[PATCH] hinic: reduce rss_init stack usage

From: Arnd Bergmann
Date: Fri Jun 28 2019 - 06:32:23 EST


On 32-bit architectures, putting an array of 256 u32 values on the
stack uses more space than the warning limit:

drivers/net/ethernet/huawei/hinic/hinic_main.c: In function 'hinic_rss_init':
drivers/net/ethernet/huawei/hinic/hinic_main.c:286:1: error: the frame size of 1068 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

I considered changing the code to use u8 values here, since that's
all the hardware supports, but dynamically allocating the array is
a more isolated fix here.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
.../net/ethernet/huawei/hinic/hinic_main.c | 20 ++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/huawei/hinic/hinic_main.c b/drivers/net/ethernet/huawei/hinic/hinic_main.c
index 1b917543feac..ceb0e247f52d 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_main.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_main.c
@@ -256,37 +256,43 @@ static int hinic_configure_max_qnum(struct hinic_dev *nic_dev)

static int hinic_rss_init(struct hinic_dev *nic_dev)
{
- u32 indir_tbl[HINIC_RSS_INDIR_SIZE] = { 0 };
u8 default_rss_key[HINIC_RSS_KEY_SIZE];
u8 tmpl_idx = nic_dev->rss_tmpl_idx;
+ u32 *indir_tbl;
int err, i;

+ indir_tbl = kcalloc(HINIC_RSS_INDIR_SIZE, sizeof(u32), GFP_KERNEL);
+ if (!indir_tbl)
+ return -ENOMEM;
+
netdev_rss_key_fill(default_rss_key, sizeof(default_rss_key));
for (i = 0; i < HINIC_RSS_INDIR_SIZE; i++)
indir_tbl[i] = ethtool_rxfh_indir_default(i, nic_dev->num_rss);

err = hinic_rss_set_template_tbl(nic_dev, tmpl_idx, default_rss_key);
if (err)
- return err;
+ goto out;

err = hinic_rss_set_indir_tbl(nic_dev, tmpl_idx, indir_tbl);
if (err)
- return err;
+ goto out;

err = hinic_set_rss_type(nic_dev, tmpl_idx, nic_dev->rss_type);
if (err)
- return err;
+ goto out;

err = hinic_rss_set_hash_engine(nic_dev, tmpl_idx,
nic_dev->rss_hash_engine);
if (err)
- return err;
+ goto out;

err = hinic_rss_cfg(nic_dev, 1, tmpl_idx);
if (err)
- return err;
+ goto out;

- return 0;
+out:
+ kfree(indir_tbl);
+ return err;
}

static void hinic_rss_deinit(struct hinic_dev *nic_dev)
--
2.20.0