diff options
| author | Omar Sandoval <osandov@fb.com> | 2018-08-21 21:54:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-22 10:52:46 -0700 |
| commit | a8dd9c4df18edc873d244790d163564a5d17626b (patch) | |
| tree | 1f405bb4f0e800ed102184f09143421bfb332dcd | |
| parent | df865e8337c397471b95f51017fea559bc8abb4a (diff) | |
proc/kcore: don't grab lock for kclist_add()
Patch series "/proc/kcore improvements", v4.
This series makes a few improvements to /proc/kcore. It fixes a couple of
small issues in v3 but is otherwise the same. Patches 1, 2, and 3 are
prep patches. Patch 4 is a fix/cleanup. Patch 5 is another prep patch.
Patches 6 and 7 are optimizations to ->read(). Patch 8 makes it possible
to enable CRASH_CORE on any architecture, which is needed for patch 9.
Patch 9 adds vmcoreinfo to /proc/kcore.
This patch (of 9):
kclist_add() is only called at init time, so there's no point in grabbing
any locks. We're also going to replace the rwlock with a rwsem, which we
don't want to try grabbing during early boot.
While we're here, mark kclist_add() with __init so that we'll get a
warning if it's called from non-init code.
Link: http://lkml.kernel.org/r/98208db1faf167aa8b08eebfa968d95c70527739.1531953780.git.osandov@fb.com
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com>
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/proc/kcore.c | 7 | ||||
| -rw-r--r-- | include/linux/kcore.h | 2 |
2 files changed, 4 insertions, 5 deletions
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index 66c373230e60..b0b9a76f28d6 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -62,16 +62,15 @@ static LIST_HEAD(kclist_head); static DEFINE_RWLOCK(kclist_lock); static int kcore_need_update = 1; -void -kclist_add(struct kcore_list *new, void *addr, size_t size, int type) +/* This doesn't grab kclist_lock, so it should only be used at init time. */ +void __init kclist_add(struct kcore_list *new, void *addr, size_t size, + int type) { new->addr = (unsigned long)addr; new->size = size; new->type = type; - write_lock(&kclist_lock); list_add_tail(&new->list, &kclist_head); - write_unlock(&kclist_lock); } static size_t get_kcore_size(int *nphdr, size_t *elf_buflen) diff --git a/include/linux/kcore.h b/include/linux/kcore.h index 8de55e4b5ee9..c20f296438fb 100644 --- a/include/linux/kcore.h +++ b/include/linux/kcore.h @@ -35,7 +35,7 @@ struct vmcoredd_node { }; #ifdef CONFIG_PROC_KCORE -extern void kclist_add(struct kcore_list *, void *, size_t, int type); +void __init kclist_add(struct kcore_list *, void *, size_t, int type); #else static inline void kclist_add(struct kcore_list *new, void *addr, size_t size, int type) |