1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
16 #include <sys/utsname.h>
20 void stack_protections(unsigned long address)
22 if (mprotect((void *) address, UM_THREAD_SIZE,
23 PROT_READ | PROT_WRITE | PROT_EXEC) < 0)
24 panic("protecting stack failed, errno = %d", errno);
32 CATCH_EINTR(err = tcgetattr(fd, &tt));
38 CATCH_EINTR(err = tcsetattr(fd, TCSADRAIN, &tt));
43 * XXX tcsetattr could have applied only some changes
44 * (and cfmakeraw() is a set of changes)
49 void setup_machinename(char *machine_out)
54 #ifdef UML_CONFIG_UML_X86
55 # ifndef UML_CONFIG_64BIT
56 if (!strcmp(host.machine, "x86_64")) {
57 strcpy(machine_out, "i686");
61 if (!strcmp(host.machine, "i686")) {
62 strcpy(machine_out, "x86_64");
67 strcpy(machine_out, host.machine);
70 void setup_hostinfo(char *buf, int len)
75 snprintf(buf, len, "%s %s %s %s %s", host.sysname, host.nodename,
76 host.release, host.version, host.machine);
80 * We cannot use glibc's abort(). It makes use of tgkill() which
81 * has no effect within UML's kernel threads.
82 * After that glibc would execute an invalid instruction to kill
83 * the calling process and UML crashes with SIGSEGV.
85 static inline void __attribute__ ((noreturn)) uml_abort(void)
91 if (!sigemptyset(&sig) && !sigaddset(&sig, SIGABRT))
92 sigprocmask(SIG_UNBLOCK, &sig, 0);
95 if (kill(getpid(), SIGABRT) < 0)
100 * UML helper threads must not handle SIGWINCH/INT/TERM
102 void os_fix_helper_signals(void)
104 signal(SIGWINCH, SIG_IGN);
105 signal(SIGINT, SIG_DFL);
106 signal(SIGTERM, SIG_DFL);
109 void os_dump_core(void)
113 signal(SIGSEGV, SIG_DFL);
116 * We are about to SIGTERM this entire process group to ensure that
117 * nothing is around to run after the kernel exits. The
118 * kernel wants to abort, not die through SIGTERM, so we
122 signal(SIGTERM, SIG_IGN);
125 * Most of the other processes associated with this UML are
126 * likely sTopped, so give them a SIGCONT so they see the
132 * Now, having sent signals to everyone but us, make sure they
133 * die by ptrace. Processes can survive what's been done to
134 * them so far - the mechanism I understand is receiving a
135 * SIGSEGV and segfaulting immediately upon return. There is
136 * always a SIGSEGV pending, and (I'm guessing) signals are
137 * processed in numeric order so the SIGTERM (signal 15 vs
138 * SIGSEGV being signal 11) is never handled.
140 * Run a waitpid loop until we get some kind of error.
141 * Hopefully, it's ECHILD, but there's not a lot we can do if
142 * it's something else. Tell os_kill_ptraced_process not to
143 * wait for the child to report its death because there's
144 * nothing reasonable to do if that fails.
147 while ((pid = waitpid(-1, NULL, WNOHANG | __WALL)) > 0)
148 os_kill_ptraced_process(pid, 0);
153 void um_early_printk(const char *s, unsigned int n)
155 printf("%.*s", n, s);
158 static int quiet_info;
160 static int __init quiet_cmd_param(char *str, int *add)
166 __uml_setup("quiet", quiet_cmd_param,
168 " Turns off information messages during boot.\n\n");
170 void os_info(const char *fmt, ...)
178 vfprintf(stderr, fmt, list);
182 void os_warn(const char *fmt, ...)
187 vfprintf(stderr, fmt, list);