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| author | Manfred Spraul <manfred@colorfullife.com> | 2017-07-12 14:35:34 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-12 16:26:02 -0700 |
| commit | 62b49c9908bcee88347efe8b4ed1b4f53c60ee66 (patch) | |
| tree | 2285e34d091f10b492c8d1741aeef6c5a1afd472 /ipc | |
| parent | e2029dfeef7b09f08ac8572e8be3d4c624d1f79a (diff) | |
| download | lwn-62b49c9908bcee88347efe8b4ed1b4f53c60ee66.tar.gz lwn-62b49c9908bcee88347efe8b4ed1b4f53c60ee66.zip | |
ipc/util.h: update documentation for ipc_getref() and ipc_putref()
Now that ipc_rcu_alloc() and ipc_rcu_free() are removed, document when
it is valid to use ipc_getref() and ipc_putref().
Link: http://lkml.kernel.org/r/20170525185107.12869-21-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/util.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/ipc/util.h b/ipc/util.h index 77336c2bdb9c..c692010e6f0a 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -112,6 +112,9 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg); * Objects are reference counted, they start with reference count 1. * getref increases the refcount, the putref call that reduces the recount * to 0 schedules the rcu destruction. Caller must guarantee locking. + * + * refcount is initialized by ipc_addid(), before that point call_rcu() + * must be used. */ int ipc_rcu_getref(struct kern_ipc_perm *ptr); void ipc_rcu_putref(struct kern_ipc_perm *ptr, |