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qemu/hw/multiboot.c
Adam Lackorzynski 9696846600 multiboot: Prevent loading of x86_64 images 
A via -kernel supplied x86_64 ELF image is being started in 32bit mode.
Detect and exit if a 64bit image has been supplied.

Signed-off-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-11-16 09:31:18 -06:00

339 lines
12 KiB
C
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/*
* QEMU PC System Emulator
*
* Copyright (c) 2003-2004 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "hw.h"
#include "fw_cfg.h"
#include "multiboot.h"
#include "loader.h"
#include "elf.h"
#include "sysemu.h"
/* Show multiboot debug output */
//#define DEBUG_MULTIBOOT
#ifdef DEBUG_MULTIBOOT
#define mb_debug(a...) fprintf(stderr, ## a)
#else
#define mb_debug(a...)
#endif
#define MULTIBOOT_STRUCT_ADDR 0x9000
#if MULTIBOOT_STRUCT_ADDR > 0xf0000
#error multiboot struct needs to fit in 16 bit real mode
#endif
enum {
/* Multiboot info */
MBI_FLAGS = 0,
MBI_MEM_LOWER = 4,
MBI_MEM_UPPER = 8,
MBI_BOOT_DEVICE = 12,
MBI_CMDLINE = 16,
MBI_MODS_COUNT = 20,
MBI_MODS_ADDR = 24,
MBI_MMAP_ADDR = 48,
MBI_SIZE = 88,
/* Multiboot modules */
MB_MOD_START = 0,
MB_MOD_END = 4,
MB_MOD_CMDLINE = 8,
MB_MOD_SIZE = 16,
/* Region offsets */
ADDR_E820_MAP = MULTIBOOT_STRUCT_ADDR + 0,
ADDR_MBI = ADDR_E820_MAP + 0x500,
/* Multiboot flags */
MULTIBOOT_FLAGS_MEMORY = 1 << 0,
MULTIBOOT_FLAGS_BOOT_DEVICE = 1 << 1,
MULTIBOOT_FLAGS_CMDLINE = 1 << 2,
MULTIBOOT_FLAGS_MODULES = 1 << 3,
MULTIBOOT_FLAGS_MMAP = 1 << 6,
};
typedef struct {
/* buffer holding kernel, cmdlines and mb_infos */
void *mb_buf;
/* address in target */
target_phys_addr_t mb_buf_phys;
/* size of mb_buf in bytes */
unsigned mb_buf_size;
/* offset of mb-info's in bytes */
target_phys_addr_t offset_mbinfo;
/* offset in buffer for cmdlines in bytes */
target_phys_addr_t offset_cmdlines;
/* offset of modules in bytes */
target_phys_addr_t offset_mods;
/* available slots for mb modules infos */
int mb_mods_avail;
/* currently used slots of mb modules */
int mb_mods_count;
} MultibootState;
static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)
{
int len = strlen(cmdline) + 1;
target_phys_addr_t p = s->offset_cmdlines;
pstrcpy((char *)s->mb_buf + p, len, cmdline);
s->offset_cmdlines += len;
return s->mb_buf_phys + p;
}
static void mb_add_mod(MultibootState *s,
target_phys_addr_t start, target_phys_addr_t end,
target_phys_addr_t cmdline_phys)
{
char *p;
assert(s->mb_mods_count < s->mb_mods_avail);
p = (char *)s->mb_buf + s->offset_mbinfo + MB_MOD_SIZE * s->mb_mods_count;
stl_p(p + MB_MOD_START, start);
stl_p(p + MB_MOD_END, end);
stl_p(p + MB_MOD_CMDLINE, cmdline_phys);
mb_debug("mod%02d: "TARGET_FMT_plx" - "TARGET_FMT_plx"\n",
s->mb_mods_count, start, end);
s->mb_mods_count++;
}
int load_multiboot(void *fw_cfg,
FILE *f,
const char *kernel_filename,
const char *initrd_filename,
const char *kernel_cmdline,
int kernel_file_size,
uint8_t *header)
{
int i, is_multiboot = 0;
uint32_t flags = 0;
uint32_t mh_entry_addr;
uint32_t mh_load_addr;
uint32_t mb_kernel_size;
MultibootState mbs;
uint8_t bootinfo[MBI_SIZE];
uint8_t *mb_bootinfo_data;
/* Ok, let's see if it is a multiboot image.
The header is 12x32bit long, so the latest entry may be 8192 - 48. */
for (i = 0; i < (8192 - 48); i += 4) {
if (ldl_p(header+i) == 0x1BADB002) {
uint32_t checksum = ldl_p(header+i+8);
flags = ldl_p(header+i+4);
checksum += flags;
checksum += (uint32_t)0x1BADB002;
if (!checksum) {
is_multiboot = 1;
break;
}
}
}
if (!is_multiboot)
return 0; /* no multiboot */
mb_debug("qemu: I believe we found a multiboot image!\n");
memset(bootinfo, 0, sizeof(bootinfo));
memset(&mbs, 0, sizeof(mbs));
if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
fprintf(stderr, "qemu: multiboot knows VBE. we don't.\n");
}
if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */
uint64_t elf_entry;
uint64_t elf_low, elf_high;
int kernel_size;
fclose(f);
if (((struct elf64_hdr*)header)->e_machine == EM_X86_64) {
fprintf(stderr, "Cannot load x86-64 image, give a 32bit one.\n");
exit(1);
}
kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry,
&elf_low, &elf_high, 0, ELF_MACHINE, 0);
if (kernel_size < 0) {
fprintf(stderr, "Error while loading elf kernel\n");
exit(1);
}
mh_load_addr = elf_low;
mb_kernel_size = elf_high - elf_low;
mh_entry_addr = elf_entry;
mbs.mb_buf = qemu_malloc(mb_kernel_size);
if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
fprintf(stderr, "Error while fetching elf kernel from rom\n");
exit(1);
}
mb_debug("qemu: loading multiboot-elf kernel (%#x bytes) with entry %#zx\n",
mb_kernel_size, (size_t)mh_entry_addr);
} else {
/* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
uint32_t mh_header_addr = ldl_p(header+i+12);
mh_load_addr = ldl_p(header+i+16);
uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
mh_entry_addr = ldl_p(header+i+28);
mb_kernel_size = kernel_file_size - mb_kernel_text_offset;
/* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_VBE.
uint32_t mh_mode_type = ldl_p(header+i+32);
uint32_t mh_width = ldl_p(header+i+36);
uint32_t mh_height = ldl_p(header+i+40);
uint32_t mh_depth = ldl_p(header+i+44); */
mb_debug("multiboot: mh_header_addr = %#x\n", mh_header_addr);
mb_debug("multiboot: mh_load_addr = %#x\n", mh_load_addr);
mb_debug("multiboot: mh_load_end_addr = %#x\n", ldl_p(header+i+20));
mb_debug("multiboot: mh_bss_end_addr = %#x\n", ldl_p(header+i+24));
mb_debug("qemu: loading multiboot kernel (%#x bytes) at %#x\n",
mb_kernel_size, mh_load_addr);
mbs.mb_buf = qemu_malloc(mb_kernel_size);
fseek(f, mb_kernel_text_offset, SEEK_SET);
if (fread(mbs.mb_buf, 1, mb_kernel_size, f) != mb_kernel_size) {
fprintf(stderr, "fread() failed\n");
exit(1);
}
fclose(f);
}
mbs.mb_buf_phys = mh_load_addr;
mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
mbs.offset_mbinfo = mbs.mb_buf_size;
/* Calculate space for cmdlines and mb_mods */
mbs.mb_buf_size += strlen(kernel_filename) + 1;
mbs.mb_buf_size += strlen(kernel_cmdline) + 1;
if (initrd_filename) {
const char *r = initrd_filename;
mbs.mb_buf_size += strlen(r) + 1;
mbs.mb_mods_avail = 1;
while ((r = strchr(r, ','))) {
mbs.mb_mods_avail++;
r++;
}
mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
}
mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
/* enlarge mb_buf to hold cmdlines and mb-info structs */
mbs.mb_buf = qemu_realloc(mbs.mb_buf, mbs.mb_buf_size);
mbs.offset_cmdlines = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
if (initrd_filename) {
char *next_initrd;
mbs.offset_mods = mbs.mb_buf_size;
do {
char *next_space;
int mb_mod_length;
uint32_t offs = mbs.mb_buf_size;
next_initrd = strchr(initrd_filename, ',');
if (next_initrd)
*next_initrd = '\0';
/* if a space comes after the module filename, treat everything
after that as parameters */
target_phys_addr_t c = mb_add_cmdline(&mbs, initrd_filename);
if ((next_space = strchr(initrd_filename, ' ')))
*next_space = '\0';
mb_debug("multiboot loading module: %s\n", initrd_filename);
mb_mod_length = get_image_size(initrd_filename);
if (mb_mod_length < 0) {
fprintf(stderr, "failed to get %s image size\n", initrd_filename);
exit(1);
}
mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
mbs.mb_buf = qemu_realloc(mbs.mb_buf, mbs.mb_buf_size);
load_image(initrd_filename, (unsigned char *)mbs.mb_buf + offs);
mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
mbs.mb_buf_phys + offs + mb_mod_length, c);
mb_debug("mod_start: %p\nmod_end: %p\n cmdline: "TARGET_FMT_plx"\n",
(char *)mbs.mb_buf + offs,
(char *)mbs.mb_buf + offs + mb_mod_length, c);
initrd_filename = next_initrd+1;
} while (next_initrd);
}
/* Commandline support */
char kcmdline[strlen(kernel_filename) + strlen(kernel_cmdline) + 2];
snprintf(kcmdline, sizeof(kcmdline), "%s %s",
kernel_filename, kernel_cmdline);
stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));
stl_p(bootinfo + MBI_MODS_ADDR, mbs.mb_buf_phys + mbs.offset_mbinfo);
stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */
/* the kernel is where we want it to be now */
stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY
| MULTIBOOT_FLAGS_BOOT_DEVICE
| MULTIBOOT_FLAGS_CMDLINE
| MULTIBOOT_FLAGS_MODULES
| MULTIBOOT_FLAGS_MMAP);
stl_p(bootinfo + MBI_MEM_LOWER, 640);
stl_p(bootinfo + MBI_MEM_UPPER, ram_size / 1024);
stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8001ffff); /* XXX: use the -boot switch? */
stl_p(bootinfo + MBI_MMAP_ADDR, ADDR_E820_MAP);
mb_debug("multiboot: mh_entry_addr = %#x\n", mh_entry_addr);
mb_debug(" mb_buf_phys = "TARGET_FMT_plx"\n", mbs.mb_buf_phys);
mb_debug(" mod_start = "TARGET_FMT_plx"\n", mbs.mb_buf_phys + mbs.offset_mods);
mb_debug(" mb_mods_count = %d\n", mbs.mb_mods_count);
/* save bootinfo off the stack */
mb_bootinfo_data = qemu_malloc(sizeof(bootinfo));
memcpy(mb_bootinfo_data, bootinfo, sizeof(bootinfo));
/* Pass variables to option rom */
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);
fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,
mbs.mb_buf, mbs.mb_buf_size);
fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);
fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
sizeof(bootinfo));
option_rom[nb_option_roms] = "multiboot.bin";
nb_option_roms++;
return 1; /* yes, we are multiboot */
}
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