Subject: [PATCH] NET: ATM: MPOA: Remove 32-bit timekeeping

From: Tina Ruchandani <[email-masked]>
Date: Thu, 29 Oct 2015 22:01:07 -0700

net/atm/mpoa_* files use 'struct timeval' to store event
timestamps. struct timeval uses a 32-bit seconds field which will
overflow in the year 2038 and beyond. Morever, the timestamps are being
compared only to get seconds elapsed, so struct timeval which stores
a seconds and microseconds field is an overkill. This patch replaces
the use of struct timeval with time64_t to store a 64-bit seconds field.

Signed-off-by: Tina Ruchandani <[email-masked]>
---
 net/atm/common.c      |  2 +-
 net/atm/mpc.c         |  9 +++++----
 net/atm/mpoa_caches.c | 49 ++++++++++++++++++++++++-------------------------
 net/atm/mpoa_caches.h |  9 +++++----
 net/atm/mpoa_proc.c   | 15 +++++++++------
 5 files changed, 44 insertions(+), 40 deletions(-)

diff --git a/net/atm/common.c b/net/atm/common.c
index 49a872d..a48a1ac 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -14,7 +14,7 @@
 #include <linux/capability.h>
 #include <linux/mm.h>
 #include <linux/sched.h>
-#include <linux/time.h>		/* struct timeval */
+#include <linux/time64.h>	/* 64-bit time for seconds */
 #include <linux/skbuff.h>
 #include <linux/bitops.h>
 #include <linux/init.h>
diff --git a/net/atm/mpc.c b/net/atm/mpc.c
index 0e98222..211468e 100644
--- a/net/atm/mpc.c
+++ b/net/atm/mpc.c
@@ -1090,7 +1090,7 @@ static void MPOA_trigger_rcvd(struct k_message *msg, struct mpoa_client *mpc)
 		msg->type = SND_MPOA_RES_RQST;
 		msg->content.in_info = entry->ctrl_info;
 		msg_to_mpoad(msg, mpc);
-		do_gettimeofday(&(entry->reply_wait));
+		entry->reply_wait = ktime_get_real_seconds();
 		mpc->in_ops->put(entry);
 		return;
 	}
@@ -1100,7 +1100,7 @@ static void MPOA_trigger_rcvd(struct k_message *msg, struct mpoa_client *mpc)
 		msg->type = SND_MPOA_RES_RQST;
 		msg->content.in_info = entry->ctrl_info;
 		msg_to_mpoad(msg, mpc);
-		do_gettimeofday(&(entry->reply_wait));
+		entry->reply_wait = ktime_get_real_seconds();
 		mpc->in_ops->put(entry);
 		return;
 	}
@@ -1176,8 +1176,9 @@ static void MPOA_res_reply_rcvd(struct k_message *msg, struct mpoa_client *mpc)
 	}
 
 	entry->ctrl_info = msg->content.in_info;
-	do_gettimeofday(&(entry->tv));
-	do_gettimeofday(&(entry->reply_wait)); /* Used in refreshing func from now on */
+	entry->tv = ktime_get_real_seconds();
+	/* Used in refreshing func from now on */
+	entry->reply_wait = ktime_get_real_seconds();
 	entry->refresh_time = 0;
 	ddprintk_cont("entry->shortcut = %p\n", entry->shortcut);
 
diff --git a/net/atm/mpoa_caches.c b/net/atm/mpoa_caches.c
index d1b2d9a..2a59830 100644
--- a/net/atm/mpoa_caches.c
+++ b/net/atm/mpoa_caches.c
@@ -116,7 +116,7 @@ static in_cache_entry *in_cache_add_entry(__be32 dst_ip,
 
 	memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
 	entry->ctrl_info.in_dst_ip = dst_ip;
-	do_gettimeofday(&(entry->tv));
+	entry->tv = ktime_get_real_seconds();
 	entry->retry_time = client->parameters.mpc_p4;
 	entry->count = 1;
 	entry->entry_state = INGRESS_INVALID;
@@ -147,7 +147,7 @@ static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
 			if (qos != NULL)
 				msg.qos = qos->qos;
 			msg_to_mpoad(&msg, mpc);
-			do_gettimeofday(&(entry->reply_wait));
+			entry->reply_wait = ktime_get_real_seconds();
 			entry->entry_state = INGRESS_RESOLVING;
 		}
 		if (entry->shortcut != NULL)
@@ -170,7 +170,7 @@ static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
 		if (qos != NULL)
 			msg.qos = qos->qos;
 		msg_to_mpoad(&msg, mpc);
-		do_gettimeofday(&(entry->reply_wait));
+		entry->reply_wait = ktime_get_real_seconds();
 	}
 
 	return CLOSED;
@@ -226,17 +226,16 @@ static void in_cache_remove_entry(in_cache_entry *entry,
 static void clear_count_and_expired(struct mpoa_client *client)
 {
 	in_cache_entry *entry, *next_entry;
-	struct timeval now;
+	time64_t now;
 
-	do_gettimeofday(&now);
+	now = ktime_get_real_seconds();
 
 	write_lock_bh(&client->ingress_lock);
 	entry = client->in_cache;
 	while (entry != NULL) {
 		entry->count = 0;
 		next_entry = entry->next;
-		if ((now.tv_sec - entry->tv.tv_sec)
-		   > entry->ctrl_info.holding_time) {
+		if ((now - entry->tv) > entry->ctrl_info.holding_time) {
 			dprintk("holding time expired, ip = %pI4\n",
 				&entry->ctrl_info.in_dst_ip);
 			client->in_ops->remove_entry(entry, client);
@@ -252,35 +251,36 @@ static void check_resolving_entries(struct mpoa_client *client)
 
 	struct atm_mpoa_qos *qos;
 	in_cache_entry *entry;
-	struct timeval now;
+	time64_t now;
 	struct k_message msg;
 
-	do_gettimeofday(&now);
+	now = ktime_get_real_seconds();
 
 	read_lock_bh(&client->ingress_lock);
 	entry = client->in_cache;
 	while (entry != NULL) {
 		if (entry->entry_state == INGRESS_RESOLVING) {
-			if ((now.tv_sec - entry->hold_down.tv_sec) <
-			    client->parameters.mpc_p6) {
+
+			if ((now - entry->hold_down)
+					< client->parameters.mpc_p6) {
 				entry = entry->next;	/* Entry in hold down */
 				continue;
 			}
-			if ((now.tv_sec - entry->reply_wait.tv_sec) >
-			    entry->retry_time) {
+			if ((now - entry->reply_wait) > entry->retry_time) {
 				entry->retry_time = MPC_C1 * (entry->retry_time);
 				/*
 				 * Retry time maximum exceeded,
 				 * put entry in hold down.
 				 */
 				if (entry->retry_time > client->parameters.mpc_p5) {
-					do_gettimeofday(&(entry->hold_down));
+					entry->hold_down =
+						ktime_get_real_seconds();
 					entry->retry_time = client->parameters.mpc_p4;
 					entry = entry->next;
 					continue;
 				}
 				/* Ask daemon to send a resolution request. */
-				memset(&(entry->hold_down), 0, sizeof(struct timeval));
+				memset(&entry->hold_down, 0, sizeof(time64_t));
 				msg.type = SND_MPOA_RES_RTRY;
 				memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN);
 				msg.content.in_info = entry->ctrl_info;
@@ -288,7 +288,7 @@ static void check_resolving_entries(struct mpoa_client *client)
 				if (qos != NULL)
 					msg.qos = qos->qos;
 				msg_to_mpoad(&msg, client);
-				do_gettimeofday(&(entry->reply_wait));
+				entry->reply_wait = ktime_get_real_seconds();
 			}
 		}
 		entry = entry->next;
@@ -299,18 +299,18 @@ static void check_resolving_entries(struct mpoa_client *client)
 /* Call this every MPC-p5 seconds. */
 static void refresh_entries(struct mpoa_client *client)
 {
-	struct timeval now;
+	time64_t now;
 	struct in_cache_entry *entry = client->in_cache;
 
 	ddprintk("refresh_entries\n");
-	do_gettimeofday(&now);
+	now = ktime_get_real_seconds();
 
 	read_lock_bh(&client->ingress_lock);
 	while (entry != NULL) {
 		if (entry->entry_state == INGRESS_RESOLVED) {
 			if (!(entry->refresh_time))
 				entry->refresh_time = (2 * (entry->ctrl_info.holding_time))/3;
-			if ((now.tv_sec - entry->reply_wait.tv_sec) >
+			if ((now - entry->reply_wait) >
 			    entry->refresh_time) {
 				dprintk("refreshing an entry.\n");
 				entry->entry_state = INGRESS_REFRESHING;
@@ -479,7 +479,7 @@ static eg_cache_entry *eg_cache_add_entry(struct k_message *msg,
 
 	memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
 	entry->ctrl_info = msg->content.eg_info;
-	do_gettimeofday(&(entry->tv));
+	entry->tv = ktime_get_real_seconds();
 	entry->entry_state = EGRESS_RESOLVED;
 	dprintk("new_eg_cache_entry cache_id %u\n",
 		ntohl(entry->ctrl_info.cache_id));
@@ -494,7 +494,7 @@ static eg_cache_entry *eg_cache_add_entry(struct k_message *msg,
 
 static void update_eg_cache_entry(eg_cache_entry *entry, uint16_t holding_time)
 {
-	do_gettimeofday(&(entry->tv));
+	entry->tv = ktime_get_real_seconds();
 	entry->entry_state = EGRESS_RESOLVED;
 	entry->ctrl_info.holding_time = holding_time;
 }
@@ -502,17 +502,16 @@ static void update_eg_cache_entry(eg_cache_entry *entry, uint16_t holding_time)
 static void clear_expired(struct mpoa_client *client)
 {
 	eg_cache_entry *entry, *next_entry;
-	struct timeval now;
+	time64_t now;
 	struct k_message msg;
 
-	do_gettimeofday(&now);
+	now = ktime_get_real_seconds();
 
 	write_lock_irq(&client->egress_lock);
 	entry = client->eg_cache;
 	while (entry != NULL) {
 		next_entry = entry->next;
-		if ((now.tv_sec - entry->tv.tv_sec)
-		   > entry->ctrl_info.holding_time) {
+		if ((now - entry->tv) > entry->ctrl_info.holding_time) {
 			msg.type = SND_EGRESS_PURGE;
 			msg.content.eg_info = entry->ctrl_info;
 			dprintk("egress_cache: holding time expired, cache_id = %u.\n",
diff --git a/net/atm/mpoa_caches.h b/net/atm/mpoa_caches.h
index 8e5f78c..874fded 100644
--- a/net/atm/mpoa_caches.h
+++ b/net/atm/mpoa_caches.h
@@ -1,6 +1,7 @@
 #ifndef MPOA_CACHES_H
 #define MPOA_CACHES_H
 
+#include <linux/time64.h>
 #include <linux/netdevice.h>
 #include <linux/types.h>
 #include <linux/atm.h>
@@ -14,9 +15,9 @@ void atm_mpoa_init_cache(struct mpoa_client *mpc);
 typedef struct in_cache_entry {
 	struct in_cache_entry *next;
 	struct in_cache_entry *prev;
-	struct timeval  tv;
-	struct timeval  reply_wait;
-	struct timeval  hold_down;
+	time64_t  tv;
+	time64_t  reply_wait;
+	time64_t  hold_down;
 	uint32_t  packets_fwded;
 	uint16_t  entry_state;
 	uint32_t retry_time;
@@ -51,7 +52,7 @@ struct in_cache_ops{
 typedef struct eg_cache_entry{
 	struct               eg_cache_entry *next;
 	struct               eg_cache_entry *prev;
-	struct               timeval  tv;
+	time64_t	     tv;
 	uint8_t              MPS_ctrl_ATM_addr[ATM_ESA_LEN];
 	struct atm_vcc       *shortcut;
 	uint32_t             packets_rcvd;
diff --git a/net/atm/mpoa_proc.c b/net/atm/mpoa_proc.c
index 2df34eb..06f2920 100644
--- a/net/atm/mpoa_proc.c
+++ b/net/atm/mpoa_proc.c
@@ -7,7 +7,7 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/proc_fs.h>
-#include <linux/time.h>
+#include <linux/ktime.h>
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
 #include <linux/atmmpc.h>
@@ -137,7 +137,7 @@ static int mpc_show(struct seq_file *m, void *v)
 	int i;
 	in_cache_entry *in_entry;
 	eg_cache_entry *eg_entry;
-	struct timeval now;
+	time64_t now;
 	unsigned char ip_string[16];
 
 	if (v == SEQ_START_TOKEN) {
@@ -147,15 +147,17 @@ static int mpc_show(struct seq_file *m, void *v)
 
 	seq_printf(m, "\nInterface %d:\n\n", mpc->dev_num);
 	seq_printf(m, "Ingress Entries:\nIP address      State      Holding time  Packets fwded  VPI  VCI\n");
-	do_gettimeofday(&now);
+	now = ktime_get_real_seconds();
 
 	for (in_entry = mpc->in_cache; in_entry; in_entry = in_entry->next) {
+		unsigned long seconds_delta = now - in_entry->tv;
+
 		sprintf(ip_string, "%pI4", &in_entry->ctrl_info.in_dst_ip);
 		seq_printf(m, "%-16s%s%-14lu%-12u",
 			   ip_string,
 			   ingress_state_string(in_entry->entry_state),
 			   in_entry->ctrl_info.holding_time -
-			   (now.tv_sec-in_entry->tv.tv_sec),
+			   seconds_delta,
 			   in_entry->packets_fwded);
 		if (in_entry->shortcut)
 			seq_printf(m, "   %-3d  %-3d",
@@ -168,13 +170,14 @@ static int mpc_show(struct seq_file *m, void *v)
 	seq_printf(m, "Egress Entries:\nIngress MPC ATM addr\nCache-id        State      Holding time  Packets recvd  Latest IP addr   VPI VCI\n");
 	for (eg_entry = mpc->eg_cache; eg_entry; eg_entry = eg_entry->next) {
 		unsigned char *p = eg_entry->ctrl_info.in_MPC_data_ATM_addr;
+		unsigned long seconds_delta = now - eg_entry->tv;
+
 		for (i = 0; i < ATM_ESA_LEN; i++)
 			seq_printf(m, "%02x", p[i]);
 		seq_printf(m, "\n%-16lu%s%-14lu%-15u",
 			   (unsigned long)ntohl(eg_entry->ctrl_info.cache_id),
 			   egress_state_string(eg_entry->entry_state),
-			   (eg_entry->ctrl_info.holding_time -
-			    (now.tv_sec-eg_entry->tv.tv_sec)),
+			   (eg_entry->ctrl_info.holding_time - seconds_delta),
 			   eg_entry->packets_rcvd);
 
 		/* latest IP address */
-- 
2.6.0.rc2.230.g3dd15c0

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