[PATCH] gianfar: reduce stack usage in gianfar_ethtool.c

From: Wang Shaoyan <redacted>

  drivers/net/gianfar_ethtool.c:765: warning: the frame size of 2048 bytes is larger than 1024 bytes

Signed-off-by: Wang Shaoyan <redacted>
---
 drivers/net/gianfar_ethtool.c |   26 +++++++++++++++++++++++---
 1 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/net/gianfar_ethtool.c b/drivers/net/gianfar_ethtool.c
index 6e35069..9bca11c 100644
--- a/drivers/net/gianfar_ethtool.c
+++ b/drivers/net/gianfar_ethtool.c

@@ -686,10 +686,26 @@ static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow, u
 {
 	unsigned int last_rule_idx = priv->cur_filer_idx;
 	unsigned int cmp_rqfpr;
-	unsigned int local_rqfpr[MAX_FILER_IDX + 1];
-	unsigned int local_rqfcr[MAX_FILER_IDX + 1];
+	unsigned int *local_rqfpr;
+	unsigned int *local_rqfcr;
 	int i = 0x0, k = 0x0;
 	int j = MAX_FILER_IDX, l = 0x0;
+	int ret = 1;
+
+	local_rqfpr = kmalloc(sizeof(unsigned int) * (MAX_FILER_IDX + 1),
+		GFP_KERNEL);
+	if (!local_rqfpr) {
+		pr_err("Out of memory\n");
+		ret = 0;
+		got err;
+	}
+	local_rqfcr = kmalloc(sizeof(unsigned int) * (MAX_FILER_IDX + 1),
+		GFP_KERNEL);
+	if (!local_rqfcr) {
+		pr_err("Out of memory\n");
+		ret = 0;
+		goto err1;
+	}
 
 	switch (class) {
 	case TCP_V4_FLOW:

@@ -765,7 +781,11 @@ static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow, u
 		priv->cur_filer_idx = priv->cur_filer_idx - 1;
 	}
 
-	return 1;
+	kfree(local_rqfcr);
+err1:
+	kfree(local_rqfpr);
+err:
+	return ret;
 }
 
 static int gfar_set_hash_opts(struct gfar_private *priv, struct ethtool_rxnfc *cmd)

-- 
1.7.0.4

From: stufever@gmail.com
Date: Tue,  9 Aug 2011 23:45:11 +0800

From: Wang Shaoyan <redacted>

  drivers/net/gianfar_ethtool.c:765: warning: the frame size of 2048 bytes is larger than 1024 bytes

Signed-off-by: Wang Shaoyan <redacted>

Would you be so kind as to actually acknowledge in some way the person
who found all the bugs in your first version of this patch? :-/

Thanks for remainding, I just want to cover up my careless asap:-)

2011/8/9 David Miller [off-list ref]:

From: stufever@gmail.com
Date: Tue,  9 Aug 2011 23:45:11 +0800

quoted

From: Wang Shaoyan <redacted>

  drivers/net/gianfar_ethtool.c:765: warning: the frame size of 2048 bytes is larger than 1024 bytes

Signed-off-by: Wang Shaoyan <redacted>

Would you be so kind as to actually acknowledge in some way the person
who found all the bugs in your first version of this patch? :-/

-- 
Wang Shaoyan

On Tue, 2011-08-09 at 23:45 +0800, stufever@gmail.com wrote:

From: Wang Shaoyan <redacted>
  drivers/net/gianfar_ethtool.c:765: warning: the frame size of 2048 bytes is larger than 1024 bytes

[]

[]

Perhaps it'd be clearer to use:

	local_rqfpr = kmalloc(...)
	local_rqfcr = kmalloc(...)
	if (!local_rqfpr || !local_rqfcr) {
		pr_err(...)
		ret = -ENOMEM;
		goto err;
	}

[...]

err:
	kfree(local_rqfpr);
	kfree(local_rqfcr);
	return ret;

Is the "local_" prefix useful?
It seems like visual noise to me.

I thought kfree should not call, when kmalloc is failed. Now I think
is fine, thanks, it is much clearer

Perhaps it'd be clearer to use:

       local_rqfpr = kmalloc(...)
       local_rqfcr = kmalloc(...)
       if (!local_rqfpr || !local_rqfcr) {
               pr_err(...)
               ret = -ENOMEM;
               goto err;
       }

[...]

err:
       kfree(local_rqfpr);
       kfree(local_rqfcr);
       return ret;

Is the "local_" prefix useful?
It seems like visual noise to me.

They are some temporary variable, we better to left them

-- 
Wang Shaoyan