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-rw-r--r--kernel/fork.c154
1 files changed, 42 insertions, 112 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 05b92c45701..e7548dee636 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -40,6 +40,7 @@
#include <linux/tracehook.h>
#include <linux/futex.h>
#include <linux/compat.h>
+#include <linux/kthread.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/rcupdate.h>
#include <linux/ptrace.h>
@@ -109,20 +110,25 @@ int nr_processes(void)
}
#ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
-# define alloc_task_struct() kmem_cache_alloc(task_struct_cachep, GFP_KERNEL)
-# define free_task_struct(tsk) kmem_cache_free(task_struct_cachep, (tsk))
+# define alloc_task_struct_node(node) \
+ kmem_cache_alloc_node(task_struct_cachep, GFP_KERNEL, node)
+# define free_task_struct(tsk) \
+ kmem_cache_free(task_struct_cachep, (tsk))
static struct kmem_cache *task_struct_cachep;
#endif
#ifndef __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-static inline struct thread_info *alloc_thread_info(struct task_struct *tsk)
+static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
+ int node)
{
#ifdef CONFIG_DEBUG_STACK_USAGE
gfp_t mask = GFP_KERNEL | __GFP_ZERO;
#else
gfp_t mask = GFP_KERNEL;
#endif
- return (struct thread_info *)__get_free_pages(mask, THREAD_SIZE_ORDER);
+ struct page *page = alloc_pages_node(node, mask, THREAD_SIZE_ORDER);
+
+ return page ? page_address(page) : NULL;
}
static inline void free_thread_info(struct thread_info *ti)
@@ -249,16 +255,16 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
struct task_struct *tsk;
struct thread_info *ti;
unsigned long *stackend;
-
+ int node = tsk_fork_get_node(orig);
int err;
prepare_to_copy(orig);
- tsk = alloc_task_struct();
+ tsk = alloc_task_struct_node(node);
if (!tsk)
return NULL;
- ti = alloc_thread_info(tsk);
+ ti = alloc_thread_info_node(tsk, node);
if (!ti) {
free_task_struct(tsk);
return NULL;
@@ -1181,12 +1187,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
pid = alloc_pid(p->nsproxy->pid_ns);
if (!pid)
goto bad_fork_cleanup_io;
-
- if (clone_flags & CLONE_NEWPID) {
- retval = pid_ns_prepare_proc(p->nsproxy->pid_ns);
- if (retval < 0)
- goto bad_fork_free_pid;
- }
}
p->pid = pid_nr(pid);
@@ -1205,6 +1205,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
* Clear TID on mm_release()?
*/
p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
+#ifdef CONFIG_BLOCK
+ p->plug = NULL;
+#endif
#ifdef CONFIG_FUTEX
p->robust_list = NULL;
#ifdef CONFIG_COMPAT
@@ -1290,7 +1293,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
tracehook_finish_clone(p, clone_flags, trace);
if (thread_group_leader(p)) {
- if (clone_flags & CLONE_NEWPID)
+ if (is_child_reaper(pid))
p->nsproxy->pid_ns->child_reaper = p;
p->signal->leader_pid = pid;
@@ -1513,38 +1516,24 @@ void __init proc_caches_init(void)
}
/*
- * Check constraints on flags passed to the unshare system call and
- * force unsharing of additional process context as appropriate.
+ * Check constraints on flags passed to the unshare system call.
*/
-static void check_unshare_flags(unsigned long *flags_ptr)
+static int check_unshare_flags(unsigned long unshare_flags)
{
+ if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
+ CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
+ CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET))
+ return -EINVAL;
/*
- * If unsharing a thread from a thread group, must also
- * unshare vm.
- */
- if (*flags_ptr & CLONE_THREAD)
- *flags_ptr |= CLONE_VM;
-
- /*
- * If unsharing vm, must also unshare signal handlers.
- */
- if (*flags_ptr & CLONE_VM)
- *flags_ptr |= CLONE_SIGHAND;
-
- /*
- * If unsharing namespace, must also unshare filesystem information.
+ * Not implemented, but pretend it works if there is nothing to
+ * unshare. Note that unsharing CLONE_THREAD or CLONE_SIGHAND
+ * needs to unshare vm.
*/
- if (*flags_ptr & CLONE_NEWNS)
- *flags_ptr |= CLONE_FS;
-}
-
-/*
- * Unsharing of tasks created with CLONE_THREAD is not supported yet
- */
-static int unshare_thread(unsigned long unshare_flags)
-{
- if (unshare_flags & CLONE_THREAD)
- return -EINVAL;
+ if (unshare_flags & (CLONE_THREAD | CLONE_SIGHAND | CLONE_VM)) {
+ /* FIXME: get_task_mm() increments ->mm_users */
+ if (atomic_read(&current->mm->mm_users) > 1)
+ return -EINVAL;
+ }
return 0;
}
@@ -1571,34 +1560,6 @@ static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
}
/*
- * Unsharing of sighand is not supported yet
- */
-static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp)
-{
- struct sighand_struct *sigh = current->sighand;
-
- if ((unshare_flags & CLONE_SIGHAND) && atomic_read(&sigh->count) > 1)
- return -EINVAL;
- else
- return 0;
-}
-
-/*
- * Unshare vm if it is being shared
- */
-static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp)
-{
- struct mm_struct *mm = current->mm;
-
- if ((unshare_flags & CLONE_VM) &&
- (mm && atomic_read(&mm->mm_users) > 1)) {
- return -EINVAL;
- }
-
- return 0;
-}
-
-/*
* Unshare file descriptor table if it is being shared
*/
static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp)
@@ -1626,45 +1587,37 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp
*/
SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
{
- int err = 0;
struct fs_struct *fs, *new_fs = NULL;
- struct sighand_struct *new_sigh = NULL;
- struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
struct files_struct *fd, *new_fd = NULL;
struct nsproxy *new_nsproxy = NULL;
int do_sysvsem = 0;
+ int err;
- check_unshare_flags(&unshare_flags);
-
- /* Return -EINVAL for all unsupported flags */
- err = -EINVAL;
- if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
- CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
- CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET))
+ err = check_unshare_flags(unshare_flags);
+ if (err)
goto bad_unshare_out;
/*
+ * If unsharing namespace, must also unshare filesystem information.
+ */
+ if (unshare_flags & CLONE_NEWNS)
+ unshare_flags |= CLONE_FS;
+ /*
* 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)))
- goto bad_unshare_cleanup_thread;
- if ((err = unshare_sighand(unshare_flags, &new_sigh)))
- goto bad_unshare_cleanup_fs;
- if ((err = unshare_vm(unshare_flags, &new_mm)))
- goto bad_unshare_cleanup_sigh;
+ goto bad_unshare_out;
if ((err = unshare_fd(unshare_flags, &new_fd)))
- goto bad_unshare_cleanup_vm;
+ goto bad_unshare_cleanup_fs;
if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy,
new_fs)))
goto bad_unshare_cleanup_fd;
- if (new_fs || new_mm || new_fd || do_sysvsem || new_nsproxy) {
+ if (new_fs || new_fd || do_sysvsem || new_nsproxy) {
if (do_sysvsem) {
/*
* CLONE_SYSVSEM is equivalent to sys_exit().
@@ -1690,19 +1643,6 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
spin_unlock(&fs->lock);
}
- if (new_mm) {
- mm = current->mm;
- active_mm = current->active_mm;
- current->mm = new_mm;
- current->active_mm = new_mm;
- if (current->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
- atomic_dec(&mm->oom_disable_count);
- atomic_inc(&new_mm->oom_disable_count);
- }
- activate_mm(active_mm, new_mm);
- new_mm = mm;
- }
-
if (new_fd) {
fd = current->files;
current->files = new_fd;
@@ -1719,20 +1659,10 @@ bad_unshare_cleanup_fd:
if (new_fd)
put_files_struct(new_fd);
-bad_unshare_cleanup_vm:
- if (new_mm)
- mmput(new_mm);
-
-bad_unshare_cleanup_sigh:
- if (new_sigh)
- if (atomic_dec_and_test(&new_sigh->count))
- kmem_cache_free(sighand_cachep, new_sigh);
-
bad_unshare_cleanup_fs:
if (new_fs)
free_fs_struct(new_fs);
-bad_unshare_cleanup_thread:
bad_unshare_out:
return err;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-23 21:00:22 +0000