qemu-e2k/hw/i386/multiboot.c
Philippe Mathieu-Daudé fa87341dab hw/i386/multiboot: Avoid dynamic stack allocation
Use autofree heap allocation instead of variable-length array on
the stack. Replace the snprintf() call by g_strdup_printf().

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20220819153931.3147384-9-peter.maydell@linaro.org
2022-09-22 16:38:28 +01:00

415 lines
14 KiB
C

/*
* 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 "qemu/osdep.h"
#include "qemu/option.h"
#include "cpu.h"
#include "hw/nvram/fw_cfg.h"
#include "multiboot.h"
#include "hw/loader.h"
#include "elf.h"
#include "sysemu/sysemu.h"
#include "qemu/error-report.h"
/* Show multiboot debug output */
//#define DEBUG_MULTIBOOT
#ifdef DEBUG_MULTIBOOT
#define mb_debug(a...) error_report(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_BOOTLOADER = 64,
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,
MULTIBOOT_FLAGS_BOOTLOADER = 1 << 9,
};
typedef struct {
/* buffer holding kernel, cmdlines and mb_infos */
void *mb_buf;
/* address in target */
hwaddr mb_buf_phys;
/* size of mb_buf in bytes */
unsigned mb_buf_size;
/* offset of mb-info's in bytes */
hwaddr offset_mbinfo;
/* offset in buffer for cmdlines in bytes */
hwaddr offset_cmdlines;
/* offset in buffer for bootloader name in bytes */
hwaddr offset_bootloader;
/* offset of modules in bytes */
hwaddr offset_mods;
/* available slots for mb modules infos */
int mb_mods_avail;
/* currently used slots of mb modules */
int mb_mods_count;
} MultibootState;
const char *bootloader_name = "qemu";
static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)
{
hwaddr p = s->offset_cmdlines;
char *b = (char *)s->mb_buf + p;
memcpy(b, cmdline, strlen(cmdline) + 1);
s->offset_cmdlines += strlen(b) + 1;
return s->mb_buf_phys + p;
}
static uint32_t mb_add_bootloader(MultibootState *s, const char *bootloader)
{
hwaddr p = s->offset_bootloader;
char *b = (char *)s->mb_buf + p;
memcpy(b, bootloader, strlen(bootloader) + 1);
s->offset_bootloader += strlen(b) + 1;
return s->mb_buf_phys + p;
}
static void mb_add_mod(MultibootState *s,
hwaddr start, hwaddr end,
hwaddr 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,
s->mb_mods_count, start, end);
s->mb_mods_count++;
}
int load_multiboot(X86MachineState *x86ms,
FWCfgState *fw_cfg,
FILE *f,
const char *kernel_filename,
const char *initrd_filename,
const char *kernel_cmdline,
int kernel_file_size,
uint8_t *header)
{
bool multiboot_dma_enabled = X86_MACHINE_GET_CLASS(x86ms)->fwcfg_dma_enabled;
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;
uint32_t cmdline_len;
GList *mods = NULL;
g_autofree char *kcmdline = NULL;
/* 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("I believe we found a multiboot image!");
memset(bootinfo, 0, sizeof(bootinfo));
memset(&mbs, 0, sizeof(mbs));
if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
error_report("multiboot knows VBE. we don't");
}
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) {
error_report("Cannot load x86-64 image, give a 32bit one.");
exit(1);
}
kernel_size = load_elf(kernel_filename, NULL, NULL, NULL, &elf_entry,
&elf_low, &elf_high, NULL, 0, I386_ELF_MACHINE,
0, 0);
if (kernel_size < 0) {
error_report("Error while loading elf kernel");
exit(1);
}
mh_load_addr = elf_low;
mb_kernel_size = elf_high - elf_low;
mh_entry_addr = elf_entry;
mbs.mb_buf = g_malloc(mb_kernel_size);
if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
error_report("Error while fetching elf kernel from rom");
exit(1);
}
mb_debug("loading multiboot-elf kernel "
"(%#x bytes) with entry %#zx",
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);
uint32_t mh_load_end_addr = ldl_p(header+i+20);
uint32_t mh_bss_end_addr = ldl_p(header+i+24);
mh_load_addr = ldl_p(header+i+16);
if (mh_header_addr < mh_load_addr) {
error_report("invalid load_addr address");
exit(1);
}
if (mh_header_addr - mh_load_addr > i) {
error_report("invalid header_addr address");
exit(1);
}
uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
uint32_t mb_load_size = 0;
mh_entry_addr = ldl_p(header+i+28);
if (mh_load_end_addr) {
if (mh_load_end_addr < mh_load_addr) {
error_report("invalid load_end_addr address");
exit(1);
}
mb_load_size = mh_load_end_addr - mh_load_addr;
} else {
if (kernel_file_size < mb_kernel_text_offset) {
error_report("invalid kernel_file_size");
exit(1);
}
mb_load_size = kernel_file_size - mb_kernel_text_offset;
}
if (mb_load_size > UINT32_MAX - mh_load_addr) {
error_report("kernel does not fit in address space");
exit(1);
}
if (mh_bss_end_addr) {
if (mh_bss_end_addr < (mh_load_addr + mb_load_size)) {
error_report("invalid bss_end_addr address");
exit(1);
}
mb_kernel_size = mh_bss_end_addr - mh_load_addr;
} else {
mb_kernel_size = mb_load_size;
}
mb_debug("multiboot: header_addr = %#x", mh_header_addr);
mb_debug("multiboot: load_addr = %#x", mh_load_addr);
mb_debug("multiboot: load_end_addr = %#x", mh_load_end_addr);
mb_debug("multiboot: bss_end_addr = %#x", mh_bss_end_addr);
mb_debug("loading multiboot kernel (%#x bytes) at %#x",
mb_load_size, mh_load_addr);
mbs.mb_buf = g_malloc(mb_kernel_size);
fseek(f, mb_kernel_text_offset, SEEK_SET);
if (fread(mbs.mb_buf, 1, mb_load_size, f) != mb_load_size) {
error_report("fread() failed");
exit(1);
}
memset(mbs.mb_buf + mb_load_size, 0, mb_kernel_size - mb_load_size);
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, bootloader name, and mb_mods */
cmdline_len = strlen(kernel_filename) + 1;
cmdline_len += strlen(kernel_cmdline) + 1;
if (initrd_filename) {
const char *r = initrd_filename;
cmdline_len += strlen(initrd_filename) + 1;
while (*r) {
char *value;
r = get_opt_value(r, &value);
mbs.mb_mods_avail++;
mods = g_list_append(mods, value);
if (*r) {
r++;
}
}
}
mbs.mb_buf_size += cmdline_len;
mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
mbs.mb_buf_size += strlen(bootloader_name) + 1;
mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
/* enlarge mb_buf to hold cmdlines, bootloader, mb-info structs */
mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
mbs.offset_cmdlines = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
mbs.offset_bootloader = mbs.offset_cmdlines + cmdline_len;
if (mods) {
GList *tmpl = mods;
mbs.offset_mods = mbs.mb_buf_size;
while (tmpl) {
char *next_space;
int mb_mod_length;
uint32_t offs = mbs.mb_buf_size;
char *one_file = tmpl->data;
/* if a space comes after the module filename, treat everything
after that as parameters */
hwaddr c = mb_add_cmdline(&mbs, one_file);
next_space = strchr(one_file, ' ');
if (next_space) {
*next_space = '\0';
}
mb_debug("multiboot loading module: %s", one_file);
mb_mod_length = get_image_size(one_file);
if (mb_mod_length < 0) {
error_report("Failed to open file '%s'", one_file);
exit(1);
}
mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
if (load_image_size(one_file, (unsigned char *)mbs.mb_buf + offs,
mbs.mb_buf_size - offs) < 0) {
error_report("Error loading file '%s'", one_file);
exit(1);
}
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,
(char *)mbs.mb_buf + offs,
(char *)mbs.mb_buf + offs + mb_mod_length, c);
g_free(one_file);
tmpl = tmpl->next;
}
g_list_free(mods);
}
/* Commandline support */
kcmdline = g_strdup_printf("%s %s", kernel_filename, kernel_cmdline);
stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));
stl_p(bootinfo + MBI_BOOTLOADER, mb_add_bootloader(&mbs, bootloader_name));
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
| MULTIBOOT_FLAGS_BOOTLOADER);
stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8000ffff); /* XXX: use the -boot switch? */
stl_p(bootinfo + MBI_MMAP_ADDR, ADDR_E820_MAP);
mb_debug("multiboot: entry_addr = %#x", mh_entry_addr);
mb_debug(" mb_buf_phys = "TARGET_FMT_plx, mbs.mb_buf_phys);
mb_debug(" mod_start = "TARGET_FMT_plx,
mbs.mb_buf_phys + mbs.offset_mods);
mb_debug(" mb_mods_count = %d", mbs.mb_mods_count);
/* save bootinfo off the stack */
mb_bootinfo_data = g_memdup(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));
if (multiboot_dma_enabled) {
option_rom[nb_option_roms].name = "multiboot_dma.bin";
} else {
option_rom[nb_option_roms].name = "multiboot.bin";
}
option_rom[nb_option_roms].bootindex = 0;
nb_option_roms++;
return 1; /* yes, we are multiboot */
}