1 #include <unistd.h>
2 #include <errno.h>
3 #include <stdio.h>
4 #include <stdlib.h>
5 #include <linux/kexec.h>
6 #include <linux/reboot.h>
7 #include <sys/reboot.h>
8 #include <sys/syscall.h>
9
10 asm(
11 " .code64\n"
12 " .data\n"
13 "purgatory_start:\n"
14
15 // Trigger kexec debug exception handling
16 " int3\n"
17
18 // Set load address for next time
19 " leaq purgatory_start_b(%rip), %r11\n"
20 " movq %r11, 8(%rsp)\n"
21
22 // Back to Linux
23 " ret\n"
24
25 // Same again
26 "purgatory_start_b:\n"
27
28 // Trigger kexec debug exception handling
29 " int3\n"
30
31 // Set load address for next time
32 " leaq purgatory_start(%rip), %r11\n"
33 " movq %r11, 8(%rsp)\n"
34
35 // Back to Linux
36 " ret\n"
37
38 "purgatory_end:\n"
39 ".previous"
40 );
41 extern char purgatory_start[], purgatory_end[];
42
main(void)43 int main (void)
44 {
45 struct kexec_segment segment = {};
46 int ret;
47
48 segment.buf = purgatory_start;
49 segment.bufsz = purgatory_end - purgatory_start;
50 segment.mem = (void *)0x400000;
51 segment.memsz = 0x1000;
52 ret = syscall(__NR_kexec_load, 0x400000, 1, &segment, KEXEC_PRESERVE_CONTEXT);
53 if (ret) {
54 perror("kexec_load");
55 exit(1);
56 }
57
58 ret = syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_KEXEC);
59 if (ret) {
60 perror("kexec reboot");
61 exit(1);
62 }
63
64 ret = syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_KEXEC);
65 if (ret) {
66 perror("kexec reboot");
67 exit(1);
68 }
69 printf("Success\n");
70 return 0;
71 }
72
73