1 /* 2 * Copyright (C) 2002 - 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 <unistd.h> 9 #include <errno.h> 10 #include <signal.h> 11 #include <fcntl.h> 12 #include <sys/mman.h> 13 #include <sys/ptrace.h> 14 #include <sys/wait.h> 15 #include <asm/unistd.h> 16 #include <init.h> 17 #include <longjmp.h> 18 #include <os.h> 19 #include <skas_ptrace.h> 20 21 #define ARBITRARY_ADDR -1 22 #define FAILURE_PID -1 23 24 #define STAT_PATH_LEN sizeof("/proc/#######/stat\0") 25 #define COMM_SCANF "%*[^)])" 26 27 unsigned long os_process_pc(int pid) 28 { 29 char proc_stat[STAT_PATH_LEN], buf[256]; 30 unsigned long pc = ARBITRARY_ADDR; 31 int fd, err; 32 33 sprintf(proc_stat, "/proc/%d/stat", pid); 34 fd = open(proc_stat, O_RDONLY, 0); 35 if (fd < 0) { 36 printk(UM_KERN_ERR "os_process_pc - couldn't open '%s', " 37 "errno = %d\n", proc_stat, errno); 38 goto out; 39 } 40 CATCH_EINTR(err = read(fd, buf, sizeof(buf))); 41 if (err < 0) { 42 printk(UM_KERN_ERR "os_process_pc - couldn't read '%s', " 43 "err = %d\n", proc_stat, errno); 44 goto out_close; 45 } 46 os_close_file(fd); 47 pc = ARBITRARY_ADDR; 48 if (sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d " 49 "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d " 50 "%*d %*d %*d %*d %*d %lu", &pc) != 1) 51 printk(UM_KERN_ERR "os_process_pc - couldn't find pc in '%s'\n", 52 buf); 53 out_close: 54 close(fd); 55 out: 56 return pc; 57 } 58 59 int os_process_parent(int pid) 60 { 61 char stat[STAT_PATH_LEN]; 62 char data[256]; 63 int parent = FAILURE_PID, n, fd; 64 65 if (pid == -1) 66 return parent; 67 68 snprintf(stat, sizeof(stat), "/proc/%d/stat", pid); 69 fd = open(stat, O_RDONLY, 0); 70 if (fd < 0) { 71 printk(UM_KERN_ERR "Couldn't open '%s', errno = %d\n", stat, 72 errno); 73 return parent; 74 } 75 76 CATCH_EINTR(n = read(fd, data, sizeof(data))); 77 close(fd); 78 79 if (n < 0) { 80 printk(UM_KERN_ERR "Couldn't read '%s', errno = %d\n", stat, 81 errno); 82 return parent; 83 } 84 85 parent = FAILURE_PID; 86 n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent); 87 if (n != 1) 88 printk(UM_KERN_ERR "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, __WALL)); 103 } 104 105 /* This is here uniquely to have access to the userspace errno, i.e. the one 106 * used by ptrace in case of error. 107 */ 108 109 long os_ptrace_ldt(long pid, long addr, long data) 110 { 111 int ret; 112 113 ret = ptrace(PTRACE_LDT, pid, addr, data); 114 115 if (ret < 0) 116 return -errno; 117 return ret; 118 } 119 120 /* Kill off a ptraced child by all means available. kill it normally first, 121 * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from 122 * which it can't exit directly. 123 */ 124 125 void os_kill_ptraced_process(int pid, int reap_child) 126 { 127 kill(pid, SIGKILL); 128 ptrace(PTRACE_KILL, pid); 129 ptrace(PTRACE_CONT, pid); 130 if (reap_child) 131 CATCH_EINTR(waitpid(pid, NULL, __WALL)); 132 } 133 134 /* Don't use the glibc version, which caches the result in TLS. It misses some 135 * syscalls, and also breaks with clone(), which does not unshare the TLS. 136 */ 137 138 int os_getpid(void) 139 { 140 return syscall(__NR_getpid); 141 } 142 143 int os_getpgrp(void) 144 { 145 return getpgrp(); 146 } 147 148 int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len, 149 int r, int w, int x) 150 { 151 void *loc; 152 int prot; 153 154 prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 155 (x ? PROT_EXEC : 0); 156 157 loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED, 158 fd, off); 159 if (loc == MAP_FAILED) 160 return -errno; 161 return 0; 162 } 163 164 int os_protect_memory(void *addr, unsigned long len, int r, int w, int x) 165 { 166 int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 167 (x ? PROT_EXEC : 0)); 168 169 if (mprotect(addr, len, prot) < 0) 170 return -errno; 171 172 return 0; 173 } 174 175 int os_unmap_memory(void *addr, int len) 176 { 177 int err; 178 179 err = munmap(addr, len); 180 if (err < 0) 181 return -errno; 182 return 0; 183 } 184 185 #ifndef MADV_REMOVE 186 #define MADV_REMOVE KERNEL_MADV_REMOVE 187 #endif 188 189 int os_drop_memory(void *addr, int length) 190 { 191 int err; 192 193 err = madvise(addr, length, MADV_REMOVE); 194 if (err < 0) 195 err = -errno; 196 return err; 197 } 198 199 int __init can_drop_memory(void) 200 { 201 void *addr; 202 int fd, ok = 0; 203 204 printk(UM_KERN_INFO "Checking host MADV_REMOVE support..."); 205 fd = create_mem_file(UM_KERN_PAGE_SIZE); 206 if (fd < 0) { 207 printk(UM_KERN_ERR "Creating test memory file failed, " 208 "err = %d\n", -fd); 209 goto out; 210 } 211 212 addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, 213 MAP_SHARED, fd, 0); 214 if (addr == MAP_FAILED) { 215 printk(UM_KERN_ERR "Mapping test memory file failed, " 216 "err = %d\n", -errno); 217 goto out_close; 218 } 219 220 if (madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0) { 221 printk(UM_KERN_ERR "MADV_REMOVE failed, err = %d\n", -errno); 222 goto out_unmap; 223 } 224 225 printk(UM_KERN_CONT "OK\n"); 226 ok = 1; 227 228 out_unmap: 229 munmap(addr, UM_KERN_PAGE_SIZE); 230 out_close: 231 close(fd); 232 out: 233 return ok; 234 } 235 236 static int os_page_mincore(void *addr) 237 { 238 char vec[2]; 239 int ret; 240 241 ret = mincore(addr, UM_KERN_PAGE_SIZE, vec); 242 if (ret < 0) { 243 if (errno == ENOMEM || errno == EINVAL) 244 return 0; 245 else 246 return -errno; 247 } 248 249 return vec[0] & 1; 250 } 251 252 int os_mincore(void *addr, unsigned long len) 253 { 254 char *vec; 255 int ret, i; 256 257 if (len <= UM_KERN_PAGE_SIZE) 258 return os_page_mincore(addr); 259 260 vec = calloc(1, (len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); 261 if (!vec) 262 return -ENOMEM; 263 264 ret = mincore(addr, UM_KERN_PAGE_SIZE, vec); 265 if (ret < 0) { 266 if (errno == ENOMEM || errno == EINVAL) 267 ret = 0; 268 else 269 ret = -errno; 270 271 goto out; 272 } 273 274 for (i = 0; i < ((len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); i++) { 275 if (!(vec[i] & 1)) { 276 ret = 0; 277 goto out; 278 } 279 } 280 281 ret = 1; 282 out: 283 free(vec); 284 return ret; 285 } 286 287 void init_new_thread_signals(void) 288 { 289 set_handler(SIGSEGV); 290 set_handler(SIGTRAP); 291 set_handler(SIGFPE); 292 set_handler(SIGILL); 293 set_handler(SIGBUS); 294 signal(SIGHUP, SIG_IGN); 295 set_handler(SIGIO); 296 signal(SIGWINCH, SIG_IGN); 297 } 298