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authorJohannes Berg <johannes.berg@intel.com>2015-01-16 22:09:00 +0100
committerDavid S. Miller <davem@davemloft.net>2015-01-18 01:03:45 -0500
commit053c095a82cf773075e83d7233b5cc19a1f73ece (patch)
treec787028efa9a73a182a0f338f87b6294cef4b8b9 /drivers
parentede58ef28e105de94475b2b69fa069c9a2ce6933 (diff)
downloadlinux-053c095a82cf773075e83d7233b5cc19a1f73ece.tar.bz2
netlink: make nlmsg_end() and genlmsg_end() void
Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/acpi/event.c7
-rw-r--r--drivers/net/ethernet/rocker/rocker.c3
-rw-r--r--drivers/net/vxlan.c3
-rw-r--r--drivers/net/wireless/mac80211_hwsim.c3
-rw-r--r--drivers/scsi/pmcraid.c8
-rw-r--r--drivers/target/target_core_user.c4
-rw-r--r--drivers/thermal/thermal_core.c6
7 files changed, 10 insertions, 24 deletions
diff --git a/drivers/acpi/event.c b/drivers/acpi/event.c
index ef2d730734dc..e24ea4e796e4 100644
--- a/drivers/acpi/event.c
+++ b/drivers/acpi/event.c
@@ -100,7 +100,6 @@ int acpi_bus_generate_netlink_event(const char *device_class,
struct acpi_genl_event *event;
void *msg_header;
int size;
- int result;
/* allocate memory */
size = nla_total_size(sizeof(struct acpi_genl_event)) +
@@ -137,11 +136,7 @@ int acpi_bus_generate_netlink_event(const char *device_class,
event->data = data;
/* send multicast genetlink message */
- result = genlmsg_end(skb, msg_header);
- if (result < 0) {
- nlmsg_free(skb);
- return result;
- }
+ genlmsg_end(skb, msg_header);
genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
return 0;
diff --git a/drivers/net/ethernet/rocker/rocker.c b/drivers/net/ethernet/rocker/rocker.c
index 964d719b150f..d54781e71cd4 100644
--- a/drivers/net/ethernet/rocker/rocker.c
+++ b/drivers/net/ethernet/rocker/rocker.c
@@ -3674,7 +3674,8 @@ static int rocker_fdb_fill_info(struct sk_buff *skb,
if (vid && nla_put_u16(skb, NDA_VLAN, vid))
goto nla_put_failure;
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 6b6b45622a0a..c5f79e7513a6 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -363,7 +363,8 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
goto nla_put_failure;
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 494e7335aa64..4a4c6586a8d2 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -2557,7 +2557,8 @@ static int mac80211_hwsim_get_radio(struct sk_buff *skb,
if (res < 0)
goto out_err;
- return genlmsg_end(skb, hdr);
+ genlmsg_end(skb, hdr);
+ return 0;
out_err:
genlmsg_cancel(skb, hdr);
diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
index 8c27b6a77ec4..cf222f46eac5 100644
--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -1473,13 +1473,7 @@ static int pmcraid_notify_aen(
}
/* send genetlink multicast message to notify appplications */
- result = genlmsg_end(skb, msg_header);
-
- if (result < 0) {
- pmcraid_err("genlmsg_end failed\n");
- nlmsg_free(skb);
- return result;
- }
+ genlmsg_end(skb, msg_header);
result = genlmsg_multicast(&pmcraid_event_family, skb,
0, 0, GFP_ATOMIC);
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 1157b559683b..1a1bcf71ec9d 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -784,9 +784,7 @@ static int tcmu_netlink_event(enum tcmu_genl_cmd cmd, const char *name, int mino
if (ret < 0)
goto free_skb;
- ret = genlmsg_end(skb, msg_header);
- if (ret < 0)
- goto free_skb;
+ genlmsg_end(skb, msg_header);
ret = genlmsg_multicast(&tcmu_genl_family, skb, 0,
TCMU_MCGRP_CONFIG, GFP_KERNEL);
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 87e0b0782023..48491d1a81d6 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1759,11 +1759,7 @@ int thermal_generate_netlink_event(struct thermal_zone_device *tz,
thermal_event->event = event;
/* send multicast genetlink message */
- result = genlmsg_end(skb, msg_header);
- if (result < 0) {
- nlmsg_free(skb);
- return result;
- }
+ genlmsg_end(skb, msg_header);
result = genlmsg_multicast(&thermal_event_genl_family, skb, 0,
0, GFP_ATOMIC);