to be uint, not size_t).
- Fixed all calls to hash-get-key functions to use size_t*. (Needed to be done
  explicitely as this conflict was often hided by casting the function to
  hash_get_key).
- Changed some buffers to memory regions to uchar* to avoid casts.
- Changed some string lengths from uint to size_t.
- Changed field->ptr to be uchar* instead of char*. This allowed us to
  get rid of a lot of casts.
- Some changes from true -> TRUE, false -> FALSE, unsigned char -> uchar
- Include zlib.h in some files as we needed declaration of crc32()
- Changed MY_FILE_ERROR to be (size_t) -1.
- Changed many variables to hold the result of my_read() / my_write() to be
  size_t. This was needed to properly detect errors (which are
  returned as (size_t) -1).
- Removed some very old VMS code
- Changed packfrm()/unpackfrm() to not be depending on uint size
  (portability fix)
- Removed windows specific code to restore cursor position as this
  causes slowdown on windows and we should not mix read() and pread()
  calls anyway as this is not thread safe. Updated function comment to
  reflect this. Changed function that depended on original behavior of
  my_pwrite() to itself restore the cursor position (one such case).
- Added some missing checking of return value of malloc().
- Changed definition of MOD_PAD_CHAR_TO_FULL_LENGTH to avoid 'long' overflow.
- Changed type of table_def::m_size from my_size_t to ulong to reflect that
  m_size is the number of elements in the array, not a string/memory
  length.
- Moved THD::max_row_length() to table.cc (as it's not depending on THD).
  Inlined max_row_length_blob() into this function.
- More function comments
- Fixed some compiler warnings when compiled without partitions.
- Removed setting of LEX_STRING() arguments in declaration (portability fix).
- Some trivial indentation/variable name changes.
- Some trivial code simplifications:
  - Replaced some calls to alloc_root + memcpy to use
    strmake_root()/strdup_root().
  - Changed some calls from memdup() to strmake() (Safety fix)
  - Simpler loops in client-simple.c
2007-05-10 12:59:39 +03:00

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/* Copyright (C) 2000-2003 MySQL 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/*
* Memory sub-system, written by Bjorn Benson
Fixed to use my_sys scheme by Michael Widenius
[This posting refers to an article entitled "oops, corrupted memory
again!" in net.lang.c. I am posting it here because it is source.]
My tool for approaching this problem is to build another level of data
abstraction on top of malloc() and free() that implements some checking.
This does a number of things for you:
- Checks for overruns and underruns on allocated data
- Keeps track of where in the program the memory was malloc'ed
- Reports on pieces of memory that were not free'ed
- Records some statistics such as maximum memory used
- Marks newly malloc'ed and newly free'ed memory with special values
You can use this scheme to:
- Find bugs such as overrun, underrun, etc because you know where
a piece of data was malloc'ed and where it was free'ed
- Find bugs where memory was not free'ed
- Find bugs where newly malloc'ed memory is used without initializing
- Find bugs where newly free'ed memory is still used
- Determine how much memory your program really uses
- and other things
To implement my scheme you must have a C compiler that has __LINE__ and
__FILE__ macros. If your compiler doesn't have these then (a) buy another:
compilers that do are available on UNIX 4.2bsd based systems and the PC,
and probably on other machines; or (b) change my scheme somehow. I have
recomendations on both these points if you would like them (e-mail please).
There are 4 functions in my package:
char *NEW( uSize ) Allocate memory of uSize bytes
(equivalent to malloc())
char *REA( pPtr, uSize) Allocate memory of uSize bytes, move data and
free pPtr.
(equivalent to realloc())
FREE( pPtr ) Free memory allocated by NEW
(equivalent to free())
TERMINATE(file) End system, report errors and stats on file
I personally use two more functions, but have not included them here:
char *STRSAVE( sPtr ) Save a copy of the string in dynamic memory
char *RENEW( pPtr, uSize )
(equivalent to realloc())
*/
#ifndef SAFEMALLOC
#define SAFEMALLOC /* Get protos from my_sys */
#endif
#include "mysys_priv.h"
#include <m_string.h>
#include "my_static.h"
#include "mysys_err.h"
ulonglong sf_malloc_mem_limit= ~(ulonglong)0;
#ifndef PEDANTIC_SAFEMALLOC
/*
Set to 1 after TERMINATE() if we had to fiddle with sf_malloc_count and
the linked list of blocks so that _sanity() will not fuss when it
is not supposed to
*/
static int sf_malloc_tampered= 0;
#endif
/* Static functions prototypes */
static int check_ptr(const char *where, uchar *ptr, const char *sFile,
uint uLine);
static int _checkchunk(struct st_irem *pRec, const char *sFile, uint uLine);
/*
Note: We only fill up the allocated block. This do not include
malloc() roundoff or the extra space required by the irem
structures.
*/
/*
NEW'ed memory is filled with this value so that references to it will
end up being very strange.
*/
#define ALLOC_VAL (uchar) 0xA5
/*
FEEE'ed memory is filled with this value so that references to it will
end up being very strange.
*/
#define FREE_VAL (uchar) 0x8F
#define MAGICKEY 0x14235296 /* A magic value for underrun key */
/*
Warning: do not change the MAGICEND? values to something with the
high bit set. Various C compilers (like the 4.2bsd one) do not do
the sign extension right later on in this code and you will get
erroneous errors.
*/
#define MAGICEND0 0x68 /* Magic values for overrun keys */
#define MAGICEND1 0x34 /* " */
#define MAGICEND2 0x7A /* " */
#define MAGICEND3 0x15 /* " */
/* Allocate some memory. */
void *_mymalloc(size_t size, const char *filename, uint lineno, myf MyFlags)
{
struct st_irem *irem;
uchar *data;
DBUG_ENTER("_mymalloc");
DBUG_PRINT("enter",("Size: %lu", (ulong) size));
if (!sf_malloc_quick)
(void) _sanity (filename, lineno);
if (size + sf_malloc_cur_memory > sf_malloc_mem_limit)
irem= 0;
else
{
/* Allocate the physical memory */
irem= (struct st_irem *) malloc (ALIGN_SIZE(sizeof(struct st_irem)) +
sf_malloc_prehunc +
size + /* size requested */
4 + /* overrun mark */
sf_malloc_endhunc);
}
/* Check if there isn't anymore memory avaiable */
if (!irem)
{
if (MyFlags & MY_FAE)
error_handler_hook=fatal_error_handler_hook;
if (MyFlags & (MY_FAE+MY_WME))
{
char buff[SC_MAXWIDTH];
my_errno=errno;
sprintf(buff,"Out of memory at line %d, '%s'", lineno, filename);
my_message(EE_OUTOFMEMORY, buff, MYF(ME_BELL+ME_WAITTANG+ME_NOREFRESH));
sprintf(buff,"needed %u byte (%ldk), memory in use: %ld bytes (%ldk)",
(uint) size, (uint) (size + 1023L) / 1024L,
sf_malloc_max_memory, (sf_malloc_max_memory + 1023L) / 1024L);
my_message(EE_OUTOFMEMORY, buff, MYF(ME_BELL+ME_WAITTANG+ME_NOREFRESH));
}
DBUG_PRINT("error",("Out of memory, in use: %ld at line %d, '%s'",
sf_malloc_max_memory,lineno, filename));
if (MyFlags & MY_FAE)
exit(1);
DBUG_RETURN ((void*) 0);
}
/* Fill up the structure */
data= (((uchar*) irem) + ALIGN_SIZE(sizeof(struct st_irem)) +
sf_malloc_prehunc);
*((uint32*) (data-sizeof(uint32)))= MAGICKEY;
data[size + 0]= MAGICEND0;
data[size + 1]= MAGICEND1;
data[size + 2]= MAGICEND2;
data[size + 3]= MAGICEND3;
irem->filename= (char *) filename;
irem->linenum= lineno;
irem->datasize= size;
irem->prev= NULL;
/* Add this remember structure to the linked list */
pthread_mutex_lock(&THR_LOCK_malloc);
if ((irem->next= sf_malloc_root))
sf_malloc_root->prev= irem;
sf_malloc_root= irem;
/* Keep the statistics */
sf_malloc_cur_memory+= size;
if (sf_malloc_cur_memory > sf_malloc_max_memory)
sf_malloc_max_memory= sf_malloc_cur_memory;
sf_malloc_count++;
pthread_mutex_unlock(&THR_LOCK_malloc);
/* Set the memory to the aribtrary wierd value */
if ((MyFlags & MY_ZEROFILL) || !sf_malloc_quick)
bfill(data, size, (char) (MyFlags & MY_ZEROFILL ? 0 : ALLOC_VAL));
/* Return a pointer to the real data */
DBUG_PRINT("exit",("ptr: 0x%lx", (long) data));
if (sf_min_adress > data)
sf_min_adress= data;
if (sf_max_adress < data)
sf_max_adress= data;
DBUG_RETURN((void*) data);
}
/*
Allocate some new memory and move old memoryblock there.
Free then old memoryblock
*/
void *_myrealloc(register void *ptr, register size_t size,
const char *filename, uint lineno, myf MyFlags)
{
struct st_irem *irem;
char *data;
DBUG_ENTER("_myrealloc");
if (!ptr && (MyFlags & MY_ALLOW_ZERO_PTR))
DBUG_RETURN(_mymalloc(size, filename, lineno, MyFlags));
if (!sf_malloc_quick)
(void) _sanity (filename, lineno);
if (check_ptr("Reallocating", (uchar*) ptr, filename, lineno))
DBUG_RETURN((uchar*) NULL);
irem= (struct st_irem *) (((char*) ptr) - ALIGN_SIZE(sizeof(struct st_irem))-
sf_malloc_prehunc);
if (*((uint32*) (((char*) ptr)- sizeof(uint32))) != MAGICKEY)
{
fprintf(stderr, "Error: Reallocating unallocated data at line %d, '%s'\n",
lineno, filename);
DBUG_PRINT("safe",("Reallocating unallocated data at line %d, '%s'",
lineno, filename));
(void) fflush(stderr);
DBUG_RETURN((uchar*) NULL);
}
if ((data= _mymalloc(size,filename,lineno,MyFlags))) /* Allocate new area */
{
size=min(size, irem->datasize); /* Move as much as possibly */
memcpy((uchar*) data, ptr, (size_t) size); /* Copy old data */
_myfree(ptr, filename, lineno, 0); /* Free not needed area */
}
else
{
if (MyFlags & MY_HOLD_ON_ERROR)
DBUG_RETURN(ptr);
if (MyFlags & MY_FREE_ON_ERROR)
_myfree(ptr, filename, lineno, 0);
}
DBUG_RETURN(data);
} /* _myrealloc */
/* Deallocate some memory. */
void _myfree(void *ptr, const char *filename, uint lineno, myf myflags)
{
struct st_irem *irem;
DBUG_ENTER("_myfree");
DBUG_PRINT("enter",("ptr: 0x%lx", (long) ptr));
if (!sf_malloc_quick)
(void) _sanity (filename, lineno);
if ((!ptr && (myflags & MY_ALLOW_ZERO_PTR)) ||
check_ptr("Freeing",(uchar*) ptr,filename,lineno))
DBUG_VOID_RETURN;
/* Calculate the address of the remember structure */
irem= (struct st_irem *) ((char*) ptr- ALIGN_SIZE(sizeof(struct st_irem))-
sf_malloc_prehunc);
/*
Check to make sure that we have a real remember structure.
Note: this test could fail for four reasons:
(1) The memory was already free'ed
(2) The memory was never new'ed
(3) There was an underrun
(4) A stray pointer hit this location
*/
if (*((uint32*) ((char*) ptr- sizeof(uint32))) != MAGICKEY)
{
fprintf(stderr, "Error: Freeing unallocated data at line %d, '%s'\n",
lineno, filename);
DBUG_PRINT("safe",("Unallocated data at line %d, '%s'",lineno,filename));
(void) fflush(stderr);
DBUG_VOID_RETURN;
}
/* Remove this structure from the linked list */
pthread_mutex_lock(&THR_LOCK_malloc);
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_cur_memory-= irem->datasize;
sf_malloc_count--;
pthread_mutex_unlock(&THR_LOCK_malloc);
#ifndef HAVE_purify
/* Mark this data as free'ed */
if (!sf_malloc_quick)
bfill(ptr, irem->datasize, (pchar) FREE_VAL);
#endif
*((uint32*) ((char*) ptr- sizeof(uint32)))= ~MAGICKEY;
/* Actually free the memory */
free((char*) irem);
DBUG_VOID_RETURN;
}
/* Check if we have a wrong pointer */
static int check_ptr(const char *where, uchar *ptr, const char *filename,
uint lineno)
{
if (!ptr)
{
fprintf(stderr, "Error: %s NULL pointer at line %d, '%s'\n",
where,lineno, filename);
DBUG_PRINT("safe",("Null pointer at line %d '%s'", lineno, filename));
(void) fflush(stderr);
return 1;
}
#ifndef _MSC_VER
if ((long) ptr & (ALIGN_SIZE(1)-1))
{
fprintf(stderr, "Error: %s wrong aligned pointer at line %d, '%s'\n",
where,lineno, filename);
DBUG_PRINT("safe",("Wrong aligned pointer at line %d, '%s'",
lineno,filename));
(void) fflush(stderr);
return 1;
}
#endif
if (ptr < sf_min_adress || ptr > sf_max_adress)
{
fprintf(stderr, "Error: %s pointer out of range at line %d, '%s'\n",
where,lineno, filename);
DBUG_PRINT("safe",("Pointer out of range at line %d '%s'",
lineno,filename));
(void) fflush(stderr);
return 1;
}
return 0;
}
/*
TERMINATE(FILE *file)
Report on all the memory pieces that have not been
free'ed as well as the statistics.
*/
void TERMINATE(FILE *file)
{
struct st_irem *irem;
DBUG_ENTER("TERMINATE");
pthread_mutex_lock(&THR_LOCK_malloc);
/*
Report the difference between number of calls to
NEW and the number of calls to FREE. >0 means more
NEWs than FREEs. <0, etc.
*/
if (sf_malloc_count)
{
if (file)
{
fprintf(file, "Warning: Not freed memory segments: %u\n",
sf_malloc_count);
(void) fflush(file);
}
DBUG_PRINT("safe",("sf_malloc_count: %u", sf_malloc_count));
}
/*
Report on all the memory that was allocated with NEW
but not free'ed with FREE.
*/
if ((irem= sf_malloc_root))
{
if (file)
{
fprintf(file, "Warning: Memory that was not free'ed (%ld bytes):\n",
sf_malloc_cur_memory);
(void) fflush(file);
}
DBUG_PRINT("safe",("Memory that was not free'ed (%ld bytes):",
sf_malloc_cur_memory));
while (irem)
{
char *data= (((char*) irem) + ALIGN_SIZE(sizeof(struct st_irem)) +
sf_malloc_prehunc);
if (file)
{
fprintf(file,
"\t%6u bytes at 0x%09lx, allocated at line %4u in '%s'",
irem->datasize, (long) data, irem->linenum, irem->filename);
fprintf(file, "\n");
(void) fflush(file);
}
DBUG_PRINT("safe",
("%6u bytes at 0x%09lx, allocated at line %4d in '%s'",
irem->datasize, (long) data, irem->linenum, irem->filename));
irem= irem->next;
}
}
/* Report the memory usage statistics */
if (file)
{
fprintf(file, "Maximum memory usage: %ld bytes (%ldk)\n",
sf_malloc_max_memory, (sf_malloc_max_memory + 1023L) / 1024L);
(void) fflush(file);
}
DBUG_PRINT("safe",("Maximum memory usage: %ld bytes (%ldk)",
sf_malloc_max_memory, (sf_malloc_max_memory + 1023L) /
1024L));
pthread_mutex_unlock(&THR_LOCK_malloc);
DBUG_VOID_RETURN;
}
/* Returns 0 if chunk is ok */
static int _checkchunk(register struct st_irem *irem, const char *filename,
uint lineno)
{
int flag=0;
char *magicp, *data;
data= (((char*) irem) + ALIGN_SIZE(sizeof(struct st_irem)) +
sf_malloc_prehunc);
/* Check for a possible underrun */
if (*((uint32*) (data- sizeof(uint32))) != MAGICKEY)
{
fprintf(stderr, "Error: Memory allocated at %s:%d was underrun,",
irem->filename, irem->linenum);
fprintf(stderr, " discovered at %s:%d\n", filename, lineno);
(void) fflush(stderr);
DBUG_PRINT("safe",("Underrun at 0x%lx, allocated at %s:%d",
(long) data, irem->filename, irem->linenum));
flag=1;
}
/* Check for a possible overrun */
magicp= data + irem->datasize;
if (*magicp++ != MAGICEND0 ||
*magicp++ != MAGICEND1 ||
*magicp++ != MAGICEND2 ||
*magicp++ != MAGICEND3)
{
fprintf(stderr, "Error: Memory allocated at %s:%d was overrun,",
irem->filename, irem->linenum);
fprintf(stderr, " discovered at '%s:%d'\n", filename, lineno);
(void) fflush(stderr);
DBUG_PRINT("safe",("Overrun at 0x%lx, allocated at %s:%d",
(long) data,
irem->filename,
irem->linenum));
flag=1;
}
return(flag);
}
/* Returns how many wrong chunks */
int _sanity(const char *filename, uint lineno)
{
reg1 struct st_irem *irem;
reg2 int flag=0;
uint count=0;
pthread_mutex_lock(&THR_LOCK_malloc);
#ifndef PEDANTIC_SAFEMALLOC
if (sf_malloc_tampered && (int) sf_malloc_count < 0)
sf_malloc_count=0;
#endif
count=sf_malloc_count;
for (irem= sf_malloc_root; irem != NULL && count-- ; irem= irem->next)
flag+= _checkchunk (irem, filename, lineno);
pthread_mutex_unlock(&THR_LOCK_malloc);
if (count || irem)
{
const char *format="Error: Safemalloc link list destroyed, discovered at '%s:%d'";
fprintf(stderr, format, filename, lineno); fputc('\n',stderr);
fprintf(stderr, "root=%p,count=%d,irem=%p\n", sf_malloc_root,count,irem);
(void) fflush(stderr);
DBUG_PRINT("safe",(format, filename, lineno));
flag=1;
}
return flag;
} /* _sanity */
/* malloc and copy */
void *_my_memdup(const void *from, size_t length, const char *filename,
uint lineno, myf MyFlags)
{
void *ptr;
if ((ptr= _mymalloc(length,filename,lineno,MyFlags)) != 0)
memcpy(ptr, from, length);
return(ptr);
} /*_my_memdup */
char *_my_strdup(const char *from, const char *filename, uint lineno,
myf MyFlags)
{
char *ptr;
size_t length= strlen(from)+1;
if ((ptr= (char*) _mymalloc(length,filename,lineno,MyFlags)) != 0)
memcpy((uchar*) ptr, (uchar*) from, (size_t) length);
return(ptr);
} /* _my_strdup */
char *_my_strndup(const char *from, size_t length,
const char *filename, uint lineno,
myf MyFlags)
{
char *ptr;
if ((ptr= (char*) _mymalloc(length+1,filename,lineno,MyFlags)) != 0)
{
memcpy((uchar*) ptr, (uchar*) from, (size_t) length);
ptr[length]=0;
}
return(ptr);
}
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