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 19 void 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 26 int 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 48 void 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 69 void 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 78 void 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 } 121