From: Roland Dreier <roland@kernel.org>
To: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>,
linux-scsi@vger.kernel.org
Subject: [PATCH] [SCSI] mpt2sas: Fix possible integer truncation of cpu_count
Date: Wed, 30 Nov 2011 16:30:33 -0800 [thread overview]
Message-ID: <1322699433-22886-1-git-send-email-roland@kernel.org> (raw)
From: Roland Dreier <roland@purestorage.com>
When computing reply_queue_count (the number of MSI-X vectors to use),
the driver does
ioc->reply_queue_count = min_t(u8, ioc->cpu_count,
ioc->msix_vector_count);
However, on a big machine, ioc->cpu_count could be outside the range
that fits in a u8; eg a system with 256 CPUs will end up
reply_queue_count set to 0.
Fix this by calculating the minimum as ints and then letting the
assignment to reply_queue_count handle integer demotion.
Signed-off-by: Roland Dreier <roland@purestorage.com>
---
drivers/scsi/mpt2sas/mpt2sas_base.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index beda04a..9596ced 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -1346,7 +1346,7 @@ _base_enable_msix(struct MPT2SAS_ADAPTER *ioc)
if (_base_check_enable_msix(ioc) != 0)
goto try_ioapic;
- ioc->reply_queue_count = min_t(u8, ioc->cpu_count,
+ ioc->reply_queue_count = min_t(int, ioc->cpu_count,
ioc->msix_vector_count);
entries = kcalloc(ioc->reply_queue_count, sizeof(struct msix_entry),
--
1.7.5.4
next reply other threads:[~2011-12-01 0:30 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-01 0:30 Roland Dreier [this message]
2011-12-02 3:52 ` [PATCH] [SCSI] mpt2sas: Fix possible integer truncation of cpu_count Nandigama, Nagalakshmi
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