linux/drivers/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
..
appletalk treewide: replace dev->trans_start update with helper 2016-05-04 14:16:49 -04:00
arcnet arcnet: com90xx: add __init attribute 2016-04-19 20:17:45 -04:00
bonding
caif
can can: ifi: Add more detailed error reporting 2016-05-09 11:07:28 +02:00
cris treewide: replace dev->trans_start update with helper 2016-05-04 14:16:49 -04:00
dsa net: dsa: mv88e6xxx: remove bridge work 2016-05-16 13:46:24 -04:00
ethernet remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
fddi
fjes fjes: Fix unnecessary spinlock_irqsave 2016-05-09 22:05:51 -04:00
hamradio Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-05-17 16:26:30 -07:00
hippi
hyperv hv_netvsc: set nvdev link after populating chn_table 2016-05-16 13:26:01 -04:00
ieee802154 net: ieee802154/adf7242: syntax error ifdef DEBUG 2016-05-19 11:30:56 -07:00
ipvlan ipvlan: Fix failure path in dev registration during link creation 2016-04-28 17:23:08 -04:00
irda net: irda: avoid null pointer dereference 2016-05-19 11:30:57 -07:00
phy Revert "phy: add support for a reset-gpio specification" 2016-05-20 17:56:59 -04:00
plip
ppp ppp: add rtnetlink device creation support 2016-04-29 16:09:44 -04:00
slip treewide: replace dev->trans_start update with helper 2016-05-04 14:16:49 -04:00
team
usb TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
vmxnet3 Driver: Vmxnet3: set CHECKSUM_UNNECESSARY for IPv6 packets 2016-04-21 15:28:05 -04:00
wan treewide: replace dev->trans_start update with helper 2016-05-04 14:16:49 -04:00
wimax treewide: replace dev->trans_start update with helper 2016-05-04 14:16:49 -04:00
wireless remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
xen-netback xen-netback: only deinitialized hash if it was initialized 2016-05-20 17:41:18 -04:00
Kconfig gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U) 2016-05-10 12:25:04 -04:00
LICENSE.SRC
Makefile gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U) 2016-05-10 12:25:04 -04:00
Space.c net: Fix coding style warnings and errors. 2016-05-19 11:48:27 -07:00
dummy.c
eql.c
geneve.c udp: prevent skbs lingering in tunnel socket queues 2016-05-20 19:56:02 -04:00
gtp.c gtp: put back reference to netns when not required anymore 2016-05-12 12:27:15 -04:00
ifb.c ifb: support more features 2016-05-09 00:00:28 -04:00
loopback.c
macsec.c macsec: fix netlink attribute for key id 2016-05-20 11:14:13 -07:00
macvlan.c macvlan: fix failure during registration v3 2016-04-26 15:17:18 -04:00
macvtap.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-09 15:59:24 -04:00
mdio.c
mii.c
netconsole.c
nlmon.c
ntb_netdev.c
rionet.c drivers: net: remove NETDEV_TX_LOCKED 2016-04-26 15:53:05 -04:00
sb1000.c
sungem_phy.c
tun.c tuntap: correctly wake up process during uninit 2016-05-20 19:28:37 -04:00
veth.c veth: Update features to include all tunnel GSO types 2016-04-21 14:14:59 -04:00
virtio_net.c
vrf.c net: vrf: protect changes to private data with rcu 2016-05-16 13:46:24 -04:00
vxlan.c udp: prevent skbs lingering in tunnel socket queues 2016-05-20 19:56:02 -04:00
xen-netfront.c