diff options
| author | Stephen M. Cameron <scameron@beardog.cce.hp.com> | 2010-07-19 22:46:28 +0400 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-08-07 20:52:30 +0400 |
| commit | adfbc1ff342ece2e482254bcc5381fadfffbbb89 (patch) | |
| tree | aefa1482a22f0378a1397546595e7980fb4acf75 /drivers/block | |
| parent | a6528d017234b483283274fbdd360f3541befe19 (diff) | |
| download | linux-adfbc1ff342ece2e482254bcc5381fadfffbbb89.tar.xz | |
cciss: sanitize max commands
cciss: sanitize max commands
Some controllers might try to tell us they support 0 commands
in performant mode. This is a lie told by buggy firmware.
We have to be wary of this lest we try to allocate a negative
number of command blocks, which will be treated as unsigned,
and get an out of memory condition.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/cciss.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c index b3060eced553..6d4c4f227d55 100644 --- a/drivers/block/cciss.c +++ b/drivers/block/cciss.c @@ -4112,13 +4112,25 @@ static int __devinit cciss_find_cfgtables(ctlr_info_t *h) return 0; } +static void __devinit cciss_get_max_perf_mode_cmds(struct ctlr_info *h) +{ + h->max_commands = readl(&(h->cfgtable->MaxPerformantModeCommands)); + if (h->max_commands < 16) { + dev_warn(&h->pdev->dev, "Controller reports " + "max supported commands of %d, an obvious lie. " + "Using 16. Ensure that firmware is up to date.\n", + h->max_commands); + h->max_commands = 16; + } +} + /* Interrogate the hardware for some limits: * max commands, max SG elements without chaining, and with chaining, * SG chain block size, etc. */ static void __devinit cciss_find_board_params(ctlr_info_t *h) { - h->max_commands = readl(&(h->cfgtable->MaxPerformantModeCommands)); + cciss_get_max_perf_mode_cmds(h); h->nr_cmds = h->max_commands - 4; /* Allow room for some ioctls */ h->maxsgentries = readl(&(h->cfgtable->MaxSGElements)); /* |