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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c51
1 files changed, 29 insertions, 22 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 6067e429f28..933e60ebcca 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -22,6 +22,7 @@
#include <linux/mempolicy.h>
#include <linux/sem.h>
#include <linux/file.h>
+#include <linux/fdtable.h>
#include <linux/key.h>
#include <linux/binfmts.h>
#include <linux/mman.h>
@@ -381,14 +382,13 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
mm->ioctx_list = NULL;
mm->free_area_cache = TASK_UNMAPPED_BASE;
mm->cached_hole_size = ~0UL;
- mm_init_cgroup(mm, p);
+ mm_init_owner(mm, p);
if (likely(!mm_alloc_pgd(mm))) {
mm->def_flags = 0;
return mm;
}
- mm_free_cgroup(mm);
free_mm(mm);
return NULL;
}
@@ -432,13 +432,13 @@ void mmput(struct mm_struct *mm)
if (atomic_dec_and_test(&mm->mm_users)) {
exit_aio(mm);
exit_mmap(mm);
+ set_mm_exe_file(mm, NULL);
if (!list_empty(&mm->mmlist)) {
spin_lock(&mmlist_lock);
list_del(&mm->mmlist);
spin_unlock(&mmlist_lock);
}
put_swap_token(mm);
- mm_free_cgroup(mm);
mmdrop(mm);
}
}
@@ -545,6 +545,8 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
if (init_new_context(tsk, mm))
goto fail_nocontext;
+ dup_mm_exe_file(oldmm, mm);
+
err = dup_mmap(mm, oldmm);
if (err)
goto free_pt;
@@ -891,7 +893,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
sig->group_exit_code = 0;
sig->group_exit_task = NULL;
sig->group_stop_count = 0;
- sig->curr_target = NULL;
+ sig->curr_target = tsk;
init_sigpending(&sig->shared_pending);
INIT_LIST_HEAD(&sig->posix_timers);
@@ -982,6 +984,13 @@ static void rt_mutex_init_task(struct task_struct *p)
#endif
}
+#ifdef CONFIG_MM_OWNER
+void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
+{
+ mm->owner = p;
+}
+#endif /* CONFIG_MM_OWNER */
+
/*
* This creates a new process as a copy of the old one,
* but does not actually start it yet.
@@ -1664,18 +1673,6 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp
}
/*
- * Unsharing of semundo for tasks created with CLONE_SYSVSEM is not
- * supported yet
- */
-static int unshare_semundo(unsigned long unshare_flags, struct sem_undo_list **new_ulistp)
-{
- if (unshare_flags & CLONE_SYSVSEM)
- return -EINVAL;
-
- return 0;
-}
-
-/*
* unshare allows a process to 'unshare' part of the process
* context which was originally shared using clone. copy_*
* functions used by do_fork() cannot be used here directly
@@ -1690,8 +1687,8 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
struct sighand_struct *new_sigh = NULL;
struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
struct files_struct *fd, *new_fd = NULL;
- struct sem_undo_list *new_ulist = NULL;
struct nsproxy *new_nsproxy = NULL;
+ int do_sysvsem = 0;
check_unshare_flags(&unshare_flags);
@@ -1703,6 +1700,13 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
CLONE_NEWNET))
goto bad_unshare_out;
+ /*
+ * CLONE_NEWIPC must also detach from the undolist: after switching
+ * to a new ipc namespace, the semaphore arrays from the old
+ * namespace are unreachable.
+ */
+ if (unshare_flags & (CLONE_NEWIPC|CLONE_SYSVSEM))
+ do_sysvsem = 1;
if ((err = unshare_thread(unshare_flags)))
goto bad_unshare_out;
if ((err = unshare_fs(unshare_flags, &new_fs)))
@@ -1713,13 +1717,17 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
goto bad_unshare_cleanup_sigh;
if ((err = unshare_fd(unshare_flags, &new_fd)))
goto bad_unshare_cleanup_vm;
- if ((err = unshare_semundo(unshare_flags, &new_ulist)))
- goto bad_unshare_cleanup_fd;
if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy,
new_fs)))
- goto bad_unshare_cleanup_semundo;
+ goto bad_unshare_cleanup_fd;
- if (new_fs || new_mm || new_fd || new_ulist || new_nsproxy) {
+ if (new_fs || new_mm || new_fd || do_sysvsem || new_nsproxy) {
+ if (do_sysvsem) {
+ /*
+ * CLONE_SYSVSEM is equivalent to sys_exit().
+ */
+ exit_sem(current);
+ }
if (new_nsproxy) {
switch_task_namespaces(current, new_nsproxy);
@@ -1755,7 +1763,6 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
if (new_nsproxy)
put_nsproxy(new_nsproxy);
-bad_unshare_cleanup_semundo:
bad_unshare_cleanup_fd:
if (new_fd)
put_files_struct(new_fd);