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[1/2] crypto: iaa - Fix nr_cpus < nr_iaa case

Message ID 20240321210846.1307596-2-tom.zanussi@linux.intel.com (mailing list archive)
State Accepted
Delegated to: Herbert Xu
Headers show
Series crypto: iaa - A couple of bugfixes | expand

Commit Message

Zanussi, Tom March 21, 2024, 9:08 p.m. UTC
If nr_cpus < nr_iaa, the calculated cpus_per_iaa will be 0, which
causes a divide-by-0 in rebalance_wq_table().

Make sure cpus_per_iaa is 1 in that case, and also in the nr_iaa == 0
case, even though cpus_per_iaa is never used if nr_iaa == 0, for
paranoia.

Reported-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
 drivers/crypto/intel/iaa/iaa_crypto_main.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

Comments

Herbert Xu March 22, 2024, 11:44 a.m. UTC | #1
On Thu, Mar 21, 2024 at 04:08:45PM -0500, Tom Zanussi wrote:
> If nr_cpus < nr_iaa, the calculated cpus_per_iaa will be 0, which
> causes a divide-by-0 in rebalance_wq_table().
> 
> Make sure cpus_per_iaa is 1 in that case, and also in the nr_iaa == 0
> case, even though cpus_per_iaa is never used if nr_iaa == 0, for
> paranoia.
> 
> Reported-by: Jerry Snitselaar <jsnitsel@redhat.com>
> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
> ---
>  drivers/crypto/intel/iaa/iaa_crypto_main.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)

Patch applied.  Thanks.
diff mbox series

Patch

diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c b/drivers/crypto/intel/iaa/iaa_crypto_main.c
index 1cd304de5388..b2191ade9011 100644
--- a/drivers/crypto/intel/iaa/iaa_crypto_main.c
+++ b/drivers/crypto/intel/iaa/iaa_crypto_main.c
@@ -806,6 +806,8 @@  static int save_iaa_wq(struct idxd_wq *wq)
 		return -EINVAL;
 
 	cpus_per_iaa = (nr_nodes * nr_cpus_per_node) / nr_iaa;
+	if (!cpus_per_iaa)
+		cpus_per_iaa = 1;
 out:
 	return 0;
 }
@@ -821,10 +823,12 @@  static void remove_iaa_wq(struct idxd_wq *wq)
 		}
 	}
 
-	if (nr_iaa)
+	if (nr_iaa) {
 		cpus_per_iaa = (nr_nodes * nr_cpus_per_node) / nr_iaa;
-	else
-		cpus_per_iaa = 0;
+		if (!cpus_per_iaa)
+			cpus_per_iaa = 1;
+	} else
+		cpus_per_iaa = 1;
 }
 
 static int wq_table_add_wqs(int iaa, int cpu)