#include <kern/assert.h>
#include <kern/debug.h>
#include <kern/kext_alloc.h>
#include <kern/misc_protos.h>
#include <mach/host_priv_server.h>
#include <mach/kern_return.h>
#include <mach/mach_vm.h>
#include <mach/vm_map.h>
#include <mach/vm_types.h>
#include <mach-o/loader.h>
#include <libkern/kernel_mach_header.h>
vm_map_t g_kext_map = 0;
static mach_vm_offset_t kext_alloc_base = 0;
static mach_vm_offset_t kext_alloc_max = 0;
void
kext_alloc_init(void)
{
#if __x86_64__
kern_return_t rval = 0;
kernel_segment_command_t *text = NULL;
mach_vm_offset_t text_end, text_start;
mach_vm_size_t text_size;
mach_vm_size_t kext_alloc_size;
text = getsegbyname(SEG_TEXT);
text_start = vm_map_trunc_page(text->vmaddr);
text_start &= ~((512ULL * 1024 * 1024 * 1024) - 1);
text_end = vm_map_round_page(text->vmaddr + text->vmsize);
text_size = text_end - text_start;
kext_alloc_base = KEXT_ALLOC_BASE(text_end);
kext_alloc_size = KEXT_ALLOC_SIZE(text_size);
kext_alloc_max = kext_alloc_base + kext_alloc_size;
rval = kmem_suballoc(kernel_map, (vm_offset_t *) &kext_alloc_base,
kext_alloc_size, TRUE,
VM_FLAGS_FIXED|VM_FLAGS_OVERWRITE,
&g_kext_map);
if (rval != KERN_SUCCESS) {
panic("kext_alloc_init: kmem_suballoc failed 0x%x\n", rval);
}
if ((kext_alloc_base + kext_alloc_size) > kext_alloc_max) {
panic("kext_alloc_init: failed to get first 2GB\n");
}
if (kernel_map->min_offset > kext_alloc_base) {
kernel_map->min_offset = kext_alloc_base;
}
printf("kext submap [0x%llx - 0x%llx], kernel text [0x%llx - 0x%llx]\n",
kext_alloc_base, kext_alloc_max, text->vmaddr,
text->vmaddr + text->vmsize);
#else
g_kext_map = kernel_map;
kext_alloc_base = VM_MIN_KERNEL_ADDRESS;
kext_alloc_max = VM_MAX_KERNEL_ADDRESS;
#endif
}
kern_return_t
kext_alloc(vm_offset_t *_addr, vm_size_t size, boolean_t fixed)
{
kern_return_t rval = 0;
mach_vm_offset_t addr = (fixed) ? *_addr : kext_alloc_base;
int flags = (fixed) ? VM_FLAGS_FIXED : VM_FLAGS_ANYWHERE;
rval = mach_vm_allocate(g_kext_map, &addr, size, flags);
if (rval != KERN_SUCCESS) {
printf("vm_allocate failed - %d\n", rval);
goto finish;
}
if ((addr + size) > kext_alloc_max) {
kext_free((vm_offset_t)addr, size);
goto finish;
}
*_addr = (vm_offset_t)addr;
rval = KERN_SUCCESS;
finish:
return rval;
}
void
kext_free(vm_offset_t addr, vm_size_t size)
{
kern_return_t rval;
rval = mach_vm_deallocate(g_kext_map, addr, size);
assert(rval == KERN_SUCCESS);
}