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 "process.h" 18 #include "irq_user.h" 19 #include "kern_util.h" 20 #include "longjmp.h" 21 #include "skas_ptrace.h" 22 #include "kern_constants.h" 23 #include "uml-config.h" 24 #include "init.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 CATCH_EINTR(err = read(fd, buf, sizeof(buf))); 46 if(err < 0){ 47 printk("os_process_pc - couldn't read '%s', err = %d\n", 48 proc_stat, errno); 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) 69 return -1; 70 71 snprintf(stat, sizeof(stat), "/proc/%d/stat", pid); 72 fd = os_open_file(stat, of_read(OPENFLAGS()), 0); 73 if(fd < 0){ 74 printk("Couldn't open '%s', err = %d\n", stat, -fd); 75 return FAILURE_PID; 76 } 77 78 CATCH_EINTR(n = read(fd, data, sizeof(data))); 79 os_close_file(fd); 80 81 if(n < 0){ 82 printk("Couldn't read '%s', err = %d\n", stat, errno); 83 return FAILURE_PID; 84 } 85 86 parent = FAILURE_PID; 87 n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent); 88 if(n != 1) 89 printk("Failed to scan '%s'\n", data); 90 91 return parent; 92 } 93 94 void os_stop_process(int pid) 95 { 96 kill(pid, SIGSTOP); 97 } 98 99 void os_kill_process(int pid, int reap_child) 100 { 101 kill(pid, SIGKILL); 102 if(reap_child) 103 CATCH_EINTR(waitpid(pid, NULL, 0)); 104 105 } 106 107 /* This is here uniquely to have access to the userspace errno, i.e. the one 108 * used by ptrace in case of error. 109 */ 110 111 long os_ptrace_ldt(long pid, long addr, long data) 112 { 113 int ret; 114 115 ret = ptrace(PTRACE_LDT, pid, addr, data); 116 117 if (ret < 0) 118 return -errno; 119 return ret; 120 } 121 122 /* Kill off a ptraced child by all means available. kill it normally first, 123 * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from 124 * which it can't exit directly. 125 */ 126 127 void os_kill_ptraced_process(int pid, int reap_child) 128 { 129 kill(pid, SIGKILL); 130 ptrace(PTRACE_KILL, pid); 131 ptrace(PTRACE_CONT, pid); 132 if(reap_child) 133 CATCH_EINTR(waitpid(pid, NULL, 0)); 134 } 135 136 #ifdef UML_CONFIG_MODE_TT 137 void os_usr1_process(int pid) 138 { 139 kill(pid, SIGUSR1); 140 } 141 #endif 142 143 /* Don't use the glibc version, which caches the result in TLS. It misses some 144 * syscalls, and also breaks with clone(), which does not unshare the TLS. 145 */ 146 147 int os_getpid(void) 148 { 149 return syscall(__NR_getpid); 150 } 151 152 int os_getpgrp(void) 153 { 154 return getpgrp(); 155 } 156 157 int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len, 158 int r, int w, int x) 159 { 160 void *loc; 161 int prot; 162 163 prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 164 (x ? PROT_EXEC : 0); 165 166 loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED, 167 fd, off); 168 if(loc == MAP_FAILED) 169 return -errno; 170 return 0; 171 } 172 173 int os_protect_memory(void *addr, unsigned long len, int r, int w, int x) 174 { 175 int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 176 (x ? PROT_EXEC : 0)); 177 178 if(mprotect(addr, len, prot) < 0) 179 return -errno; 180 return 0; 181 } 182 183 int os_unmap_memory(void *addr, int len) 184 { 185 int err; 186 187 err = munmap(addr, len); 188 if(err < 0) 189 return -errno; 190 return 0; 191 } 192 193 #ifndef MADV_REMOVE 194 #define MADV_REMOVE KERNEL_MADV_REMOVE 195 #endif 196 197 int os_drop_memory(void *addr, int length) 198 { 199 int err; 200 201 err = madvise(addr, length, MADV_REMOVE); 202 if(err < 0) 203 err = -errno; 204 return err; 205 } 206 207 int __init can_drop_memory(void) 208 { 209 void *addr; 210 int fd, ok = 0; 211 212 printk("Checking host MADV_REMOVE support..."); 213 fd = create_mem_file(UM_KERN_PAGE_SIZE); 214 if(fd < 0){ 215 printk("Creating test memory file failed, err = %d\n", -fd); 216 goto out; 217 } 218 219 addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, 220 MAP_SHARED, fd, 0); 221 if(addr == MAP_FAILED){ 222 printk("Mapping test memory file failed, err = %d\n", -errno); 223 goto out_close; 224 } 225 226 if(madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0){ 227 printk("MADV_REMOVE failed, err = %d\n", -errno); 228 goto out_unmap; 229 } 230 231 printk("OK\n"); 232 ok = 1; 233 234 out_unmap: 235 munmap(addr, UM_KERN_PAGE_SIZE); 236 out_close: 237 close(fd); 238 out: 239 return ok; 240 } 241 242 #ifdef UML_CONFIG_MODE_TT 243 void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int)) 244 { 245 int flags = 0, pages; 246 247 if(sig_stack != NULL){ 248 pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER); 249 set_sigstack(sig_stack, pages * UM_KERN_PAGE_SIZE); 250 flags = SA_ONSTACK; 251 } 252 if(usr1_handler){ 253 struct sigaction sa; 254 255 sa.sa_handler = usr1_handler; 256 sigemptyset(&sa.sa_mask); 257 sa.sa_flags = flags; 258 sa.sa_restorer = NULL; 259 if(sigaction(SIGUSR1, &sa, NULL) < 0) 260 panic("init_new_thread_stack - sigaction failed - " 261 "errno = %d\n", errno); 262 } 263 } 264 #endif 265 266 void init_new_thread_signals(void) 267 { 268 set_handler(SIGSEGV, (__sighandler_t) sig_handler, SA_ONSTACK, 269 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 270 set_handler(SIGTRAP, (__sighandler_t) sig_handler, SA_ONSTACK, 271 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 272 set_handler(SIGFPE, (__sighandler_t) sig_handler, SA_ONSTACK, 273 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 274 set_handler(SIGILL, (__sighandler_t) sig_handler, SA_ONSTACK, 275 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 276 set_handler(SIGBUS, (__sighandler_t) sig_handler, SA_ONSTACK, 277 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 278 set_handler(SIGUSR2, (__sighandler_t) sig_handler, 279 SA_ONSTACK, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, 280 -1); 281 signal(SIGHUP, SIG_IGN); 282 283 init_irq_signals(1); 284 } 285 286 int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr) 287 { 288 jmp_buf buf; 289 int n; 290 291 *jmp_ptr = &buf; 292 n = UML_SETJMP(&buf); 293 if(n != 0) 294 return n; 295 (*fn)(arg); 296 return 0; 297 } 298