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 /* Don't use the glibc version, which caches the result in TLS. It misses some 137 * syscalls, and also breaks with clone(), which does not unshare the TLS. 138 */ 139 140 int os_getpid(void) 141 { 142 return syscall(__NR_getpid); 143 } 144 145 int os_getpgrp(void) 146 { 147 return getpgrp(); 148 } 149 150 int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len, 151 int r, int w, int x) 152 { 153 void *loc; 154 int prot; 155 156 prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 157 (x ? PROT_EXEC : 0); 158 159 loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED, 160 fd, off); 161 if(loc == MAP_FAILED) 162 return -errno; 163 return 0; 164 } 165 166 int os_protect_memory(void *addr, unsigned long len, int r, int w, int x) 167 { 168 int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 169 (x ? PROT_EXEC : 0)); 170 171 if(mprotect(addr, len, prot) < 0) 172 return -errno; 173 return 0; 174 } 175 176 int os_unmap_memory(void *addr, int len) 177 { 178 int err; 179 180 err = munmap(addr, len); 181 if(err < 0) 182 return -errno; 183 return 0; 184 } 185 186 #ifndef MADV_REMOVE 187 #define MADV_REMOVE KERNEL_MADV_REMOVE 188 #endif 189 190 int os_drop_memory(void *addr, int length) 191 { 192 int err; 193 194 err = madvise(addr, length, MADV_REMOVE); 195 if(err < 0) 196 err = -errno; 197 return err; 198 } 199 200 int __init can_drop_memory(void) 201 { 202 void *addr; 203 int fd, ok = 0; 204 205 printk("Checking host MADV_REMOVE support..."); 206 fd = create_mem_file(UM_KERN_PAGE_SIZE); 207 if(fd < 0){ 208 printk("Creating test memory file failed, 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("Mapping test memory file failed, err = %d\n", -errno); 216 goto out_close; 217 } 218 219 if(madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0){ 220 printk("MADV_REMOVE failed, err = %d\n", -errno); 221 goto out_unmap; 222 } 223 224 printk("OK\n"); 225 ok = 1; 226 227 out_unmap: 228 munmap(addr, UM_KERN_PAGE_SIZE); 229 out_close: 230 close(fd); 231 out: 232 return ok; 233 } 234 235 void init_new_thread_signals(void) 236 { 237 set_handler(SIGSEGV, (__sighandler_t) sig_handler, SA_ONSTACK, 238 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 239 set_handler(SIGTRAP, (__sighandler_t) sig_handler, SA_ONSTACK, 240 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 241 set_handler(SIGFPE, (__sighandler_t) sig_handler, SA_ONSTACK, 242 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 243 set_handler(SIGILL, (__sighandler_t) sig_handler, SA_ONSTACK, 244 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 245 set_handler(SIGBUS, (__sighandler_t) sig_handler, SA_ONSTACK, 246 SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); 247 signal(SIGHUP, SIG_IGN); 248 249 init_irq_signals(1); 250 } 251 252 int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr) 253 { 254 jmp_buf buf; 255 int n; 256 257 *jmp_ptr = &buf; 258 n = UML_SETJMP(&buf); 259 if(n != 0) 260 return n; 261 (*fn)(arg); 262 return 0; 263 } 264