11da177e4SLinus Torvalds /* 2ba180fd4SJeff Dike * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 31da177e4SLinus Torvalds * Licensed under the GPL 41da177e4SLinus Torvalds */ 51da177e4SLinus Torvalds 61da177e4SLinus Torvalds #include <stdio.h> 7ba180fd4SJeff Dike #include <unistd.h> 81da177e4SLinus Torvalds #include <errno.h> 91da177e4SLinus Torvalds #include <signal.h> 10512b6fb1SJeff Dike #include <fcntl.h> 111da177e4SLinus Torvalds #include <sys/mman.h> 12ba180fd4SJeff Dike #include <sys/ptrace.h> 131da177e4SLinus Torvalds #include <sys/wait.h> 14ba180fd4SJeff Dike #include <asm/unistd.h> 1536e45463SJeff Dike #include "init.h" 16ba180fd4SJeff Dike #include "longjmp.h" 17ba180fd4SJeff Dike #include "os.h" 18ba180fd4SJeff Dike #include "process.h" 19ba180fd4SJeff Dike #include "skas_ptrace.h" 201da177e4SLinus Torvalds 211da177e4SLinus Torvalds #define ARBITRARY_ADDR -1 221da177e4SLinus Torvalds #define FAILURE_PID -1 231da177e4SLinus Torvalds 241da177e4SLinus Torvalds #define STAT_PATH_LEN sizeof("/proc/#######/stat\0") 251da177e4SLinus Torvalds #define COMM_SCANF "%*[^)])" 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds unsigned long os_process_pc(int pid) 281da177e4SLinus Torvalds { 291da177e4SLinus Torvalds char proc_stat[STAT_PATH_LEN], buf[256]; 30512b6fb1SJeff Dike unsigned long pc = ARBITRARY_ADDR; 311da177e4SLinus Torvalds int fd, err; 321da177e4SLinus Torvalds 331da177e4SLinus Torvalds sprintf(proc_stat, "/proc/%d/stat", pid); 34512b6fb1SJeff Dike fd = open(proc_stat, O_RDONLY, 0); 351da177e4SLinus Torvalds if (fd < 0) { 36ba180fd4SJeff Dike printk(UM_KERN_ERR "os_process_pc - couldn't open '%s', " 37512b6fb1SJeff Dike "errno = %d\n", proc_stat, errno); 38512b6fb1SJeff Dike goto out; 391da177e4SLinus Torvalds } 40a61f334fSJeff Dike CATCH_EINTR(err = read(fd, buf, sizeof(buf))); 411da177e4SLinus Torvalds if (err < 0) { 42ba180fd4SJeff Dike printk(UM_KERN_ERR "os_process_pc - couldn't read '%s', " 43ba180fd4SJeff Dike "err = %d\n", proc_stat, errno); 44512b6fb1SJeff Dike goto out_close; 451da177e4SLinus Torvalds } 461da177e4SLinus Torvalds os_close_file(fd); 471da177e4SLinus Torvalds pc = ARBITRARY_ADDR; 481da177e4SLinus Torvalds if (sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d " 491da177e4SLinus Torvalds "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d " 50512b6fb1SJeff Dike "%*d %*d %*d %*d %*d %lu", &pc) != 1) 51ba180fd4SJeff Dike printk(UM_KERN_ERR "os_process_pc - couldn't find pc in '%s'\n", 52ba180fd4SJeff Dike buf); 53512b6fb1SJeff Dike out_close: 54512b6fb1SJeff Dike close(fd); 55512b6fb1SJeff Dike out: 56ef0470c0SJeff Dike return pc; 571da177e4SLinus Torvalds } 581da177e4SLinus Torvalds 591da177e4SLinus Torvalds int os_process_parent(int pid) 601da177e4SLinus Torvalds { 611da177e4SLinus Torvalds char stat[STAT_PATH_LEN]; 621da177e4SLinus Torvalds char data[256]; 63512b6fb1SJeff Dike int parent = FAILURE_PID, n, fd; 641da177e4SLinus Torvalds 65ef0470c0SJeff Dike if (pid == -1) 66512b6fb1SJeff Dike return parent; 671da177e4SLinus Torvalds 681da177e4SLinus Torvalds snprintf(stat, sizeof(stat), "/proc/%d/stat", pid); 69512b6fb1SJeff Dike fd = open(stat, O_RDONLY, 0); 701da177e4SLinus Torvalds if (fd < 0) { 71512b6fb1SJeff Dike printk(UM_KERN_ERR "Couldn't open '%s', errno = %d\n", stat, 72512b6fb1SJeff Dike errno); 73512b6fb1SJeff Dike return parent; 741da177e4SLinus Torvalds } 751da177e4SLinus Torvalds 76a61f334fSJeff Dike CATCH_EINTR(n = read(fd, data, sizeof(data))); 77512b6fb1SJeff Dike close(fd); 781da177e4SLinus Torvalds 791da177e4SLinus Torvalds if (n < 0) { 80512b6fb1SJeff Dike printk(UM_KERN_ERR "Couldn't read '%s', errno = %d\n", stat, 81ba180fd4SJeff Dike errno); 82512b6fb1SJeff Dike return parent; 831da177e4SLinus Torvalds } 841da177e4SLinus Torvalds 851da177e4SLinus Torvalds parent = FAILURE_PID; 861da177e4SLinus Torvalds n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent); 871da177e4SLinus Torvalds if (n != 1) 88ba180fd4SJeff Dike printk(UM_KERN_ERR "Failed to scan '%s'\n", data); 891da177e4SLinus Torvalds 90ef0470c0SJeff Dike return parent; 911da177e4SLinus Torvalds } 921da177e4SLinus Torvalds 931da177e4SLinus Torvalds void os_stop_process(int pid) 941da177e4SLinus Torvalds { 951da177e4SLinus Torvalds kill(pid, SIGSTOP); 961da177e4SLinus Torvalds } 971da177e4SLinus Torvalds 981da177e4SLinus Torvalds void os_kill_process(int pid, int reap_child) 991da177e4SLinus Torvalds { 1001da177e4SLinus Torvalds kill(pid, SIGKILL); 1011da177e4SLinus Torvalds if (reap_child) 1024dbed85aSStanislaw Gruszka CATCH_EINTR(waitpid(pid, NULL, __WALL)); 1031da177e4SLinus Torvalds } 1041da177e4SLinus Torvalds 10507f4e2c6SPaolo 'Blaisorblade' Giarrusso /* This is here uniquely to have access to the userspace errno, i.e. the one 10607f4e2c6SPaolo 'Blaisorblade' Giarrusso * used by ptrace in case of error. 10707f4e2c6SPaolo 'Blaisorblade' Giarrusso */ 10807f4e2c6SPaolo 'Blaisorblade' Giarrusso 10907f4e2c6SPaolo 'Blaisorblade' Giarrusso long os_ptrace_ldt(long pid, long addr, long data) 11007f4e2c6SPaolo 'Blaisorblade' Giarrusso { 11107f4e2c6SPaolo 'Blaisorblade' Giarrusso int ret; 11207f4e2c6SPaolo 'Blaisorblade' Giarrusso 11307f4e2c6SPaolo 'Blaisorblade' Giarrusso ret = ptrace(PTRACE_LDT, pid, addr, data); 11407f4e2c6SPaolo 'Blaisorblade' Giarrusso 11507f4e2c6SPaolo 'Blaisorblade' Giarrusso if (ret < 0) 11607f4e2c6SPaolo 'Blaisorblade' Giarrusso return -errno; 11707f4e2c6SPaolo 'Blaisorblade' Giarrusso return ret; 11807f4e2c6SPaolo 'Blaisorblade' Giarrusso } 11907f4e2c6SPaolo 'Blaisorblade' Giarrusso 1201da177e4SLinus Torvalds /* Kill off a ptraced child by all means available. kill it normally first, 1211da177e4SLinus Torvalds * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from 1221da177e4SLinus Torvalds * which it can't exit directly. 1231da177e4SLinus Torvalds */ 1241da177e4SLinus Torvalds 1251da177e4SLinus Torvalds void os_kill_ptraced_process(int pid, int reap_child) 1261da177e4SLinus Torvalds { 1271da177e4SLinus Torvalds kill(pid, SIGKILL); 1281da177e4SLinus Torvalds ptrace(PTRACE_KILL, pid); 1291da177e4SLinus Torvalds ptrace(PTRACE_CONT, pid); 1301da177e4SLinus Torvalds if (reap_child) 1314dbed85aSStanislaw Gruszka CATCH_EINTR(waitpid(pid, NULL, __WALL)); 1321da177e4SLinus Torvalds } 1331da177e4SLinus Torvalds 1341da177e4SLinus Torvalds /* Don't use the glibc version, which caches the result in TLS. It misses some 13560d339f6SGennady Sharapov * syscalls, and also breaks with clone(), which does not unshare the TLS. 13660d339f6SGennady Sharapov */ 13760d339f6SGennady Sharapov 1381da177e4SLinus Torvalds int os_getpid(void) 1391da177e4SLinus Torvalds { 140ef0470c0SJeff Dike return syscall(__NR_getpid); 1411da177e4SLinus Torvalds } 1421da177e4SLinus Torvalds 143cd2ee4a3SJeff Dike int os_getpgrp(void) 144cd2ee4a3SJeff Dike { 145cd2ee4a3SJeff Dike return getpgrp(); 146cd2ee4a3SJeff Dike } 147cd2ee4a3SJeff Dike 1481da177e4SLinus Torvalds int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len, 1491da177e4SLinus Torvalds int r, int w, int x) 1501da177e4SLinus Torvalds { 1511da177e4SLinus Torvalds void *loc; 1521da177e4SLinus Torvalds int prot; 1531da177e4SLinus Torvalds 1541da177e4SLinus Torvalds prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 1551da177e4SLinus Torvalds (x ? PROT_EXEC : 0); 1561da177e4SLinus Torvalds 1571da177e4SLinus Torvalds loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED, 1581da177e4SLinus Torvalds fd, off); 1591da177e4SLinus Torvalds if (loc == MAP_FAILED) 160ef0470c0SJeff Dike return -errno; 161ef0470c0SJeff Dike return 0; 1621da177e4SLinus Torvalds } 1631da177e4SLinus Torvalds 1641da177e4SLinus Torvalds int os_protect_memory(void *addr, unsigned long len, int r, int w, int x) 1651da177e4SLinus Torvalds { 1661da177e4SLinus Torvalds int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | 1671da177e4SLinus Torvalds (x ? PROT_EXEC : 0)); 1681da177e4SLinus Torvalds 1691da177e4SLinus Torvalds if (mprotect(addr, len, prot) < 0) 170ef0470c0SJeff Dike return -errno; 171ba180fd4SJeff Dike 172ef0470c0SJeff Dike return 0; 1731da177e4SLinus Torvalds } 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds int os_unmap_memory(void *addr, int len) 1761da177e4SLinus Torvalds { 1771da177e4SLinus Torvalds int err; 1781da177e4SLinus Torvalds 1791da177e4SLinus Torvalds err = munmap(addr, len); 1801da177e4SLinus Torvalds if (err < 0) 181ef0470c0SJeff Dike return -errno; 182ef0470c0SJeff Dike return 0; 1831da177e4SLinus Torvalds } 1841da177e4SLinus Torvalds 18502dea087SJeff Dike #ifndef MADV_REMOVE 186b73781c8SJeff Dike #define MADV_REMOVE KERNEL_MADV_REMOVE 18702dea087SJeff Dike #endif 18802dea087SJeff Dike 18997a1fcbbSJeff Dike int os_drop_memory(void *addr, int length) 19002dea087SJeff Dike { 19102dea087SJeff Dike int err; 19202dea087SJeff Dike 19302dea087SJeff Dike err = madvise(addr, length, MADV_REMOVE); 19402dea087SJeff Dike if (err < 0) 19502dea087SJeff Dike err = -errno; 19602dea087SJeff Dike return err; 19702dea087SJeff Dike } 19802dea087SJeff Dike 19936e45463SJeff Dike int __init can_drop_memory(void) 20002dea087SJeff Dike { 20102dea087SJeff Dike void *addr; 202e3104f50SJeff Dike int fd, ok = 0; 20302dea087SJeff Dike 204ba180fd4SJeff Dike printk(UM_KERN_INFO "Checking host MADV_REMOVE support..."); 20502dea087SJeff Dike fd = create_mem_file(UM_KERN_PAGE_SIZE); 20602dea087SJeff Dike if (fd < 0) { 207ba180fd4SJeff Dike printk(UM_KERN_ERR "Creating test memory file failed, " 208ba180fd4SJeff Dike "err = %d\n", -fd); 209e3104f50SJeff Dike goto out; 21002dea087SJeff Dike } 21102dea087SJeff Dike 21202dea087SJeff Dike addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, 213b73781c8SJeff Dike MAP_SHARED, fd, 0); 21402dea087SJeff Dike if (addr == MAP_FAILED) { 215ba180fd4SJeff Dike printk(UM_KERN_ERR "Mapping test memory file failed, " 216ba180fd4SJeff Dike "err = %d\n", -errno); 217e3104f50SJeff Dike goto out_close; 21802dea087SJeff Dike } 21902dea087SJeff Dike 22002dea087SJeff Dike if (madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0) { 221ba180fd4SJeff Dike printk(UM_KERN_ERR "MADV_REMOVE failed, err = %d\n", -errno); 222e3104f50SJeff Dike goto out_unmap; 22302dea087SJeff Dike } 22402dea087SJeff Dike 2255134d8feSJeff Dike printk(UM_KERN_CONT "OK\n"); 226e3104f50SJeff Dike ok = 1; 227e3104f50SJeff Dike 228e3104f50SJeff Dike out_unmap: 229e3104f50SJeff Dike munmap(addr, UM_KERN_PAGE_SIZE); 230e3104f50SJeff Dike out_close: 231e3104f50SJeff Dike close(fd); 232e3104f50SJeff Dike out: 233e3104f50SJeff Dike return ok; 23402dea087SJeff Dike } 23502dea087SJeff Dike 236e64bd134SJeff Dike void init_new_thread_signals(void) 23760d339f6SGennady Sharapov { 238*00361683SAl Viro set_handler(SIGSEGV); 239*00361683SAl Viro set_handler(SIGTRAP); 240*00361683SAl Viro set_handler(SIGFPE); 241*00361683SAl Viro set_handler(SIGILL); 242*00361683SAl Viro set_handler(SIGBUS); 24360d339f6SGennady Sharapov signal(SIGHUP, SIG_IGN); 244*00361683SAl Viro set_handler(SIGIO); 2453a24ebf0SJeff Dike signal(SIGWINCH, SIG_IGN); 246db271cf0SRichard Weinberger signal(SIGTERM, SIG_DFL); 24760d339f6SGennady Sharapov } 24860d339f6SGennady Sharapov 249fab95c55SJeff Dike int run_kernel_thread(int (*fn)(void *), void *arg, jmp_buf **jmp_ptr) 25060d339f6SGennady Sharapov { 251ad28e029SJeff Dike jmp_buf buf; 252a5df0d1aSJeff Dike int n; 25360d339f6SGennady Sharapov 25460d339f6SGennady Sharapov *jmp_ptr = &buf; 255a5df0d1aSJeff Dike n = UML_SETJMP(&buf); 25660d339f6SGennady Sharapov if (n != 0) 257a5df0d1aSJeff Dike return n; 25860d339f6SGennady Sharapov (*fn)(arg); 259a5df0d1aSJeff Dike return 0; 26060d339f6SGennady Sharapov } 261