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