linux/net
Arnd Bergmann 287980e49f remove lots of IS_ERR_VALUE abuses
Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27 15:26:11 -07:00
..
6lowpan 6lowpan: move mac802154 header 2016-04-13 10:41:10 +02:00
9p remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
802
8021q vlan: propagate gso_max_segs 2016-03-17 21:05:01 -04:00
appletalk appletalk: fix erroneous return value 2016-02-18 14:59:34 -05:00
atm treewide: replace dev->trans_start update with helper 2016-05-04 14:16:49 -04:00
ax25 ax25: add link layer header validation function 2016-03-09 22:13:01 -05:00
batman-adv batman-adv: initialize ELP orig address on secondary interfaces 2016-05-18 11:49:44 +08:00
bluetooth Bluetooth: fix power_on vs close race 2016-05-13 16:50:23 +02:00
bridge Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-09 15:59:24 -04:00
caif net: caif: fix misleading indentation 2016-03-14 13:09:50 -04:00
can sock: enable timestamping using control messages 2016-04-04 15:50:30 -04:00
ceph libceph: make ceph_osdc_wait_request() uninterruptible 2016-05-26 01:15:40 +02:00
core net: define gso types for IPx over IPv4 and IPv6 2016-05-20 18:03:15 -04:00
dcb net/dcb: make dcbnl.c explicitly non-modular 2015-10-09 07:52:27 -07:00
dccp dccp: do not assume DCCP code is non preemptible 2016-05-02 17:02:25 -04:00
decnet decnet: Do not build routes to devices without decnet private data. 2016-04-10 23:01:30 -04:00
dns_resolver KEYS: Add a facility to restrict new links into a keyring 2016-04-11 22:37:37 +01:00
dsa dsa: Rename switch chip data to cd 2016-05-11 19:36:28 -04:00
ethernet eth: Pull header from first fragment via eth_get_headlen 2016-02-24 13:58:05 -05:00
hsr net/hsr: Use setup_timer and mod_timer. 2016-05-16 14:00:43 -04:00
ieee802154 Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2016-04-26 13:15:56 -04:00
ipv4 udp: prevent skbs lingering in tunnel socket queues 2016-05-20 19:56:02 -04:00
ipv6 udp: prevent skbs lingering in tunnel socket queues 2016-05-20 19:56:02 -04:00
ipx net: Pass kern from net_proto_family.create to sk_alloc 2015-05-11 10:50:17 -04:00
irda TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
iucv af_iucv: Validate socket address length in iucv_sock_bind() 2016-01-19 14:21:08 -05:00
kcm kcm: fix a signedness in kcm_splice_read() 2016-05-19 11:26:51 -07:00
key af_key: fix two typos 2015-10-23 03:05:19 -07:00
l2tp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-04 00:52:29 -04:00
l3mdev net: l3mdev: Allow send on enslaved interface 2016-05-09 22:33:52 -04:00
lapb
llc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-09 15:59:24 -04:00
mac80211 Some more work for 4.7, notably: 2016-05-12 11:46:58 -04:00
mac802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
mpls gso: Remove arbitrary checks for unsupported GSO 2016-05-20 18:03:15 -04:00
netfilter net: define gso types for IPx over IPv4 and IPv6 2016-05-20 18:03:15 -04:00
netlabel netlabel: fix a problem with netlbl_secattr_catmap_setrng() 2016-04-05 16:10:47 -04:00
netlink netlink: Fix dump skb leak/double free 2016-05-16 22:05:15 -04:00
netrom netfilter: Remove spurios included of netfilter.h 2015-06-18 21:14:32 +02:00
nfc nfc: nci: Add nci_nfcc_loopback to the nci core 2016-05-04 01:48:16 +02:00
openvswitch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-15 13:32:48 -04:00
packet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-04-23 18:51:33 -04:00
phonet sock: struct proto hash function may error 2016-02-11 03:54:14 -05:00
qrtr Merge tag 'qcom-soc-for-4.7-2' into net-next 2016-05-17 14:11:19 -04:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-20 20:01:26 -07:00
rfkill rfkill: Use switch to demux userspace operations 2016-04-05 10:48:53 +02:00
rose Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-24 02:58:51 -07:00
rxrpc Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
sched net_sched: close another race condition in tcf_mirred_release() 2016-05-17 12:40:28 -04:00
sctp sctp: prepare for socket backlog behavior change 2016-05-02 17:02:26 -04:00
sunrpc NFS client updates for Linux 4.7 2016-05-26 10:33:33 -07:00
switchdev switchdev: pass pointer to fib_info instead of copy 2016-05-17 13:58:49 -04:00
tipc tipc: block BH in TCP callbacks 2016-05-19 11:36:49 -07:00
unix constify security_path_{mkdir,mknod,symlink} 2016-03-28 00:47:27 -04:00
vmw_vsock Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-09 15:59:24 -04:00
wimax net:wimax: Fix doucble word "the the" in networking.xml 2015-08-09 22:43:52 -07:00
wireless mm/page_ref: use page_ref helper instead of direct modification of _count 2016-05-19 19:12:14 -07:00
x25 net: fix a kernel infoleak in x25 module 2016-05-09 22:45:33 -04:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-09 15:59:24 -04:00
Kconfig bpf: add generic constant blinding for use in jits 2016-05-16 13:49:32 -04:00
Makefile net: Add Qualcomm IPC router 2016-05-08 23:46:14 -04:00
compat.c net: switch importing msghdr from userland to {compat_,}import_iovec() 2015-04-09 00:02:26 -04:00
socket.c fs: poll/select/recvmmsg: use timespec64 for timeout events 2016-05-19 19:12:14 -07:00
sysctl_net.c net: sysctl: fix a kmemleak warning 2015-10-23 06:22:08 -07:00