Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <errno.h>
9#include <signal.h>
10#include <string.h>
11#include <termios.h>
12#include <wait.h>
13#include <sys/mman.h>
14#include <sys/utsname.h>
15#include "kern_constants.h"
16#include "os.h"
17#include "user.h"
18
19void stack_protections(unsigned long address)
20{
21 if (mprotect((void *) address, UM_THREAD_SIZE,
22 PROT_READ | PROT_WRITE | PROT_EXEC) < 0)
23 panic("protecting stack failed, errno = %d", errno);
24}
25
26int raw(int fd)
27{
28 struct termios tt;
29 int err;
30
31 CATCH_EINTR(err = tcgetattr(fd, &tt));
32 if (err < 0)
33 return -errno;
34
35 cfmakeraw(&tt);
36
37 CATCH_EINTR(err = tcsetattr(fd, TCSADRAIN, &tt));
38 if (err < 0)
39 return -errno;
40
41 /*
42 * XXX tcsetattr could have applied only some changes
43 * (and cfmakeraw() is a set of changes)
44 */
45 return 0;
46}
47
48void setup_machinename(char *machine_out)
49{
50 struct utsname host;
51
52 uname(&host);
53#ifdef UML_CONFIG_UML_X86
54# ifndef UML_CONFIG_64BIT
55 if (!strcmp(host.machine, "x86_64")) {
56 strcpy(machine_out, "i686");
57 return;
58 }
59# else
60 if (!strcmp(host.machine, "i686")) {
61 strcpy(machine_out, "x86_64");
62 return;
63 }
64# endif
65#endif
66 strcpy(machine_out, host.machine);
67}
68
69void setup_hostinfo(char *buf, int len)
70{
71 struct utsname host;
72
73 uname(&host);
74 snprintf(buf, len, "%s %s %s %s %s", host.sysname, host.nodename,
75 host.release, host.version, host.machine);
76}
77
78void os_dump_core(void)
79{
80 int pid;
81
82 signal(SIGSEGV, SIG_DFL);
83
84 /*
85 * We are about to SIGTERM this entire process group to ensure that
86 * nothing is around to run after the kernel exits. The
87 * kernel wants to abort, not die through SIGTERM, so we
88 * ignore it here.
89 */
90
91 signal(SIGTERM, SIG_IGN);
92 kill(0, SIGTERM);
93 /*
94 * Most of the other processes associated with this UML are
95 * likely sTopped, so give them a SIGCONT so they see the
96 * SIGTERM.
97 */
98 kill(0, SIGCONT);
99
100 /*
101 * Now, having sent signals to everyone but us, make sure they
102 * die by ptrace. Processes can survive what's been done to
103 * them so far - the mechanism I understand is receiving a
104 * SIGSEGV and segfaulting immediately upon return. There is
105 * always a SIGSEGV pending, and (I'm guessing) signals are
106 * processed in numeric order so the SIGTERM (signal 15 vs
107 * SIGSEGV being signal 11) is never handled.
108 *
109 * Run a waitpid loop until we get some kind of error.
110 * Hopefully, it's ECHILD, but there's not a lot we can do if
111 * it's something else. Tell os_kill_ptraced_process not to
112 * wait for the child to report its death because there's
113 * nothing reasonable to do if that fails.
114 */
115
116 while ((pid = waitpid(-1, NULL, WNOHANG | __WALL)) > 0)
117 os_kill_ptraced_process(pid, 0);
118
119 abort();
120}