Messages in this thread Patch in this message | | | From | "Ed L. Cashin" <> | Date | Tue, 26 Jun 2007 14:50:12 -0400 | Subject | [PATCH 09/12] remove race between use and initialization of locks |
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This change was originally submitted by Alexey Dobriyan in an email with ...
Message-ID: <20070325190221.GA5308@martell.zuzino.mipt.ru>
and the comment,
Some drivers do register_chrdev() before lock or semaphore used in corresponding file_operations is initialized.
Andrew Morton commented that these locks should be initialized at compile time, but Alexey Debriyan pointed out that the Documentation tells us to use dynamic initialization whenever possible, and then the discussion petered out.
http://preview.tinyurl.com/2pxq6p
I believe we made these locks dynamic because of the notice in Documentation/spinlocks.txt, which says that static initializers are deprecated:
UPDATE March 21 2005 Amit Gud <gud@eth.net>
Macros SPIN_LOCK_UNLOCKED and RW_LOCK_UNLOCKED are deprecated and will be removed soon. So for any new code dynamic initialization should be used: ...
In any case, the patch below makes the code correct and in keeping with the existing documentation. If the existing docs are wrong, I'd be happy to follow up with a patch that corrects them and makes these aoechr.c locks static.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ed L. Cashin <ecashin@coraid.com> --- drivers/block/aoe/aoechr.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c index 10b38a7..2b4f873 100644 --- a/drivers/block/aoe/aoechr.c +++ b/drivers/block/aoe/aoechr.c @@ -256,13 +256,13 @@ aoechr_init(void) { int n, i; + sema_init(&emsgs_sema, 0); + spin_lock_init(&emsgs_lock); n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops); if (n < 0) { printk(KERN_ERR "aoe: can't register char device\n"); return n; } - sema_init(&emsgs_sema, 0); - spin_lock_init(&emsgs_lock); aoe_class = class_create(THIS_MODULE, "aoe"); if (IS_ERR(aoe_class)) { unregister_chrdev(AOE_MAJOR, "aoechr"); -- 1.5.2.1 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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