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nfp: flower: use struct_size() helper

PATCH Applied Gustavo A. R. Silva 3 participants 3 messages Jun 5, 2019

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Networking Network drivers Netronome Ethernet drivers
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Gustavo A. R. Silva

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#0 lore raw

PATCH 1/1 nfp: flower: use struct_size() helper

One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example:

struct nfp_tun_active_tuns {
	...
        struct route_ip_info {
                __be32 ipv4;
                __be32 egress_port;
                __be32 extra[2];
        } tun_info[];
};

Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes.

So, replace the following form:

sizeof(struct nfp_tun_active_tuns) + sizeof(struct route_ip_info) * count

with:

struct_size(payload, tun_info, count)

This code was detected with the help of Coccinelle.

Signed-off-by Gustavo A. R. Silva <[email protected]>
---
 drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c +1 -2
index 8c67505865a4..a7a80f4b722a 100644
@@ -162,8 +162,7 @@ void nfp_tunnel_keep_alive(struct nfp_app *app, struct sk_buff *skb)
 	}
 
 	pay_len = nfp_flower_cmsg_get_data_len(skb);
-	if (pay_len != sizeof(struct nfp_tun_active_tuns) +
-	    sizeof(struct route_ip_info) * count) {
+	if (pay_len != struct_size(payload, tun_info, count)) {
 		nfp_flower_cmsg_warn(app, "Corruption in tunnel keep-alive message.\n");
 		return;
 	}
Signature · 1 line
2.21.0
Acked-by on v1 1/1
#1 lore raw
Quoted 20 lines · Gustavo A. R. Silva

One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example:

struct nfp_tun_active_tuns {
	...
        struct route_ip_info {
                __be32 ipv4;
                __be32 egress_port;
                __be32 extra[2];
        } tun_info[];
};

Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes.

So, replace the following form:

sizeof(struct nfp_tun_active_tuns) + sizeof(struct route_ip_info) * count

Quoted 7 lines

with:

struct_size(payload, tun_info, count)

This code was detected with the help of Coccinelle.

Signed-off-by Gustavo A. R. Silva <[email protected]>
Acked-by Jakub Kicinski <[email protected]>

Thanks!

maintainer Applied
#2 lore raw
In reply to Gustavo A. R. Silva

From: "Gustavo A. R. Silva" <[email protected]>
Date: Wed, 5 Jun 2019 15:38:27 -0500

Quoted 20 lines

One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example:

struct nfp_tun_active_tuns {
	...
        struct route_ip_info {
                __be32 ipv4;
                __be32 egress_port;
                __be32 extra[2];
        } tun_info[];
};

Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes.

So, replace the following form:

sizeof(struct nfp_tun_active_tuns) + sizeof(struct route_ip_info) * count

Quoted 7 lines

with:

struct_size(payload, tun_info, count)

This code was detected with the help of Coccinelle.

Signed-off-by Gustavo A. R. Silva <[email protected]>

Applied.