SQLite

  { "rmdir",        (sqlite3_syscall_ptr)rmdir,           0 },
#define osRmdir     ((int(*)(const char*))aSyscall[19].pCurrent)

  { "fchown",       (sqlite3_syscall_ptr)posixFchown,     0 },
#define osFchown    ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)

  { "mmap",       (sqlite3_syscall_ptr)mmap,     0 },
#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[21].pCurrent)

}; /* End of the overrideable system calls */

/*
** This is the xSetSystemCall() method of sqlite3_vfs for all of the
** "unix" VFSes.  Return SQLITE_OK opon successfully updating the
** system call pointer, or SQLITE_NOTFOUND if there is no configurable
** system call named zName.

  if( nMap!=pFd->mmapSize ){
    unixUnmapfile(pFd);

    if( nMap>0 ){
      void *pNew;
      int flags = PROT_READ;
      if( (pFd->ctrlFlags & UNIXFILE_RDONLY)==0 ) flags |= PROT_WRITE;
      pNew = osMmap(0, nMap, flags, MAP_SHARED, pFd->h, 0);
      if( pNew==MAP_FAILED ){
        return SQLITE_IOERR_MMAP;
      }

      pFd->pMapRegion = pNew;
      pFd->mmapSize = nMap;
      pFd->mmapOrigsize = nMap;

    UNIXVFS("unix-proxy",    proxyIoFinder ),
#endif
  };
  unsigned int i;          /* Loop counter */

  /* Double-check that the aSyscall[] array has been constructed
  ** correctly.  See ticket [bb3a86e890c8e96ab] */
  assert( ArraySize(aSyscall)==22 );

  /* Register all VFSes defined in the aVfs[] array */
  for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){
    sqlite3_vfs_register(&aVfs[i], i==0);
  }
  return SQLITE_OK; 
}

**   test_syscall install LIST
**     Install wrapper functions for all system calls in argument LIST.
**     LIST must be a list consisting of zero or more of the following
**     literal values:
**
**         open        close      access   getcwd   stat      fstat    
**         ftruncate   fcntl      read     pread    pread64   write
**         pwrite      pwrite64   fchmod   fallocate mmap
**
**   test_syscall uninstall
**     Uninstall all wrapper functions.
**
**   test_syscall fault ?COUNT PERSIST?
**     If [test_syscall fault] is invoked without the two arguments, fault
**     injection is disabled. Otherwise, fault injection is configured to

#include "sqliteInt.h"
#if SQLITE_OS_UNIX

/* From test1.c */
extern const char *sqlite3TestErrorName(int);

#include <sys/mman.h>
#include <sys/types.h>
#include <errno.h>

static struct TestSyscallGlobal {
  int bPersist;                   /* 1 for persistent errors, 0 for transient */
  int nCount;                     /* Fail after this many more calls */
  int nFail;                      /* Number of failures that have occurred */

static int ts_pread(int fd, void *aBuf, size_t nBuf, off_t off);
static int ts_pread64(int fd, void *aBuf, size_t nBuf, off_t off);
static int ts_write(int fd, const void *aBuf, size_t nBuf);
static int ts_pwrite(int fd, const void *aBuf, size_t nBuf, off_t off);
static int ts_pwrite64(int fd, const void *aBuf, size_t nBuf, off_t off);
static int ts_fchmod(int fd, mode_t mode);
static int ts_fallocate(int fd, off_t off, off_t len);
static void *ts_mmap(void *, size_t, int, int, int, off_t);


struct TestSyscallArray {
  const char *zName;
  sqlite3_syscall_ptr xTest;
  sqlite3_syscall_ptr xOrig;
  int default_errno;              /* Default value for errno following errors */

  /*  9 */ { "pread",     (sqlite3_syscall_ptr)ts_pread,     0, 0, 0 },
  /* 10 */ { "pread64",   (sqlite3_syscall_ptr)ts_pread64,   0, 0, 0 },
  /* 11 */ { "write",     (sqlite3_syscall_ptr)ts_write,     0, 0, 0 },
  /* 12 */ { "pwrite",    (sqlite3_syscall_ptr)ts_pwrite,    0, 0, 0 },
  /* 13 */ { "pwrite64",  (sqlite3_syscall_ptr)ts_pwrite64,  0, 0, 0 },
  /* 14 */ { "fchmod",    (sqlite3_syscall_ptr)ts_fchmod,    0, 0, 0 },
  /* 15 */ { "fallocate", (sqlite3_syscall_ptr)ts_fallocate, 0, 0, 0 },
  /* 16 */ { "mmap",      (sqlite3_syscall_ptr)ts_mmap,      0, 0, 0 },
           { 0, 0, 0, 0, 0 }
};

#define orig_open      ((int(*)(const char *, int, int))aSyscall[0].xOrig)
#define orig_close     ((int(*)(int))aSyscall[1].xOrig)
#define orig_access    ((int(*)(const char*,int))aSyscall[2].xOrig)
#define orig_getcwd    ((char*(*)(char*,size_t))aSyscall[3].xOrig)

#define orig_write     ((ssize_t(*)(int,const void*,size_t))aSyscall[11].xOrig)
#define orig_pwrite    ((ssize_t(*)(int,const void*,size_t,off_t))\
                       aSyscall[12].xOrig)
#define orig_pwrite64  ((ssize_t(*)(int,const void*,size_t,off_t))\
                       aSyscall[13].xOrig)
#define orig_fchmod    ((int(*)(int,mode_t))aSyscall[14].xOrig)
#define orig_fallocate ((int(*)(int,off_t,off_t))aSyscall[15].xOrig)
#define orig_mmap      ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[16].xOrig)

/*
** This function is called exactly once from within each invocation of a
** system call wrapper in this file. It returns 1 if the function should
** fail, or 0 if it should succeed.
*/
static int tsIsFail(void){

*/
static int ts_fallocate(int fd, off_t off, off_t len){
  if( tsIsFail() ){
    return tsErrno("fallocate");
  }
  return orig_fallocate(fd, off, len);
}

static void *ts_mmap(
  void *pAddr, 
  size_t nByte, 
  int prot, 
  int flags, 
  int fd, 
  off_t iOff
){
  if( tsIsFailErrno("mmap") ){
    return MAP_FAILED;
  }
  return orig_mmap(pAddr, nByte, prot, flags, fd, iOff);
}

static int test_syscall_install(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){

# by -test scripts.
#
proc faultsim_test_result_int {args} {
  upvar testrc testrc testresult testresult testnfail testnfail
  set t [list $testrc $testresult]
  set r $args
  if { ($testnfail==0 && $t != [lindex $r 0]) || [lsearch $r $t]<0 } {
    error "nfail=$testnfail rc=$testrc result=$testresult list=$r"
  }
}

#--------------------------------------------------------------------------
# Usage do_one_faultsim_test NAME ?OPTIONS...? 
#
# The first argument, <test number>, is used as a prefix of the test names

    INSERT INTO t1 VALUES(randomblob(10000), randomblob(10000));
    SELECT length(a) + length(b) FROM t1;
    COMMIT;
  }
} -test {
  faultsim_test_result {0 20000}
}

#-------------------------------------------------------------------------
# Test errors in mmap().
#
proc vfsfault_install {} { 
  test_syscall reset
  test_syscall install {mmap}
}

faultsim_delete_and_reopen
execsql {
  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES(1, 2);
}
faultsim_save_and_close

do_faultsim_test 4 -faults vfsfault-* -prep {
  faultsim_restore_and_reopen
  file_control_chunksize_test db main 8192
  execsql { 
    PRAGMA mmap_size = 1000000;
  }
} -body {
  test_syscall errno mmap     EACCES

  execsql {
    SELECT * FROM t1;
  }
} -test {
  faultsim_test_result {0 {1 2}} {1 {disk I/O error}}
}

finish_test