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![]() 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> |
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.. | ||
ast.c | ||
ast.h | ||
config.c | ||
config.h | ||
debug_fs.c | ||
dir.c | ||
dir.h | ||
dlm_internal.h | ||
Kconfig | ||
lock.c | ||
lock.h | ||
lockspace.c | ||
lockspace.h | ||
lowcomms.c | ||
lowcomms.h | ||
lvb_table.h | ||
main.c | ||
Makefile | ||
member.c | ||
member.h | ||
memory.c | ||
memory.h | ||
midcomms.c | ||
midcomms.h | ||
netlink.c | ||
plock.c | ||
rcom.c | ||
rcom.h | ||
recover.c | ||
recover.h | ||
recoverd.c | ||
recoverd.h | ||
requestqueue.c | ||
requestqueue.h | ||
user.c | ||
user.h | ||
util.c | ||
util.h |