diff options
| author | David Howells <dhowells@redhat.com> | 2018-06-13 19:43:19 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2018-06-15 00:48:57 -0400 |
| commit | 24074a35c5c975c94cd9691ae962855333aac47f (patch) | |
| tree | 1b59ef017c85f158edf696564fe441fa2356ca3e | |
| parent | de52cf922a4a17d0a4cd34d697db62a01c1bd092 (diff) | |
| download | linux-24074a35c5c975c94cd9691ae962855333aac47f.tar.bz2 | |
proc: Make inline name size calculation automatic
Make calculation of the size of the inline name in struct proc_dir_entry
automatic, rather than having to manually encode the numbers and failing to
allow for lockdep.
Require a minimum inline name size of 33+1 to allow for names that look
like two hex numbers with a dash between.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/proc/generic.c | 2 | ||||
| -rw-r--r-- | fs/proc/inode.c | 5 | ||||
| -rw-r--r-- | fs/proc/internal.h | 18 | ||||
| -rw-r--r-- | fs/proc/root.c | 3 |
4 files changed, 16 insertions, 12 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c index d0e5a68ae14a..210bd4b16947 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -410,7 +410,7 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, if (!ent) goto out; - if (qstr.len + 1 <= sizeof(ent->inline_name)) { + if (qstr.len + 1 <= SIZEOF_PDE_INLINE_NAME) { ent->name = ent->inline_name; } else { ent->name = kmalloc(qstr.len + 1, GFP_KERNEL); diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 2cf3b74391ca..85ffbd27f288 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -105,9 +105,8 @@ void __init proc_init_kmemcache(void) kmem_cache_create("pde_opener", sizeof(struct pde_opener), 0, SLAB_ACCOUNT|SLAB_PANIC, NULL); proc_dir_entry_cache = kmem_cache_create_usercopy( - "proc_dir_entry", sizeof(struct proc_dir_entry), 0, SLAB_PANIC, - offsetof(struct proc_dir_entry, inline_name), - sizeof_field(struct proc_dir_entry, inline_name), NULL); + "proc_dir_entry", SIZEOF_PDE_SLOT, 0, SLAB_PANIC, + OFFSETOF_PDE_NAME, SIZEOF_PDE_INLINE_NAME, NULL); } static int proc_show_options(struct seq_file *seq, struct dentry *root) diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 916ccc39073d..d8d11fd9fdb0 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -62,14 +62,20 @@ struct proc_dir_entry { char *name; umode_t mode; u8 namelen; -#ifdef CONFIG_64BIT -#define SIZEOF_PDE_INLINE_NAME (192-155) -#else -#define SIZEOF_PDE_INLINE_NAME (128-95) -#endif - char inline_name[SIZEOF_PDE_INLINE_NAME]; + char inline_name[]; } __randomize_layout; +#define OFFSETOF_PDE_NAME offsetof(struct proc_dir_entry, inline_name) +#define SIZEOF_PDE_SLOT \ + (OFFSETOF_PDE_NAME + 34 <= 64 ? 64 : \ + OFFSETOF_PDE_NAME + 34 <= 128 ? 128 : \ + OFFSETOF_PDE_NAME + 34 <= 192 ? 192 : \ + OFFSETOF_PDE_NAME + 34 <= 256 ? 256 : \ + OFFSETOF_PDE_NAME + 34 <= 512 ? 512 : \ + 0) + +#define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE_SLOT - OFFSETOF_PDE_NAME) + extern struct kmem_cache *proc_dir_entry_cache; void pde_free(struct proc_dir_entry *pde); diff --git a/fs/proc/root.c b/fs/proc/root.c index 61b7340b357a..f4b1a9d2eca6 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -204,8 +204,7 @@ struct proc_dir_entry proc_root = { .proc_fops = &proc_root_operations, .parent = &proc_root, .subdir = RB_ROOT, - .name = proc_root.inline_name, - .inline_name = "/proc", + .name = "/proc", }; int pid_ns_prepare_proc(struct pid_namespace *ns) |