diff options
| -rw-r--r-- | kernel/exit.c | 80 |
1 files changed, 56 insertions, 24 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 2b332d170327..2567de3487bd 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1090,20 +1090,23 @@ asmlinkage void sys_exit_group(int error_code) do_group_exit((error_code & 0xff) << 8); } -static int eligible_child(pid_t pid, int options, struct task_struct *p) +static struct pid *task_pid_type(struct task_struct *task, enum pid_type type) +{ + struct pid *pid = NULL; + if (type == PIDTYPE_PID) + pid = task->pids[type].pid; + else if (type < PIDTYPE_MAX) + pid = task->group_leader->pids[type].pid; + return pid; +} + +static int eligible_child(enum pid_type type, struct pid *pid, int options, + struct task_struct *p) { int err; - struct pid_namespace *ns; - ns = current->nsproxy->pid_ns; - if (pid > 0) { - if (task_pid_nr_ns(p, ns) != pid) - return 0; - } else if (!pid) { - if (task_pgrp_nr_ns(p, ns) != task_pgrp_vnr(current)) - return 0; - } else if (pid != -1) { - if (task_pgrp_nr_ns(p, ns) != -pid) + if (type < PIDTYPE_MAX) { + if (task_pid_type(p, type) != pid) return 0; } @@ -1127,7 +1130,7 @@ static int eligible_child(pid_t pid, int options, struct task_struct *p) if (likely(!err)) return 1; - if (pid <= 0) + if (type != PIDTYPE_PID) return 0; /* This child was explicitly requested, abort */ read_unlock(&tasklist_lock); @@ -1447,8 +1450,9 @@ static int wait_task_continued(struct task_struct *p, int noreap, return retval; } -static long do_wait(pid_t pid, int options, struct siginfo __user *infop, - int __user *stat_addr, struct rusage __user *ru) +static long do_wait(enum pid_type type, struct pid *pid, int options, + struct siginfo __user *infop, int __user *stat_addr, + struct rusage __user *ru) { DECLARE_WAITQUEUE(wait, current); struct task_struct *tsk; @@ -1456,6 +1460,11 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop, add_wait_queue(¤t->signal->wait_chldexit,&wait); repeat: + /* If there is nothing that can match our critier just get out */ + retval = -ECHILD; + if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type]))) + goto end; + /* * We will set this flag if we see any child that might later * match our criteria, even if we are not able to reap it yet. @@ -1468,7 +1477,7 @@ repeat: struct task_struct *p; list_for_each_entry(p, &tsk->children, sibling) { - int ret = eligible_child(pid, options, p); + int ret = eligible_child(type, pid, options, p); if (!ret) continue; @@ -1515,7 +1524,7 @@ repeat: if (!flag) { list_for_each_entry(p, &tsk->ptrace_children, ptrace_list) { - flag = eligible_child(pid, options, p); + flag = eligible_child(type, pid, options, p); if (!flag) continue; if (likely(flag > 0)) @@ -1570,10 +1579,12 @@ end: return retval; } -asmlinkage long sys_waitid(int which, pid_t pid, +asmlinkage long sys_waitid(int which, pid_t upid, struct siginfo __user *infop, int options, struct rusage __user *ru) { + struct pid *pid = NULL; + enum pid_type type; long ret; if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED)) @@ -1583,37 +1594,58 @@ asmlinkage long sys_waitid(int which, pid_t pid, switch (which) { case P_ALL: - pid = -1; + type = PIDTYPE_MAX; break; case P_PID: - if (pid <= 0) + type = PIDTYPE_PID; + if (upid <= 0) return -EINVAL; break; case P_PGID: - if (pid <= 0) + type = PIDTYPE_PGID; + if (upid <= 0) return -EINVAL; - pid = -pid; break; default: return -EINVAL; } - ret = do_wait(pid, options, infop, NULL, ru); + if (type < PIDTYPE_MAX) + pid = find_get_pid(upid); + ret = do_wait(type, pid, options, infop, NULL, ru); + put_pid(pid); /* avoid REGPARM breakage on x86: */ prevent_tail_call(ret); return ret; } -asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr, +asmlinkage long sys_wait4(pid_t upid, int __user *stat_addr, int options, struct rusage __user *ru) { + struct pid *pid = NULL; + enum pid_type type; long ret; if (options & ~(WNOHANG|WUNTRACED|WCONTINUED| __WNOTHREAD|__WCLONE|__WALL)) return -EINVAL; - ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru); + + if (upid == -1) + type = PIDTYPE_MAX; + else if (upid < 0) { + type = PIDTYPE_PGID; + pid = find_get_pid(-upid); + } else if (upid == 0) { + type = PIDTYPE_PGID; + pid = get_pid(task_pgrp(current)); + } else /* upid > 0 */ { + type = PIDTYPE_PID; + pid = find_get_pid(upid); + } + + ret = do_wait(type, pid, options | WEXITED, NULL, stat_addr, ru); + put_pid(pid); /* avoid REGPARM breakage on x86: */ prevent_tail_call(ret); |