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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c76
1 files changed, 50 insertions, 26 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index ca9df8c2933..f929b83c1e1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -80,6 +80,7 @@
#include <asm/tlbflush.h>
#include <trace/events/sched.h>
+#include <trace/events/sys_calls.h>
#define CREATE_TRACE_POINTS
#include <trace/events/task.h>
@@ -326,6 +327,8 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
if (err)
goto free_ti;
+ tsk->flags &= ~PF_SU;
+
tsk->stack = ti;
#ifdef CONFIG_SECCOMP
/*
@@ -569,6 +572,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
mm->cached_hole_size = ~0UL;
mm_init_aio(mm);
mm_init_owner(mm, p);
+ clear_tlb_flush_pending(mm);
if (likely(!mm_alloc_pgd(mm))) {
mm->def_flags = 0;
@@ -1234,10 +1238,11 @@ static struct task_struct *copy_process(unsigned long clone_flags,
return ERR_PTR(-EINVAL);
/*
- * If the new process will be in a different pid namespace
- * don't allow the creation of threads.
+ * If the new process will be in a different pid namespace don't
+ * allow it to share a thread group or signal handlers with the
+ * forking task.
*/
- if ((clone_flags & (CLONE_VM|CLONE_NEWPID)) &&
+ if ((clone_flags & (CLONE_SIGHAND | CLONE_NEWPID)) &&
(task_active_pid_ns(current) != current->nsproxy->pid_ns))
return ERR_PTR(-EINVAL);
@@ -1380,7 +1385,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto bad_fork_cleanup_policy;
retval = audit_alloc(p);
if (retval)
- goto bad_fork_cleanup_policy;
+ goto bad_fork_cleanup_perf;
/* copy all the process information */
retval = copy_semundo(clone_flags, p);
if (retval)
@@ -1515,14 +1520,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto bad_fork_free_pid;
}
- if (clone_flags & CLONE_THREAD) {
- current->signal->nr_threads++;
- atomic_inc(&current->signal->live);
- atomic_inc(&current->signal->sigcnt);
- p->group_leader = current->group_leader;
- list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
- }
-
if (likely(p->pid)) {
ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
@@ -1540,6 +1537,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
list_add_tail_rcu(&p->tasks, &init_task.tasks);
__this_cpu_inc(process_counts);
} else {
+ current->signal->nr_threads++;
+ atomic_inc(&current->signal->live);
+ atomic_inc(&current->signal->sigcnt);
+ p->group_leader = current->group_leader;
+ list_add_tail_rcu(&p->thread_group,
+ &p->group_leader->thread_group);
list_add_tail_rcu(&p->thread_node,
&p->signal->thread_head);
}
@@ -1549,7 +1552,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
total_forks++;
spin_unlock(&current->sighand->siglock);
+ syscall_tracepoint_update(p);
write_unlock_irq(&tasklist_lock);
+
proc_fork_connector(p);
cgroup_post_fork(p);
if (clone_flags & CLONE_THREAD)
@@ -1584,8 +1589,9 @@ bad_fork_cleanup_semundo:
exit_sem(p);
bad_fork_cleanup_audit:
audit_free(p);
-bad_fork_cleanup_policy:
+bad_fork_cleanup_perf:
perf_event_free_task(p);
+bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
mpol_put(p->mempolicy);
bad_fork_cleanup_cgroup:
@@ -1677,10 +1683,12 @@ long do_fork(unsigned long clone_flags,
*/
if (!IS_ERR(p)) {
struct completion vfork;
+ struct pid *pid;
trace_sched_process_fork(current, p);
- nr = task_pid_vnr(p);
+ pid = get_task_pid(p, PIDTYPE_PID);
+ nr = pid_vnr(pid);
if (clone_flags & CLONE_PARENT_SETTID)
put_user(nr, parent_tidptr);
@@ -1695,12 +1703,14 @@ long do_fork(unsigned long clone_flags,
/* forking complete and child started to run, tell ptracer */
if (unlikely(trace))
- ptrace_event(trace, nr);
+ ptrace_event_pid(trace, pid);
if (clone_flags & CLONE_VFORK) {
if (!wait_for_vfork_done(p, &vfork))
- ptrace_event(PTRACE_EVENT_VFORK_DONE, nr);
+ ptrace_event_pid(PTRACE_EVENT_VFORK_DONE, pid);
}
+
+ put_pid(pid);
} else {
nr = PTR_ERR(p);
}
@@ -1747,6 +1757,12 @@ SYSCALL_DEFINE5(clone, unsigned long, newsp, unsigned long, clone_flags,
int __user *, parent_tidptr,
int __user *, child_tidptr,
int, tls_val)
+#elif defined(CONFIG_CLONE_BACKWARDS3)
+SYSCALL_DEFINE6(clone, unsigned long, clone_flags, unsigned long, newsp,
+ int, stack_size,
+ int __user *, parent_tidptr,
+ int __user *, child_tidptr,
+ int, tls_val)
#else
SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
int __user *, parent_tidptr,
@@ -1811,13 +1827,21 @@ static int check_unshare_flags(unsigned long unshare_flags)
CLONE_NEWUSER|CLONE_NEWPID))
return -EINVAL;
/*
- * Not implemented, but pretend it works if there is nothing to
- * unshare. Note that unsharing CLONE_THREAD or CLONE_SIGHAND
- * needs to unshare vm.
+ * Not implemented, but pretend it works if there is nothing
+ * to unshare. Note that unsharing the address space or the
+ * signal handlers also need to unshare the signal queues (aka
+ * CLONE_THREAD).
*/
if (unshare_flags & (CLONE_THREAD | CLONE_SIGHAND | CLONE_VM)) {
- /* FIXME: get_task_mm() increments ->mm_users */
- if (atomic_read(&current->mm->mm_users) > 1)
+ if (!thread_group_empty(current))
+ return -EINVAL;
+ }
+ if (unshare_flags & (CLONE_SIGHAND | CLONE_VM)) {
+ if (atomic_read(&current->sighand->count) > 1)
+ return -EINVAL;
+ }
+ if (unshare_flags & CLONE_VM) {
+ if (!current_is_single_threaded())
return -EINVAL;
}
@@ -1891,16 +1915,16 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
if (unshare_flags & CLONE_NEWPID)
unshare_flags |= CLONE_THREAD;
/*
- * If unsharing a thread from a thread group, must also unshare vm.
- */
- if (unshare_flags & CLONE_THREAD)
- unshare_flags |= CLONE_VM;
- /*
* If unsharing vm, must also unshare signal handlers.
*/
if (unshare_flags & CLONE_VM)
unshare_flags |= CLONE_SIGHAND;
/*
+ * If unsharing a signal handlers, must also unshare the signal queues.
+ */
+ if (unshare_flags & CLONE_SIGHAND)
+ unshare_flags |= CLONE_THREAD;
+ /*
* If unsharing namespace, must also unshare filesystem information.
*/
if (unshare_flags & CLONE_NEWNS)
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-22 04:08:33 +0000