diff options
Diffstat (limited to 'arch/um/os-Linux/process.c')
| -rw-r--r-- | arch/um/os-Linux/process.c | 153 |
1 files changed, 59 insertions, 94 deletions
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c index b8f34c9e53ae..3a2a84ab9325 100644 --- a/arch/um/os-Linux/process.c +++ b/arch/um/os-Linux/process.c @@ -1,119 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 /* + * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de) * 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 <limits.h> +#include <linux/futex.h> #include <sys/mman.h> #include <sys/ptrace.h> +#include <sys/prctl.h> #include <sys/wait.h> #include <asm/unistd.h> #include <init.h> #include <longjmp.h> #include <os.h> -#include <skas_ptrace.h> +#include <skas/skas.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) +void os_alarm_process(int pid) { - char proc_stat[STAT_PATH_LEN], buf[256]; - unsigned long pc = ARBITRARY_ADDR; - int fd, err; + if (pid <= 0) + return; - 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; + kill(pid, SIGALRM); } -int os_process_parent(int pid) +void os_kill_process(int pid, int reap_child) { - 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; - } + if (pid <= 0) + return; - 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); + /* Block signals until child is reaped */ + block_signals(); - 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)); -} - -/* 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; + unblock_signals(); } /* Kill off a ptraced child by all means available. kill it normally first, @@ -123,11 +52,27 @@ long os_ptrace_ldt(long pid, long addr, long data) void os_kill_ptraced_process(int pid, int reap_child) { + if (pid <= 0) + return; + + /* Block signals until child is reaped */ + block_signals(); + kill(pid, SIGKILL); ptrace(PTRACE_KILL, pid); ptrace(PTRACE_CONT, pid); if (reap_child) CATCH_EINTR(waitpid(pid, NULL, __WALL)); + + unblock_signals(); +} + +pid_t os_reap_child(void) +{ + int status; + + /* Try to reap a child */ + return waitpid(-1, &status, WNOHANG); } /* Don't use the glibc version, which caches the result in TLS. It misses some @@ -139,11 +84,6 @@ 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) { @@ -241,6 +181,31 @@ void init_new_thread_signals(void) set_handler(SIGBUS); signal(SIGHUP, SIG_IGN); set_handler(SIGIO); + /* We (currently) only use the child reaper IRQ in seccomp mode */ + if (using_seccomp) + set_handler(SIGCHLD); signal(SIGWINCH, SIG_IGN); - signal(SIGTERM, SIG_DFL); +} + +void os_set_pdeathsig(void) +{ + prctl(PR_SET_PDEATHSIG, SIGKILL); +} + +int os_futex_wait(void *uaddr, unsigned int val) +{ + int r; + + CATCH_EINTR(r = syscall(__NR_futex, uaddr, FUTEX_WAIT, val, + NULL, NULL, 0)); + return r < 0 ? -errno : r; +} + +int os_futex_wake(void *uaddr) +{ + int r; + + CATCH_EINTR(r = syscall(__NR_futex, uaddr, FUTEX_WAKE, INT_MAX, + NULL, NULL, 0)); + return r < 0 ? -errno : r; } |