/*
* The file size of a mach-o file is limited to 32 bits; this is because
* this is the limit on the kalloc() of enough bytes for a mach_header and
* the contents of its sizeofcmds, which is currently constrained to 32
* bits in the file format itself. We read into the kernel buffer the
* commands section, and then parse it in order to parse the mach-o file
* format load_command segment(s). We are only interested in a subset of
* the total set of possible commands. If "map"==VM_MAP_NULL or
* "thread"==THREAD_NULL, do not make permament VM modifications,
* just preflight the parse.
*/
static
load_return_t
parse_machfile(
uint8_t *vp,
struct mach_header *header,
off_t file_offset,
off_t macho_size,
int depth,
int64_t aslr_offset,
int64_t dyld_aslr_offset,
load_result_t *result
)
{
uint32_t ncmds;
struct load_command *lcp;
struct dylinker_command *dlp = 0;
integer_t dlarchbits = 0;
void * control;
load_return_t ret = LOAD_SUCCESS;
caddr_t addr;
vm_size_t size,kl_size;
size_t offset;
size_t oldoffset; /* for overflow check */
int pass;
size_t mach_header_sz = sizeof(struct mach_header);
boolean_t abi64;
boolean_t got_code_signatures = FALSE;
int64_t slide = 0;
if (header->magic == MH_MAGIC_64 ||
header->magic == MH_CIGAM_64) {
mach_header_sz = sizeof(struct mach_header_64);
}
/*
* Break infinite recursion
*/
if (depth > 6) {
printf("parse_machfile 1: %s\n", load_to_string(LOAD_FAILURE));
return(LOAD_FAILURE);
}
depth++;
/*
* Check to see if right machine type.
*/
// this should be implemented by qemu somehow.
/*if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != (cpu_type() & ~CPU_ARCH_MASK)) ||
!grade_binary(header->cputype,
header->cpusubtype & ~CPU_SUBTYPE_MASK))
return(LOAD_BADARCH);*/
abi64 = ((header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64);
switch (header->filetype) {
case MH_OBJECT:
case MH_EXECUTE:
case MH_PRELOAD:
if (depth != 1) {
printf("parse_machfile 2: %s\n", load_to_string(LOAD_FAILURE));
return (LOAD_FAILURE);
}
break;
case MH_FVMLIB:
case MH_DYLIB:
if (depth == 1) {
printf("parse_machfile 2: %s\n", load_to_string(LOAD_FAILURE));
return (LOAD_FAILURE);
}
break;
case MH_DYLINKER:
if (depth != 2) {
printf("parse_machfile 3: %s\n", load_to_string(LOAD_FAILURE));
return (LOAD_FAILURE);
}
break;
default:
printf("parse_machfile 4: %s, header->filetype = %d\n", load_to_string(LOAD_FAILURE), header->filetype);
return (LOAD_FAILURE);
}
/*
* Map portion that must be accessible directly into
* kernel's map.
*/
if ((off_t)(mach_header_sz + header->sizeofcmds) > macho_size) {
printf("parse_machfile 5: %s header->sizeofcmds: %d macho_size %d\n", load_to_string(LOAD_BADMACHO), header->sizeofcmds, macho_size);
return(LOAD_BADMACHO);
}
/*
* Round size of Mach-O commands up to page boundry.
*/
size = round_page(mach_header_sz + header->sizeofcmds);
if (size <= 0) {
printf("parse_machfile 6: %s\n", load_to_string(LOAD_BADMACHO));
return(LOAD_BADMACHO);
}
/*
* Map the load commands into kernel memory.
*/
addr = 0;
kl_size = size;
addr = (caddr_t)(vp);
if (addr == NULL) {
printf("parse_machfile 7: %s\n", load_to_string(LOAD_NOSPACE));
return(LOAD_NOSPACE);
}
/*
* For PIE and dyld, slide everything by the ASLR offset.
*/
if ((header->flags & MH_PIE) || (header->filetype == MH_DYLINKER)) {
slide = aslr_offset;
}
/*
* Scan through the commands, processing each one as necessary.
* We parse in three passes through the headers:
* 1: thread state, uuid, code signature
* 2: segments
* 3: dyld, encryption, check entry point
*/
for (pass = 1; pass <= 3; pass++) {
/*
* Check that the entry point is contained in an executable segments
*/
if ((pass == 3) && (result->validentry == 0)) {
ret = LOAD_FAILURE;
break;
}
/*
* Loop through each of the load_commands indicated by the
* Mach-O header; if an absurd value is provided, we just
* run off the end of the reserved section by incrementing
* the offset too far, so we are implicitly fail-safe.
*/
offset = mach_header_sz;
ncmds = header->ncmds;
while (ncmds--) {
/*
* Get a pointer to the command.
*/
lcp = (struct load_command *)(addr + offset);
oldoffset = offset;
offset += lcp->cmdsize;
/*
* Perform prevalidation of the struct load_command
* before we attempt to use its contents. Invalid
* values are ones which result in an overflow, or
* which can not possibly be valid commands, or which
* straddle or exist past the reserved section at the
* start of the image.
*/
if (oldoffset > offset ||
lcp->cmdsize < sizeof(struct load_command) ||
offset > header->sizeofcmds + mach_header_sz) {
ret = LOAD_BADMACHO;
break;
}
/*
* Act on struct load_command's for which kernel
* intervention is required.
*/
printf("Command: %s\n", command_to_string(lcp->cmd));
switch(lcp->cmd) {
case LC_SEGMENT:
if (pass != 2)
break;
if (abi64) {
/*
* Having an LC_SEGMENT command for the
* wrong ABI is invalid <rdar://problem/11021230>
*/
ret = LOAD_BADMACHO;
break;
}
ret = load_segment(lcp,
header->filetype,
control,
file_offset,
macho_size,
vp,
slide,
result);
break;
case LC_SEGMENT_64:
if (pass != 2)
break;
if (!abi64) {
/*
* Having an LC_SEGMENT_64 command for the
* wrong ABI is invalid <rdar://problem/11021230>
*/
ret = LOAD_BADMACHO;
break;
}
ret = load_segment(lcp,
header->filetype,
control,
file_offset,
macho_size,
vp,
slide,
result);
break;
case LC_UNIXTHREAD:
if (pass != 1)
break;
ret = load_unixthread(
(struct thread_command *) lcp,
result);
break;
case LC_MAIN:
if (pass != 1)
break;
if (depth != 1)
break;
ret = load_main(
(struct entry_point_command *) lcp,
result);
break;
case LC_LOAD_DYLINKER:
if (pass != 3)
break;
if ((depth == 1) && (dlp == 0)) {
dlp = (struct dylinker_command *)lcp;
dlarchbits = (header->cputype & CPU_ARCH_MASK);
} else {
ret = LOAD_FAILURE;
}
break;
case LC_UUID:
if (pass == 1 && depth == 1) {
ret = load_uuid((struct uuid_command *) lcp,
(char *)addr + mach_header_sz + header->sizeofcmds,
result);
}
break;
case LC_CODE_SIGNATURE:
/* CODE SIGNING */
if (pass != 1)
break;
/* pager -> uip ->
load signatures & store in uip
set VM object "signed_pages"
*/
/*ret = load_code_signature(
(struct linkedit_data_command *) lcp,
vp,
file_offset,
macho_size,
header->cputype,
result);*/
if (ret != LOAD_SUCCESS) {
printf("proc: load code signature error %d ", ret);
ret = LOAD_SUCCESS; /* ignore error */
} else {
got_code_signatures = TRUE;
}
break;
#if CONFIG_CODE_DECRYPTION
case LC_ENCRYPTION_INFO:
case LC_ENCRYPTION_INFO_64:
if (pass != 3)
break;
ret = set_code_unprotect(
(struct encryption_info_command *) lcp,
addr, map, slide, vp,
header->cputype, header->cpusubtype);
if (ret != LOAD_SUCCESS) {
printf("proc %d: set_code_unprotect() error %d "
"for file \"%s\"\n",
p->p_pid, ret, vp->v_name);
/*
* Don't let the app run if it's
* encrypted but we failed to set up the
* decrypter. If the keys are missing it will
* return LOAD_DECRYPTFAIL.
*/
if (ret == LOAD_DECRYPTFAIL) {
/* failed to load due to missing FP keys */
proc_lock(p);
p->p_lflag |= P_LTERM_DECRYPTFAIL;
proc_unlock(p);
}
psignal(p, SIGKILL);
}
break;
#endif
default:
/* Other commands are ignored by the kernel */
ret = LOAD_SUCCESS;
break;
}
printf("parse_machfile 9: ret %s\n", load_to_string(ret));
if (ret != LOAD_SUCCESS)
break;
}
if (ret != LOAD_SUCCESS)
break;
}
if (ret == LOAD_SUCCESS) {
if (! got_code_signatures) {
//struct cs_blob *blob;
/* no embedded signatures: look for detached ones */
//blob = ubc_cs_blob_get(vp, -1, file_offset);
//if (blob != NULL) {
//unsigned int cs_flag_data = blob->csb_flags;
//if(0 != ubc_cs_generation_check(vp)) {
// if (0 != ubc_cs_blob_revalidate(vp, blob)) {
// /* clear out the flag data if revalidation fails */
// cs_flag_data = 0;
// result->csflags &= ~CS_VALID;
// }
//}
/* get flags to be applied to the process */
//result->csflags |= cs_flag_data;
//}
}
/* Make sure if we need dyld, we got it */
if (result->needs_dynlinker && !dlp) {
ret = LOAD_FAILURE;
}
if ((ret == LOAD_SUCCESS) && (dlp != 0)) {
/*
* load the dylinker, and slide it by the independent DYLD ASLR
* offset regardless of the PIE-ness of the main binary.
*/
ret = load_dylinker(dlp, dlarchbits, depth, dyld_aslr_offset, result);
}
if((ret == LOAD_SUCCESS) && (depth == 1)) {
if (result->thread_count == 0) {
ret = LOAD_FAILURE;
}
}
}
printf("parse_machfile 8: %s\n", load_to_string(ret));
return(ret);
}
/*
Loads a Mach-O executable into memory, along with any threads,
stacks, and dylinker.
Returns 0 on success, -1 on any failure.
fd[offset..offset+size) is a Mach-O thin file.
filetype is MH_EXECUTE or MH_DYLINKER.
The mapped but empty stack is returned in *out_stack.
The executable's Mach headers are returned in *out_text.
The executable's entry point is returned in *out_entry.
The dylinker's entry point (if any) is returned in *out_linker_entry.
GrP fixme need to return whether dylinker was found - stack layout is different
*/
static int
load_thin_file(int fd, vki_off_t offset, vki_off_t size, unsigned long filetype,
const char *filename,
vki_uint8_t **out_stack_start, vki_uint8_t **out_stack_end,
vki_uint8_t **out_text, vki_uint8_t **out_entry, vki_uint8_t **out_linker_entry)
{
struct MACH_HEADER mh;
vki_uint8_t *headers;
vki_uint8_t *headers_end;
struct load_command *lc;
struct load_command *lcend;
struct SEGMENT_COMMAND *segcmd;
struct thread_command *threadcmd;
struct dylinker_command *dycmd;
int err;
SysRes res;
vki_size_t len;
vki_uint8_t *stack_start = NULL; // allocated thread stack (hot end)
vki_uint8_t *stack_end = NULL; // allocated thread stack (cold end)
vki_uint8_t *entry = NULL; // static entry point
vki_uint8_t *text = NULL; // start of text segment (i.e. the mach headers)
vki_uint8_t *linker_entry = NULL; // dylinker entry point
// Read Mach-O header
if (sizeof(mh) > size) {
print("bad executable (no Mach-O header)\n");
}
res = VG_(pread)(fd, &mh, sizeof(mh), offset);
if (sr_isError(res) || sr_Res(res) != sizeof(mh)) {
print("bad executable (no Mach-O header)\n");
return -1;
}
// Sanity-check the header itself
if (mh.magic != MAGIC) {
print("bad executable (no Mach-O magic)\n");
return -1;
}
if (mh.filetype != filetype) {
// expecting MH_EXECUTE or MH_DYLINKER
print("bad executable (wrong file type)\n");
return -1;
}
// Map all headers into memory
len = sizeof(mh) + mh.sizeofcmds;
if (len > size) {
print("bad executable (missing load commands)\n");
return -1;
}
headers = VG_(malloc)("ume.macho.headers", len);
res = VG_(pread)(fd, headers, len, offset);
if (sr_isError(res)) {
print("couldn't read load commands from executable\n");
return -1;
}
headers_end = headers + len;
// Map some segments into client memory:
// LC_SEGMENT (text, data, etc)
// UNIXSTACK (stack)
// LOAD_DYLINKER (dyld)
lcend = (struct load_command *)(headers + mh.sizeofcmds + sizeof(mh));
for (lc = (struct load_command *)(headers + sizeof(mh));
lc < lcend;
lc = (struct load_command *)(lc->cmdsize + (vki_uint8_t *)lc))
{
if ((vki_uint8_t *)lc < headers ||
lc->cmdsize+(vki_uint8_t *)lc > headers_end) {
print("bad executable (invalid load commands)\n");
return -1;
}
switch (lc->cmd) {
case LC_SEGMENT_CMD:
if (lc->cmdsize < sizeof(struct SEGMENT_COMMAND)) {
print("bad executable (invalid load commands)\n");
return -1;
}
segcmd = (struct SEGMENT_COMMAND *)lc;
err = load_segment(fd, offset, size, &text, &stack_start,
segcmd, filename);
if (err) return -1;
break;
case LC_UNIXTHREAD:
if (stack_end || entry) {
print("bad executable (multiple thread commands)\n");
return -1;
}
if (lc->cmdsize < sizeof(struct thread_command)) {
print("bad executable (invalid load commands)\n");
return -1;
}
threadcmd = (struct thread_command *)lc;
err = load_unixthread(&stack_start, &stack_end, &entry, threadcmd);
if (err) return -1;
break;
case LC_LOAD_DYLINKER:
if (filetype == MH_DYLINKER) {
print("bad executable (dylinker needs a dylinker)\n");
return -1;
}
if (linker_entry) {
print("bad executable (multiple dylinker commands)\n");
}
if (lc->cmdsize < sizeof(struct dylinker_command)) {
print("bad executable (invalid load commands)\n");
return -1;
}
dycmd = (struct dylinker_command *)lc;
err = load_dylinker(&linker_entry, dycmd);
if (err) return -1;
break;
case LC_THREAD:
if (filetype == MH_EXECUTE) {
print("bad executable (stackless thread)\n");
return -1;
}
if (stack_end || entry) {
print("bad executable (multiple thread commands)\n");
return -1;
}
if (lc->cmdsize < sizeof(struct thread_command)) {
print("bad executable (invalid load commands)\n");
return -1;
}
threadcmd = (struct thread_command *)lc;
err = load_thread(&entry, threadcmd);
if (err) return -1;
break;
default:
break;
}
}
// Done with the headers
VG_(free)(headers);
if (filetype == MH_EXECUTE) {
// Verify the necessary pieces for an executable:
// a stack
// a text segment
// an entry point (static or linker)
if (!stack_end || !stack_start) {
print("bad executable (no stack)\n");
return -1;
}
if (!text) {
print("bad executable (no text segment)\n");
return -1;
}
if (!entry && !linker_entry) {
print("bad executable (no entry point)\n");
return -1;
}
}
else if (filetype == MH_DYLINKER) {
// Verify the necessary pieces for a dylinker:
// an entry point
if (!entry) {
print("bad executable (no entry point)\n");
return -1;
}
}
if (out_stack_start) *out_stack_start = stack_start;
if (out_stack_end) *out_stack_end = stack_end;
if (out_text) *out_text = text;
if (out_entry) *out_entry = entry;
if (out_linker_entry) *out_linker_entry = linker_entry;
return 0;
}
/*
* The file size of a mach-o file is limited to 32 bits; this is because
* this is the limit on the kalloc() of enough bytes for a mach_header and
* the contents of its sizeofcmds, which is currently constrained to 32
* bits in the file format itself. We read into the kernel buffer the
* commands section, and then parse it in order to parse the mach-o file
* format load_command segment(s). We are only interested in a subset of
* the total set of possible commands. If "map"==VM_MAP_NULL or
* "thread"==THREAD_NULL, do not make permament VM modifications,
* just preflight the parse.
*/
static
load_return_t
parse_machfile(
struct vnode *vp,
vm_map_t map,
thread_t thread,
struct mach_header *header,
off_t file_offset,
off_t macho_size,
int depth,
int64_t aslr_offset,
load_result_t *result
)
{
uint32_t ncmds;
struct load_command *lcp;
struct dylinker_command *dlp = 0;
struct uuid_command *uulp = 0;
integer_t dlarchbits = 0;
void * control;
load_return_t ret = LOAD_SUCCESS;
caddr_t addr;
void * kl_addr;
vm_size_t size,kl_size;
size_t offset;
size_t oldoffset; /* for overflow check */
int pass;
proc_t p = current_proc(); /* XXXX */
int error;
int resid=0;
size_t mach_header_sz = sizeof(struct mach_header);
boolean_t abi64;
boolean_t got_code_signatures = FALSE;
int64_t slide = 0;
if (header->magic == MH_MAGIC_64 ||
header->magic == MH_CIGAM_64) {
mach_header_sz = sizeof(struct mach_header_64);
}
/*
* Break infinite recursion
*/
if (depth > 6) {
return(LOAD_FAILURE);
}
depth++;
/*
* Check to see if right machine type.
*/
if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != cpu_type()) ||
!grade_binary(header->cputype,
header->cpusubtype & ~CPU_SUBTYPE_MASK))
return(LOAD_BADARCH);
abi64 = ((header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64);
switch (header->filetype) {
case MH_OBJECT:
case MH_EXECUTE:
case MH_PRELOAD:
if (depth != 1) {
return (LOAD_FAILURE);
}
break;
case MH_FVMLIB:
case MH_DYLIB:
if (depth == 1) {
return (LOAD_FAILURE);
}
break;
case MH_DYLINKER:
if (depth != 2) {
return (LOAD_FAILURE);
}
break;
default:
return (LOAD_FAILURE);
}
/*
* Get the pager for the file.
*/
control = ubc_getobject(vp, UBC_FLAGS_NONE);
/*
* Map portion that must be accessible directly into
* kernel's map.
*/
if ((off_t)(mach_header_sz + header->sizeofcmds) > macho_size)
return(LOAD_BADMACHO);
/*
* Round size of Mach-O commands up to page boundry.
*/
size = round_page(mach_header_sz + header->sizeofcmds);
if (size <= 0)
return(LOAD_BADMACHO);
/*
* Map the load commands into kernel memory.
*/
addr = 0;
kl_size = size;
kl_addr = kalloc(size);
addr = (caddr_t)kl_addr;
if (addr == NULL)
return(LOAD_NOSPACE);
error = vn_rdwr(UIO_READ, vp, addr, size, file_offset,
UIO_SYSSPACE, 0, kauth_cred_get(), &resid, p);
if (error) {
if (kl_addr )
kfree(kl_addr, kl_size);
return(LOAD_IOERROR);
}
/*
* For PIE and dyld, slide everything by the ASLR offset.
*/
aslr_offset = 0;
if ((header->flags & MH_PIE) || (header->filetype == MH_DYLINKER)) {
slide = aslr_offset;
}
/*
* Scan through the commands, processing each one as necessary.
*/
for (pass = 1; pass <= 3; pass++) {
/*
* Check that the entry point is contained in an executable segments
*/
if ((pass == 3) && (result->validentry == 0)) {
thread_state_initialize(thread);
ret = LOAD_FAILURE;
break;
}
/*
* Loop through each of the load_commands indicated by the
* Mach-O header; if an absurd value is provided, we just
* run off the end of the reserved section by incrementing
* the offset too far, so we are implicitly fail-safe.
*/
offset = mach_header_sz;
ncmds = header->ncmds;
while (ncmds--) {
/*
* Get a pointer to the command.
*/
lcp = (struct load_command *)(addr + offset);
oldoffset = offset;
offset += lcp->cmdsize;
/*
* Perform prevalidation of the struct load_command
* before we attempt to use its contents. Invalid
* values are ones which result in an overflow, or
* which can not possibly be valid commands, or which
* straddle or exist past the reserved section at the
* start of the image.
*/
if (oldoffset > offset ||
lcp->cmdsize < sizeof(struct load_command) ||
offset > header->sizeofcmds + mach_header_sz) {
ret = LOAD_BADMACHO;
break;
}
/*
* Act on struct load_command's for which kernel
* intervention is required.
*/
switch(lcp->cmd) {
case LC_SEGMENT:
case LC_SEGMENT_64:
if (pass != 2)
break;
ret = load_segment(lcp,
header->filetype,
control,
file_offset,
macho_size,
vp,
map,
slide,
result);
break;
case LC_UNIXTHREAD:
if (pass != 1)
break;
ret = load_unixthread(
(struct thread_command *) lcp,
thread,
slide,
result);
break;
case LC_MAIN:
if (pass != 1)
break;
if (depth != 1)
break;
ret = load_main(
(struct entry_point_command *) lcp,
thread,
slide,
result);
break;
case LC_LOAD_DYLINKER:
if (pass != 3)
break;
if ((depth == 1) && (dlp == 0)) {
dlp = (struct dylinker_command *)lcp;
dlarchbits = (header->cputype & CPU_ARCH_MASK);
} else {
ret = LOAD_FAILURE;
}
break;
case LC_UUID:
if (pass == 1 && depth == 1) {
uulp = (struct uuid_command *)lcp;
memcpy(&result->uuid[0], &uulp->uuid[0], sizeof(result->uuid));
}
break;
case LC_CODE_SIGNATURE:
/* CODE SIGNING */
if (pass != 1)
break;
/* pager -> uip ->
load signatures & store in uip
set VM object "signed_pages"
*/
ret = load_code_signature(
(struct linkedit_data_command *) lcp,
vp,
file_offset,
macho_size,
header->cputype,
(depth == 1) ? result : NULL);
if (ret != LOAD_SUCCESS) {
printf("proc %d: load code signature error %d "
"for file \"%s\"\n",
p->p_pid, ret, vp->v_name);
ret = LOAD_SUCCESS; /* ignore error */
} else {
got_code_signatures = TRUE;
}
break;
#if CONFIG_CODE_DECRYPTION
#ifndef __arm__
case LC_ENCRYPTION_INFO:
if (pass != 3)
break;
ret = set_code_unprotect(
(struct encryption_info_command *) lcp,
addr, map, slide, vp);
if (ret != LOAD_SUCCESS) {
printf("proc %d: set_code_unprotect() error %d "
"for file \"%s\"\n",
p->p_pid, ret, vp->v_name);
/* Don't let the app run if it's
* encrypted but we failed to set up the
* decrypter */
psignal(p, SIGKILL);
}
break;
#endif
#endif
default:
/* Other commands are ignored by the kernel */
ret = LOAD_SUCCESS;
break;
}
if (ret != LOAD_SUCCESS)
break;
}
if (ret != LOAD_SUCCESS)
break;
}
if (ret == LOAD_SUCCESS) {
if (! got_code_signatures) {
struct cs_blob *blob;
/* no embedded signatures: look for detached ones */
blob = ubc_cs_blob_get(vp, -1, file_offset);
if (blob != NULL) {
/* get flags to be applied to the process */
result->csflags |= blob->csb_flags;
}
}
/* Make sure if we need dyld, we got it */
if (result->needs_dynlinker && !dlp) {
ret = LOAD_FAILURE;
}
if ((ret == LOAD_SUCCESS) && (dlp != 0)) {
/* load the dylinker, and always slide it by the ASLR
* offset regardless of PIE */
ret = load_dylinker(dlp, dlarchbits, map, thread, depth, aslr_offset, result);
}
if((ret == LOAD_SUCCESS) && (depth == 1)) {
if (result->thread_count == 0) {
ret = LOAD_FAILURE;
}
}
}
if (kl_addr )
kfree(kl_addr, kl_size);
return(ret);
}
/*
* The file size of a mach-o file is limited to 32 bits; this is because
* this is the limit on the kalloc() of enough bytes for a mach_header and
* the contents of its sizeofcmds, which is currently constrained to 32
* bits in the file format itself. We read into the kernel buffer the
* commands section, and then parse it in order to parse the mach-o file
* format load_command segment(s). We are only interested in a subset of
* the total set of possible commands.
*/
static
load_return_t
parse_machfile(
struct vnode *vp,
vm_map_t map,
thread_t thread,
struct mach_header *header,
off_t file_offset,
off_t macho_size,
int depth,
load_result_t *result
)
{
uint32_t ncmds;
struct load_command *lcp;
struct dylinker_command *dlp = 0;
integer_t dlarchbits = 0;
void * pager;
load_return_t ret = LOAD_SUCCESS;
caddr_t addr;
void * kl_addr;
vm_size_t size,kl_size;
size_t offset;
size_t oldoffset; /* for overflow check */
int pass;
proc_t p = current_proc(); /* XXXX */
int error;
int resid=0;
task_t task;
size_t mach_header_sz = sizeof(struct mach_header);
boolean_t abi64;
boolean_t got_code_signatures = FALSE;
if (header->magic == MH_MAGIC_64 ||
header->magic == MH_CIGAM_64) {
mach_header_sz = sizeof(struct mach_header_64);
}
/*
* Break infinite recursion
*/
if (depth > 6) {
return(LOAD_FAILURE);
}
task = (task_t)get_threadtask(thread);
depth++;
/*
* Check to see if right machine type.
*/
if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != cpu_type()) ||
!grade_binary(header->cputype,
header->cpusubtype & ~CPU_SUBTYPE_MASK))
return(LOAD_BADARCH);
abi64 = ((header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64);
switch (header->filetype) {
case MH_OBJECT:
case MH_EXECUTE:
case MH_PRELOAD:
if (depth != 1) {
return (LOAD_FAILURE);
}
break;
case MH_FVMLIB:
case MH_DYLIB:
if (depth == 1) {
return (LOAD_FAILURE);
}
break;
case MH_DYLINKER:
if (depth != 2) {
return (LOAD_FAILURE);
}
break;
default:
return (LOAD_FAILURE);
}
/*
* Get the pager for the file.
*/
pager = (void *) ubc_getpager(vp);
/*
* Map portion that must be accessible directly into
* kernel's map.
*/
if ((mach_header_sz + header->sizeofcmds) > macho_size)
return(LOAD_BADMACHO);
/*
* Round size of Mach-O commands up to page boundry.
*/
size = round_page(mach_header_sz + header->sizeofcmds);
if (size <= 0)
return(LOAD_BADMACHO);
/*
* Map the load commands into kernel memory.
*/
addr = 0;
kl_size = size;
kl_addr = kalloc(size);
addr = (caddr_t)kl_addr;
if (addr == NULL)
return(LOAD_NOSPACE);
error = vn_rdwr(UIO_READ, vp, addr, size, file_offset,
UIO_SYSSPACE32, 0, kauth_cred_get(), &resid, p);
if (error) {
if (kl_addr )
kfree(kl_addr, kl_size);
return(LOAD_IOERROR);
}
/* (void)ubc_map(vp, PROT_EXEC); */ /* NOT HERE */
/*
* Scan through the commands, processing each one as necessary.
*/
for (pass = 1; pass <= 2; pass++) {
/*
* Loop through each of the load_commands indicated by the
* Mach-O header; if an absurd value is provided, we just
* run off the end of the reserved section by incrementing
* the offset too far, so we are implicitly fail-safe.
*/
offset = mach_header_sz;
ncmds = header->ncmds;
while (ncmds--) {
/*
* Get a pointer to the command.
*/
lcp = (struct load_command *)(addr + offset);
oldoffset = offset;
offset += lcp->cmdsize;
/*
* Perform prevalidation of the struct load_command
* before we attempt to use its contents. Invalid
* values are ones which result in an overflow, or
* which can not possibly be valid commands, or which
* straddle or exist past the reserved section at the
* start of the image.
*/
if (oldoffset > offset ||
lcp->cmdsize < sizeof(struct load_command) ||
offset > header->sizeofcmds + mach_header_sz) {
ret = LOAD_BADMACHO;
break;
}
/*
* Act on struct load_command's for which kernel
* intervention is required.
*/
switch(lcp->cmd) {
case LC_SEGMENT_64:
if (pass != 1)
break;
ret = load_segment_64(
(struct segment_command_64 *)lcp,
pager,
file_offset,
macho_size,
ubc_getsize(vp),
map,
result);
break;
case LC_SEGMENT:
if (pass != 1)
break;
ret = load_segment(
(struct segment_command *) lcp,
pager,
file_offset,
macho_size,
ubc_getsize(vp),
map,
result);
break;
case LC_THREAD:
if (pass != 2)
break;
ret = load_thread((struct thread_command *)lcp,
thread,
result);
break;
case LC_UNIXTHREAD:
if (pass != 2)
break;
ret = load_unixthread(
(struct thread_command *) lcp,
thread,
result);
break;
case LC_LOAD_DYLINKER:
if (pass != 2)
break;
if ((depth == 1) && (dlp == 0)) {
dlp = (struct dylinker_command *)lcp;
dlarchbits = (header->cputype & CPU_ARCH_MASK);
} else {
ret = LOAD_FAILURE;
}
break;
case LC_CODE_SIGNATURE:
/* CODE SIGNING */
if (pass != 2)
break;
/* pager -> uip ->
load signatures & store in uip
set VM object "signed_pages"
*/
ret = load_code_signature(
(struct linkedit_data_command *) lcp,
vp,
file_offset,
macho_size,
header->cputype,
(depth == 1) ? result : NULL);
if (ret != LOAD_SUCCESS) {
printf("proc %d: load code signature error %d "
"for file \"%s\"\n",
p->p_pid, ret, vp->v_name);
ret = LOAD_SUCCESS; /* ignore error */
} else {
got_code_signatures = TRUE;
}
break;
default:
/* Other commands are ignored by the kernel */
ret = LOAD_SUCCESS;
break;
}
if (ret != LOAD_SUCCESS)
break;
}
if (ret != LOAD_SUCCESS)
break;
}
if (ret == LOAD_SUCCESS) {
if (! got_code_signatures) {
struct cs_blob *blob;
/* no embedded signatures: look for detached ones */
blob = ubc_cs_blob_get(vp, -1, file_offset);
if (blob != NULL) {
/* get flags to be applied to the process */
result->csflags |= blob->csb_flags;
}
}
if (dlp != 0)
ret = load_dylinker(dlp, dlarchbits, map, thread, depth, result, abi64);
if(depth == 1) {
if (result->thread_count == 0) {
ret = LOAD_FAILURE;
} else if ( abi64 ) {
#ifdef __ppc__
/* Map in 64-bit commpage */
/* LP64todo - make this clean */
/*
* PPC51: ppc64 is limited to 51-bit addresses.
* Memory above that limit is handled specially
* at the pmap level.
*/
pmap_map_sharedpage(current_task(), get_map_pmap(map));
#endif /* __ppc__ */
}
}
}
if (kl_addr )
kfree(kl_addr, kl_size);
if (ret == LOAD_SUCCESS)
(void)ubc_map(vp, PROT_READ | PROT_EXEC);
return(ret);
}
