On 09/18/2012 01:57 AM, Dan Carpenter wrote:
> Hello Tino Reichardt,
>
> The patch 0d59722ea777: "fs/jfs: TRIM support for JFS Filesystem"
> from Aug 29, 2012, leads to the following static checker warning:
> fs/jfs/jfs_dmap.c:1650 dbDiscardAG()
> warn: check 'range_cnt' for negative values
>
> 1648 nblocks = bmp->db_agfree[agno];
> 1649 range_cnt = min_t(int, range_cnt, nblocks / minlen + 1);
> ^^^
> Could we make this unsigned? The caller checks that minlen is >= 1 and
> probably someone checks nblocks as well, but it's annoying to have to
> audit this.
Dan, the following patch applies on top of the Sept. 18 linux-next
build or git://github.com/kleikamp/linux-shaggy.git jfs-next
>
> 1650 totrim = kmalloc(sizeof(struct range2trim) * range_cnt,
> GFP_NOFS);
> 1651 if (totrim == NULL) {
> 1652 jfs_error(bmp->db_ipbmap->i_sb,
> 1653 "dbDiscardAG: no memory for trim array");
> 1654 IWRITE_UNLOCK(ipbmap);
> 1655 return 0;
> 1656 }
>
> regards,
> dan carpenter
jfs: Fix do_div precision in commit b40c2e66
In a hasty fix to replace a 64-bit division with do_div, I
unintentionally assigned the divisor to a 32-bit variable.
Signed-off-by: Dave Kleikamp <[email protected]>
Cc: Tino Reichardt <[email protected]>
---
fs/jfs/jfs_dmap.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 174feb6..9a55f53 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -1641,14 +1641,15 @@ s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen)
/* max blkno / nblocks pairs to trim */
int count = 0, range_cnt;
+ u64 max_ranges;
/* prevent others from writing new stuff here, while trimming */
IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
nblocks = bmp->db_agfree[agno];
- range_cnt = nblocks;
- do_div(range_cnt, (int)minlen);
- range_cnt = min(range_cnt + 1, 32 * 1024);
+ max_ranges = nblocks;
+ do_div(max_ranges, minlen);
+ range_cnt = min_t(u64, max_ranges + 1, 32 * 1024);
totrim = kmalloc(sizeof(struct range2trim) * range_cnt, GFP_NOFS);
if (totrim == NULL) {
jfs_error(bmp->db_ipbmap->i_sb,
--
1.7.12
------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions
will include endpoint security, mobile security and the latest in malware
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
Jfs-discussion mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/jfs-discussion
