From: "Stephen C. Biggs" <s.biggs@softier.com>
To: linux-kernel@vger.kernel.org
Subject: Bug in kernel code?
Date: Tue, 27 Aug 2002 17:25:17 -0700 [thread overview]
Message-ID: <3D6BB5FD.16049.2F324B@localhost> (raw)
I posted this to the newsgroup news:linux-kernel but got no response...
I'll try here.
While going thru the kernel code for 2.4.17 (uClinux patch) I noticed a
problem with functions in 3 files:
dcache_init in fs/dcache.c, inode_init in fs/inode.c and in mnt_init in
fs/namespace.c
At least on my Redhat 7.3 2.4.18-10 source, in the function
static void __init dcache_init(unsigned long mempages)
{
struct list_head *d;
unsigned long order;
unsigned int nr_hash;
int i;
/*
* A constructor could be added for stable state like the lists,
* but it is probably not worth it because of the cache nature
* of the dcache.
* If fragmentation is too bad then the SLAB_HWCACHE_ALIGN
* flag could be removed here, to hint to the allocator that
* it should not try to get multiple page regions.
*/
dentry_cache = kmem_cache_create("dentry_cache",
sizeof(struct dentry),
0,
SLAB_HWCACHE_ALIGN,
NULL, NULL);
if (!dentry_cache)
panic("Cannot create dentry cache");
#if PAGE_SHIFT < 13
mempages >>= (13 - PAGE_SHIFT);
#endif
mempages *= sizeof(struct list_head);
for (order = 0; ((1UL << order) << PAGE_SHIFT) < mempages; order++)
;
do {
u32 tmp;
nr_hash = (1UL << order) * PAGE_SIZE /
sizeof(struct list_head);
d_hash_mask = (nr_hash - 1);
tmp = nr_hash;
d_hash_shift = 0;
while ((tmp >>= 1UL) != 0UL)
d_hash_shift++;
dentry_hashtable = (struct list_head *)
__get_free_pages(GFP_ATOMIC, order);
} while (dentry_hashtable == NULL && --order >= 0);
........... Notice the --order >=0 in the do while test... since order
is declared as an unsigned long, this test is a pointless comparison and
never fails, causing an infinite loop if the hashtable is empty.
My fix to this is to change the test to have
while (dentry_hashtable == NULL && order-- != 0);
Could someone check me on this?
next reply other threads:[~2002-08-28 0:21 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-08-28 0:25 Stephen C. Biggs [this message]
[not found] <3D6BB5C3.16057.2E515C@localhost>
[not found] ` <20020827.172304.22017977.davem@redhat.com>
2002-08-28 0:32 ` Bug in kernel code? Stephen C. Biggs
2002-08-28 0:29 ` David S. Miller
2002-08-28 0:40 ` Stephen C. Biggs
2002-08-28 0:42 ` David S. Miller
2002-08-28 1:09 ` Stephen C. Biggs
2002-08-28 1:09 ` David S. Miller
2002-08-28 1:24 ` Stephen C. Biggs
2002-08-28 1:23 ` David S. Miller
2002-08-28 2:42 ` Stephen C. Biggs
2002-08-28 3:39 ` David S. Miller
2002-08-28 3:57 ` Luca Barbieri
2002-08-28 3:58 ` David S. Miller
2002-08-28 4:10 ` Luca Barbieri
2002-08-28 4:07 ` David S. Miller
2002-08-28 4:29 ` Luca Barbieri
2002-08-28 4:29 ` Stephen Biggs
2002-08-28 4:26 ` David S. Miller
2002-08-28 21:54 ` H. Peter Anvin
2002-08-28 0:54 ` Stephen C. Biggs
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3D6BB5FD.16049.2F324B@localhost \
--to=s.biggs@softier.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox