gems-kernel/source/THIRDPARTY/xnu/bsd/kern/mach_fat.c
2024-06-03 11:29:39 -05:00

326 lines
10 KiB
C

/*
* Copyright (c) 1991-2015 Apple Computer, Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <vm/vm_kern.h>
#include <mach/kern_return.h>
#include <mach/vm_param.h>
#include <kern/cpu_number.h>
#include <mach-o/fat.h>
#include <kern/mach_loader.h>
#include <kern/mach_fat.h>
#include <libkern/OSByteOrder.h>
#include <machine/exec.h>
/**********************************************************************
* Routine: fatfile_getarch()
*
* Function: Locate the architecture-dependant contents of a fat
* file that match this CPU.
*
* Args: header: A pointer to the fat file header.
* size: How large the fat file header is (including fat_arch array)
* req_cpu_type: The required cpu type.
* mask_bits: Bits to mask from the sub-image type when
* grading it vs. the req_cpu_type
* imgp: Image params
* archret (out): Pointer to fat_arch structure to hold
* the results.
*
* Returns: KERN_SUCCESS: Valid architecture found.
* KERN_FAILURE: No valid architecture found.
**********************************************************************/
static load_return_t
fatfile_getarch(
vm_offset_t data_ptr,
vm_size_t data_size,
cpu_type_t req_cpu_type,
cpu_type_t mask_bits,
cpu_subtype_t req_subcpu_type,
struct image_params *imgp,
struct fat_arch *archret)
{
load_return_t lret;
struct fat_arch *arch;
struct fat_arch *best_arch;
int grade;
int best_grade;
size_t nfat_arch, max_nfat_arch;
cpu_type_t testtype;
cpu_subtype_t testsubtype;
cpu_subtype_t testfeatures;
struct fat_header *header;
if (sizeof(struct fat_header) > data_size) {
return LOAD_FAILURE;
}
header = (struct fat_header *)data_ptr;
nfat_arch = OSSwapBigToHostInt32(header->nfat_arch);
max_nfat_arch = (data_size - sizeof(struct fat_header)) / sizeof(struct fat_arch);
if (nfat_arch > max_nfat_arch) {
/* nfat_arch would cause us to read off end of buffer */
return LOAD_BADMACHO;
}
/*
* Scan the fat_arch's looking for the best one. */
best_arch = NULL;
best_grade = 0;
arch = (struct fat_arch *) (data_ptr + sizeof(struct fat_header));
for (; nfat_arch-- > 0; arch++) {
testtype = OSSwapBigToHostInt32(arch->cputype);
testsubtype = OSSwapBigToHostInt32(arch->cpusubtype) & ~CPU_SUBTYPE_MASK;
testfeatures = OSSwapBigToHostInt32(arch->cpusubtype) & CPU_SUBTYPE_MASK;
/*
* Check to see if right cpu/subcpu type.
*/
if (!binary_match(mask_bits, req_cpu_type, req_subcpu_type, testtype, testsubtype)) {
continue;
}
/*
* Get the grade of the cpu subtype
*/
grade = grade_binary(testtype, testsubtype, testfeatures, TRUE);
/*
* Remember it if it's the best we've seen.
*/
if (grade > best_grade) {
best_grade = grade;
best_arch = arch;
}
}
/* On X86_64, allow 32 bit exec only for simulator binaries.
* Failing here without re-running the grading algorithm is safe because i386
* has the lowest possible grade value (so there can't be a lower best grade
* that would be allowed if this check denied the i386 slice). */
if (best_arch != NULL &&
validate_potential_simulator_binary(OSSwapBigToHostInt32(best_arch->cputype),
imgp, OSSwapBigToHostInt32(best_arch->offset),
OSSwapBigToHostInt32(best_arch->size)) != LOAD_SUCCESS) {
best_arch = NULL;
best_grade = 0;
}
/*
* Return our results.
*/
if (best_arch == NULL) {
lret = LOAD_BADARCH;
} else {
archret->cputype =
OSSwapBigToHostInt32(best_arch->cputype);
archret->cpusubtype =
OSSwapBigToHostInt32(best_arch->cpusubtype);
archret->offset =
OSSwapBigToHostInt32(best_arch->offset);
archret->size =
OSSwapBigToHostInt32(best_arch->size);
archret->align =
OSSwapBigToHostInt32(best_arch->align);
lret = LOAD_SUCCESS;
}
/*
* Free the memory we allocated and return.
*/
return lret;
}
load_return_t
fatfile_getbestarch(
vm_offset_t data_ptr,
vm_size_t data_size,
struct image_params *imgp,
struct fat_arch *archret,
__unused bool affinity)
{
int primary_type = cpu_type();
/*
* Ignore all architectural bits when determining if an image
* in a fat file should be skipped or graded.
*/
load_return_t ret = fatfile_getarch(data_ptr, data_size, primary_type, CPU_ARCH_MASK, CPU_SUBTYPE_ANY, imgp, archret);
return ret;
}
load_return_t
fatfile_getbestarch_for_cputype(
cpu_type_t cputype,
cpu_subtype_t cpusubtype,
vm_offset_t data_ptr,
vm_size_t data_size,
struct image_params *imgp,
struct fat_arch *archret)
{
/*
* Scan the fat_arch array for exact matches for this cpu_type_t only
*/
return fatfile_getarch(data_ptr, data_size, cputype, 0, cpusubtype, imgp, archret);
}
/**********************************************************************
* Routine: fatfile_getarch_with_bits()
*
* Function: Locate the architecture-dependant contents of a fat
* file that match this CPU.
*
* Args: vp: The vnode for the fat file.
* archbits: Architecture specific feature bits
* header: A pointer to the fat file header.
* archret (out): Pointer to fat_arch structure to hold
* the results.
*
* Returns: KERN_SUCCESS: Valid architecture found.
* KERN_FAILURE: No valid architecture found.
**********************************************************************/
load_return_t
fatfile_getarch_with_bits(
integer_t archbits,
vm_offset_t data_ptr,
vm_size_t data_size,
struct fat_arch *archret)
{
/*
* Scan the fat_arch array for matches with the requested
* architectural bits set, and for the current hardware cpu CPU.
*/
return fatfile_getarch(data_ptr, data_size, (archbits & CPU_ARCH_MASK) | (cpu_type() & ~CPU_ARCH_MASK), 0, CPU_SUBTYPE_ANY, NULL, archret);
}
/*
* Validate the fat_header and fat_arch array in memory. We check that:
*
* 1) arch count would not exceed the data buffer
* 2) arch list does not contain duplicate cputype/cpusubtype tuples
* 3) arch list does not have two overlapping slices. The area
* at the front of the file containing the fat headers is implicitly
* a range that a slice should also not try to cover
*/
load_return_t
fatfile_validate_fatarches(vm_offset_t data_ptr, vm_size_t data_size, off_t file_size)
{
uint32_t magic;
size_t nfat_arch, max_nfat_arch, i, j;
size_t fat_header_size;
struct fat_arch *arches;
struct fat_header *header;
if (sizeof(struct fat_header) > data_size) {
return LOAD_FAILURE;
}
header = (struct fat_header *)data_ptr;
magic = OSSwapBigToHostInt32(header->magic);
nfat_arch = OSSwapBigToHostInt32(header->nfat_arch);
if (magic != FAT_MAGIC) {
/* must be FAT_MAGIC big endian */
return LOAD_FAILURE;
}
max_nfat_arch = (data_size - sizeof(struct fat_header)) / sizeof(struct fat_arch);
if (nfat_arch > max_nfat_arch) {
/* nfat_arch would cause us to read off end of buffer */
return LOAD_BADMACHO;
}
/* now that we know the fat_arch list fits in the buffer, how much does it use? */
fat_header_size = sizeof(struct fat_header) + nfat_arch * sizeof(struct fat_arch);
arches = (struct fat_arch *)(data_ptr + sizeof(struct fat_header));
for (i = 0; i < nfat_arch; i++) {
uint32_t i_begin = OSSwapBigToHostInt32(arches[i].offset);
uint32_t i_size = OSSwapBigToHostInt32(arches[i].size);
uint32_t i_cputype = OSSwapBigToHostInt32(arches[i].cputype);
uint32_t i_cpusubtype = OSSwapBigToHostInt32(arches[i].cpusubtype);
if (i_begin < fat_header_size) {
/* slice is trying to claim part of the file used by fat headers themselves */
return LOAD_BADMACHO;
}
if ((UINT32_MAX - i_size) < i_begin) {
/* start + size would overflow */
return LOAD_BADMACHO;
}
uint32_t i_end = i_begin + i_size;
if ((off_t)i_end > file_size) {
/* start + size would exceed file size */
return LOAD_BADMACHO;
}
for (j = i + 1; j < nfat_arch; j++) {
uint32_t j_begin = OSSwapBigToHostInt32(arches[j].offset);
uint32_t j_size = OSSwapBigToHostInt32(arches[j].size);
uint32_t j_cputype = OSSwapBigToHostInt32(arches[j].cputype);
uint32_t j_cpusubtype = OSSwapBigToHostInt32(arches[j].cpusubtype);
if ((i_cputype == j_cputype) && (i_cpusubtype == j_cpusubtype)) {
/* duplicate cputype/cpusubtype, results in ambiguous references */
return LOAD_BADMACHO;
}
if ((UINT32_MAX - j_size) < j_begin) {
/* start + size would overflow */
return LOAD_BADMACHO;
}
uint32_t j_end = j_begin + j_size;
if (i_begin <= j_begin) {
if (i_end <= j_begin) {
/* I completely precedes J */
} else {
/* I started before J, but ends somewhere in or after J */
return LOAD_BADMACHO;
}
} else {
if (i_begin >= j_end) {
/* I started after J started but also after J ended */
} else {
/* I started after J started but before it ended, so there is overlap */
return LOAD_BADMACHO;
}
}
}
}
return LOAD_SUCCESS;
}