From: Omar Sandoval <osandov@osandov.com>
To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>,
Eric Biederman <ebiederm@xmission.com>,
James Morse <james.morse@arm.com>,
Bhupesh Sharma <bhsharma@redhat.com>,
kernel-team@fb.com
Subject: [PATCH v3 1/8] proc/kcore: don't grab lock for kclist_add()
Date: Wed, 18 Jul 2018 15:58:41 -0700 [thread overview]
Message-ID: <98208db1faf167aa8b08eebfa968d95c70527739.1531953780.git.osandov@fb.com> (raw)
In-Reply-To: <cover.1531953780.git.osandov@fb.com>
From: Omar Sandoval <osandov@fb.com>
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.
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
fs/proc/kcore.c | 7 +++----
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)
--
2.18.0
next prev parent reply other threads:[~2018-07-18 22:58 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 22:58 [PATCH v3 0/8] /proc/kcore improvements Omar Sandoval
2018-07-18 22:58 ` Omar Sandoval [this message]
2018-07-18 22:58 ` [PATCH v3 2/8] proc/kcore: don't grab lock for memory hotplug notifier Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 3/8] proc/kcore: replace kclist_lock rwlock with rwsem Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 4/8] proc/kcore: fix memory hotplug vs multiple opens race Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 5/8] proc/kcore: hold lock during read Omar Sandoval
2018-07-24 15:11 ` Tetsuo Handa
2018-07-25 23:34 ` Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 6/8] proc/kcore: clean up ELF header generation Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 7/8] proc/kcore: optimize multiple page reads Omar Sandoval
2018-08-28 10:59 ` KASAN error in " Dominique Martinet
2018-08-29 4:04 ` [PATCH] proc/kcore: fix invalid memory access in multi-page read optimization Dominique Martinet
2018-09-04 18:03 ` Omar Sandoval
2018-09-04 22:24 ` Dominique Martinet
2018-09-04 22:35 ` [PATCH v2] " Dominique Martinet
2018-09-04 22:38 ` [PATCH v3] " Dominique Martinet
2018-09-04 22:41 ` Omar Sandoval
2018-09-05 19:56 ` Bhupesh Sharma
2018-09-05 20:57 ` Andrew Morton
2018-09-05 22:00 ` Dominique Martinet
2018-07-18 22:58 ` [PATCH v3 8/8] proc/kcore: add vmcoreinfo note to /proc/kcore Omar Sandoval
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