void NaClReplaceDescIfValidationCacheAssertsMappable(
struct NaClDesc **desc_in_out,
struct NaClValidationCache *validation_cache) {
struct NaClDesc *desc = *desc_in_out;
struct NaClDesc *replacement;
struct NaClFileToken file_token;
if (NACL_FI("validation_cache_replacement_bypass", 0, 1)) {
NaClDescMarkSafeForMmap(desc);
} else if (!NaClDescGetFileToken(desc, &file_token)) {
NaClLog(4,
"NaClReplaceDescIfValidationCacheAssertsMappable: no valid"
" file token\n");
} else {
replacement = NaClExchangeFileTokenForMappableDesc(&file_token,
validation_cache);
if (NULL != replacement) {
NaClDescUnref(desc);
*desc_in_out = replacement;
}
}
}
NaClErrorCode NaClElfImageLoad(struct NaClElfImage *image,
struct NaClDesc *ndp,
struct NaClApp *nap) {
int segnum;
uintptr_t vaddr;
uintptr_t paddr;
uintptr_t end_vaddr;
ssize_t read_ret;
int safe_for_mmap;
for (segnum = 0; segnum < image->ehdr.e_phnum; ++segnum) {
const Elf_Phdr *php = &image->phdrs[segnum];
Elf_Off offset = (Elf_Off) NaClTruncAllocPage(php->p_offset);
Elf_Off filesz = php->p_offset + php->p_filesz - offset;
/* did we decide that we will load this segment earlier? */
if (!image->loadable[segnum]) {
continue;
}
NaClLog(2, "loading segment %d\n", segnum);
if (0 == php->p_filesz) {
NaClLog(4, "zero-sized segment. ignoring...\n");
continue;
}
end_vaddr = php->p_vaddr + php->p_filesz;
/* integer overflow? */
if (end_vaddr < php->p_vaddr) {
NaClLog(LOG_FATAL, "parameter error should have been detected already\n");
}
/*
* is the end virtual address within the NaCl application's
* address space? if it is, it implies that the start virtual
* address is also.
*/
if (end_vaddr >= ((uintptr_t) 1U << nap->addr_bits)) {
NaClLog(LOG_FATAL, "parameter error should have been detected already\n");
}
vaddr = NaClTruncAllocPage(php->p_vaddr);
paddr = NaClUserToSysAddr(nap, vaddr);
CHECK(kNaClBadAddress != paddr);
/*
* Check NaClDescIsSafeForMmap(ndp) to see if it might be okay to
* mmap.
*/
NaClLog(4, "NaClElfImageLoad: checking descriptor mmap safety\n");
safe_for_mmap = NaClDescIsSafeForMmap(ndp);
if (safe_for_mmap) {
NaClLog(4, "NaClElfImageLoad: safe-for-mmap\n");
}
if (!safe_for_mmap &&
NACL_FI("ELF_LOAD_BYPASS_DESCRIPTOR_SAFETY_CHECK", 0, 1)) {
NaClLog(LOG_WARNING, "WARNING: BYPASSING DESCRIPTOR SAFETY CHECK\n");
safe_for_mmap = 1;
}
if (safe_for_mmap) {
NaClErrorCode map_status;
NaClLog(4, "NaClElfImageLoad: safe-for-mmap\n");
map_status = NaClElfFileMapSegment(nap, ndp, php->p_flags,
offset, filesz, vaddr, paddr);
/*
* NB: -Werror=switch-enum forces us to not use a switch.
*/
if (LOAD_OK == map_status) {
/* Segment has been handled -- proceed to next segment */
continue;
} else if (LOAD_STATUS_UNKNOWN != map_status) {
/*
* A real error! Return it so that this can be reported to
* the embedding code (via start_module status).
*/
return map_status;
}
/* Fall through: pread-based fallback requested */
}
NaClLog(4,
"PReading %"NACL_PRIdElf_Xword" (0x%"NACL_PRIxElf_Xword") bytes to"
" address 0x%"NACL_PRIxPTR", position %"
NACL_PRIdElf_Off" (0x%"NACL_PRIxElf_Off")\n",
filesz, filesz,
paddr,
offset, offset);
/*
* Tell valgrind that this memory is accessible and undefined. For more
* details see
* http://code.google.com/p/nativeclient/wiki/ValgrindMemcheck#Implementation_details
*/
NACL_MAKE_MEM_UNDEFINED((void *) paddr, filesz);
read_ret = (*NACL_VTBL(NaClDesc, ndp)->
PRead)(ndp, (void *) paddr, filesz, (nacl_off64_t) offset);
if (NaClSSizeIsNegErrno(&read_ret) || (size_t) read_ret != filesz) {
NaClLog(LOG_ERROR, "load failure segment %d", segnum);
return LOAD_SEGMENT_BAD_PARAM;
}
/* region from p_filesz to p_memsz should already be zero filled */
/* Tell Valgrind that we've mapped a segment of nacl_file. */
NaClFileMappingForValgrind(paddr, filesz, offset);
}
return LOAD_OK;
}
