1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
16 #include <sys/utsname.h>
17 #include <sys/random.h>
21 void stack_protections(unsigned long address)
23 if (mprotect((void *) address, UM_THREAD_SIZE,
24 PROT_READ | PROT_WRITE | PROT_EXEC) < 0)
25 panic("protecting stack failed, errno = %d", errno);
33 CATCH_EINTR(err = tcgetattr(fd, &tt));
39 CATCH_EINTR(err = tcsetattr(fd, TCSADRAIN, &tt));
44 * XXX tcsetattr could have applied only some changes
45 * (and cfmakeraw() is a set of changes)
50 void setup_machinename(char *machine_out)
55 #ifdef UML_CONFIG_UML_X86
56 # ifndef UML_CONFIG_64BIT
57 if (!strcmp(host.machine, "x86_64")) {
58 strcpy(machine_out, "i686");
62 if (!strcmp(host.machine, "i686")) {
63 strcpy(machine_out, "x86_64");
68 strcpy(machine_out, host.machine);
71 void setup_hostinfo(char *buf, int len)
76 snprintf(buf, len, "%s %s %s %s %s", host.sysname, host.nodename,
77 host.release, host.version, host.machine);
81 * We cannot use glibc's abort(). It makes use of tgkill() which
82 * has no effect within UML's kernel threads.
83 * After that glibc would execute an invalid instruction to kill
84 * the calling process and UML crashes with SIGSEGV.
86 static inline void __attribute__ ((noreturn)) uml_abort(void)
92 if (!sigemptyset(&sig) && !sigaddset(&sig, SIGABRT))
93 sigprocmask(SIG_UNBLOCK, &sig, 0);
96 if (kill(getpid(), SIGABRT) < 0)
100 ssize_t os_getrandom(void *buf, size_t len, unsigned int flags)
102 return getrandom(buf, len, flags);
106 * UML helper threads must not handle SIGWINCH/INT/TERM
108 void os_fix_helper_signals(void)
110 signal(SIGWINCH, SIG_IGN);
111 signal(SIGINT, SIG_DFL);
112 signal(SIGTERM, SIG_DFL);
115 void os_dump_core(void)
119 signal(SIGSEGV, SIG_DFL);
122 * We are about to SIGTERM this entire process group to ensure that
123 * nothing is around to run after the kernel exits. The
124 * kernel wants to abort, not die through SIGTERM, so we
128 signal(SIGTERM, SIG_IGN);
131 * Most of the other processes associated with this UML are
132 * likely sTopped, so give them a SIGCONT so they see the
138 * Now, having sent signals to everyone but us, make sure they
139 * die by ptrace. Processes can survive what's been done to
140 * them so far - the mechanism I understand is receiving a
141 * SIGSEGV and segfaulting immediately upon return. There is
142 * always a SIGSEGV pending, and (I'm guessing) signals are
143 * processed in numeric order so the SIGTERM (signal 15 vs
144 * SIGSEGV being signal 11) is never handled.
146 * Run a waitpid loop until we get some kind of error.
147 * Hopefully, it's ECHILD, but there's not a lot we can do if
148 * it's something else. Tell os_kill_ptraced_process not to
149 * wait for the child to report its death because there's
150 * nothing reasonable to do if that fails.
153 while ((pid = waitpid(-1, NULL, WNOHANG | __WALL)) > 0)
154 os_kill_ptraced_process(pid, 0);
159 void um_early_printk(const char *s, unsigned int n)
161 printf("%.*s", n, s);
164 static int quiet_info;
166 static int __init quiet_cmd_param(char *str, int *add)
172 __uml_setup("quiet", quiet_cmd_param,
174 " Turns off information messages during boot.\n\n");
176 void os_info(const char *fmt, ...)
184 vfprintf(stderr, fmt, list);
188 void os_warn(const char *fmt, ...)
193 vfprintf(stderr, fmt, list);