1 /* 2 * Copyright (C) 2002 Jeff Dike (jdike@addtoit.com) 3 * Licensed under the GPL 4 */ 5 6 #include <unistd.h> 7 #include <stdio.h> 8 #include <errno.h> 9 #include <signal.h> 10 #include <setjmp.h> 11 #include <linux/unistd.h> 12 #include <sys/mman.h> 13 #include <sys/wait.h> 14 #include "ptrace_user.h" 15 #include "os.h" 16 #include "user.h" 17 #include "user_util.h" 18 #include "process.h" 19 #include "irq_user.h" 20 #include "kern_util.h" 21 #include "longjmp.h" 22 #include "skas_ptrace.h" 23 24 #define ARBITRARY_ADDR -1 25 #define FAILURE_PID -1 26 27 #define STAT_PATH_LEN sizeof("/proc/#######/stat\0") 28 #define COMM_SCANF "%*[^)])" 29 30 unsigned long os_process_pc(int pid) 31 { 32 char proc_stat[STAT_PATH_LEN], buf[256]; 33 unsigned long pc; 34 int fd, err; 35 36 sprintf(proc_stat, "/proc/%d/stat", pid); 37 fd = os_open_file(proc_stat, of_read(OPENFLAGS()), 0); 38 if(fd < 0){ 39 printk("os_process_pc - couldn't open '%s', err = %d\n", 40 proc_stat, -fd); 41 return(ARBITRARY_ADDR); 42 } 43 err = os_read_file(fd, buf, sizeof(buf)); 44 if(err < 0){ 45 printk("os_process_pc - couldn't read '%s', err = %d\n", 46 proc_stat, -err); 47 os_close_file(fd); 48 return(ARBITRARY_ADDR); 49 } 50 os_close_file(fd); 51 pc = ARBITRARY_ADDR; 52 if(sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d " 53 "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d " 54 "%*d %*d %*d %*d %*d %lu", &pc) != 1){ 55 printk("os_process_pc - couldn't find pc in '%s'\n", buf); 56 } 57 return(pc); 58 } 59 60 int os_process_parent(int pid) 61 { 62 char stat[STAT_PATH_LEN]; 63 char data[256]; 64 int parent, n, fd; 65 66 if(pid == -1) return(-1); 67 68 snprintf(stat, sizeof(stat), "/proc/%d/stat", pid); 69 fd = os_open_file(stat, of_read(OPENFLAGS()), 0); 70 if(fd < 0){ 71 printk("Couldn't open '%s', err = %d\n", stat, -fd); 72 return(FAILURE_PID); 73 } 74 75 n = os_read_file(fd, data, sizeof(data)); 76 os_close_file(fd); 77 78 if(n < 0){ 79 printk("Couldn't read '%s', err = %d\n", stat, -n); 80 return(FAILURE_PID); 81 } 82 83 parent = FAILURE_PID; 84 n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent); 85 if(n != 1) 86 printk("Failed to scan '%s'\n", data); 87 88 return(parent); 89 } 90 91 void os_stop_process(int pid) 92 { 93 kill(pid, SIGSTOP); 94 } 95 96 void os_kill_process(int pid, int reap_child) 97 { 98 kill(pid, SIGKILL); 99 if(reap_child) 100 CATCH_EINTR(waitpid(pid, NULL, 0)); 101 102 } 103 104 /* This is here uniquely to have access to the userspace errno, i.e. the one 105 * used by ptrace in case of error. 106 */ 107 108 long os_ptrace_ldt(long pid, long addr, long data) 109 { 110 int ret; 111 112 ret = ptrace(PTRACE_LDT, pid, addr, data); 113 114 if (ret < 0) 115 return -errno; 116 return ret; 117 } 118 119 /* Kill off a ptraced child by all means available. kill it normally first, 120 * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from 121 * which it can't exit directly. 122 */ 123 124 void os_kill_ptraced_process(int pid, int reap_child) 125 { 126 kill(pid, SIGKILL); 127 ptrace(PTRACE_KILL, pid); 128 ptrace(PTRACE_CONT, pid); 129 if(reap_child) 130 CATCH_EINTR(waitpid(pid, NULL, 0)); 131 } 132 133 void os_usr1_process(int pid) 134 { 135 kill(pid, SIGUSR1); 136 } 137 138 /* Don't use the glibc version, which caches the result in TLS. It misses some 139 * syscalls, and also breaks with clone(), which does not unshare the TLS. 140 */ 141 142 inline _syscall0(pid_t, getpid) 143 144 int os_getpid(void) 145 { 146 return(getpid()); 147 } 148 149 int os_getpgrp(void) 150 { 151 return getpgrp(); 152 } 153 154 int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len, 155 int r, int w, int x) 156 { 157 void *loc; 158 int prot; 159 160 prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 161 (x ? PROT_EXEC : 0); 162 163 loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED, 164 fd, off); 165 if(loc == MAP_FAILED) 166 return(-errno); 167 return(0); 168 } 169 170 int os_protect_memory(void *addr, unsigned long len, int r, int w, int x) 171 { 172 int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 173 (x ? PROT_EXEC : 0)); 174 175 if(mprotect(addr, len, prot) < 0) 176 return(-errno); 177 return(0); 178 } 179 180 int os_unmap_memory(void *addr, int len) 181 { 182 int err; 183 184 err = munmap(addr, len); 185 if(err < 0) 186 return(-errno); 187 return(0); 188 } 189 190 void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int)) 191 { 192 int flags = 0, pages; 193 194 if(sig_stack != NULL){ 195 pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER); 196 set_sigstack(sig_stack, pages * page_size()); 197 flags = SA_ONSTACK; 198 } 199 if(usr1_handler) set_handler(SIGUSR1, usr1_handler, flags, -1); 200 } 201 202 void init_new_thread_signals(int altstack) 203 { 204 int flags = altstack ? SA_ONSTACK : 0; 205 206 set_handler(SIGSEGV, (__sighandler_t) sig_handler, flags, 207 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 208 set_handler(SIGTRAP, (__sighandler_t) sig_handler, flags, 209 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 210 set_handler(SIGFPE, (__sighandler_t) sig_handler, flags, 211 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 212 set_handler(SIGILL, (__sighandler_t) sig_handler, flags, 213 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 214 set_handler(SIGBUS, (__sighandler_t) sig_handler, flags, 215 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 216 set_handler(SIGUSR2, (__sighandler_t) sig_handler, 217 flags, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 218 signal(SIGHUP, SIG_IGN); 219 220 init_irq_signals(altstack); 221 } 222 223 int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr) 224 { 225 sigjmp_buf buf; 226 int n, enable; 227 228 *jmp_ptr = &buf; 229 n = UML_SIGSETJMP(&buf, enable); 230 if(n != 0) 231 return(n); 232 (*fn)(arg); 233 return(0); 234 } 235