Gustavo A. R. Silva
2020-Nov-20 18:21 UTC
[Bridge] [PATCH 000/141] Fix fall-through warnings for Clang
Hi all,
This series aims to fix almost all remaining fall-through warnings in
order to enable -Wimplicit-fallthrough for Clang.
In preparation to enable -Wimplicit-fallthrough for Clang, explicitly
add multiple break/goto/return/fallthrough statements instead of just
letting the code fall through to the next case.
Notice that in order to enable -Wimplicit-fallthrough for Clang, this
change[1] is meant to be reverted at some point. So, this patch helps
to move in that direction.
Something important to mention is that there is currently a discrepancy
between GCC and Clang when dealing with switch fall-through to empty case
statements or to cases that only contain a break/continue/return
statement[2][3][4].
Now that the -Wimplicit-fallthrough option has been globally enabled[5],
any compiler should really warn on missing either a fallthrough annotation
or any of the other case-terminating statements (break/continue/return/
goto) when falling through to the next case statement. Making exceptions
to this introduces variation in case handling which may continue to lead
to bugs, misunderstandings, and a general lack of robustness. The point
of enabling options like -Wimplicit-fallthrough is to prevent human error
and aid developers in spotting bugs before their code is even built/
submitted/committed, therefore eliminating classes of bugs. So, in order
to really accomplish this, we should, and can, move in the direction of
addressing any error-prone scenarios and get rid of the unintentional
fallthrough bug-class in the kernel, entirely, even if there is some minor
redundancy. Better to have explicit case-ending statements than continue to
have exceptions where one must guess as to the right result. The compiler
will eliminate any actual redundancy.
Note that there is already a patch in mainline that addresses almost
40,000 of these issues[6].
I'm happy to carry this whole series in my own tree if people are OK
with it. :)
[1] commit e2079e93f562c ("kbuild: Do not enable -Wimplicit-fallthrough for
clang for now")
[2] ClangBuiltLinux#636
[3] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91432
[4] https://godbolt.org/z/xgkvIh
[5] commit a035d552a93b ("Makefile: Globally enable fall-through
warning")
[6] commit 4169e889e588 ("include: jhash/signal: Fix fall-through warnings
for Clang")
Thanks!
Gustavo A. R. Silva (141):
afs: Fix fall-through warnings for Clang
ASoC: codecs: Fix fall-through warnings for Clang
cifs: Fix fall-through warnings for Clang
drm/amdgpu: Fix fall-through warnings for Clang
drm/radeon: Fix fall-through warnings for Clang
gfs2: Fix fall-through warnings for Clang
gpio: Fix fall-through warnings for Clang
IB/hfi1: Fix fall-through warnings for Clang
igb: Fix fall-through warnings for Clang
ima: Fix fall-through warnings for Clang
ipv4: Fix fall-through warnings for Clang
ixgbe: Fix fall-through warnings for Clang
media: dvb-frontends: Fix fall-through warnings for Clang
media: usb: dvb-usb-v2: Fix fall-through warnings for Clang
netfilter: Fix fall-through warnings for Clang
nfsd: Fix fall-through warnings for Clang
nfs: Fix fall-through warnings for Clang
qed: Fix fall-through warnings for Clang
qlcnic: Fix fall-through warnings for Clang
scsi: aic7xxx: Fix fall-through warnings for Clang
scsi: aic94xx: Fix fall-through warnings for Clang
scsi: bfa: Fix fall-through warnings for Clang
staging: rtl8723bs: core: Fix fall-through warnings for Clang
staging: vt6655: Fix fall-through warnings for Clang
bnxt_en: Fix fall-through warnings for Clang
ceph: Fix fall-through warnings for Clang
drbd: Fix fall-through warnings for Clang
drm/amd/display: Fix fall-through warnings for Clang
e1000: Fix fall-through warnings for Clang
ext2: Fix fall-through warnings for Clang
ext4: Fix fall-through warnings for Clang
floppy: Fix fall-through warnings for Clang
fm10k: Fix fall-through warnings for Clang
IB/mlx4: Fix fall-through warnings for Clang
IB/qedr: Fix fall-through warnings for Clang
ice: Fix fall-through warnings for Clang
Input: pcspkr - Fix fall-through warnings for Clang
isofs: Fix fall-through warnings for Clang
ixgbevf: Fix fall-through warnings for Clang
kprobes/x86: Fix fall-through warnings for Clang
mm: Fix fall-through warnings for Clang
net: 3c509: Fix fall-through warnings for Clang
net: cassini: Fix fall-through warnings for Clang
net/mlx4: Fix fall-through warnings for Clang
net: mscc: ocelot: Fix fall-through warnings for Clang
netxen_nic: Fix fall-through warnings for Clang
nfp: Fix fall-through warnings for Clang
perf/x86: Fix fall-through warnings for Clang
pinctrl: Fix fall-through warnings for Clang
RDMA/mlx5: Fix fall-through warnings for Clang
reiserfs: Fix fall-through warnings for Clang
security: keys: Fix fall-through warnings for Clang
selinux: Fix fall-through warnings for Clang
target: Fix fall-through warnings for Clang
uprobes/x86: Fix fall-through warnings for Clang
vxge: Fix fall-through warnings for Clang
watchdog: Fix fall-through warnings for Clang
xen-blkfront: Fix fall-through warnings for Clang
regulator: as3722: Fix fall-through warnings for Clang
habanalabs: Fix fall-through warnings for Clang
tee: Fix fall-through warnings for Clang
HID: usbhid: Fix fall-through warnings for Clang
HID: input: Fix fall-through warnings for Clang
ACPI: Fix fall-through warnings for Clang
airo: Fix fall-through warnings for Clang
ALSA: hdspm: Fix fall-through warnings for Clang
ALSA: pcsp: Fix fall-through warnings for Clang
ALSA: sb: Fix fall-through warnings for Clang
ath5k: Fix fall-through warnings for Clang
atm: fore200e: Fix fall-through warnings for Clang
braille_console: Fix fall-through warnings for Clang
can: peak_usb: Fix fall-through warnings for Clang
carl9170: Fix fall-through warnings for Clang
cfg80211: Fix fall-through warnings for Clang
crypto: ccree - Fix fall-through warnings for Clang
decnet: Fix fall-through warnings for Clang
dm raid: Fix fall-through warnings for Clang
drm/amd/pm: Fix fall-through warnings for Clang
drm: Fix fall-through warnings for Clang
drm/i915/gem: Fix fall-through warnings for Clang
drm/nouveau/clk: Fix fall-through warnings for Clang
drm/nouveau: Fix fall-through warnings for Clang
drm/nouveau/therm: Fix fall-through warnings for Clang
drm/via: Fix fall-through warnings for Clang
firewire: core: Fix fall-through warnings for Clang
hwmon: (corsair-cpro) Fix fall-through warnings for Clang
hwmon: (max6621) Fix fall-through warnings for Clang
i3c: master: cdns: Fix fall-through warnings for Clang
ide: Fix fall-through warnings for Clang
iio: adc: cpcap: Fix fall-through warnings for Clang
iwlwifi: iwl-drv: Fix fall-through warnings for Clang
libata: Fix fall-through warnings for Clang
mac80211: Fix fall-through warnings for Clang
media: atomisp: Fix fall-through warnings for Clang
media: dvb_frontend: Fix fall-through warnings for Clang
media: rcar_jpu: Fix fall-through warnings for Clang
media: saa7134: Fix fall-through warnings for Clang
mmc: sdhci-of-arasan: Fix fall-through warnings for Clang
mt76: mt7615: Fix fall-through warnings for Clang
mtd: cfi: Fix fall-through warnings for Clang
mtd: mtdchar: Fix fall-through warnings for Clang
mtd: onenand: Fix fall-through warnings for Clang
mtd: rawnand: fsmc: Fix fall-through warnings for Clang
mtd: rawnand: stm32_fmc2: Fix fall-through warnings for Clang
net: ax25: Fix fall-through warnings for Clang
net: bridge: Fix fall-through warnings for Clang
net: core: Fix fall-through warnings for Clang
netfilter: ipt_REJECT: Fix fall-through warnings for Clang
net: netrom: Fix fall-through warnings for Clang
net/packet: Fix fall-through warnings for Clang
net: plip: Fix fall-through warnings for Clang
net: rose: Fix fall-through warnings for Clang
nl80211: Fix fall-through warnings for Clang
phy: qcom-usb-hs: Fix fall-through warnings for Clang
rds: Fix fall-through warnings for Clang
rt2x00: Fix fall-through warnings for Clang
rtl8xxxu: Fix fall-through warnings for Clang
rtw88: Fix fall-through warnings for Clang
rxrpc: Fix fall-through warnings for Clang
scsi: aacraid: Fix fall-through warnings for Clang
scsi: aha1740: Fix fall-through warnings for Clang
scsi: csiostor: Fix fall-through warnings for Clang
scsi: lpfc: Fix fall-through warnings for Clang
scsi: stex: Fix fall-through warnings for Clang
sctp: Fix fall-through warnings for Clang
slimbus: messaging: Fix fall-through warnings for Clang
staging: qlge: Fix fall-through warnings for Clang
staging: vt6656: Fix fall-through warnings for Clang
SUNRPC: Fix fall-through warnings for Clang
tipc: Fix fall-through warnings for Clang
tpm: Fix fall-through warnings for Clang
ubi: Fix fall-through warnings for Clang
usb: Fix fall-through warnings for Clang
video: fbdev: lxfb_ops: Fix fall-through warnings for Clang
video: fbdev: pm2fb: Fix fall-through warnings for Clang
virtio_net: Fix fall-through warnings for Clang
wcn36xx: Fix fall-through warnings for Clang
xen/manage: Fix fall-through warnings for Clang
xfrm: Fix fall-through warnings for Clang
zd1201: Fix fall-through warnings for Clang
Input: libps2 - Fix fall-through warnings for Clang
arch/x86/events/core.c | 2 +-
arch/x86/kernel/kprobes/core.c | 1 +
arch/x86/kernel/uprobes.c | 2 ++
drivers/accessibility/braille/braille_console.c | 1 +
drivers/acpi/sbshc.c | 1 +
drivers/ata/libata-eh.c | 1 +
drivers/atm/fore200e.c | 1 +
drivers/block/drbd/drbd_receiver.c | 1 +
drivers/block/drbd/drbd_req.c | 1 +
drivers/block/floppy.c | 1 +
drivers/block/xen-blkfront.c | 1 +
drivers/char/tpm/eventlog/tpm1.c | 1 +
drivers/crypto/ccree/cc_cipher.c | 3 +++
drivers/firewire/core-topology.c | 1 +
drivers/gpio/gpio-ath79.c | 1 +
drivers/gpio/gpiolib-acpi.c | 1 +
drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 1 +
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 1 +
drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 1 +
drivers/gpu/drm/amd/amdgpu/vi.c | 1 +
drivers/gpu/drm/amd/display/dc/bios/bios_parser.c | 1 +
drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c | 2 ++
drivers/gpu/drm/amd/display/dc/core/dc_link.c | 1 +
drivers/gpu/drm/amd/pm/powerplay/si_dpm.c | 2 +-
.../gpu/drm/amd/pm/powerplay/smumgr/polaris10_smumgr.c | 1 +
drivers/gpu/drm/drm_bufs.c | 1 +
drivers/gpu/drm/i915/gem/i915_gem_shrinker.c | 1 +
drivers/gpu/drm/nouveau/nouveau_bo.c | 1 +
drivers/gpu/drm/nouveau/nouveau_connector.c | 1 +
drivers/gpu/drm/nouveau/nvkm/subdev/clk/nv50.c | 1 +
drivers/gpu/drm/nouveau/nvkm/subdev/therm/gf119.c | 1 +
drivers/gpu/drm/radeon/ci_dpm.c | 2 +-
drivers/gpu/drm/radeon/r300.c | 1 +
drivers/gpu/drm/radeon/si_dpm.c | 2 +-
drivers/gpu/drm/via/via_irq.c | 1 +
drivers/hid/hid-input.c | 1 +
drivers/hid/usbhid/hid-core.c | 2 ++
drivers/hwmon/corsair-cpro.c | 1 +
drivers/hwmon/max6621.c | 2 +-
drivers/i3c/master/i3c-master-cdns.c | 2 ++
drivers/ide/siimage.c | 1 +
drivers/iio/adc/cpcap-adc.c | 1 +
drivers/infiniband/hw/hfi1/qp.c | 1 +
drivers/infiniband/hw/hfi1/tid_rdma.c | 5 +++++
drivers/infiniband/hw/mlx4/mad.c | 1 +
drivers/infiniband/hw/mlx5/qp.c | 1 +
drivers/infiniband/hw/qedr/main.c | 1 +
drivers/input/misc/pcspkr.c | 1 +
drivers/input/serio/libps2.c | 2 +-
drivers/md/dm-raid.c | 1 +
drivers/media/dvb-core/dvb_frontend.c | 1 +
drivers/media/dvb-frontends/cx24120.c | 1 +
drivers/media/dvb-frontends/dib0090.c | 2 ++
drivers/media/dvb-frontends/drxk_hard.c | 1 +
drivers/media/dvb-frontends/m88rs2000.c | 1 +
drivers/media/pci/saa7134/saa7134-tvaudio.c | 1 +
drivers/media/platform/rcar_jpu.c | 1 +
drivers/media/usb/dvb-usb-v2/af9015.c | 1 +
drivers/media/usb/dvb-usb-v2/lmedm04.c | 1 +
drivers/misc/habanalabs/gaudi/gaudi.c | 1 +
drivers/mmc/host/sdhci-of-arasan.c | 4 ++++
drivers/mtd/chips/cfi_cmdset_0001.c | 1 +
drivers/mtd/chips/cfi_cmdset_0002.c | 2 ++
drivers/mtd/chips/cfi_cmdset_0020.c | 2 ++
drivers/mtd/mtdchar.c | 1 +
drivers/mtd/nand/onenand/onenand_samsung.c | 1 +
drivers/mtd/nand/raw/fsmc_nand.c | 1 +
drivers/mtd/nand/raw/stm32_fmc2_nand.c | 2 ++
drivers/mtd/ubi/build.c | 1 +
drivers/net/can/usb/peak_usb/pcan_usb_core.c | 2 ++
drivers/net/ethernet/3com/3c509.c | 1 +
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 1 +
drivers/net/ethernet/intel/e1000/e1000_hw.c | 1 +
drivers/net/ethernet/intel/fm10k/fm10k_mbx.c | 2 ++
drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 1 +
drivers/net/ethernet/intel/igb/e1000_phy.c | 1 +
drivers/net/ethernet/intel/igb/igb_ethtool.c | 1 +
drivers/net/ethernet/intel/igb/igb_ptp.c | 1 +
drivers/net/ethernet/intel/ixgbe/ixgbe_82599.c | 2 ++
drivers/net/ethernet/intel/ixgbe/ixgbe_common.c | 1 +
drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c | 1 +
drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c | 1 +
drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 1 +
drivers/net/ethernet/mellanox/mlx4/resource_tracker.c | 1 +
drivers/net/ethernet/mscc/ocelot_vcap.c | 1 +
drivers/net/ethernet/neterion/vxge/vxge-config.c | 1 +
drivers/net/ethernet/netronome/nfp/nfp_net_repr.c | 1 +
drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c | 1 +
drivers/net/ethernet/qlogic/qed/qed_l2.c | 1 +
drivers/net/ethernet/qlogic/qed/qed_sriov.c | 1 +
drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c | 1 +
drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c | 1 +
drivers/net/ethernet/sun/cassini.c | 1 +
drivers/net/plip/plip.c | 2 ++
drivers/net/virtio_net.c | 1 +
drivers/net/wireless/ath/ath5k/mac80211-ops.c | 1 +
drivers/net/wireless/ath/carl9170/tx.c | 1 +
drivers/net/wireless/ath/wcn36xx/smd.c | 2 +-
drivers/net/wireless/cisco/airo.c | 1 +
drivers/net/wireless/intel/iwlwifi/iwl-drv.c | 2 +-
drivers/net/wireless/mediatek/mt76/mt7615/eeprom.c | 2 +-
drivers/net/wireless/ralink/rt2x00/rt2x00queue.c | 1 +
drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 8 ++++----
drivers/net/wireless/realtek/rtw88/fw.c | 2 +-
drivers/net/wireless/zydas/zd1201.c | 2 +-
drivers/phy/qualcomm/phy-qcom-usb-hs.c | 1 +
drivers/pinctrl/renesas/pinctrl-rza1.c | 1 +
drivers/regulator/as3722-regulator.c | 3 ++-
drivers/scsi/aacraid/commsup.c | 1 +
drivers/scsi/aha1740.c | 1 +
drivers/scsi/aic7xxx/aic79xx_core.c | 4 +++-
drivers/scsi/aic7xxx/aic7xxx_core.c | 4 ++--
drivers/scsi/aic94xx/aic94xx_scb.c | 2 ++
drivers/scsi/aic94xx/aic94xx_task.c | 2 ++
drivers/scsi/bfa/bfa_fcs_lport.c | 2 +-
drivers/scsi/bfa/bfa_ioc.c | 6 ++++--
drivers/scsi/csiostor/csio_wr.c | 1 +
drivers/scsi/lpfc/lpfc_bsg.c | 1 +
drivers/scsi/stex.c | 1 +
drivers/slimbus/messaging.c | 1 +
drivers/staging/media/atomisp/pci/runtime/isys/src/rx.c | 1 +
drivers/staging/qlge/qlge_main.c | 1 +
drivers/staging/rtl8723bs/core/rtw_cmd.c | 1 +
drivers/staging/rtl8723bs/core/rtw_mlme_ext.c | 1 +
drivers/staging/rtl8723bs/core/rtw_wlan_util.c | 1 +
drivers/staging/vt6655/device_main.c | 1 +
drivers/staging/vt6655/rxtx.c | 2 ++
drivers/staging/vt6656/main_usb.c | 1 +
drivers/target/target_core_iblock.c | 1 +
drivers/target/target_core_pr.c | 1 +
drivers/tee/tee_core.c | 1 +
drivers/usb/gadget/function/f_fs.c | 2 ++
drivers/usb/gadget/function/f_loopback.c | 2 +-
drivers/usb/gadget/function/f_sourcesink.c | 1 +
drivers/usb/gadget/udc/dummy_hcd.c | 2 ++
drivers/usb/host/fotg210-hcd.c | 2 +-
drivers/usb/host/isp116x-hcd.c | 1 +
drivers/usb/host/max3421-hcd.c | 1 +
drivers/usb/host/oxu210hp-hcd.c | 1 +
drivers/usb/misc/yurex.c | 1 +
drivers/usb/musb/tusb6010.c | 1 +
drivers/usb/storage/ene_ub6250.c | 1 +
drivers/usb/storage/uas.c | 1 +
drivers/video/fbdev/geode/lxfb_ops.c | 1 +
drivers/video/fbdev/pm2fb.c | 1 +
drivers/watchdog/machzwd.c | 1 +
drivers/xen/manage.c | 1 +
fs/afs/cmservice.c | 5 +++++
fs/afs/fsclient.c | 4 ++++
fs/afs/vlclient.c | 1 +
fs/ceph/dir.c | 2 ++
fs/cifs/inode.c | 1 +
fs/cifs/sess.c | 1 +
fs/cifs/smbdirect.c | 1 +
fs/ext2/inode.c | 1 +
fs/ext4/super.c | 1 +
fs/gfs2/inode.c | 2 ++
fs/gfs2/recovery.c | 1 +
fs/isofs/rock.c | 1 +
fs/nfs/nfs3acl.c | 1 +
fs/nfs/nfs4client.c | 1 +
fs/nfs/nfs4proc.c | 2 ++
fs/nfs/nfs4state.c | 1 +
fs/nfs/pnfs.c | 2 ++
fs/nfsd/nfs4state.c | 1 +
fs/nfsd/nfsctl.c | 1 +
fs/reiserfs/namei.c | 1 +
mm/mm_init.c | 1 +
mm/vmscan.c | 1 +
net/ax25/af_ax25.c | 1 +
net/bridge/br_input.c | 1 +
net/core/dev.c | 1 +
net/decnet/dn_route.c | 2 +-
net/ipv4/ah4.c | 1 +
net/ipv4/esp4.c | 1 +
net/ipv4/fib_semantics.c | 1 +
net/ipv4/ip_vti.c | 1 +
net/ipv4/ipcomp.c | 1 +
net/ipv4/netfilter/ipt_REJECT.c | 1 +
net/mac80211/cfg.c | 2 ++
net/netfilter/nf_conntrack_proto_dccp.c | 1 +
net/netfilter/nf_tables_api.c | 1 +
net/netfilter/nft_ct.c | 1 +
net/netrom/nr_route.c | 4 ++++
net/packet/af_packet.c | 1 +
net/rds/tcp_connect.c | 1 +
net/rds/threads.c | 2 ++
net/rose/rose_route.c | 2 ++
net/rxrpc/af_rxrpc.c | 1 +
net/sctp/input.c | 3 ++-
net/sunrpc/rpc_pipe.c | 1 +
net/sunrpc/xprtsock.c | 1 +
net/tipc/link.c | 1 +
net/wireless/nl80211.c | 1 +
net/wireless/util.c | 1 +
net/xfrm/xfrm_interface.c | 1 +
security/integrity/ima/ima_main.c | 1 +
security/integrity/ima/ima_policy.c | 2 ++
security/keys/process_keys.c | 1 +
security/selinux/hooks.c | 1 +
sound/drivers/pcsp/pcsp_input.c | 1 +
sound/isa/sb/sb8_main.c | 1 +
sound/pci/rme9652/hdspm.c | 1 +
sound/soc/codecs/adav80x.c | 1 +
sound/soc/codecs/arizona.c | 1 +
sound/soc/codecs/cs42l52.c | 1 +
sound/soc/codecs/cs42l56.c | 1 +
sound/soc/codecs/cs47l92.c | 1 +
sound/soc/codecs/wm8962.c | 1 +
209 files changed, 264 insertions(+), 26 deletions(-)
--
2.27.0
Joe Perches
2020-Nov-20 18:28 UTC
[Bridge] [PATCH 000/141] Fix fall-through warnings for Clang
On Fri, 2020-11-20 at 12:21 -0600, Gustavo A. R. Silva wrote:> Hi all, > > This series aims to fix almost all remaining fall-through warnings in > order to enable -Wimplicit-fallthrough for Clang. > > In preparation to enable -Wimplicit-fallthrough for Clang, explicitly > add multiple break/goto/return/fallthrough statements instead of just > letting the code fall through to the next case. > > Notice that in order to enable -Wimplicit-fallthrough for Clang, this > change[1] is meant to be reverted at some point. So, this patch helps > to move in that direction.This was a bit hard to parse for a second or three. Thanks Gustavo. How was this change done?
Gustavo A. R. Silva
2020-Nov-20 18:35 UTC
[Nouveau] [PATCH 081/141] drm/nouveau/clk: Fix fall-through warnings for Clang
In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars at kernel.org> --- drivers/gpu/drm/nouveau/nvkm/subdev/clk/nv50.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/nv50.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/nv50.c index da1770e47490..ae2733035ac2 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/nv50.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/nv50.c @@ -313,6 +313,7 @@ nv50_clk_read(struct nvkm_clk *base, enum nv_clk_src src) default: break; } + break; default: break; } -- 2.27.0
Gustavo A. R. Silva
2020-Nov-20 18:35 UTC
[Nouveau] [PATCH 082/141] drm/nouveau: Fix fall-through warnings for Clang
In preparation to enable -Wimplicit-fallthrough for Clang, fix a couple of warnings by explicitly adding a couple of break statements instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars at kernel.org> --- drivers/gpu/drm/nouveau/nouveau_bo.c | 1 + drivers/gpu/drm/nouveau/nouveau_connector.c | 1 + 2 files changed, 2 insertions(+) diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c index 56b335a55966..037f312c948d 100644 --- a/drivers/gpu/drm/nouveau/nouveau_bo.c +++ b/drivers/gpu/drm/nouveau/nouveau_bo.c @@ -461,6 +461,7 @@ nouveau_bo_pin(struct nouveau_bo *nvbo, uint32_t domain, bool contig) break; case TTM_PL_TT: error |= !(domain & NOUVEAU_GEM_DOMAIN_GART); + break; default: break; } diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c index 8b4b3688c7ae..585344965504 100644 --- a/drivers/gpu/drm/nouveau/nouveau_connector.c +++ b/drivers/gpu/drm/nouveau/nouveau_connector.c @@ -157,6 +157,7 @@ nouveau_conn_atomic_set_property(struct drm_connector *connector, default: break; } + break; case DRM_MODE_SCALE_FULLSCREEN: case DRM_MODE_SCALE_CENTER: case DRM_MODE_SCALE_ASPECT: -- 2.27.0
Gustavo A. R. Silva
2020-Nov-20 18:35 UTC
[Nouveau] [PATCH 083/141] drm/nouveau/therm: Fix fall-through warnings for Clang
In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars at kernel.org> --- drivers/gpu/drm/nouveau/nvkm/subdev/therm/gf119.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/gf119.c b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/gf119.c index 0981b02790e2..bb2e71bf537f 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/gf119.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/gf119.c @@ -41,6 +41,7 @@ pwm_info(struct nvkm_therm *therm, int line) default: break; } + break; default: break; } -- 2.27.0
Gustavo A. R. Silva
2020-Nov-20 18:37 UTC
[Bridge] [PATCH 106/141] net: bridge: Fix fall-through warnings for Clang
In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars at kernel.org> --- net/bridge/br_input.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 59a318b9f646..8db219d979c5 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -148,6 +148,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb break; case BR_PKT_UNICAST: dst = br_fdb_find_rcu(br, eth_hdr(skb)->h_dest, vid); + break; default: break; } -- 2.27.0
Jakub Kicinski
2020-Nov-20 18:53 UTC
[Bridge] [PATCH 000/141] Fix fall-through warnings for Clang
On Fri, 20 Nov 2020 12:21:39 -0600 Gustavo A. R. Silva wrote:> This series aims to fix almost all remaining fall-through warnings in > order to enable -Wimplicit-fallthrough for Clang. > > In preparation to enable -Wimplicit-fallthrough for Clang, explicitly > add multiple break/goto/return/fallthrough statements instead of just > letting the code fall through to the next case. > > Notice that in order to enable -Wimplicit-fallthrough for Clang, this > change[1] is meant to be reverted at some point. So, this patch helps > to move in that direction. > > Something important to mention is that there is currently a discrepancy > between GCC and Clang when dealing with switch fall-through to empty case > statements or to cases that only contain a break/continue/return > statement[2][3][4].Are we sure we want to make this change? Was it discussed before? Are there any bugs Clangs puritanical definition of fallthrough helped find? IMVHO compiler warnings are supposed to warn about issues that could be bugs. Falling through to default: break; can hardly be a bug?!
Gustavo A. R. Silva
2020-Nov-20 19:02 UTC
[Nouveau] [PATCH 000/141] Fix fall-through warnings for Clang
On 11/20/20 12:28, Joe Perches wrote:> On Fri, 2020-11-20 at 12:21 -0600, Gustavo A. R. Silva wrote: >> Hi all, >> >> This series aims to fix almost all remaining fall-through warnings in >> order to enable -Wimplicit-fallthrough for Clang. >> >> In preparation to enable -Wimplicit-fallthrough for Clang, explicitly >> add multiple break/goto/return/fallthrough statements instead of just >> letting the code fall through to the next case. >> >> Notice that in order to enable -Wimplicit-fallthrough for Clang, this >> change[1] is meant to be reverted at some point. So, this patch helps >> to move in that direction. > > This was a bit hard to parse for a second or three. > > Thanks Gustavo. > > How was this change done?I audited case by case in order to determine the best fit for each situation. Depending on the surrounding logic, sometimes it makes more sense a goto or a fallthrough rather than merely a break. Thanks -- Gustavo
Gustavo A. R. Silva
2020-Nov-20 19:04 UTC
[Nouveau] [PATCH 000/141] Fix fall-through warnings for Clang
Hi, On 11/20/20 12:53, Jakub Kicinski wrote:> On Fri, 20 Nov 2020 12:21:39 -0600 Gustavo A. R. Silva wrote: >> This series aims to fix almost all remaining fall-through warnings in >> order to enable -Wimplicit-fallthrough for Clang. >> >> In preparation to enable -Wimplicit-fallthrough for Clang, explicitly >> add multiple break/goto/return/fallthrough statements instead of just >> letting the code fall through to the next case. >> >> Notice that in order to enable -Wimplicit-fallthrough for Clang, this >> change[1] is meant to be reverted at some point. So, this patch helps >> to move in that direction. >> >> Something important to mention is that there is currently a discrepancy >> between GCC and Clang when dealing with switch fall-through to empty case >> statements or to cases that only contain a break/continue/return >> statement[2][3][4]. > > Are we sure we want to make this change? Was it discussed before? > > Are there any bugs Clangs puritanical definition of fallthrough helped > find? > > IMVHO compiler warnings are supposed to warn about issues that could > be bugs. Falling through to default: break; can hardly be a bug?!The justification for this is explained in this same changelog text: Now that the -Wimplicit-fallthrough option has been globally enabled[5], any compiler should really warn on missing either a fallthrough annotation or any of the other case-terminating statements (break/continue/return/ goto) when falling through to the next case statement. Making exceptions to this introduces variation in case handling which may continue to lead to bugs, misunderstandings, and a general lack of robustness. The point of enabling options like -Wimplicit-fallthrough is to prevent human error and aid developers in spotting bugs before their code is even built/ submitted/committed, therefore eliminating classes of bugs. So, in order to really accomplish this, we should, and can, move in the direction of addressing any error-prone scenarios and get rid of the unintentional fallthrough bug-class in the kernel, entirely, even if there is some minor redundancy. Better to have explicit case-ending statements than continue to have exceptions where one must guess as to the right result. The compiler will eliminate any actual redundancy. Note that there is already a patch in mainline that addresses almost 40,000 of these issues[6]. [1] commit e2079e93f562c ("kbuild: Do not enable -Wimplicit-fallthrough for clang for now") [2] ClangBuiltLinux#636 [3] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91432 [4] https://godbolt.org/z/xgkvIh [5] commit a035d552a93b ("Makefile: Globally enable fall-through warning") [6] commit 4169e889e588 ("include: jhash/signal: Fix fall-through warnings for Clang") Thanks -- Gustavo
Kees Cook
2020-Nov-20 19:30 UTC
[Nouveau] [PATCH 000/141] Fix fall-through warnings for Clang
On Fri, Nov 20, 2020 at 10:53:44AM -0800, Jakub Kicinski wrote:> On Fri, 20 Nov 2020 12:21:39 -0600 Gustavo A. R. Silva wrote: > > This series aims to fix almost all remaining fall-through warnings in > > order to enable -Wimplicit-fallthrough for Clang. > > > > In preparation to enable -Wimplicit-fallthrough for Clang, explicitly > > add multiple break/goto/return/fallthrough statements instead of just > > letting the code fall through to the next case. > > > > Notice that in order to enable -Wimplicit-fallthrough for Clang, this > > change[1] is meant to be reverted at some point. So, this patch helps > > to move in that direction. > > > > Something important to mention is that there is currently a discrepancy > > between GCC and Clang when dealing with switch fall-through to empty case > > statements or to cases that only contain a break/continue/return > > statement[2][3][4]. > > Are we sure we want to make this change? Was it discussed before? > > Are there any bugs Clangs puritanical definition of fallthrough helped > find? > > IMVHO compiler warnings are supposed to warn about issues that could > be bugs. Falling through to default: break; can hardly be a bug?!It's certainly a place where the intent is not always clear. I think this makes all the cases unambiguous, and doesn't impact the machine code, since the compiler will happily optimize away any behavioral redundancy. -- Kees Cook
Miguel Ojeda
2020-Nov-20 22:21 UTC
[Nouveau] [PATCH 000/141] Fix fall-through warnings for Clang
Hi Gustavo, On Fri, Nov 20, 2020 at 7:21 PM Gustavo A. R. Silva <gustavoars at kernel.org> wrote:> > Hi all, > > This series aims to fix almost all remaining fall-through warnings in > order to enable -Wimplicit-fallthrough for Clang.Thanks for this. Since this warning is reliable in both/all compilers and we are eventually getting rid of all the cases, what about going even further and making it an error right after? Cheers, Miguel
Jason Gunthorpe
2020-Nov-23 20:03 UTC
[Nouveau] [PATCH 000/141] Fix fall-through warnings for Clang
On Fri, Nov 20, 2020 at 12:21:39PM -0600, Gustavo A. R. Silva wrote:> IB/hfi1: Fix fall-through warnings for Clang > IB/mlx4: Fix fall-through warnings for Clang > IB/qedr: Fix fall-through warnings for Clang > RDMA/mlx5: Fix fall-through warnings for ClangI picked these four to the rdma tree, thanks Jason
Mark Brown
2020-Nov-23 20:38 UTC
[Nouveau] [PATCH 000/141] Fix fall-through warnings for Clang
On Fri, 20 Nov 2020 12:21:39 -0600, Gustavo A. R. Silva wrote:> This series aims to fix almost all remaining fall-through warnings in > order to enable -Wimplicit-fallthrough for Clang. > > In preparation to enable -Wimplicit-fallthrough for Clang, explicitly > add multiple break/goto/return/fallthrough statements instead of just > letting the code fall through to the next case. > > [...]Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next Thanks! [1/1] regulator: as3722: Fix fall-through warnings for Clang commit: b52b417ccac4fae5b1f2ec4f1d46eb91e4493dc5 All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
Martin K. Petersen
2020-Dec-01 05:52 UTC
[Nouveau] [PATCH 000/141] Fix fall-through warnings for Clang
Gustavo,> This series aims to fix almost all remaining fall-through warnings in > order to enable -Wimplicit-fallthrough for Clang.Applied 20-22,54,120-124 to 5.11/scsi-staging, thanks. -- Martin K. Petersen Oracle Linux Engineering
Martin K. Petersen
2020-Dec-08 04:52 UTC
(subset) [PATCH 000/141] Fix fall-through warnings for Clang
On Fri, 20 Nov 2020 12:21:39 -0600, Gustavo A. R. Silva wrote:> This series aims to fix almost all remaining fall-through warnings in > order to enable -Wimplicit-fallthrough for Clang. > > In preparation to enable -Wimplicit-fallthrough for Clang, explicitly > add multiple break/goto/return/fallthrough statements instead of just > letting the code fall through to the next case. > > [...]Applied to 5.11/scsi-queue, thanks! [054/141] target: Fix fall-through warnings for Clang https://git.kernel.org/mkp/scsi/c/492096ecfa39 -- Martin K. Petersen Oracle Linux Engineering
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