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net: remove VLA usage

PATCH In review Laszlo Toth 2 participants 3 messages Mar 8, 2018 – Mar 9, 2018

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Laszlo Toth

author
#0 lore raw

PATCH 1/1 net: remove VLA usage

Separated snmp_seq_show_tcp_udp() to tcp and udp variants, so the usage of max_t() for the array size can be emitted.

Signed-off-by Laszlo Toth <[email protected]>
---
 net/ipv4/proc.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)
net/ipv4/proc.c +16 -8
index dc5edc8..67f7d76 100644
@@ -46,8 +46,6 @@
 #include <net/sock.h>
 #include <net/raw.h>
 
-#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX)
-
 /*
  *	Report socket allocation statistics [[email protected]]
  */

@@ -398,13 +396,13 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
 	return 0;
 }
 
-static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
+static int snmp_seq_show_tcp(struct seq_file *seq, void *v)
 {
-	unsigned long buff[TCPUDP_MIB_MAX];
+	unsigned long buff[TCP_MIB_MAX];
 	struct net *net = seq->private;
 	int i;
 
-	memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+	memset(buff, 0, TCP_MIB_MAX * sizeof(unsigned long));
 
 	seq_puts(seq, "\nTcp:");
 	for (i = 0; snmp4_tcp_list[i].name; i++)

@@ -421,7 +419,16 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
 			seq_printf(seq, " %lu", buff[i]);
 	}
 
-	memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+	return 0;
+}
+
+static int snmp_seq_show_udp(struct seq_file *seq, void *v)
+{
+	unsigned long buff[UDP_MIB_MAX];
+	struct net *net = seq->private;
+	int i;
+
+	memset(buff, 0, UDP_MIB_MAX * sizeof(unsigned long));
 
 	snmp_get_cpu_field_batch(buff, snmp4_udp_list,
 				 net->mib.udp_statistics);

@@ -432,7 +439,7 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
 	for (i = 0; snmp4_udp_list[i].name; i++)
 		seq_printf(seq, " %lu", buff[i]);
 
-	memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+	memset(buff, 0, UDP_MIB_MAX * sizeof(unsigned long));
 
 	/* the UDP and UDP-Lite MIBs are the same */
 	seq_puts(seq, "\nUdpLite:");

@@ -455,7 +462,8 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
 	icmp_put(seq);	/* RFC 2011 compatibility */
 	icmpmsg_put(seq);
 
-	snmp_seq_show_tcp_udp(seq, v);
+	snmp_seq_show_tcp(seq, v);
+	snmp_seq_show_udp(seq, v);
 
 	return 0;
 }
Signature · 1 line
2.7.4
maintainer
#1 lore raw

From: Laszlo Toth <[email protected]>
Date: Thu, 8 Mar 2018 01:19:53 +0100

Quoted 4 lines

Separated snmp_seq_show_tcp_udp() to tcp and udp variants, so the usage of max_t() for the array size can be emitted.

Signed-off-by Laszlo Toth <[email protected]>

But it's a max on a constant value, computed at compile time.

I don't see at all why this is necessary.

If the compiler can't figure this out, fix it.

If the compiler warns on this with -Wvla, fix it.

Because there is no reason to have two separate routines for this.

Thank you.

author
#2 lore raw
Quoted 13 lines · David Miller

From: Laszlo Toth <[email protected]>
Date: Thu, 8 Mar 2018 01:19:53 +0100

Quoted 4 lines

Separated snmp_seq_show_tcp_udp() to tcp and udp variants, so the usage of max_t() for the array size can be emitted.

Signed-off-by Laszlo Toth <[email protected]>

But it's a max on a constant value, computed at compile time.

I don't see at all why this is necessary.

Quoted 7 lines

If the compiler can't figure this out, fix it.

If the compiler warns on this with -Wvla, fix it.

Because there is no reason to have two separate routines for this.

Thank you.

Yea, since then they'll fix max* defines, so this is unnecessary. Let's just ignore it.

Laszlo