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Diffstat (limited to 'kexec/arch/i386/kexec-elf-x86.c')
-rw-r--r--kexec/arch/i386/kexec-elf-x86.c331
1 files changed, 331 insertions, 0 deletions
diff --git a/kexec/arch/i386/kexec-elf-x86.c b/kexec/arch/i386/kexec-elf-x86.c
new file mode 100644
index 0000000..8eba242
--- /dev/null
+++ b/kexec/arch/i386/kexec-elf-x86.c
@@ -0,0 +1,331 @@
+/*
+ * kexec: Linux boots Linux
+ *
+ * Copyright (C) 2003-2005 Eric Biederman (ebiederm@xmission.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#define _GNU_SOURCE
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <elf.h>
+#include <x86/x86-linux.h>
+#include "../../kexec.h"
+#include "../../kexec-syscall.h"
+#include "../../kexec-elf.h"
+#include "../../kexec-elf-boot.h"
+#include "x86-linux-setup.h"
+#include "kexec-x86.h"
+#include "crashdump-x86.h"
+#include <arch/options.h>
+
+static const int probe_debug = 0;
+
+int elf_x86_any_probe(const char *buf, off_t len, enum coretype arch)
+{
+
+ struct mem_ehdr ehdr;
+ int result;
+ result = build_elf_exec_info(buf, len, &ehdr, 0);
+ if (result < 0) {
+ if (probe_debug) {
+ fprintf(stderr, "Not an ELF executable\n");
+ }
+ goto out;
+ }
+
+ /* Verify the architecuture specific bits */
+ switch (arch) {
+ case CORE_TYPE_ELF32:
+ if ((ehdr.e_machine != EM_386) && (ehdr.e_machine != EM_486)) {
+ if (probe_debug)
+ fprintf(stderr, "Not i386 ELF executable\n");
+ result = -1;
+ goto out;
+ }
+ break;
+
+ case CORE_TYPE_ELF64:
+ if (ehdr.e_machine != EM_X86_64) {
+ if (probe_debug)
+ fprintf(stderr, "Not x86_64 ELF executable\n");
+ result = -1;
+ goto out;
+ }
+ break;
+
+ case CORE_TYPE_UNDEF:
+ default:
+ if (
+ (ehdr.e_machine != EM_386) &&
+ (ehdr.e_machine != EM_486) &&
+ (ehdr.e_machine != EM_X86_64)
+ ) {
+ if (probe_debug)
+ fprintf(stderr, "Not i386 or x86_64 ELF executable\n");
+ result = -1;
+ goto out;
+ }
+ break;
+ }
+
+ result = 0;
+ out:
+ free_elf_info(&ehdr);
+ return result;
+}
+
+int elf_x86_probe(const char *buf, off_t len) {
+ return elf_x86_any_probe(buf, len, CORE_TYPE_ELF32);
+}
+
+void elf_x86_usage(void)
+{
+ printf( " --command-line=STRING Set the kernel command line to STRING\n"
+ " --append=STRING Set the kernel command line to STRING\n"
+ " --reuse-cmdline Use kernel command line from running system.\n"
+ " --initrd=FILE Use FILE as the kernel's initial ramdisk.\n"
+ " --ramdisk=FILE Use FILE as the kernel's initial ramdisk.\n"
+ " --args-linux Pass linux kernel style options\n"
+ " --args-elf Pass elf boot notes\n"
+ );
+
+
+}
+
+int elf_x86_load(int argc, char **argv, const char *buf, off_t len,
+ struct kexec_info *info)
+{
+ struct mem_ehdr ehdr;
+ char *command_line = NULL, *modified_cmdline = NULL;
+ const char *append = NULL;
+ char *tmp_cmdline = NULL;
+ const char *error_msg = NULL;
+ int result;
+ int command_line_len;
+ const char *ramdisk;
+ unsigned long entry, max_addr;
+ int arg_style;
+#define ARG_STYLE_ELF 0
+#define ARG_STYLE_LINUX 1
+#define ARG_STYLE_NONE 2
+ int opt;
+
+ /* See options.h -- add any more there, too. */
+ static const struct option options[] = {
+ KEXEC_ARCH_OPTIONS
+ { "command-line", 1, NULL, OPT_APPEND },
+ { "append", 1, NULL, OPT_APPEND },
+ { "reuse-cmdline", 0, NULL, OPT_REUSE_CMDLINE },
+ { "initrd", 1, NULL, OPT_RAMDISK },
+ { "ramdisk", 1, NULL, OPT_RAMDISK },
+ { "args-elf", 0, NULL, OPT_ARGS_ELF },
+ { "args-linux", 0, NULL, OPT_ARGS_LINUX },
+ { "args-none", 0, NULL, OPT_ARGS_NONE },
+ { 0, 0, NULL, 0 },
+ };
+
+ static const char short_options[] = KEXEC_OPT_STR "";
+
+ /*
+ * Parse the command line arguments
+ */
+ arg_style = ARG_STYLE_ELF;
+ ramdisk = 0;
+ result = 0;
+ while((opt = getopt_long(argc, argv, short_options, options, 0)) != -1) {
+ switch(opt) {
+ default:
+ /* Ignore core options */
+ if (opt < OPT_ARCH_MAX) {
+ break;
+ }
+ case OPT_APPEND:
+ append = optarg;
+ break;
+ case OPT_REUSE_CMDLINE:
+ tmp_cmdline = get_command_line();
+ break;
+ case OPT_RAMDISK:
+ ramdisk = optarg;
+ break;
+ case OPT_ARGS_ELF:
+ arg_style = ARG_STYLE_ELF;
+ break;
+ case OPT_ARGS_LINUX:
+ arg_style = ARG_STYLE_LINUX;
+ break;
+ case OPT_ARGS_NONE:
+#ifdef __i386__
+ arg_style = ARG_STYLE_NONE;
+#else
+ die("--args-none only works on arch i386\n");
+#endif
+ break;
+ }
+ }
+ command_line = concat_cmdline(tmp_cmdline, append);
+ if (tmp_cmdline) {
+ free(tmp_cmdline);
+ }
+ command_line_len = 0;
+ if (command_line) {
+ command_line_len = strlen(command_line) +1;
+ } else {
+ command_line = strdup("\0");
+ command_line_len = 1;
+ }
+
+ /* Need to append some command line parameters internally in case of
+ * taking crash dumps.
+ */
+ if (info->kexec_flags & (KEXEC_ON_CRASH|KEXEC_PRESERVE_CONTEXT)) {
+ modified_cmdline = xmalloc(COMMAND_LINE_SIZE);
+ memset((void *)modified_cmdline, 0, COMMAND_LINE_SIZE);
+ if (command_line) {
+ strncpy(modified_cmdline, command_line,
+ COMMAND_LINE_SIZE);
+ modified_cmdline[COMMAND_LINE_SIZE - 1] = '\0';
+ }
+ }
+
+ /* Load the ELF executable */
+ elf_exec_build_load(info, &ehdr, buf, len, 0);
+
+ entry = ehdr.e_entry;
+ max_addr = elf_max_addr(&ehdr);
+
+ /* Do we want arguments? */
+ if (arg_style != ARG_STYLE_NONE) {
+ /* Load the setup code */
+ elf_rel_build_load(info, &info->rhdr, purgatory, purgatory_size,
+ 0, ULONG_MAX, 1, 0);
+ }
+ if (arg_style == ARG_STYLE_NONE) {
+ info->entry = (void *)entry;
+
+ }
+ else if (arg_style == ARG_STYLE_ELF) {
+ unsigned long note_base;
+ struct entry32_regs regs;
+ uint32_t arg1, arg2;
+
+ /* Setup the ELF boot notes */
+ note_base = elf_boot_notes(info, max_addr,
+ command_line, command_line_len);
+
+ /* Initialize the stack arguments */
+ arg2 = 0; /* No return address */
+ arg1 = note_base;
+ elf_rel_set_symbol(&info->rhdr, "stack_arg32_1", &arg1, sizeof(arg1));
+ elf_rel_set_symbol(&info->rhdr, "stack_arg32_2", &arg2, sizeof(arg2));
+
+ /* Initialize the registers */
+ elf_rel_get_symbol(&info->rhdr, "entry32_regs", &regs, sizeof(regs));
+ regs.eip = entry; /* The entry point */
+ regs.esp = elf_rel_get_addr(&info->rhdr, "stack_arg32_2");
+ elf_rel_set_symbol(&info->rhdr, "entry32_regs", &regs, sizeof(regs));
+
+ if (ramdisk) {
+ error_msg = "Ramdisks not supported with generic elf arguments";
+ goto out;
+ }
+ }
+ else if (arg_style == ARG_STYLE_LINUX) {
+ struct x86_linux_faked_param_header *hdr;
+ unsigned long param_base;
+ const char *ramdisk_buf;
+ off_t ramdisk_length;
+ struct entry32_regs regs;
+ int rc = 0;
+
+ /* Get the linux parameter header */
+ hdr = xmalloc(sizeof(*hdr));
+
+ /* Hack: With some ld versions, vmlinux program headers show
+ * a gap of two pages between bss segment and data segment
+ * but effectively kernel considers it as bss segment and
+ * overwrites the any data placed there. Hence bloat the
+ * memsz of parameter segment to 16K to avoid being placed
+ * in such gaps.
+ * This is a makeshift solution until it is fixed in kernel
+ */
+ param_base = add_buffer(info, hdr, sizeof(*hdr), 16*1024,
+ 16, 0, max_addr, 1);
+
+ /* Initialize the parameter header */
+ memset(hdr, 0, sizeof(*hdr));
+ init_linux_parameters(&hdr->hdr);
+
+ /* Add a ramdisk to the current image */
+ ramdisk_buf = NULL;
+ ramdisk_length = 0;
+ if (ramdisk) {
+ ramdisk_buf = slurp_file(ramdisk, &ramdisk_length);
+ }
+
+ /* If panic kernel is being loaded, additional segments need
+ * to be created. */
+ if (info->kexec_flags & (KEXEC_ON_CRASH|KEXEC_PRESERVE_CONTEXT)) {
+ rc = load_crashdump_segments(info, modified_cmdline,
+ max_addr, 0);
+ if (rc < 0) {
+ result = -1;
+ goto out;
+ }
+ /* Use new command line. */
+ free(command_line);
+ command_line = modified_cmdline;
+ command_line_len = strlen(modified_cmdline) + 1;
+ modified_cmdline = NULL;
+ }
+
+ /* Tell the kernel what is going on */
+ setup_linux_bootloader_parameters(info, &hdr->hdr, param_base,
+ offsetof(struct x86_linux_faked_param_header, command_line),
+ command_line, command_line_len,
+ ramdisk_buf, ramdisk_length);
+
+ /* Fill in the information bios calls would usually provide */
+ setup_linux_system_parameters(info, &hdr->hdr);
+
+ /* Initialize the registers */
+ elf_rel_get_symbol(&info->rhdr, "entry32_regs", &regs, sizeof(regs));
+ regs.ebx = 0; /* Bootstrap processor */
+ regs.esi = param_base; /* Pointer to the parameters */
+ regs.eip = entry; /* The entry point */
+ regs.esp = elf_rel_get_addr(&info->rhdr, "stack_end"); /* Stack, unused */
+ elf_rel_set_symbol(&info->rhdr, "entry32_regs", &regs, sizeof(regs));
+ }
+ else {
+ error_msg = "Unknown argument style\n";
+ }
+
+out:
+ free(command_line);
+ free(modified_cmdline);
+ if (error_msg)
+ die("%s", error_msg);
+ return result;
+}
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