diff options
| author | Kees Cook <keescook@chromium.org> | 2022-05-03 23:54:58 +0300 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2022-05-08 11:32:30 +0300 |
| commit | 3b5eed3c71a2fb60aa4405ad92a2a6ad2677f220 (patch) | |
| tree | 9f122f5c493ce4dfde5a4ebe01ecf16783623114 /include | |
| parent | e6f3b3c9c109ed57230996cf4a4c1b8ae7e36a81 (diff) | |
| download | linux-3b5eed3c71a2fb60aa4405ad92a2a6ad2677f220.tar.xz | |
netfs: Eliminate Clang randstruct warning
Clang's structure layout randomization feature gets upset when it sees
struct inode (which is randomized) cast to struct netfs_i_context. This
is due to seeing the inode pointer as being treated as an array of inodes,
rather than "something else, following struct inode".
Since netfs can't use container_of() (since it doesn't know what the
true containing struct is), it uses this direct offset instead. Adjust
the code to better reflect what is happening: an arbitrary pointer is
being adjusted and cast to something else: use a "void *" for the math.
The resulting binary output is the same, but Clang no longer sees an
unexpected cross-structure cast:
In file included from ../fs/nfs/inode.c:50:
In file included from ../fs/nfs/fscache.h:15:
In file included from ../include/linux/fscache.h:18:
../include/linux/netfs.h:298:9: error: casting from randomized structure pointer type 'struct inode *' to 'struct netfs_i_context *'
return (struct netfs_i_context *)(inode + 1);
^
1 error generated.
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220503205503.3054173-2-keescook@chromium.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/lkml/7562f8eccd7cc0e447becfe9912179088784e3b9.camel@kernel.org
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netfs.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/netfs.h b/include/linux/netfs.h index c7bf1eaf51d5..0c33b715cbfd 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -295,7 +295,7 @@ extern void netfs_stats_show(struct seq_file *); */ static inline struct netfs_i_context *netfs_i_context(struct inode *inode) { - return (struct netfs_i_context *)(inode + 1); + return (void *)inode + sizeof(*inode); } /** @@ -307,7 +307,7 @@ static inline struct netfs_i_context *netfs_i_context(struct inode *inode) */ static inline struct inode *netfs_inode(struct netfs_i_context *ctx) { - return ((struct inode *)ctx) - 1; + return (void *)ctx - sizeof(struct inode); } /** |