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-rw-r--r--kernel/exit.c293
1 files changed, 148 insertions, 145 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index b6c90b5..628d41f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -375,9 +375,8 @@ static void set_special_pids(struct pid *pid)
}
/*
- * Let kernel threads use this to say that they
- * allow a certain signal (since daemonize() will
- * have disabled all of them by default).
+ * Let kernel threads use this to say that they allow a certain signal.
+ * Must not be used if kthread was cloned with CLONE_SIGHAND.
*/
int allow_signal(int sig)
{
@@ -385,14 +384,14 @@ int allow_signal(int sig)
return -EINVAL;
spin_lock_irq(&current->sighand->siglock);
+ /* This is only needed for daemonize()'ed kthreads */
sigdelset(&current->blocked, sig);
- if (!current->mm) {
- /* Kernel threads handle their own signals.
- Let the signal code know it'll be handled, so
- that they don't get converted to SIGKILL or
- just silently dropped */
- current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
- }
+ /*
+ * Kernel threads handle their own signals. Let the signal code
+ * know it'll be handled, so that they don't get converted to
+ * SIGKILL or just silently dropped.
+ */
+ current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
return 0;
@@ -591,7 +590,7 @@ retry:
/*
* Search in the siblings
*/
- list_for_each_entry(c, &p->parent->children, sibling) {
+ list_for_each_entry(c, &p->real_parent->children, sibling) {
if (c->mm == mm)
goto assign_new_owner;
}
@@ -758,7 +757,7 @@ static void reparent_thread(struct task_struct *father, struct task_struct *p,
p->exit_signal = SIGCHLD;
/* If it has exited notify the new parent about this child's death. */
- if (!p->ptrace &&
+ if (!task_ptrace(p) &&
p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
do_notify_parent(p, p->exit_signal);
if (task_detached(p)) {
@@ -783,7 +782,7 @@ static void forget_original_parent(struct task_struct *father)
list_for_each_entry_safe(p, n, &father->children, sibling) {
p->real_parent = reaper;
if (p->parent == father) {
- BUG_ON(p->ptrace);
+ BUG_ON(task_ptrace(p));
p->parent = p->real_parent;
}
reparent_thread(father, p, &dead_children);
@@ -1081,6 +1080,18 @@ SYSCALL_DEFINE1(exit_group, int, error_code)
return 0;
}
+struct wait_opts {
+ enum pid_type wo_type;
+ int wo_flags;
+ struct pid *wo_pid;
+
+ struct siginfo __user *wo_info;
+ int __user *wo_stat;
+ struct rusage __user *wo_rusage;
+
+ int notask_error;
+};
+
static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
{
struct pid *pid = NULL;
@@ -1091,13 +1102,12 @@ static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
return pid;
}
-static int eligible_child(enum pid_type type, struct pid *pid, int options,
- struct task_struct *p)
+static int eligible_child(struct wait_opts *wo, struct task_struct *p)
{
int err;
- if (type < PIDTYPE_MAX) {
- if (task_pid_type(p, type) != pid)
+ if (wo->wo_type < PIDTYPE_MAX) {
+ if (task_pid_type(p, wo->wo_type) != wo->wo_pid)
return 0;
}
@@ -1106,8 +1116,8 @@ static int eligible_child(enum pid_type type, struct pid *pid, int options,
* set; otherwise, wait for non-clone children *only*. (Note:
* A "clone" child here is one that reports to its parent
* using a signal other than SIGCHLD.) */
- if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
- && !(options & __WALL))
+ if (((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
+ && !(wo->wo_flags & __WALL))
return 0;
err = security_task_wait(p);
@@ -1117,14 +1127,15 @@ static int eligible_child(enum pid_type type, struct pid *pid, int options,
return 1;
}
-static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid,
- int why, int status,
- struct siginfo __user *infop,
- struct rusage __user *rusagep)
+static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
+ pid_t pid, uid_t uid, int why, int status)
{
- int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0;
+ struct siginfo __user *infop;
+ int retval = wo->wo_rusage
+ ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
put_task_struct(p);
+ infop = wo->wo_info;
if (!retval)
retval = put_user(SIGCHLD, &infop->si_signo);
if (!retval)
@@ -1148,19 +1159,18 @@ static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid,
* the lock and this task is uninteresting. If we return nonzero, we have
* released the lock and the system call should return.
*/
-static int wait_task_zombie(struct task_struct *p, int options,
- struct siginfo __user *infop,
- int __user *stat_addr, struct rusage __user *ru)
+static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
{
unsigned long state;
int retval, status, traced;
pid_t pid = task_pid_vnr(p);
uid_t uid = __task_cred(p)->uid;
+ struct siginfo __user *infop;
- if (!likely(options & WEXITED))
+ if (!likely(wo->wo_flags & WEXITED))
return 0;
- if (unlikely(options & WNOWAIT)) {
+ if (unlikely(wo->wo_flags & WNOWAIT)) {
int exit_code = p->exit_code;
int why, status;
@@ -1173,8 +1183,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
status = exit_code & 0x7f;
}
- return wait_noreap_copyout(p, pid, uid, why,
- status, infop, ru);
+ return wait_noreap_copyout(wo, p, pid, uid, why, status);
}
/*
@@ -1188,11 +1197,13 @@ static int wait_task_zombie(struct task_struct *p, int options,
}
traced = ptrace_reparented(p);
-
- if (likely(!traced)) {
+ /*
+ * It can be ptraced but not reparented, check
+ * !task_detached() to filter out sub-threads.
+ */
+ if (likely(!traced) && likely(!task_detached(p))) {
struct signal_struct *psig;
struct signal_struct *sig;
- struct task_cputime cputime;
/*
* The resource counters for the group leader are in its
@@ -1205,26 +1216,23 @@ static int wait_task_zombie(struct task_struct *p, int options,
* p->signal fields, because they are only touched by
* __exit_signal, which runs with tasklist_lock
* write-locked anyway, and so is excluded here. We do
- * need to protect the access to p->parent->signal fields,
+ * need to protect the access to parent->signal fields,
* as other threads in the parent group can be right
* here reaping other children at the same time.
- *
- * We use thread_group_cputime() to get times for the thread
- * group, which consolidates times for all threads in the
- * group including the group leader.
*/
- thread_group_cputime(p, &cputime);
- spin_lock_irq(&p->parent->sighand->siglock);
- psig = p->parent->signal;
+ spin_lock_irq(&p->real_parent->sighand->siglock);
+ psig = p->real_parent->signal;
sig = p->signal;
psig->cutime =
cputime_add(psig->cutime,
- cputime_add(cputime.utime,
- sig->cutime));
+ cputime_add(p->utime,
+ cputime_add(sig->utime,
+ sig->cutime)));
psig->cstime =
cputime_add(psig->cstime,
- cputime_add(cputime.stime,
- sig->cstime));
+ cputime_add(p->stime,
+ cputime_add(sig->stime,
+ sig->cstime)));
psig->cgtime =
cputime_add(psig->cgtime,
cputime_add(p->gtime,
@@ -1246,7 +1254,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
sig->oublock + sig->coublock;
task_io_accounting_add(&psig->ioac, &p->ioac);
task_io_accounting_add(&psig->ioac, &sig->ioac);
- spin_unlock_irq(&p->parent->sighand->siglock);
+ spin_unlock_irq(&p->real_parent->sighand->siglock);
}
/*
@@ -1255,11 +1263,14 @@ static int wait_task_zombie(struct task_struct *p, int options,
*/
read_unlock(&tasklist_lock);
- retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
+ retval = wo->wo_rusage
+ ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
status = (p->signal->flags & SIGNAL_GROUP_EXIT)
? p->signal->group_exit_code : p->exit_code;
- if (!retval && stat_addr)
- retval = put_user(status, stat_addr);
+ if (!retval && wo->wo_stat)
+ retval = put_user(status, wo->wo_stat);
+
+ infop = wo->wo_info;
if (!retval && infop)
retval = put_user(SIGCHLD, &infop->si_signo);
if (!retval && infop)
@@ -1327,15 +1338,18 @@ static int *task_stopped_code(struct task_struct *p, bool ptrace)
* the lock and this task is uninteresting. If we return nonzero, we have
* released the lock and the system call should return.
*/
-static int wait_task_stopped(int ptrace, struct task_struct *p,
- int options, struct siginfo __user *infop,
- int __user *stat_addr, struct rusage __user *ru)
+static int wait_task_stopped(struct wait_opts *wo,
+ int ptrace, struct task_struct *p)
{
+ struct siginfo __user *infop;
int retval, exit_code, *p_code, why;
uid_t uid = 0; /* unneeded, required by compiler */
pid_t pid;
- if (!(options & WUNTRACED))
+ /*
+ * Traditionally we see ptrace'd stopped tasks regardless of options.
+ */
+ if (!ptrace && !(wo->wo_flags & WUNTRACED))
return 0;
exit_code = 0;
@@ -1349,7 +1363,7 @@ static int wait_task_stopped(int ptrace, struct task_struct *p,
if (!exit_code)
goto unlock_sig;
- if (!unlikely(options & WNOWAIT))
+ if (!unlikely(wo->wo_flags & WNOWAIT))
*p_code = 0;
/* don't need the RCU readlock here as we're holding a spinlock */
@@ -1371,14 +1385,15 @@ unlock_sig:
why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
read_unlock(&tasklist_lock);
- if (unlikely(options & WNOWAIT))
- return wait_noreap_copyout(p, pid, uid,
- why, exit_code,
- infop, ru);
+ if (unlikely(wo->wo_flags & WNOWAIT))
+ return wait_noreap_copyout(wo, p, pid, uid, why, exit_code);
- retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
- if (!retval && stat_addr)
- retval = put_user((exit_code << 8) | 0x7f, stat_addr);
+ retval = wo->wo_rusage
+ ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
+ if (!retval && wo->wo_stat)
+ retval = put_user((exit_code << 8) | 0x7f, wo->wo_stat);
+
+ infop = wo->wo_info;
if (!retval && infop)
retval = put_user(SIGCHLD, &infop->si_signo);
if (!retval && infop)
@@ -1405,15 +1420,13 @@ unlock_sig:
* the lock and this task is uninteresting. If we return nonzero, we have
* released the lock and the system call should return.
*/
-static int wait_task_continued(struct task_struct *p, int options,
- struct siginfo __user *infop,
- int __user *stat_addr, struct rusage __user *ru)
+static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
{
int retval;
pid_t pid;
uid_t uid;
- if (!unlikely(options & WCONTINUED))
+ if (!unlikely(wo->wo_flags & WCONTINUED))
return 0;
if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
@@ -1425,7 +1438,7 @@ static int wait_task_continued(struct task_struct *p, int options,
spin_unlock_irq(&p->sighand->siglock);
return 0;
}
- if (!unlikely(options & WNOWAIT))
+ if (!unlikely(wo->wo_flags & WNOWAIT))
p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
uid = __task_cred(p)->uid;
spin_unlock_irq(&p->sighand->siglock);
@@ -1434,17 +1447,17 @@ static int wait_task_continued(struct task_struct *p, int options,
get_task_struct(p);
read_unlock(&tasklist_lock);
- if (!infop) {
- retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
+ if (!wo->wo_info) {
+ retval = wo->wo_rusage
+ ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
put_task_struct(p);
- if (!retval && stat_addr)
- retval = put_user(0xffff, stat_addr);
+ if (!retval && wo->wo_stat)
+ retval = put_user(0xffff, wo->wo_stat);
if (!retval)
retval = pid;
} else {
- retval = wait_noreap_copyout(p, pid, uid,
- CLD_CONTINUED, SIGCONT,
- infop, ru);
+ retval = wait_noreap_copyout(wo, p, pid, uid,
+ CLD_CONTINUED, SIGCONT);
BUG_ON(retval == 0);
}
@@ -1454,19 +1467,16 @@ static int wait_task_continued(struct task_struct *p, int options,
/*
* Consider @p for a wait by @parent.
*
- * -ECHILD should be in *@notask_error before the first call.
+ * -ECHILD should be in ->notask_error before the first call.
* Returns nonzero for a final return, when we have unlocked tasklist_lock.
* Returns zero if the search for a child should continue;
- * then *@notask_error is 0 if @p is an eligible child,
+ * then ->notask_error is 0 if @p is an eligible child,
* or another error from security_task_wait(), or still -ECHILD.
*/
-static int wait_consider_task(struct task_struct *parent, int ptrace,
- struct task_struct *p, int *notask_error,
- enum pid_type type, struct pid *pid, int options,
- struct siginfo __user *infop,
- int __user *stat_addr, struct rusage __user *ru)
+static int wait_consider_task(struct wait_opts *wo, struct task_struct *parent,
+ int ptrace, struct task_struct *p)
{
- int ret = eligible_child(type, pid, options, p);
+ int ret = eligible_child(wo, p);
if (!ret)
return ret;
@@ -1478,17 +1488,17 @@ static int wait_consider_task(struct task_struct *parent, int ptrace,
* to look for security policy problems, rather
* than for mysterious wait bugs.
*/
- if (*notask_error)
- *notask_error = ret;
+ if (wo->notask_error)
+ wo->notask_error = ret;
return 0;
}
- if (likely(!ptrace) && unlikely(p->ptrace)) {
+ if (likely(!ptrace) && unlikely(task_ptrace(p))) {
/*
* This child is hidden by ptrace.
* We aren't allowed to see it now, but eventually we will.
*/
- *notask_error = 0;
+ wo->notask_error = 0;
return 0;
}
@@ -1499,34 +1509,30 @@ static int wait_consider_task(struct task_struct *parent, int ptrace,
* We don't reap group leaders with subthreads.
*/
if (p->exit_state == EXIT_ZOMBIE && !delay_group_leader(p))
- return wait_task_zombie(p, options, infop, stat_addr, ru);
+ return wait_task_zombie(wo, p);
/*
* It's stopped or running now, so it might
* later continue, exit, or stop again.
*/
- *notask_error = 0;
+ wo->notask_error = 0;
if (task_stopped_code(p, ptrace))
- return wait_task_stopped(ptrace, p, options,
- infop, stat_addr, ru);
+ return wait_task_stopped(wo, ptrace, p);
- return wait_task_continued(p, options, infop, stat_addr, ru);
+ return wait_task_continued(wo, p);
}
/*
* Do the work of do_wait() for one thread in the group, @tsk.
*
- * -ECHILD should be in *@notask_error before the first call.
+ * -ECHILD should be in ->notask_error before the first call.
* Returns nonzero for a final return, when we have unlocked tasklist_lock.
* Returns zero if the search for a child should continue; then
- * *@notask_error is 0 if there were any eligible children,
+ * ->notask_error is 0 if there were any eligible children,
* or another error from security_task_wait(), or still -ECHILD.
*/
-static int do_wait_thread(struct task_struct *tsk, int *notask_error,
- enum pid_type type, struct pid *pid, int options,
- struct siginfo __user *infop, int __user *stat_addr,
- struct rusage __user *ru)
+static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk)
{
struct task_struct *p;
@@ -1535,9 +1541,7 @@ static int do_wait_thread(struct task_struct *tsk, int *notask_error,
* Do not consider detached threads.
*/
if (!task_detached(p)) {
- int ret = wait_consider_task(tsk, 0, p, notask_error,
- type, pid, options,
- infop, stat_addr, ru);
+ int ret = wait_consider_task(wo, tsk, 0, p);
if (ret)
return ret;
}
@@ -1546,22 +1550,12 @@ static int do_wait_thread(struct task_struct *tsk, int *notask_error,
return 0;
}
-static int ptrace_do_wait(struct task_struct *tsk, int *notask_error,
- enum pid_type type, struct pid *pid, int options,
- struct siginfo __user *infop, int __user *stat_addr,
- struct rusage __user *ru)
+static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
{
struct task_struct *p;
- /*
- * Traditionally we see ptrace'd stopped tasks regardless of options.
- */
- options |= WUNTRACED;
-
list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
- int ret = wait_consider_task(tsk, 1, p, notask_error,
- type, pid, options,
- infop, stat_addr, ru);
+ int ret = wait_consider_task(wo, tsk, 1, p);
if (ret)
return ret;
}
@@ -1569,65 +1563,59 @@ static int ptrace_do_wait(struct task_struct *tsk, int *notask_error,
return 0;
}
-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)
+static long do_wait(struct wait_opts *wo)
{
DECLARE_WAITQUEUE(wait, current);
struct task_struct *tsk;
int retval;
- trace_sched_process_wait(pid);
+ trace_sched_process_wait(wo->wo_pid);
add_wait_queue(&current->signal->wait_chldexit,&wait);
repeat:
/*
* If there is nothing that can match our critiera just get out.
- * We will clear @retval to zero if we see any child that might later
- * match our criteria, even if we are not able to reap it yet.
+ * We will clear ->notask_error to zero if we see any child that
+ * might later match our criteria, even if we are not able to reap
+ * it yet.
*/
- retval = -ECHILD;
- if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type])))
- goto end;
+ wo->notask_error = -ECHILD;
+ if ((wo->wo_type < PIDTYPE_MAX) &&
+ (!wo->wo_pid || hlist_empty(&wo->wo_pid->tasks[wo->wo_type])))
+ goto notask;
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
read_lock(&tasklist_lock);
tsk = current;
do {
- int tsk_result = do_wait_thread(tsk, &retval,
- type, pid, options,
- infop, stat_addr, ru);
- if (!tsk_result)
- tsk_result = ptrace_do_wait(tsk, &retval,
- type, pid, options,
- infop, stat_addr, ru);
- if (tsk_result) {
- /*
- * tasklist_lock is unlocked and we have a final result.
- */
- retval = tsk_result;
+ retval = do_wait_thread(wo, tsk);
+ if (retval)
+ goto end;
+
+ retval = ptrace_do_wait(wo, tsk);
+ if (retval)
goto end;
- }
- if (options & __WNOTHREAD)
+ if (wo->wo_flags & __WNOTHREAD)
break;
- tsk = next_thread(tsk);
- BUG_ON(tsk->signal != current->signal);
- } while (tsk != current);
+ } while_each_thread(current, tsk);
read_unlock(&tasklist_lock);
- if (!retval && !(options & WNOHANG)) {
+notask:
+ retval = wo->notask_error;
+ if (!retval && !(wo->wo_flags & WNOHANG)) {
retval = -ERESTARTSYS;
if (!signal_pending(current)) {
schedule();
goto repeat;
}
}
-
end:
- current->state = TASK_RUNNING;
+ __set_current_state(TASK_RUNNING);
remove_wait_queue(&current->signal->wait_chldexit,&wait);
- if (infop) {
+ if (wo->wo_info) {
+ struct siginfo __user *infop = wo->wo_info;
+
if (retval > 0)
retval = 0;
else {
@@ -1656,6 +1644,7 @@ end:
SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
infop, int, options, struct rusage __user *, ru)
{
+ struct wait_opts wo;
struct pid *pid = NULL;
enum pid_type type;
long ret;
@@ -1685,7 +1674,14 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
if (type < PIDTYPE_MAX)
pid = find_get_pid(upid);
- ret = do_wait(type, pid, options, infop, NULL, ru);
+
+ wo.wo_type = type;
+ wo.wo_pid = pid;
+ wo.wo_flags = options;
+ wo.wo_info = infop;
+ wo.wo_stat = NULL;
+ wo.wo_rusage = ru;
+ ret = do_wait(&wo);
put_pid(pid);
/* avoid REGPARM breakage on x86: */
@@ -1696,6 +1692,7 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
int, options, struct rusage __user *, ru)
{
+ struct wait_opts wo;
struct pid *pid = NULL;
enum pid_type type;
long ret;
@@ -1717,7 +1714,13 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
pid = find_get_pid(upid);
}
- ret = do_wait(type, pid, options | WEXITED, NULL, stat_addr, ru);
+ wo.wo_type = type;
+ wo.wo_pid = pid;
+ wo.wo_flags = options | WEXITED;
+ wo.wo_info = NULL;
+ wo.wo_stat = stat_addr;
+ wo.wo_rusage = ru;
+ ret = do_wait(&wo);
put_pid(pid);
/* avoid REGPARM breakage on x86: */
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