anonfd: Allow making anon files read-only
It seems a couple places such as arch/ia64/kernel/perfmon.c and
drivers/infiniband/core/uverbs_main.c could use anon_inode_getfile()
instead of a private pseudo-fs + alloc_file(), if only there were a way
to get a read-only file. So provide this by having anon_inode_getfile()
create a read-only file if we pass O_RDONLY in flags.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index e0eb4a2..1f38270 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4724,7 +4724,7 @@
if (IS_ERR(event))
goto err_put_context;
- err = anon_inode_getfd("[perf_event]", &perf_fops, event, 0);
+ err = anon_inode_getfd("[perf_event]", &perf_fops, event, O_RDWR);
if (err < 0)
goto err_free_put_context;
