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 <sys/mman.h> 11 #include <sys/wait.h> 12 #include <sys/mman.h> 13 #include <sys/syscall.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 #include "kern_constants.h" 24 #include "uml-config.h" 25 26 #define ARBITRARY_ADDR -1 27 #define FAILURE_PID -1 28 29 #define STAT_PATH_LEN sizeof("/proc/#######/stat\0") 30 #define COMM_SCANF "%*[^)])" 31 32 unsigned long os_process_pc(int pid) 33 { 34 char proc_stat[STAT_PATH_LEN], buf[256]; 35 unsigned long pc; 36 int fd, err; 37 38 sprintf(proc_stat, "/proc/%d/stat", pid); 39 fd = os_open_file(proc_stat, of_read(OPENFLAGS()), 0); 40 if(fd < 0){ 41 printk("os_process_pc - couldn't open '%s', err = %d\n", 42 proc_stat, -fd); 43 return(ARBITRARY_ADDR); 44 } 45 err = os_read_file(fd, buf, sizeof(buf)); 46 if(err < 0){ 47 printk("os_process_pc - couldn't read '%s', err = %d\n", 48 proc_stat, -err); 49 os_close_file(fd); 50 return(ARBITRARY_ADDR); 51 } 52 os_close_file(fd); 53 pc = ARBITRARY_ADDR; 54 if(sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d " 55 "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d " 56 "%*d %*d %*d %*d %*d %lu", &pc) != 1){ 57 printk("os_process_pc - couldn't find pc in '%s'\n", buf); 58 } 59 return(pc); 60 } 61 62 int os_process_parent(int pid) 63 { 64 char stat[STAT_PATH_LEN]; 65 char data[256]; 66 int parent, n, fd; 67 68 if(pid == -1) return(-1); 69 70 snprintf(stat, sizeof(stat), "/proc/%d/stat", pid); 71 fd = os_open_file(stat, of_read(OPENFLAGS()), 0); 72 if(fd < 0){ 73 printk("Couldn't open '%s', err = %d\n", stat, -fd); 74 return(FAILURE_PID); 75 } 76 77 n = os_read_file(fd, data, sizeof(data)); 78 os_close_file(fd); 79 80 if(n < 0){ 81 printk("Couldn't read '%s', err = %d\n", stat, -n); 82 return(FAILURE_PID); 83 } 84 85 parent = FAILURE_PID; 86 n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent); 87 if(n != 1) 88 printk("Failed to scan '%s'\n", data); 89 90 return(parent); 91 } 92 93 void os_stop_process(int pid) 94 { 95 kill(pid, SIGSTOP); 96 } 97 98 void os_kill_process(int pid, int reap_child) 99 { 100 kill(pid, SIGKILL); 101 if(reap_child) 102 CATCH_EINTR(waitpid(pid, NULL, 0)); 103 104 } 105 106 /* This is here uniquely to have access to the userspace errno, i.e. the one 107 * used by ptrace in case of error. 108 */ 109 110 long os_ptrace_ldt(long pid, long addr, long data) 111 { 112 int ret; 113 114 ret = ptrace(PTRACE_LDT, pid, addr, data); 115 116 if (ret < 0) 117 return -errno; 118 return ret; 119 } 120 121 /* Kill off a ptraced child by all means available. kill it normally first, 122 * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from 123 * which it can't exit directly. 124 */ 125 126 void os_kill_ptraced_process(int pid, int reap_child) 127 { 128 kill(pid, SIGKILL); 129 ptrace(PTRACE_KILL, pid); 130 ptrace(PTRACE_CONT, pid); 131 if(reap_child) 132 CATCH_EINTR(waitpid(pid, NULL, 0)); 133 } 134 135 #ifdef UML_CONFIG_MODE_TT 136 void os_usr1_process(int pid) 137 { 138 kill(pid, SIGUSR1); 139 } 140 #endif 141 142 /* Don't use the glibc version, which caches the result in TLS. It misses some 143 * syscalls, and also breaks with clone(), which does not unshare the TLS. 144 */ 145 146 int os_getpid(void) 147 { 148 return(syscall(__NR_getpid)); 149 } 150 151 int os_getpgrp(void) 152 { 153 return getpgrp(); 154 } 155 156 int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len, 157 int r, int w, int x) 158 { 159 void *loc; 160 int prot; 161 162 prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 163 (x ? PROT_EXEC : 0); 164 165 loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED, 166 fd, off); 167 if(loc == MAP_FAILED) 168 return(-errno); 169 return(0); 170 } 171 172 int os_protect_memory(void *addr, unsigned long len, int r, int w, int x) 173 { 174 int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 175 (x ? PROT_EXEC : 0)); 176 177 if(mprotect(addr, len, prot) < 0) 178 return(-errno); 179 return(0); 180 } 181 182 int os_unmap_memory(void *addr, int len) 183 { 184 int err; 185 186 err = munmap(addr, len); 187 if(err < 0) 188 return(-errno); 189 return(0); 190 } 191 192 #ifndef MADV_REMOVE 193 #define MADV_REMOVE KERNEL_MADV_REMOVE 194 #endif 195 196 int os_drop_memory(void *addr, int length) 197 { 198 int err; 199 200 err = madvise(addr, length, MADV_REMOVE); 201 if(err < 0) 202 err = -errno; 203 return err; 204 } 205 206 int can_drop_memory(void) 207 { 208 void *addr; 209 int fd, ok = 0; 210 211 printk("Checking host MADV_REMOVE support..."); 212 fd = create_mem_file(UM_KERN_PAGE_SIZE); 213 if(fd < 0){ 214 printk("Creating test memory file failed, err = %d\n", -fd); 215 goto out; 216 } 217 218 addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, 219 MAP_SHARED, fd, 0); 220 if(addr == MAP_FAILED){ 221 printk("Mapping test memory file failed, err = %d\n", -errno); 222 goto out_close; 223 } 224 225 if(madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0){ 226 printk("MADV_REMOVE failed, err = %d\n", -errno); 227 goto out_unmap; 228 } 229 230 printk("OK\n"); 231 ok = 1; 232 233 out_unmap: 234 munmap(addr, UM_KERN_PAGE_SIZE); 235 out_close: 236 close(fd); 237 out: 238 return ok; 239 } 240 241 void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int)) 242 { 243 int flags = 0, pages; 244 245 if(sig_stack != NULL){ 246 pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER); 247 set_sigstack(sig_stack, pages * page_size()); 248 flags = SA_ONSTACK; 249 } 250 if(usr1_handler){ 251 struct sigaction sa; 252 253 sa.sa_handler = usr1_handler; 254 sigemptyset(&sa.sa_mask); 255 sa.sa_flags = flags; 256 sa.sa_restorer = NULL; 257 if(sigaction(SIGUSR1, &sa, NULL) < 0) 258 panic("init_new_thread_stack - sigaction failed - " 259 "errno = %d\n", errno); 260 } 261 } 262 263 void init_new_thread_signals(void) 264 { 265 set_handler(SIGSEGV, (__sighandler_t) sig_handler, SA_ONSTACK, 266 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 267 set_handler(SIGTRAP, (__sighandler_t) sig_handler, SA_ONSTACK, 268 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 269 set_handler(SIGFPE, (__sighandler_t) sig_handler, SA_ONSTACK, 270 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 271 set_handler(SIGILL, (__sighandler_t) sig_handler, SA_ONSTACK, 272 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 273 set_handler(SIGBUS, (__sighandler_t) sig_handler, SA_ONSTACK, 274 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 275 set_handler(SIGUSR2, (__sighandler_t) sig_handler, 276 SA_ONSTACK, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, 277 -1); 278 signal(SIGHUP, SIG_IGN); 279 280 init_irq_signals(1); 281 } 282 283 int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr) 284 { 285 jmp_buf buf; 286 int n; 287 288 *jmp_ptr = &buf; 289 n = UML_SETJMP(&buf); 290 if(n != 0) 291 return n; 292 (*fn)(arg); 293 return 0; 294 } 295