Remove unused support for SysV shared memory

src/trusted/desc/linux/nacl_desc_sysv_shm.c

Index: src/trusted/desc/linux/nacl_desc_sysv_shm.c
diff --git a/src/trusted/desc/linux/nacl_desc_sysv_shm.c b/src/trusted/desc/linux/nacl_desc_sysv_shm.c
deleted file mode 100644
index 8e120a9f2bfa00c4771af53a5dbd0f4ab9b67b5e..0000000000000000000000000000000000000000
--- a/src/trusted/desc/linux/nacl_desc_sysv_shm.c
+++ /dev/null
@@ -1,430 +0,0 @@
-/*
- * Copyright (c) 2012 The Native Client Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-/*
- * NaCl Service Runtime.  Transferrable shared memory objects.
- */
-
-#include "native_client/src/include/portability.h"
-#include "native_client/src/include/nacl_platform.h"
-
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-#include <sys/shm.h>
-
-#include "native_client/src/trusted/desc/nacl_desc_base.h"
-#include "native_client/src/trusted/desc/nacl_desc_effector.h"
-#include "native_client/src/trusted/desc/linux/nacl_desc_sysv_shm.h"
-
-#include "native_client/src/shared/platform/nacl_find_addrsp.h"
-#include "native_client/src/shared/platform/nacl_log.h"
-#include "native_client/src/shared/platform/nacl_sync_checked.h"
-
-#include "native_client/src/trusted/service_runtime/internal_errno.h"
-#include "native_client/src/trusted/service_runtime/nacl_config.h"
-#include "native_client/src/trusted/service_runtime/include/bits/mman.h"
-#include "native_client/src/trusted/service_runtime/include/sys/errno.h"
-#include "native_client/src/trusted/service_runtime/include/sys/fcntl.h"
-#include "native_client/src/trusted/service_runtime/include/sys/stat.h"
-#include "native_client/src/trusted/service_runtime/sel_util.h"
-
-
-#if !defined(SIZE_T_MAX)
-# define SIZE_T_MAX (~((size_t) 0))
-#endif
-
-/*
- * This file contains the implementation of the NaClDescSysvShm
- * subclass of NaClDesc.
- *
- * NaClDescSysvShm is the subclass that wraps SysV shared memory descriptors.
- *
- * Support for SysV shared memory descriptors is much more restricted than
- * for other types of descriptors.  In particular:
- * 1) NaCl provides no method for untrusted creation of SysV shared memory.
- * 2) Importing does not confer ownership of the descriptor, and hence
- *    we do not do the shmctl(IPC_RMID) to close it.  The lifetime of the
- *    descriptor is controlled by the X server that created it, and returned
- *    it for use by Chrome.
- */
-
-static int NaClDescSysvShmSubclassCtorIntern(struct NaClDescSysvShm *self,
-                                             int id,
-                                             nacl_off64_t size,
-                                             int rmid_in_dtor) {
-  struct NaClDesc *basep = (struct NaClDesc *) self;
-
-  /*
-   * off_t is signed, but size_t is not; historically size_t is for
-   * sizeof and similar, and off_t is also used for stat structure
-   * st_size member.  This runtime test detects large object sizes
-   * that are silently converted to negative values.  Additionally,
-   * the size must be a multiple of 4K.
-   */
-  basep->base.vtbl = (struct NaClRefCountVtbl const *) NULL;
-  if ((size_t) size != NaClRoundPage((size_t) size)
-      || size < 0
-      || SIZE_T_MAX < (uint64_t) size) {
-    return 0;
-  }
-
-  self->id = id;
-  self->size = size;
-  self->rmid_in_dtor = rmid_in_dtor;
-  basep->base.vtbl = (struct NaClRefCountVtbl const *) &kNaClDescSysvShmVtbl;
-  return 1;
-}
-
-static int NaClDescSysvShmCtorIntern(struct NaClDescSysvShm *self,
-                                     int                    id,
-                                     nacl_off64_t           size,
-                                     int                    rmid_in_dtor) {
-  struct NaClDesc *basep = (struct NaClDesc *) self;
-  int rv;
-
-  NACL_VTBL(NaClRefCount, self) = (struct NaClRefCountVtbl const *) NULL;
-
-  if (!NaClDescCtor(basep)) {
-    return 0;
-  }
-  rv = NaClDescSysvShmSubclassCtorIntern(self, id, size, rmid_in_dtor);
-  if (!rv) {
-    (*NACL_VTBL(NaClRefCount, self)->Dtor)((struct NaClRefCount *) self);
-  }
-  (*NACL_VTBL(NaClDesc, basep)->SetFlags)(basep, NACL_ABI_O_RDWR);
-  return rv;
-}
-
-int NaClDescSysvShmImportSubclassCtor(struct NaClDescSysvShm  *self,
-                              int                     id,
-                              nacl_off64_t            size) {
-  return NaClDescSysvShmSubclassCtorIntern(self, id, size, 0);
-}
-
-int NaClDescSysvShmImportCtor(struct NaClDescSysvShm  *self,
-                              int                     id,
-                              nacl_off64_t            size) {
-  return NaClDescSysvShmCtorIntern(self, id, size, 0);
-}
-
-/*
- * Creates a NaClDesc containing a new shared memory region.
- */
-int NaClDescSysvShmCtor(struct NaClDescSysvShm  *self,
-                        nacl_off64_t            size) {
-  int id;
-  int retval;
-
-  if (size < 0 || SIZE_T_MAX < (uint64_t) size) {
-    return 0;
-  }
-  /* Create the region. */
-  id = shmget(IPC_PRIVATE,
-              (int) size,
-              IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR);
-  if (-1 == id) {
-    return 0;
-  }
-  /* Construct the descriptor. */
-  retval = NaClDescSysvShmCtorIntern(self, id, size, 1);
-  /* If the constructor failed, mark the region for freeing. */
-  if (0 == retval) {
-    (void) shmctl(id, IPC_RMID, NULL);
-    return 0;
-  }
-  /* Return success. */
-  return 1;
-}
-
-static void NaClDescSysvShmDtor(struct NaClRefCount *vself) {
-  struct NaClDescSysvShm  *self = (struct NaClDescSysvShm *) vself;
-
-  /*
-   * Importing does NOT confer ownership of the id. Hence the Dtor does not
-   * do the shmctl(IPC_RMID).
-   */
-  if (self->rmid_in_dtor) {
-    (void) shmctl(self->id, IPC_RMID, NULL);
-  }
-  /* NACL_INVALID_HANDLE is also an invalid id for shmat. */
-  self->id = NACL_INVALID_HANDLE;
-  vself->vtbl = (struct NaClRefCountVtbl const *) &kNaClDescVtbl;
-  (*vself->vtbl->Dtor)(vself);
-}
-
-/*
- * For now, we just use shmat.  This means that the NaCl module's mmap
- * syscall must ask for the entire size, with a zero offset.  In the
- * future, we may choose to shmat to elsewhere in the trusted address
- * space, and then mremap from there into the untrusted address space,
- * using MREMAP_FIXED to ask for the new location.  This approach has
- * its own hazards, however since on x86-32 we are short on address
- * space already, and requiring shmat, mremap, munmap means that we
- * have to have enough trusted address space free to temporarily hold
- * the maximum sized sysv shm object.
- */
-static uintptr_t NaClDescSysvShmMap(struct NaClDesc         *vself,
-                                    struct NaClDescEffector *effp,
-                                    void                    *start_addr,
-                                    size_t                  len,
-                                    int                     prot,
-                                    int                     flags,
-                                    nacl_off64_t            offset) {
-  struct NaClDescSysvShm  *self = (struct NaClDescSysvShm *) vself;
-
-  int           host_flags;
-  void          *result;
-
-  UNREFERENCED_PARAMETER(effp);
-
-  NaClLog(4,
-          "NaClDescSysVShmMmap(,,0x%08"NACL_PRIxPTR",0x%"NACL_PRIxS","
-          "0x%x,0x%x,0x%08"NACL_PRIxNACL_OFF64")\n",
-          (uintptr_t) start_addr, len, prot, flags, offset);
-  /*
-   * shm must have NACL_ABI_MAP_SHARED in flags.  we check, and may
-   * relax this in the future.
-   */
-  if ((NACL_ABI_MAP_SHARED) !=
-      (flags & (NACL_ABI_MAP_SHARING_MASK))) {
-    NaClLog(LOG_INFO,
-            ("NaClDescSysvShmMap: Mapping not"
-             " NACL_ABI_MAP_SHARED\n"));
-    return -NACL_ABI_EINVAL;
-  }
-
-  if (0 != (NACL_ABI_MAP_FIXED & flags) && NULL == start_addr) {
-    NaClLog(LOG_INFO,
-            ("NaClDescSysvShmMap: Mapping NACL_ABI_MAP_FIXED"
-             " but start_addr is NULL\n"));
-    return -NACL_ABI_EINVAL;
-  }
-  /* post-condition: if NULL == start_addr, then NACL_ABI_MAP_FIXED not set */
-
-  if (NULL == start_addr) {
-    uintptr_t addr;
-
-    if (!NaClFindAddressSpace(&addr, len)) {
-      NaClLog(1, "NaClDescSysvShmMap: could not find address space\n");
-      return -NACL_ABI_ENOMEM;
-    }
-    if (-1 == munmap((void *) addr, len)) {
-      NaClLog(LOG_FATAL,
-              "Could not unmap found space at 0x%"NACL_PRIxPTR"\n",
-              addr);
-    }
-    start_addr = (void *) addr;
-  }
-
-  /*
-   * shmat can only map the shared memory region starting at its beginning
-   * and continuing for its entire size.
-   */
-  if (0 != offset || self->size > len) {
-    NaClLog(LOG_INFO,
-            "NaClDescSysvShmMap: Mapping at non-zero offset or length"
-            " mismatch\n");
-    return -NACL_ABI_EINVAL;
-  }
-  /*
-   * prot must be not be PROT_NONE nor contain other than PROT_{READ|WRITE}
-   */
-  if (NACL_ABI_PROT_NONE == prot) {
-    NaClLog(LOG_INFO, "NaClDescSysvShmMap: PROT_NONE not supported\n");
-    return -NACL_ABI_EINVAL;
-  }
-  if (0 == (NACL_ABI_PROT_READ & prot)) {
-    NaClLog(LOG_INFO, "NaClDescSysvShmMap: PROT_READ not set\n");
-    return -NACL_ABI_EINVAL;
-  }
-  if (0 != (~(NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE) & prot)) {
-    NaClLog(LOG_INFO,
-            "NaClDescSysvShmMap: prot has other bits than PROT_{READ|WRITE}\n");
-    return -NACL_ABI_EINVAL;
-  }
-  /*
-   * Map from NACL_ABI_ prot and flags bits to shmat flags.
-   */
-  host_flags = SHM_REMAP;
-  if (NACL_ABI_PROT_READ == prot) {
-    host_flags |= SHM_RDONLY;
-  }
-
-  /*
-   * TODO(bsy): !NACL_ABI_MAP_FIXED, start_addr == NULL, find address
-   * space (assuming no race), and set start_addr appropriately.
-   *
-   * If SHM_REMAP is defined, use it.  Else munmap and then shmat,
-   * leaving a timing hole for multithreaded race.  Fail if we lose
-   * the race and let the user code retry.
-   */
-  /*
-   * Attach (map) the shared memory region.
-   */
-  result = shmat(self->id, (void *) start_addr, host_flags);
-  if (NACL_MAP_FAILED == result) {
-    NaClLog(LOG_FATAL, "NaClDescSysvMap: shmat failed %d\n", errno);
-  }
-  if (result != start_addr) {
-    NaClLog(LOG_FATAL,
-            ("NaClDescSysvShmMap: NACL_MAP_FIXED but"
-             " got 0x%08"NACL_PRIxPTR" instead of 0x%08"NACL_PRIxPTR"\n"),
-            (uintptr_t) result, (uintptr_t) start_addr);
-  }
-
-  return (uintptr_t) start_addr;
-}
-
-static int NaClDescSysvShmFstat(struct NaClDesc         *vself,
-                                struct nacl_abi_stat    *stbp) {
-  struct NaClDescSysvShm  *self = (struct NaClDescSysvShm *) vself;
-
-  if (self->size > INT32_MAX) {
-    return -NACL_ABI_EOVERFLOW;
-  }
-
-  stbp->nacl_abi_st_dev = 0;
-  stbp->nacl_abi_st_ino = 0x6c43614e;
-  stbp->nacl_abi_st_mode = (NACL_ABI_S_IFSHM_SYSV |
-                            NACL_ABI_S_IRUSR |
-                            NACL_ABI_S_IWUSR);
-  stbp->nacl_abi_st_nlink = 1;
-  stbp->nacl_abi_st_uid = -1;
-  stbp->nacl_abi_st_gid = -1;
-  stbp->nacl_abi_st_rdev = 0;
-  /* TODO(sehr): this should really use shmctl instead. */
-  stbp->nacl_abi_st_size = (nacl_abi_off_t) self->size;
-  stbp->nacl_abi_st_blksize = 0;
-  stbp->nacl_abi_st_blocks = 0;
-  stbp->nacl_abi_st_atime = 0;
-  stbp->nacl_abi_st_mtime = 0;
-  stbp->nacl_abi_st_ctime = 0;
-
-  return 0;
-}
-
-static int NaClDescSysvShmExternalizeSize(struct NaClDesc *vself,
-                                          size_t          *nbytes,
-                                          size_t          *nhandles) {
-  struct NaClDescSysvShm  *self = (struct NaClDescSysvShm *) vself;
-  int rv;
-
-  rv = NaClDescExternalizeSize(vself, nbytes, nhandles);
-  if (0 != rv) {
-    return rv;
-  }
-  *nbytes += sizeof self->id + sizeof(nacl_off64_t);
-
-  return 0;
-}
-
-static int NaClDescSysvShmExternalize(struct NaClDesc           *vself,
-                                      struct NaClDescXferState  *xfer) {
-  struct NaClDescSysvShm  *self = (struct NaClDescSysvShm *) vself;
-  nacl_off64_t size64 = self->size;
-  int rv;
-
-  rv = NaClDescExternalize(vself, xfer);
-  if (0 != rv) {
-    return rv;
-  }
-  memcpy(xfer->next_byte, &self->id, sizeof self->id);
-  xfer->next_byte += sizeof self->id;
-  memcpy(xfer->next_byte, &size64, sizeof size64);
-  xfer->next_byte += sizeof size64;
-  return 0;
-}
-
-struct NaClDescVtbl const kNaClDescSysvShmVtbl = {
-  {
-    NaClDescSysvShmDtor,
-  },
-  NaClDescSysvShmMap,
-  NACL_DESC_UNMAP_NOT_IMPLEMENTED
-  NaClDescReadNotImplemented,
-  NaClDescWriteNotImplemented,
-  NaClDescSeekNotImplemented,
-  NaClDescPReadNotImplemented,
-  NaClDescPWriteNotImplemented,
-  NaClDescSysvShmFstat,
-  NaClDescGetdentsNotImplemented,
-  NaClDescSysvShmExternalizeSize,
-  NaClDescSysvShmExternalize,
-  NaClDescLockNotImplemented,
-  NaClDescTryLockNotImplemented,
-  NaClDescUnlockNotImplemented,
-  NaClDescWaitNotImplemented,
-  NaClDescTimedWaitAbsNotImplemented,
-  NaClDescSignalNotImplemented,
-  NaClDescBroadcastNotImplemented,
-  NaClDescSendMsgNotImplemented,
-  NaClDescRecvMsgNotImplemented,
-  NaClDescLowLevelSendMsgNotImplemented,
-  NaClDescLowLevelRecvMsgNotImplemented,
-  NaClDescConnectAddrNotImplemented,
-  NaClDescAcceptConnNotImplemented,
-  NaClDescPostNotImplemented,
-  NaClDescSemWaitNotImplemented,
-  NaClDescGetValueNotImplemented,
-  NaClDescSetMetadata,
-  NaClDescGetMetadata,
-  NaClDescSetFlags,
-  NaClDescGetFlags,
-  NaClDescIsattyNotImplemented,
-  NACL_DESC_SYSV_SHM,
-};
-
-int NaClDescSysvShmInternalize(struct NaClDesc               **out_desc,
-                               struct NaClDescXferState      *xfer,
-                               struct NaClDescQuotaInterface *quota_interface) {
-  int                   rv;
-  struct NaClDescSysvShm *ndisp;
-  int                   id;
-  nacl_off64_t          size;
-
-  UNREFERENCED_PARAMETER(quota_interface);
-  rv = -NACL_ABI_EIO;
-
-  ndisp = malloc(sizeof *ndisp);
-  if (NULL == ndisp) {
-    rv = -NACL_ABI_ENOMEM;
-    goto cleanup;
-  }
-
-  if (!NaClDescInternalizeCtor((struct NaClDesc *) ndisp, xfer)) {
-    free(ndisp);
-    ndisp = NULL;
-    rv = -NACL_ABI_ENOMEM;
-    goto cleanup;
-  }
-
-  if (xfer->next_byte + sizeof ndisp->id + sizeof ndisp->size >
-      xfer->byte_buffer_end) {
-    rv = -NACL_ABI_EIO;
-    goto cleanup;
-  }
-
-  memcpy(&id, xfer->next_byte, sizeof id);
-  xfer->next_byte += sizeof id;
-  memcpy(&size, xfer->next_byte, sizeof size);
-  xfer->next_byte += sizeof size;
-
-  if (!NaClDescSysvShmImportSubclassCtor(ndisp, id, size)) {
-    rv = -NACL_ABI_EIO;
-    goto cleanup;
-  }
-
-  *out_desc = (struct NaClDesc *) ndisp;
-  rv = 0;
-
-cleanup:
-  if (rv < 0) {
-    NaClDescSafeUnref((struct NaClDesc *) ndisp);
-  }
-  return rv;
-}