aboutsummaryrefslogtreecommitdiffstats
path: root/ipc/util.c
diff options
context:
space:
mode:
authorPierre Peiffer <Pierre.Peiffer@bull.net>2007-10-19 02:40:57 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 14:53:49 -0400
commit283bb7fada7e33a759d8fc9bd7a44532e4ad420e (patch)
treec6704baf10edd10ca64310f2d168969434bb7dcf /ipc/util.c
parent3ac88a41ff747b8c2f290f86b5243b2f8fce2cc0 (diff)
IPC: fix error case when idr-cache is empty in ipcget()
With the use of idr to store the ipc, the case where the idr cache is empty, when idr_get_new is called (this may happen even if we call idr_pre_get() before), is not well handled: it lets semget()/shmget()/msgget() return ENOSPC when this cache is empty, what 1. does not reflect the facts and 2. does not conform to the man(s). This patch fixes this by retrying the whole process of allocation in this case. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/util.c')
-rw-r--r--ipc/util.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/ipc/util.c b/ipc/util.c
index b42fbd58973..1aa0ebf71ba 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -262,7 +262,7 @@ int ipc_get_maxid(struct ipc_ids *ids)
262 * Add an entry 'new' to the IPC ids idr. The permissions object is 262 * Add an entry 'new' to the IPC ids idr. The permissions object is
263 * initialised and the first free entry is set up and the id assigned 263 * initialised and the first free entry is set up and the id assigned
264 * is returned. The 'new' entry is returned in a locked state on success. 264 * is returned. The 'new' entry is returned in a locked state on success.
265 * On failure the entry is not locked and -1 is returned. 265 * On failure the entry is not locked and a negative err-code is returned.
266 * 266 *
267 * Called with ipc_ids.rw_mutex held as a writer. 267 * Called with ipc_ids.rw_mutex held as a writer.
268 */ 268 */
@@ -275,11 +275,11 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
275 size = IPCMNI; 275 size = IPCMNI;
276 276
277 if (ids->in_use >= size) 277 if (ids->in_use >= size)
278 return -1; 278 return -ENOSPC;
279 279
280 err = idr_get_new(&ids->ipcs_idr, new, &id); 280 err = idr_get_new(&ids->ipcs_idr, new, &id);
281 if (err) 281 if (err)
282 return -1; 282 return err;
283 283
284 ids->in_use++; 284 ids->in_use++;
285 285
@@ -311,7 +311,7 @@ int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
311 struct ipc_ops *ops, struct ipc_params *params) 311 struct ipc_ops *ops, struct ipc_params *params)
312{ 312{
313 int err; 313 int err;
314 314retry:
315 err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL); 315 err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
316 316
317 if (!err) 317 if (!err)
@@ -321,6 +321,9 @@ int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
321 err = ops->getnew(ns, params); 321 err = ops->getnew(ns, params);
322 up_write(&ids->rw_mutex); 322 up_write(&ids->rw_mutex);
323 323
324 if (err == -EAGAIN)
325 goto retry;
326
324 return err; 327 return err;
325} 328}
326 329
@@ -374,7 +377,7 @@ int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
374 struct kern_ipc_perm *ipcp; 377 struct kern_ipc_perm *ipcp;
375 int flg = params->flg; 378 int flg = params->flg;
376 int err; 379 int err;
377 380retry:
378 err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL); 381 err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
379 382
380 /* 383 /*
@@ -411,6 +414,9 @@ int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
411 } 414 }
412 up_write(&ids->rw_mutex); 415 up_write(&ids->rw_mutex);
413 416
417 if (err == -EAGAIN)
418 goto retry;
419
414 return err; 420 return err;
415} 421}
416 422