Add assert statements to os_unix.c to ensure that any mapped region of the database file is not being read or written using the xRead() or xWrite() methods.

FossilOrigin-Name: 765615f9fba7c1765eb741cb98a09a28b464ee55

manifest

@@ -1,5 +1,5 @@
-C Fix\scases\swhere\sxRead()\swas\sbeing\sused\sto\sread\sfrom\sa\smemory\smapped\spart\sof\sthe\sdatabase\sfile.
-D 2013-03-21T20:39:55.225
+C Add\sassert\sstatements\sto\sos_unix.c\sto\sensure\sthat\sany\smapped\sregion\sof\sthe\sdatabase\sfile\sis\snot\sbeing\sread\sor\swritten\susing\sthe\sxRead()\sor\sxWrite()\smethods.
+D 2013-03-22T08:58:38.319
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 9a804abbd3cae82d196e4d33aba13239e32522a5
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -160,7 +160,7 @@ F src/notify.c 976dd0f6171d4588e89e874fcc765e92914b6d30
 F src/os.c 87ea1cd1259c5840848e34007d72e772a2ab7528
 F src/os.h 8d92f87f5fe14b060a853ca704b8ef6d3daee79b
 F src/os_common.h 92815ed65f805560b66166e3583470ff94478f04
-F src/os_unix.c be66c31337361a72227638d6f41c7f2031739642
+F src/os_unix.c 18153e6fc03580e95d28fb39d47a4e8b64b36187
 F src/os_win.c f7da4dc0a2545c0a430080380809946ae4d676d6
 F src/pager.c 520001015155efee9599c807dfd38e5fff9c6e36
 F src/pager.h 241d72dc0905df042da165f086d03505cb0bb50c
@@ -1039,7 +1039,7 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P c8eac290a7240d69494bd0dad5ed1fdc2505f703
-R 0cdb7517bc23cd336050741c62097e56
+P 5c9e9df27b9f2c46cd55388a858d4e78ee564975
+R eb2eb83f96de836951dbdb14158ccee8
 U dan
-Z 0dd43854f08b06a022f11b1a174cdf13
+Z 42c0bd3cd106c51e7465866daa07e0a3

manifest.uuid

@@ -1 +1 @@
-5c9e9df27b9f2c46cd55388a858d4e78ee564975
+765615f9fba7c1765eb741cb98a09a28b464ee55

src/os_unix.c

@@ -249,6 +249,8 @@ struct unixFile {
   unsigned char transCntrChng;   /* True if the transaction counter changed */
   unsigned char dbUpdate;        /* True if any part of database file changed */
   unsigned char inNormalWrite;   /* True if in a normal write operation */
+  sqlite3_int64 mmapSize;        /* Size of xMremap() */
+  void *pMapRegion;              /* Area memory mapped */
 #endif
 #ifdef SQLITE_TEST
   /* In test mode, increase the size of this structure a bit so that 
@@ -3072,6 +3074,7 @@ static int unixRead(
   unixFile *pFile = (unixFile *)id;
   int got;
   assert( id );
+  assert( offset>=pFile->mmapSize );  /* Never read from the mmapped region */
 
   /* If this is a database file (not a journal, master-journal or temp
   ** file), the bytes in the locking range should never be read or written. */
@@ -3154,6 +3157,7 @@ static int unixWrite(
   int wrote = 0;
   assert( id );
   assert( amt>0 );
+  assert( offset>=pFile->mmapSize );   /* Never write into the mmapped region */
 
   /* If this is a database file (not a journal, master-journal or temp
   ** file), the bytes in the locking range should never be read or written. */
@@ -4457,6 +4461,8 @@ static int unixMremap(
   i64 nOldRnd;                    /* nOld rounded up */
 
   assert( iOff==0 );
+  assert( p->mmapSize==nOld );
+  assert( p->pMapRegion==0 || p->pMapRegion==(*ppMap) );
 
   /* If the SQLITE_MREMAP_EXTEND flag is set, then the size of the requested 
   ** mapping (nNew bytes) may be greater than the size of the database file.
@@ -4494,6 +4500,7 @@ static int unixMremap(
   /* On OSX or Linux, reuse the old mapping if it is the right size. */
 #if defined(__APPLE__) || defined(__linux__)
   if( nNewRnd==nOldRnd ){
+    VVA_ONLY( p->mmapSize = nNew; )
     return SQLITE_OK;
   }
 #endif
@@ -4502,6 +4509,7 @@ static int unixMremap(
   if( nOldRnd!=0 ){
     void *pOld = *ppMap;
     munmap(pOld, nOldRnd);
+    VVA_ONLY( p->mmapSize = 0; p->pMapRegion = 0; );
   }
 
   /* And, if required, use mmap() to create a new mapping. */
@@ -4511,7 +4519,10 @@ static int unixMremap(
     pNew = mmap(0, nNewRnd, flags, MAP_SHARED, p->h, iOff);
     if( pNew==MAP_FAILED ){
       pNew = 0;
+      VVA_ONLY( p->mmapSize = 0; p->pMapRegion = 0; )
       rc = SQLITE_IOERR_MREMAP;
+    }else{
+      VVA_ONLY( p->mmapSize = nNew; p->pMapRegion = pNew; )
     }
   }
 
@@ -4846,6 +4857,7 @@ static int fillInUnixFile(
   pNew->pVfs = pVfs;
   pNew->zPath = zFilename;
   pNew->ctrlFlags = (u8)ctrlFlags;
+  VVA_ONLY( pNew->mmapSize = 0; )
   if( sqlite3_uri_boolean(((ctrlFlags & UNIXFILE_URI) ? zFilename : 0),
                            "psow", SQLITE_POWERSAFE_OVERWRITE) ){
     pNew->ctrlFlags |= UNIXFILE_PSOW;