NaClErrorCode NaClAllocateSpace(void **mem, size_t addrsp_size) {
int result;
CHECK(NULL != mem);
NaClAddrSpaceBeforeAlloc(addrsp_size);
#if NACL_LINUX
/*
* On 32 bit Linux, a 1 gigabyte block of address space may be reserved at
* the zero-end of the address space during process creation, to address
* sandbox layout requirements on ARM and performance issues on Intel ATOM.
* Look for this prereserved block and if found, pass its address to the
* page allocation function.
*/
if (NaClFindPrereservedSandboxMemory(mem, addrsp_size)) {
void *tmp_mem = (void *) NACL_TRAMPOLINE_START;
CHECK(*mem == 0);
addrsp_size -= NACL_TRAMPOLINE_START;
result = NaCl_page_alloc_at_addr(&tmp_mem, addrsp_size);
} else {
/* Zero-based sandbox not prereserved. Attempt to allocate anyway. */
result = NaCl_page_alloc(mem, addrsp_size);
}
#elif NACL_WINDOWS
/*
* On 32 bit Windows, a 1 gigabyte block of address space is reserved before
* starting up this process to make sure we can create the sandbox. Look for
* this prereserved block and if found, pass its address to the page
* allocation function.
*/
if (0 == NaClFindPrereservedSandboxMemory(mem, addrsp_size)) {
result = NaCl_page_alloc_at_addr(mem, addrsp_size);
} else {
result = NaCl_page_alloc(mem, addrsp_size);
}
#else
result = NaCl_page_alloc(mem, addrsp_size);
#endif
if (0 != result) {
NaClLog(2,
"NaClAllocateSpace: NaCl_page_alloc 0x%08"NACL_PRIxPTR
" failed\n",
(uintptr_t) *mem);
return LOAD_NO_MEMORY;
}
NaClLog(4, "NaClAllocateSpace: %"NACL_PRIxPTR", %"NACL_PRIxS"\n",
(uintptr_t) *mem,
addrsp_size);
return LOAD_OK;
}
/* NOTE: This routine is almost identical to the x86_32 version.
*/
NaClErrorCode NaClAllocateSpaceAslr(void **mem, size_t addrsp_size,
enum NaClAslrMode aslr_mode) {
int result;
void *tmp_mem = (void *) NACL_TRAMPOLINE_START;
UNREFERENCED_PARAMETER(aslr_mode);
CHECK(NULL != mem);
/*
* On ARM, we cheat slightly: we add two pages to the requested
* allocation! This accomodates the guard region we require at the
* top end of untrusted memory.
*/
addrsp_size += NACL_ADDRSPACE_UPPER_GUARD_SIZE;
NaClAddrSpaceBeforeAlloc(addrsp_size);
/*
* On 32 bit Linux, a 1 gigabyte block of address space may be reserved at
* the zero-end of the address space during process creation, to address
* sandbox layout requirements on ARM and performance issues on Intel ATOM.
* Look for this prereserved block and if found, pass its address to the
* page allocation function.
*/
if (!NaClFindPrereservedSandboxMemory(mem, addrsp_size)) {
/* On ARM, we should always have prereserved sandbox memory. */
NaClLog(LOG_ERROR, "NaClAllocateSpace:"
" Could not find correct amount of prereserved memory"
" (looked for 0x%016"NACL_PRIxS" bytes).\n",
addrsp_size);
return LOAD_NO_MEMORY;
}
/*
* When creating a zero-based sandbox, we do not allocate the first 64K of
* pages beneath the trampolines, because -- on Linux at least -- we cannot.
* Instead, we allocate starting at the trampolines, and then coerce the
* "mem" out parameter.
*/
CHECK(*mem == NULL);
addrsp_size -= NACL_TRAMPOLINE_START;
result = NaCl_page_alloc_at_addr(&tmp_mem, addrsp_size);
if (0 != result) {
NaClLog(2,
"NaClAllocateSpace: NaCl_page_alloc_at_addr 0x%08"NACL_PRIxPTR
" failed\n",
(uintptr_t) tmp_mem);
return LOAD_NO_MEMORY;
}
NaClLog(4, "NaClAllocateSpace: %"NACL_PRIxPTR", %"NACL_PRIxS"\n",
(uintptr_t) *mem,
addrsp_size);
return LOAD_OK;
}
