/* * Copyright (C) 2002 Jeff Dike (jdike@addtoit.com) * Licensed under the GPL */ #include <unistd.h> #include <stdio.h> #include <errno.h> #include <signal.h> #include <sys/mman.h> #include <sys/wait.h> #include <sys/mman.h> #include <sys/syscall.h> #include "ptrace_user.h" #include "os.h" #include "user.h" #include "user_util.h" #include "process.h" #include "irq_user.h" #include "kern_util.h" #include "longjmp.h" #include "skas_ptrace.h" #include "kern_constants.h" #include "uml-config.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; int fd, err; sprintf(proc_stat, "/proc/%d/stat", pid); fd = os_open_file(proc_stat, of_read(OPENFLAGS()), 0); if(fd < 0){ printk("os_process_pc - couldn't open '%s', err = %d\n", proc_stat, -fd); return(ARBITRARY_ADDR); } err = os_read_file(fd, buf, sizeof(buf)); if(err < 0){ printk("os_process_pc - couldn't read '%s', err = %d\n", proc_stat, -err); os_close_file(fd); return(ARBITRARY_ADDR); } 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("os_process_pc - couldn't find pc in '%s'\n", buf); } return(pc); } int os_process_parent(int pid) { char stat[STAT_PATH_LEN]; char data[256]; int parent, n, fd; if(pid == -1) return(-1); snprintf(stat, sizeof(stat), "/proc/%d/stat", pid); fd = os_open_file(stat, of_read(OPENFLAGS()), 0); if(fd < 0){ printk("Couldn't open '%s', err = %d\n", stat, -fd); return(FAILURE_PID); } n = os_read_file(fd, data, sizeof(data)); os_close_file(fd); if(n < 0){ printk("Couldn't read '%s', err = %d\n", stat, -n); return(FAILURE_PID); } parent = FAILURE_PID; n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent); if(n != 1) printk("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, 0)); } /* This is here uniquely to have access to the userspace errno, i.e. the one * used by ptrace in case of error. */ long os_ptrace_ldt(long pid, long addr, long data) { int ret; ret = ptrace(PTRACE_LDT, pid, addr, data); if (ret < 0) return -errno; return ret; } /* 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, 0)); } #ifdef UML_CONFIG_MODE_TT void os_usr1_process(int pid) { kill(pid, SIGUSR1); } #endif /* 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 can_drop_memory(void) { void *addr; int fd, ok = 0; printk("Checking host MADV_REMOVE support..."); fd = create_mem_file(UM_KERN_PAGE_SIZE); if(fd < 0){ printk("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("Mapping test memory file failed, err = %d\n", -errno); goto out_close; } if(madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0){ printk("MADV_REMOVE failed, err = %d\n", -errno); goto out_unmap; } printk("OK\n"); ok = 1; out_unmap: munmap(addr, UM_KERN_PAGE_SIZE); out_close: close(fd); out: return ok; } void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int)) { int flags = 0, pages; if(sig_stack != NULL){ pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER); set_sigstack(sig_stack, pages * page_size()); flags = SA_ONSTACK; } if(usr1_handler){ struct sigaction sa; sa.sa_handler = usr1_handler; sigemptyset(&sa.sa_mask); sa.sa_flags = flags; sa.sa_restorer = NULL; if(sigaction(SIGUSR1, &sa, NULL) < 0) panic("init_new_thread_stack - sigaction failed - " "errno = %d\n", errno); } } void init_new_thread_signals(void) { set_handler(SIGSEGV, (__sighandler_t) sig_handler, SA_ONSTACK, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); set_handler(SIGTRAP, (__sighandler_t) sig_handler, SA_ONSTACK, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); set_handler(SIGFPE, (__sighandler_t) sig_handler, SA_ONSTACK, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); set_handler(SIGILL, (__sighandler_t) sig_handler, SA_ONSTACK, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); set_handler(SIGBUS, (__sighandler_t) sig_handler, SA_ONSTACK, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); set_handler(SIGUSR2, (__sighandler_t) sig_handler, SA_ONSTACK, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); signal(SIGHUP, SIG_IGN); init_irq_signals(1); } int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr) { jmp_buf buf; int n; *jmp_ptr = &buf; n = UML_SETJMP(&buf); if(n != 0) return n; (*fn)(arg); return 0; }