From 790d43fd412fbb30bfb61504250e88ece790f485 Mon Sep 17 00:00:00 2001 From: Alexander Viro Date: Tue, 13 Jul 2004 19:37:04 -0700 Subject: [PATCH] sparse: read_descriptor_t annotation We have a fun situation with read_descriptor_t - all its instances end up passed to some actor; these actors use desc->buf as their private data; there are 5 of them and they expect resp: struct lo_read_data * struct svc_rqst * struct file * struct rpc_xprt * char __user * IOW, there is no type safety whatsoever; the field is essentially untyped, we rely on the fact that actor is chosen by the same code that sets ->buf and expect it to put something of the right type there. Right now desc->buf is declared as char __user *. Moreover, the last argument of ->sendfile() (what should be stored in ->buf) is void __user *, even though it's actually _never_ a userland pointer. If nothing else, ->sendfile() should take void * instead; that alone removes a bunch of bogus warnings. I went further and replaced desc->buf with a union of void * and char __user *. --- include/linux/fs.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index 3d24beb4ac36..819e67e3a95b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -852,7 +852,10 @@ struct block_device_operations { typedef struct { size_t written; size_t count; - char __user * buf; + union { + char __user * buf; + void *data; + } arg; int error; } read_descriptor_t; @@ -883,7 +886,7 @@ struct file_operations { int (*lock) (struct file *, int, struct file_lock *); ssize_t (*readv) (struct file *, const struct iovec *, unsigned long, loff_t *); ssize_t (*writev) (struct file *, const struct iovec *, unsigned long, loff_t *); - ssize_t (*sendfile) (struct file *, loff_t *, size_t, read_actor_t, void __user *); + ssize_t (*sendfile) (struct file *, loff_t *, size_t, read_actor_t, void *); ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int); unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); long (*fcntl)(int fd, unsigned int cmd, @@ -1410,7 +1413,7 @@ extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, lof extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos); ssize_t generic_file_write_nolock(struct file *file, const struct iovec *iov, unsigned long nr_segs, loff_t *ppos); -extern ssize_t generic_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void __user *); +extern ssize_t generic_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *); extern void do_generic_mapping_read(struct address_space *mapping, struct file_ra_state *, struct file *, loff_t *, read_descriptor_t *, read_actor_t); -- cgit v1.2.3