aboutsummaryrefslogtreecommitdiff
path: root/kernel/exit.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/exit.c')
-rw-r--r--kernel/exit.c84
1 files changed, 40 insertions, 44 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 80137a5d946..f80dec3f187 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -40,19 +40,24 @@
#include <linux/cn_proc.h>
#include <linux/mutex.h>
#include <linux/futex.h>
-#include <linux/compat.h>
#include <linux/pipe_fs_i.h>
#include <linux/audit.h> /* for audit_free() */
#include <linux/resource.h>
#include <linux/blkdev.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/tracehook.h>
+#include <linux/init_task.h>
#include <trace/sched.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include <asm/pgtable.h>
#include <asm/mmu_context.h>
+#include "cred-internals.h"
+
+DEFINE_TRACE(sched_process_free);
+DEFINE_TRACE(sched_process_exit);
+DEFINE_TRACE(sched_process_wait);
static void exit_mm(struct task_struct * tsk);
@@ -141,6 +146,11 @@ static void __exit_signal(struct task_struct *tsk)
if (sig) {
flush_sigqueue(&sig->shared_pending);
taskstats_tgid_free(sig);
+ /*
+ * Make sure ->signal can't go away under rq->lock,
+ * see account_group_exec_runtime().
+ */
+ task_rq_unlock_wait(tsk);
__cleanup_signal(sig);
}
}
@@ -160,7 +170,10 @@ void release_task(struct task_struct * p)
int zap_leader;
repeat:
tracehook_prepare_release_task(p);
- atomic_dec(&p->user->processes);
+ /* don't need to get the RCU readlock here - the process is dead and
+ * can't be modifying its own credentials */
+ atomic_dec(&__task_cred(p)->user->processes);
+
proc_flush_task(p);
write_lock_irq(&tasklist_lock);
tracehook_finish_release_task(p);
@@ -335,12 +348,12 @@ static void reparent_to_kthreadd(void)
/* cpus_allowed? */
/* rt_priority? */
/* signals? */
- security_task_reparent_to_init(current);
memcpy(current->signal->rlim, init_task.signal->rlim,
sizeof(current->signal->rlim));
- atomic_inc(&(INIT_USER->__count));
+
+ atomic_inc(&init_cred.usage);
+ commit_creds(&init_cred);
write_unlock_irq(&tasklist_lock);
- switch_uid(INIT_USER);
}
void __set_special_pids(struct pid *pid)
@@ -629,35 +642,31 @@ retry:
/*
* We found no owner yet mm_users > 1: this implies that we are
* most likely racing with swapoff (try_to_unuse()) or /proc or
- * ptrace or page migration (get_task_mm()). Mark owner as NULL,
- * so that subsystems can understand the callback and take action.
+ * ptrace or page migration (get_task_mm()). Mark owner as NULL.
*/
- down_write(&mm->mmap_sem);
- cgroup_mm_owner_callbacks(mm->owner, NULL);
mm->owner = NULL;
- up_write(&mm->mmap_sem);
return;
assign_new_owner:
BUG_ON(c == p);
get_task_struct(c);
- read_unlock(&tasklist_lock);
- down_write(&mm->mmap_sem);
/*
* The task_lock protects c->mm from changing.
* We always want mm->owner->mm == mm
*/
task_lock(c);
+ /*
+ * Delay read_unlock() till we have the task_lock()
+ * to ensure that c does not slip away underneath us
+ */
+ read_unlock(&tasklist_lock);
if (c->mm != mm) {
task_unlock(c);
- up_write(&mm->mmap_sem);
put_task_struct(c);
goto retry;
}
- cgroup_mm_owner_callbacks(mm->owner, c);
mm->owner = c;
task_unlock(c);
- up_write(&mm->mmap_sem);
put_task_struct(c);
}
#endif /* CONFIG_MM_OWNER */
@@ -1024,8 +1033,6 @@ NORET_TYPE void do_exit(long code)
* task into the wait for ever nirwana as well.
*/
tsk->flags |= PF_EXITPIDONE;
- if (tsk->io_context)
- exit_io_context();
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
}
@@ -1044,24 +1051,13 @@ NORET_TYPE void do_exit(long code)
preempt_count());
acct_update_integrals(tsk);
- if (tsk->mm) {
- update_hiwater_rss(tsk->mm);
- update_hiwater_vm(tsk->mm);
- }
+
group_dead = atomic_dec_and_test(&tsk->signal->live);
if (group_dead) {
hrtimer_cancel(&tsk->signal->real_timer);
exit_itimers(tsk->signal);
}
acct_collect(code, group_dead);
-#ifdef CONFIG_FUTEX
- if (unlikely(tsk->robust_list))
- exit_robust_list(tsk);
-#ifdef CONFIG_COMPAT
- if (unlikely(tsk->compat_robust_list))
- compat_exit_robust_list(tsk);
-#endif
-#endif
if (group_dead)
tty_audit_exit();
if (unlikely(tsk->audit_context))
@@ -1082,7 +1078,6 @@ NORET_TYPE void do_exit(long code)
check_stack_usage();
exit_thread();
cgroup_exit(tsk, 1);
- exit_keys(tsk);
if (group_dead && tsk->signal->leader)
disassociate_ctty(1);
@@ -1127,7 +1122,6 @@ NORET_TYPE void do_exit(long code)
preempt_disable();
/* causes final put_task_struct in finish_task_switch(). */
tsk->state = TASK_DEAD;
-
schedule();
BUG();
/* Avoid "noreturn function does return". */
@@ -1147,7 +1141,7 @@ NORET_TYPE void complete_and_exit(struct completion *comp, long code)
EXPORT_SYMBOL(complete_and_exit);
-asmlinkage long sys_exit(int error_code)
+SYSCALL_DEFINE1(exit, int, error_code)
{
do_exit((error_code&0xff)<<8);
}
@@ -1188,9 +1182,11 @@ do_group_exit(int exit_code)
* wait4()-ing process will get the correct exit code - even if this
* thread is not the thread group leader.
*/
-asmlinkage void sys_exit_group(int error_code)
+SYSCALL_DEFINE1(exit_group, int, error_code)
{
do_group_exit((error_code & 0xff) << 8);
+ /* NOTREACHED */
+ return 0;
}
static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
@@ -1267,12 +1263,12 @@ static int wait_task_zombie(struct task_struct *p, int options,
unsigned long state;
int retval, status, traced;
pid_t pid = task_pid_vnr(p);
+ uid_t uid = __task_cred(p)->uid;
if (!likely(options & WEXITED))
return 0;
if (unlikely(options & WNOWAIT)) {
- uid_t uid = p->uid;
int exit_code = p->exit_code;
int why, status;
@@ -1325,10 +1321,10 @@ static int wait_task_zombie(struct task_struct *p, int options,
* 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;
sig = p->signal;
- thread_group_cputime(p, &cputime);
psig->cutime =
cputime_add(psig->cutime,
cputime_add(cputime.utime,
@@ -1393,7 +1389,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
if (!retval && infop)
retval = put_user(pid, &infop->si_pid);
if (!retval && infop)
- retval = put_user(p->uid, &infop->si_uid);
+ retval = put_user(uid, &infop->si_uid);
if (!retval)
retval = pid;
@@ -1458,7 +1454,8 @@ static int wait_task_stopped(int ptrace, struct task_struct *p,
if (!unlikely(options & WNOWAIT))
p->exit_code = 0;
- uid = p->uid;
+ /* don't need the RCU readlock here as we're holding a spinlock */
+ uid = __task_cred(p)->uid;
unlock_sig:
spin_unlock_irq(&p->sighand->siglock);
if (!exit_code)
@@ -1532,10 +1529,10 @@ static int wait_task_continued(struct task_struct *p, int options,
}
if (!unlikely(options & WNOWAIT))
p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
+ uid = __task_cred(p)->uid;
spin_unlock_irq(&p->sighand->siglock);
pid = task_pid_vnr(p);
- uid = p->uid;
get_task_struct(p);
read_unlock(&tasklist_lock);
@@ -1757,9 +1754,8 @@ end:
return retval;
}
-asmlinkage long sys_waitid(int which, pid_t upid,
- struct siginfo __user *infop, int options,
- struct rusage __user *ru)
+SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
+ infop, int, options, struct rusage __user *, ru)
{
struct pid *pid = NULL;
enum pid_type type;
@@ -1798,8 +1794,8 @@ asmlinkage long sys_waitid(int which, pid_t upid,
return ret;
}
-asmlinkage long sys_wait4(pid_t upid, int __user *stat_addr,
- int options, struct rusage __user *ru)
+SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
+ int, options, struct rusage __user *, ru)
{
struct pid *pid = NULL;
enum pid_type type;
@@ -1836,7 +1832,7 @@ asmlinkage long sys_wait4(pid_t upid, int __user *stat_addr,
* sys_waitpid() remains for compatibility. waitpid() should be
* implemented by calling sys_wait4() from libc.a.
*/
-asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options)
+SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options)
{
return sys_wait4(pid, stat_addr, options, NULL);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-04 00:15:25 +0000