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-rw-r--r--src/malloc.c164
1 files changed, 121 insertions, 43 deletions
diff --git a/src/malloc.c b/src/malloc.c
index 577836ef9..356750682 100644
--- a/src/malloc.c
+++ b/src/malloc.c
@@ -161,7 +161,6 @@ int sqlite3MallocInit(void){
if( sqlite3GlobalConfig.m.xMalloc==0 ){
sqlite3MemSetDefault();
}
- memset(&mem0, 0, sizeof(mem0));
mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
if( sqlite3GlobalConfig.pPage==0 || sqlite3GlobalConfig.szPage<512
|| sqlite3GlobalConfig.nPage<=0 ){
@@ -272,17 +271,33 @@ static void mallocWithAlarm(int n, void **pp){
}
/*
+** Maximum size of any single memory allocation.
+**
+** This is not a limit on the total amount of memory used. This is
+** a limit on the size parameter to sqlite3_malloc() and sqlite3_realloc().
+**
+** The upper bound is slightly less than 2GiB: 0x7ffffeff == 2,147,483,391
+** This provides a 256-byte safety margin for defense against 32-bit
+** signed integer overflow bugs when computing memory allocation sizes.
+** Paranoid applications might want to reduce the maximum allocation size
+** further for an even larger safety margin. 0x3fffffff or 0x0fffffff
+** or even smaller would be reasonable upper bounds on the size of a memory
+** allocations for most applications.
+*/
+#ifndef SQLITE_MAX_ALLOCATION_SIZE
+# define SQLITE_MAX_ALLOCATION_SIZE 2147483391
+#endif
+#if SQLITE_MAX_ALLOCATION_SIZE>2147483391
+# error Maximum size for SQLITE_MAX_ALLOCATION_SIZE is 2147483391
+#endif
+
+/*
** Allocate memory. This routine is like sqlite3_malloc() except that it
** assumes the memory subsystem has already been initialized.
*/
void *sqlite3Malloc(u64 n){
void *p;
- if( n==0 || n>=0x7fffff00 ){
- /* A memory allocation of a number of bytes which is near the maximum
- ** signed integer value might cause an integer overflow inside of the
- ** xMalloc(). Hence we limit the maximum size to 0x7fffff00, giving
- ** 255 bytes of overhead. SQLite itself will never use anything near
- ** this amount. The only way to reach the limit is with sqlite3_malloc() */
+ if( n==0 || n>SQLITE_MAX_ALLOCATION_SIZE ){
p = 0;
}else if( sqlite3GlobalConfig.bMemstat ){
sqlite3_mutex_enter(mem0.mutex);
@@ -317,8 +332,8 @@ void *sqlite3_malloc64(sqlite3_uint64 n){
** TRUE if p is a lookaside memory allocation from db
*/
#ifndef SQLITE_OMIT_LOOKASIDE
-static int isLookaside(sqlite3 *db, void *p){
- return SQLITE_WITHIN(p, db->lookaside.pStart, db->lookaside.pEnd);
+static int isLookaside(sqlite3 *db, const void *p){
+ return SQLITE_WITHIN(p, db->lookaside.pStart, db->lookaside.pTrueEnd);
}
#else
#define isLookaside(A,B) 0
@@ -328,32 +343,30 @@ static int isLookaside(sqlite3 *db, void *p){
** Return the size of a memory allocation previously obtained from
** sqlite3Malloc() or sqlite3_malloc().
*/
-int sqlite3MallocSize(void *p){
+int sqlite3MallocSize(const void *p){
assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
- return sqlite3GlobalConfig.m.xSize(p);
+ return sqlite3GlobalConfig.m.xSize((void*)p);
}
-static int lookasideMallocSize(sqlite3 *db, void *p){
+static int lookasideMallocSize(sqlite3 *db, const void *p){
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
return p<db->lookaside.pMiddle ? db->lookaside.szTrue : LOOKASIDE_SMALL;
#else
return db->lookaside.szTrue;
#endif
}
-int sqlite3DbMallocSize(sqlite3 *db, void *p){
+int sqlite3DbMallocSize(sqlite3 *db, const void *p){
assert( p!=0 );
#ifdef SQLITE_DEBUG
- if( db==0 || !isLookaside(db,p) ){
- if( db==0 ){
- assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
- assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
- }else{
- assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
- assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
- }
+ if( db==0 ){
+ assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
+ assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
+ }else if( !isLookaside(db,p) ){
+ assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
+ assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
}
#endif
if( db ){
- if( ((uptr)p)<(uptr)(db->lookaside.pEnd) ){
+ if( ((uptr)p)<(uptr)(db->lookaside.pTrueEnd) ){
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
if( ((uptr)p)>=(uptr)(db->lookaside.pMiddle) ){
assert( sqlite3_mutex_held(db->mutex) );
@@ -366,7 +379,7 @@ int sqlite3DbMallocSize(sqlite3 *db, void *p){
}
}
}
- return sqlite3GlobalConfig.m.xSize(p);
+ return sqlite3GlobalConfig.m.xSize((void*)p);
}
sqlite3_uint64 sqlite3_msize(void *p){
assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
@@ -409,14 +422,11 @@ void sqlite3DbFreeNN(sqlite3 *db, void *p){
assert( db==0 || sqlite3_mutex_held(db->mutex) );
assert( p!=0 );
if( db ){
- if( db->pnBytesFreed ){
- measureAllocationSize(db, p);
- return;
- }
if( ((uptr)p)<(uptr)(db->lookaside.pEnd) ){
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
if( ((uptr)p)>=(uptr)(db->lookaside.pMiddle) ){
LookasideSlot *pBuf = (LookasideSlot*)p;
+ assert( db->pnBytesFreed==0 );
#ifdef SQLITE_DEBUG
memset(p, 0xaa, LOOKASIDE_SMALL); /* Trash freed content */
#endif
@@ -427,6 +437,7 @@ void sqlite3DbFreeNN(sqlite3 *db, void *p){
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
if( ((uptr)p)>=(uptr)(db->lookaside.pStart) ){
LookasideSlot *pBuf = (LookasideSlot*)p;
+ assert( db->pnBytesFreed==0 );
#ifdef SQLITE_DEBUG
memset(p, 0xaa, db->lookaside.szTrue); /* Trash freed content */
#endif
@@ -435,6 +446,10 @@ void sqlite3DbFreeNN(sqlite3 *db, void *p){
return;
}
}
+ if( db->pnBytesFreed ){
+ measureAllocationSize(db, p);
+ return;
+ }
}
assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
@@ -442,6 +457,43 @@ void sqlite3DbFreeNN(sqlite3 *db, void *p){
sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
sqlite3_free(p);
}
+void sqlite3DbNNFreeNN(sqlite3 *db, void *p){
+ assert( db!=0 );
+ assert( sqlite3_mutex_held(db->mutex) );
+ assert( p!=0 );
+ if( ((uptr)p)<(uptr)(db->lookaside.pEnd) ){
+#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
+ if( ((uptr)p)>=(uptr)(db->lookaside.pMiddle) ){
+ LookasideSlot *pBuf = (LookasideSlot*)p;
+ assert( db->pnBytesFreed==0 );
+#ifdef SQLITE_DEBUG
+ memset(p, 0xaa, LOOKASIDE_SMALL); /* Trash freed content */
+#endif
+ pBuf->pNext = db->lookaside.pSmallFree;
+ db->lookaside.pSmallFree = pBuf;
+ return;
+ }
+#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
+ if( ((uptr)p)>=(uptr)(db->lookaside.pStart) ){
+ LookasideSlot *pBuf = (LookasideSlot*)p;
+ assert( db->pnBytesFreed==0 );
+#ifdef SQLITE_DEBUG
+ memset(p, 0xaa, db->lookaside.szTrue); /* Trash freed content */
+#endif
+ pBuf->pNext = db->lookaside.pFree;
+ db->lookaside.pFree = pBuf;
+ return;
+ }
+ }
+ if( db->pnBytesFreed ){
+ measureAllocationSize(db, p);
+ return;
+ }
+ assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
+ assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
+ sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
+ sqlite3_free(p);
+}
void sqlite3DbFree(sqlite3 *db, void *p){
assert( db==0 || sqlite3_mutex_held(db->mutex) );
if( p ) sqlite3DbFreeNN(db, p);
@@ -474,12 +526,17 @@ void *sqlite3Realloc(void *pOld, u64 nBytes){
if( nOld==nNew ){
pNew = pOld;
}else if( sqlite3GlobalConfig.bMemstat ){
+ sqlite3_int64 nUsed;
sqlite3_mutex_enter(mem0.mutex);
sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);
nDiff = nNew - nOld;
- if( nDiff>0 && sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >=
+ if( nDiff>0 && (nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED)) >=
mem0.alarmThreshold-nDiff ){
sqlite3MallocAlarm(nDiff);
+ if( mem0.hardLimit>0 && nUsed >= mem0.hardLimit - nDiff ){
+ sqlite3_mutex_leave(mem0.mutex);
+ return 0;
+ }
}
pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
@@ -719,11 +776,9 @@ char *sqlite3DbStrDup(sqlite3 *db, const char *z){
char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){
char *zNew;
assert( db!=0 );
- if( z==0 ){
- return 0;
- }
+ assert( z!=0 || n==0 );
assert( (n&0x7fffffff)==n );
- zNew = sqlite3DbMallocRawNN(db, n+1);
+ zNew = z ? sqlite3DbMallocRawNN(db, n+1) : 0;
if( zNew ){
memcpy(zNew, z, (size_t)n);
zNew[n] = 0;
@@ -738,9 +793,14 @@ char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){
*/
char *sqlite3DbSpanDup(sqlite3 *db, const char *zStart, const char *zEnd){
int n;
+#ifdef SQLITE_DEBUG
+ /* Because of the way the parser works, the span is guaranteed to contain
+ ** at least one non-space character */
+ for(n=0; sqlite3Isspace(zStart[n]); n++){ assert( &zStart[n]<zEnd ); }
+#endif
while( sqlite3Isspace(zStart[0]) ) zStart++;
n = (int)(zEnd - zStart);
- while( ALWAYS(n>0) && sqlite3Isspace(zStart[n-1]) ) n--;
+ while( sqlite3Isspace(zStart[n-1]) ) n--;
return sqlite3DbStrNDup(db, zStart, n);
}
@@ -748,8 +808,9 @@ char *sqlite3DbSpanDup(sqlite3 *db, const char *zStart, const char *zEnd){
** Free any prior content in *pz and replace it with a copy of zNew.
*/
void sqlite3SetString(char **pz, sqlite3 *db, const char *zNew){
+ char *z = sqlite3DbStrDup(db, zNew);
sqlite3DbFree(db, *pz);
- *pz = sqlite3DbStrDup(db, zNew);
+ *pz = z;
}
/*
@@ -757,8 +818,15 @@ void sqlite3SetString(char **pz, sqlite3 *db, const char *zNew){
** has happened. This routine will set db->mallocFailed, and also
** temporarily disable the lookaside memory allocator and interrupt
** any running VDBEs.
+**
+** Always return a NULL pointer so that this routine can be invoked using
+**
+** return sqlite3OomFault(db);
+**
+** and thereby avoid unnecessary stack frame allocations for the overwhelmingly
+** common case where no OOM occurs.
*/
-void sqlite3OomFault(sqlite3 *db){
+void *sqlite3OomFault(sqlite3 *db){
if( db->mallocFailed==0 && db->bBenignMalloc==0 ){
db->mallocFailed = 1;
if( db->nVdbeExec>0 ){
@@ -766,9 +834,16 @@ void sqlite3OomFault(sqlite3 *db){
}
DisableLookaside;
if( db->pParse ){
+ Parse *pParse;
+ sqlite3ErrorMsg(db->pParse, "out of memory");
db->pParse->rc = SQLITE_NOMEM_BKPT;
+ for(pParse=db->pParse->pOuterParse; pParse; pParse = pParse->pOuterParse){
+ pParse->nErr++;
+ pParse->rc = SQLITE_NOMEM;
+ }
}
}
+ return 0;
}
/*
@@ -788,12 +863,15 @@ void sqlite3OomClear(sqlite3 *db){
}
/*
-** Take actions at the end of an API call to indicate an OOM error
+** Take actions at the end of an API call to deal with error codes.
*/
-static SQLITE_NOINLINE int apiOomError(sqlite3 *db){
- sqlite3OomClear(db);
- sqlite3Error(db, SQLITE_NOMEM);
- return SQLITE_NOMEM_BKPT;
+static SQLITE_NOINLINE int apiHandleError(sqlite3 *db, int rc){
+ if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){
+ sqlite3OomClear(db);
+ sqlite3Error(db, SQLITE_NOMEM);
+ return SQLITE_NOMEM_BKPT;
+ }
+ return rc & db->errMask;
}
/*
@@ -815,8 +893,8 @@ int sqlite3ApiExit(sqlite3* db, int rc){
*/
assert( db!=0 );
assert( sqlite3_mutex_held(db->mutex) );
- if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){
- return apiOomError(db);
+ if( db->mallocFailed || rc ){
+ return apiHandleError(db, rc);
}
- return rc & db->errMask;
+ return 0;
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-18 01:53:12 +0000