/* * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Licensed under the GPL */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <signal.h> #include <fcntl.h> #include <sys/mman.h> #include <sys/ptrace.h> #include <sys/wait.h> #include <asm/unistd.h> #include <init.h> #include <longjmp.h> #include <os.h> #define ARBITRARY_ADDR -1 #define FAILURE_PID -1 #define STAT_PATH_LEN sizeof("/proc/#######/stat\0") #define COMM_SCANF "%*[^)])" unsigned long os_process_pc(int pid) { char proc_stat[STAT_PATH_LEN], buf[256]; unsigned long pc = ARBITRARY_ADDR; int fd, err; sprintf(proc_stat, "/proc/%d/stat", pid); fd = open(proc_stat, O_RDONLY, 0); if (fd < 0) { printk(UM_KERN_ERR "os_process_pc - couldn't open '%s', " "errno = %d\n", proc_stat, errno); goto out; } CATCH_EINTR(err = read(fd, buf, sizeof(buf))); if (err < 0) { printk(UM_KERN_ERR "os_process_pc - couldn't read '%s', " "err = %d\n", proc_stat, errno); goto out_close; } os_close_file(fd); pc = ARBITRARY_ADDR; if (sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d " "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d " "%*d %*d %*d %*d %*d %lu", &pc) != 1) printk(UM_KERN_ERR "os_process_pc - couldn't find pc in '%s'\n", buf); out_close: close(fd); out: return pc; } int os_process_parent(int pid) { char stat[STAT_PATH_LEN]; char data[256]; int parent = FAILURE_PID, n, fd; if (pid == -1) return parent; snprintf(stat, sizeof(stat), "/proc/%d/stat", pid); fd = open(stat, O_RDONLY, 0); if (fd < 0) { printk(UM_KERN_ERR "Couldn't open '%s', errno = %d\n", stat, errno); return parent; } CATCH_EINTR(n = read(fd, data, sizeof(data))); close(fd); if (n < 0) { printk(UM_KERN_ERR "Couldn't read '%s', errno = %d\n", stat, errno); return parent; } parent = FAILURE_PID; n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent); if (n != 1) printk(UM_KERN_ERR "Failed to scan '%s'\n", data); return parent; } void os_stop_process(int pid) { kill(pid, SIGSTOP); } void os_kill_process(int pid, int reap_child) { kill(pid, SIGKILL); if (reap_child) CATCH_EINTR(waitpid(pid, NULL, __WALL)); } /* Kill off a ptraced child by all means available. kill it normally first, * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from * which it can't exit directly. */ void os_kill_ptraced_process(int pid, int reap_child) { kill(pid, SIGKILL); ptrace(PTRACE_KILL, pid); ptrace(PTRACE_CONT, pid); if (reap_child) CATCH_EINTR(waitpid(pid, NULL, __WALL)); } /* Don't use the glibc version, which caches the result in TLS. It misses some * syscalls, and also breaks with clone(), which does not unshare the TLS. */ int os_getpid(void) { return syscall(__NR_getpid); } int os_getpgrp(void) { return getpgrp(); } int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len, int r, int w, int x) { void *loc; int prot; prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | (x ? PROT_EXEC : 0); loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED, fd, off); if (loc == MAP_FAILED) return -errno; return 0; } int os_protect_memory(void *addr, unsigned long len, int r, int w, int x) { int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) | (x ? PROT_EXEC : 0)); if (mprotect(addr, len, prot) < 0) return -errno; return 0; } int os_unmap_memory(void *addr, int len) { int err; err = munmap(addr, len); if (err < 0) return -errno; return 0; } #ifndef MADV_REMOVE #define MADV_REMOVE KERNEL_MADV_REMOVE #endif int os_drop_memory(void *addr, int length) { int err; err = madvise(addr, length, MADV_REMOVE); if (err < 0) err = -errno; return err; } int __init can_drop_memory(void) { void *addr; int fd, ok = 0; printk(UM_KERN_INFO "Checking host MADV_REMOVE support..."); fd = create_mem_file(UM_KERN_PAGE_SIZE); if (fd < 0) { printk(UM_KERN_ERR "Creating test memory file failed, " "err = %d\n", -fd); goto out; } addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); if (addr == MAP_FAILED) { printk(UM_KERN_ERR "Mapping test memory file failed, " "err = %d\n", -errno); goto out_close; } if (madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0) { printk(UM_KERN_ERR "MADV_REMOVE failed, err = %d\n", -errno); goto out_unmap; } printk(UM_KERN_CONT "OK\n"); ok = 1; out_unmap: munmap(addr, UM_KERN_PAGE_SIZE); out_close: close(fd); out: return ok; } static int os_page_mincore(void *addr) { char vec[2]; int ret; ret = mincore(addr, UM_KERN_PAGE_SIZE, vec); if (ret < 0) { if (errno == ENOMEM || errno == EINVAL) return 0; else return -errno; } return vec[0] & 1; } int os_mincore(void *addr, unsigned long len) { char *vec; int ret, i; if (len <= UM_KERN_PAGE_SIZE) return os_page_mincore(addr); vec = calloc(1, (len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); if (!vec) return -ENOMEM; ret = mincore(addr, UM_KERN_PAGE_SIZE, vec); if (ret < 0) { if (errno == ENOMEM || errno == EINVAL) ret = 0; else ret = -errno; goto out; } for (i = 0; i < ((len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); i++) { if (!(vec[i] & 1)) { ret = 0; goto out; } } ret = 1; out: free(vec); return ret; } void init_new_thread_signals(void) { set_handler(SIGSEGV); set_handler(SIGTRAP); set_handler(SIGFPE); set_handler(SIGILL); set_handler(SIGBUS); signal(SIGHUP, SIG_IGN); set_handler(SIGIO); signal(SIGWINCH, SIG_IGN); }