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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-01-30 16:35:18 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-01-30 16:35:18 -0500
commit444f378b237a0f728f5c4aba752c08d13c209344 (patch)
tree248fd00bb2e60cb0890fce38b6a66fed65f977e4
parent8c8c4bafc3a20a6fb9078315ff865bc42276f9ba (diff)
Revert "[PATCH] namespaces: fix exit race by splitting exit"
This reverts commit 7a238fcba0629b6f2edbcd37458bae56fcf36be5 in preparation for a better and simpler fix proposed by Eric Biederman (and fixed up by Serge Hallyn) Acked-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/nsproxy.h30
-rw-r--r--kernel/exit.c6
-rw-r--r--kernel/fork.c4
-rw-r--r--kernel/nsproxy.c16
4 files changed, 16 insertions, 40 deletions
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
index 678e1d38effb..0b9f0dc30d61 100644
--- a/include/linux/nsproxy.h
+++ b/include/linux/nsproxy.h
@@ -35,30 +35,22 @@ struct nsproxy *dup_namespaces(struct nsproxy *orig);
35int copy_namespaces(int flags, struct task_struct *tsk); 35int copy_namespaces(int flags, struct task_struct *tsk);
36void get_task_namespaces(struct task_struct *tsk); 36void get_task_namespaces(struct task_struct *tsk);
37void free_nsproxy(struct nsproxy *ns); 37void free_nsproxy(struct nsproxy *ns);
38struct nsproxy *put_nsproxy(struct nsproxy *ns);
39 38
40static inline void finalize_put_nsproxy(struct nsproxy *ns) 39static inline void put_nsproxy(struct nsproxy *ns)
41{ 40{
42 if (ns) 41 if (atomic_dec_and_test(&ns->count)) {
43 free_nsproxy(ns); 42 free_nsproxy(ns);
43 }
44} 44}
45 45
46static inline void put_and_finalize_nsproxy(struct nsproxy *ns) 46static inline void exit_task_namespaces(struct task_struct *p)
47{ 47{
48 finalize_put_nsproxy(put_nsproxy(ns)); 48 struct nsproxy *ns = p->nsproxy;
49} 49 if (ns) {
50 50 task_lock(p);
51static inline struct nsproxy *preexit_task_namespaces(struct task_struct *p) 51 p->nsproxy = NULL;
52{ 52 task_unlock(p);
53 return put_nsproxy(p->nsproxy); 53 put_nsproxy(ns);
54} 54 }
55
56static inline void exit_task_namespaces(struct task_struct *p,
57 struct nsproxy *ns)
58{
59 task_lock(p);
60 p->nsproxy = NULL;
61 task_unlock(p);
62 finalize_put_nsproxy(ns);
63} 55}
64#endif 56#endif
diff --git a/kernel/exit.c b/kernel/exit.c
index a5bf5329ff97..35401720635b 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -396,7 +396,7 @@ void daemonize(const char *name, ...)
396 current->fs = fs; 396 current->fs = fs;
397 atomic_inc(&fs->count); 397 atomic_inc(&fs->count);
398 398
399 put_and_finalize_nsproxy(current->nsproxy); 399 exit_task_namespaces(current);
400 current->nsproxy = init_task.nsproxy; 400 current->nsproxy = init_task.nsproxy;
401 get_task_namespaces(current); 401 get_task_namespaces(current);
402 402
@@ -853,7 +853,6 @@ static void exit_notify(struct task_struct *tsk)
853fastcall NORET_TYPE void do_exit(long code) 853fastcall NORET_TYPE void do_exit(long code)
854{ 854{
855 struct task_struct *tsk = current; 855 struct task_struct *tsk = current;
856 struct nsproxy *ns;
857 int group_dead; 856 int group_dead;
858 857
859 profile_task_exit(tsk); 858 profile_task_exit(tsk);
@@ -939,9 +938,8 @@ fastcall NORET_TYPE void do_exit(long code)
939 938
940 tsk->exit_code = code; 939 tsk->exit_code = code;
941 proc_exit_connector(tsk); 940 proc_exit_connector(tsk);
942 ns = preexit_task_namespaces(tsk);
943 exit_notify(tsk); 941 exit_notify(tsk);
944 exit_task_namespaces(tsk, ns); 942 exit_task_namespaces(tsk);
945#ifdef CONFIG_NUMA 943#ifdef CONFIG_NUMA
946 mpol_free(tsk->mempolicy); 944 mpol_free(tsk->mempolicy);
947 tsk->mempolicy = NULL; 945 tsk->mempolicy = NULL;
diff --git a/kernel/fork.c b/kernel/fork.c
index 4cf868458f06..fc723e595cd5 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1265,7 +1265,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
1265 return p; 1265 return p;
1266 1266
1267bad_fork_cleanup_namespaces: 1267bad_fork_cleanup_namespaces:
1268 put_and_finalize_nsproxy(p->nsproxy); 1268 exit_task_namespaces(p);
1269bad_fork_cleanup_keys: 1269bad_fork_cleanup_keys:
1270 exit_keys(p); 1270 exit_keys(p);
1271bad_fork_cleanup_mm: 1271bad_fork_cleanup_mm:
@@ -1711,7 +1711,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
1711 } 1711 }
1712 1712
1713 if (new_nsproxy) 1713 if (new_nsproxy)
1714 put_and_finalize_nsproxy(new_nsproxy); 1714 put_nsproxy(new_nsproxy);
1715 1715
1716bad_unshare_cleanup_ipc: 1716bad_unshare_cleanup_ipc:
1717 if (new_ipc) 1717 if (new_ipc)
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 7b05bce75cde..f5b9ee6f6bbb 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -117,7 +117,7 @@ int copy_namespaces(int flags, struct task_struct *tsk)
117 goto out_pid; 117 goto out_pid;
118 118
119out: 119out:
120 put_and_finalize_nsproxy(old_ns); 120 put_nsproxy(old_ns);
121 return err; 121 return err;
122 122
123out_pid: 123out_pid:
@@ -135,20 +135,6 @@ out_ns:
135 goto out; 135 goto out;
136} 136}
137 137
138struct nsproxy *put_nsproxy(struct nsproxy *ns)
139{
140 if (ns) {
141 if (atomic_dec_and_test(&ns->count)) {
142 if (ns->mnt_ns) {
143 put_mnt_ns(ns->mnt_ns);
144 ns->mnt_ns = NULL;
145 }
146 return ns;
147 }
148 }
149 return NULL;
150}
151
152void free_nsproxy(struct nsproxy *ns) 138void free_nsproxy(struct nsproxy *ns)
153{ 139{
154 if (ns->mnt_ns) 140 if (ns->mnt_ns)