On Thu, Jun 4, 2020 at 1:32 AM Kees Cook [off-list ref] wrote:

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

As recommended[2] by[3] Linus[4], remove the macro.

Most of the 300 uses don't cause any warnings on gcc 9.3.0, so they're in
a single treewide commit in this series. A few others needed to actually
get cleaned up, and I broke those out into individual patches.

-Kees

Hi Kees,

what is the base for your patchset?
I would like to test on top of Linux v5.7.

Can you place the series in your Git tree for easy fetching, please?

Thanks.

Regards,
- Sedat -

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ (local)
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ (local)
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ (local)
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ (local)

Kees Cook (10):
  x86/mm/numa: Remove uninitialized_var() usage
  drbd: Remove uninitialized_var() usage
  b43: Remove uninitialized_var() usage
  rtlwifi: rtl8192cu: Remove uninitialized_var() usage
  ide: Remove uninitialized_var() usage
  clk: st: Remove uninitialized_var() usage
  spi: davinci: Remove uninitialized_var() usage
  checkpatch: Remove awareness of uninitialized_var() macro
  treewide: Remove uninitialized_var() usage
  compiler: Remove uninitialized_var() macro

 arch/arm/mach-sa1100/assabet.c                 |  2 +-
 arch/arm/mm/alignment.c                        |  2 +-
 arch/ia64/kernel/process.c                     |  2 +-
 arch/ia64/mm/discontig.c                       |  2 +-
 arch/ia64/mm/tlb.c                             |  2 +-
 arch/mips/lib/dump_tlb.c                       |  2 +-
 arch/mips/mm/init.c                            |  2 +-
 arch/mips/mm/tlb-r4k.c                         |  6 +++---
 arch/powerpc/kvm/book3s_64_mmu_radix.c         |  2 +-
 arch/powerpc/kvm/book3s_pr.c                   |  2 +-
 arch/powerpc/kvm/powerpc.c                     |  2 +-
 arch/powerpc/platforms/52xx/mpc52xx_pic.c      |  2 +-
 arch/s390/kernel/smp.c                         |  2 +-
 arch/x86/kernel/quirks.c                       | 10 +++++-----
 arch/x86/kvm/mmu/mmu.c                         |  2 +-
 arch/x86/kvm/mmu/paging_tmpl.h                 |  2 +-
 arch/x86/kvm/x86.c                             |  2 +-
 arch/x86/mm/numa.c                             | 18 +++++++++---------
 block/blk-merge.c                              |  2 +-
 drivers/acpi/acpi_pad.c                        |  2 +-
 drivers/ata/libata-scsi.c                      |  2 +-
 drivers/atm/zatm.c                             |  2 +-
 drivers/block/drbd/drbd_nl.c                   |  6 +++---
 drivers/block/drbd/drbd_state.c                |  2 +-
 drivers/block/rbd.c                            |  2 +-
 drivers/clk/clk-gate.c                         |  2 +-
 drivers/clk/spear/clk-vco-pll.c                |  2 +-
 drivers/clk/st/clkgen-fsyn.c                   |  1 -
 drivers/crypto/nx/nx-842-powernv.c             |  2 +-
 drivers/firewire/ohci.c                        | 14 +++++++-------
 drivers/gpu/drm/bridge/sil-sii8620.c           |  2 +-
 drivers/gpu/drm/drm_edid.c                     |  2 +-
 drivers/gpu/drm/exynos/exynos_drm_dsi.c        |  6 +++---
 drivers/gpu/drm/i915/display/intel_fbc.c       |  2 +-
 drivers/gpu/drm/i915/gt/intel_lrc.c            |  2 +-
 drivers/gpu/drm/i915/intel_uncore.c            |  2 +-
 .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c    |  4 ++--
 drivers/i2c/busses/i2c-rk3x.c                  |  2 +-
 drivers/ide/ide-acpi.c                         |  2 +-
 drivers/ide/ide-atapi.c                        |  2 +-
 drivers/ide/ide-io-std.c                       |  4 ++--
 drivers/ide/ide-io.c                           |  8 ++++----
 drivers/ide/ide-sysfs.c                        |  2 +-
 drivers/ide/ide-taskfile.c                     |  1 -
 drivers/ide/umc8672.c                          |  2 +-
 drivers/idle/intel_idle.c                      |  2 +-
 drivers/infiniband/core/uverbs_cmd.c           |  4 ++--
 drivers/infiniband/hw/cxgb4/cm.c               |  2 +-
 drivers/infiniband/hw/cxgb4/cq.c               |  2 +-
 drivers/infiniband/hw/mlx4/qp.c                |  6 +++---
 drivers/infiniband/hw/mlx5/cq.c                |  6 +++---
 drivers/infiniband/hw/mlx5/devx.c              |  2 +-
 drivers/infiniband/hw/mlx5/qp.c                |  2 +-
 drivers/infiniband/hw/mthca/mthca_qp.c         | 10 +++++-----
 drivers/infiniband/sw/siw/siw_qp_rx.c          |  2 +-
 drivers/input/serio/serio_raw.c                |  2 +-
 drivers/input/touchscreen/sur40.c              |  2 +-
 drivers/iommu/intel-iommu.c                    |  2 +-
 drivers/md/dm-io.c                             |  2 +-
 drivers/md/dm-ioctl.c                          |  2 +-
 drivers/md/dm-snap-persistent.c                |  2 +-
 drivers/md/dm-table.c                          |  2 +-
 drivers/md/dm-writecache.c                     |  2 +-
 drivers/md/raid5.c                             |  2 +-
 drivers/media/dvb-frontends/rtl2832.c          |  2 +-
 drivers/media/tuners/qt1010.c                  |  4 ++--
 drivers/media/usb/gspca/vicam.c                |  2 +-
 drivers/media/usb/uvc/uvc_video.c              |  8 ++++----
 drivers/memstick/host/jmb38x_ms.c              |  2 +-
 drivers/memstick/host/tifm_ms.c                |  2 +-
 drivers/mmc/host/sdhci.c                       |  2 +-
 drivers/mtd/nand/raw/nand_ecc.c                |  2 +-
 drivers/mtd/nand/raw/s3c2410.c                 |  2 +-
 drivers/mtd/parsers/afs.c                      |  4 ++--
 drivers/mtd/ubi/eba.c                          |  2 +-
 drivers/net/can/janz-ican3.c                   |  2 +-
 drivers/net/ethernet/broadcom/bnx2.c           |  4 ++--
 .../ethernet/mellanox/mlx5/core/pagealloc.c    |  4 ++--
 drivers/net/ethernet/neterion/s2io.c           |  2 +-
 drivers/net/ethernet/qlogic/qla3xxx.c          |  2 +-
 drivers/net/ethernet/sun/cassini.c             |  2 +-
 drivers/net/ethernet/sun/niu.c                 |  6 +++---
 drivers/net/wan/z85230.c                       |  2 +-
 drivers/net/wireless/ath/ath10k/core.c         |  2 +-
 drivers/net/wireless/ath/ath6kl/init.c         |  2 +-
 drivers/net/wireless/ath/ath9k/init.c          |  2 +-
 drivers/net/wireless/broadcom/b43/debugfs.c    |  2 +-
 drivers/net/wireless/broadcom/b43/dma.c        |  2 +-
 drivers/net/wireless/broadcom/b43/lo.c         |  2 +-
 drivers/net/wireless/broadcom/b43/phy_n.c      | 12 ++++++++----
 drivers/net/wireless/broadcom/b43/xmit.c       | 12 ++++++------
 .../net/wireless/broadcom/b43legacy/debugfs.c  |  2 +-
 drivers/net/wireless/broadcom/b43legacy/main.c |  2 +-
 drivers/net/wireless/intel/iwlegacy/3945.c     |  2 +-
 drivers/net/wireless/intel/iwlegacy/4965-mac.c |  2 +-
 .../wireless/realtek/rtlwifi/rtl8192cu/hw.c    |  8 ++++----
 drivers/pci/pcie/aer.c                         |  2 +-
 drivers/platform/x86/hdaps.c                   |  4 ++--
 drivers/scsi/dc395x.c                          |  2 +-
 drivers/scsi/pm8001/pm8001_hwi.c               |  2 +-
 drivers/scsi/pm8001/pm80xx_hwi.c               |  2 +-
 drivers/spi/spi-davinci.c                      |  1 -
 drivers/ssb/driver_chipcommon.c                |  4 ++--
 drivers/tty/cyclades.c                         |  2 +-
 drivers/tty/isicom.c                           |  2 +-
 drivers/usb/musb/cppi_dma.c                    |  2 +-
 drivers/usb/storage/sddr55.c                   |  4 ++--
 drivers/vhost/net.c                            |  6 +++---
 drivers/video/fbdev/matrox/matroxfb_maven.c    |  6 +++---
 drivers/video/fbdev/pm3fb.c                    |  6 +++---
 drivers/video/fbdev/riva/riva_hw.c             |  3 +--
 drivers/virtio/virtio_ring.c                   |  6 +++---
 fs/afs/dir.c                                   |  2 +-
 fs/afs/security.c                              |  2 +-
 fs/dlm/netlink.c                               |  2 +-
 fs/erofs/data.c                                |  4 ++--
 fs/erofs/zdata.c                               |  2 +-
 fs/f2fs/data.c                                 |  2 +-
 fs/fat/dir.c                                   |  2 +-
 fs/fuse/control.c                              |  4 ++--
 fs/fuse/cuse.c                                 |  2 +-
 fs/fuse/file.c                                 |  2 +-
 fs/gfs2/aops.c                                 |  2 +-
 fs/gfs2/bmap.c                                 |  2 +-
 fs/gfs2/lops.c                                 |  2 +-
 fs/hfsplus/unicode.c                           |  2 +-
 fs/isofs/namei.c                               |  4 ++--
 fs/jffs2/erase.c                               |  2 +-
 fs/nfsd/nfsctl.c                               |  2 +-
 fs/ocfs2/alloc.c                               |  4 ++--
 fs/ocfs2/dir.c                                 | 14 +++++++-------
 fs/ocfs2/extent_map.c                          |  4 ++--
 fs/ocfs2/namei.c                               |  2 +-
 fs/ocfs2/refcounttree.c                        |  2 +-
 fs/ocfs2/xattr.c                               |  2 +-
 fs/omfs/file.c                                 |  2 +-
 fs/overlayfs/copy_up.c                         |  4 ++--
 fs/ubifs/commit.c                              |  6 +++---
 fs/ubifs/dir.c                                 |  2 +-
 fs/ubifs/file.c                                |  4 ++--
 fs/ubifs/journal.c                             |  4 ++--
 fs/ubifs/lpt.c                                 |  2 +-
 fs/ubifs/tnc.c                                 |  6 +++---
 fs/ubifs/tnc_misc.c                            |  4 ++--
 fs/udf/balloc.c                                |  2 +-
 fs/xfs/xfs_bmap_util.c                         |  2 +-
 include/linux/compiler-clang.h                 |  2 --
 include/linux/compiler-gcc.h                   |  6 ------
 include/linux/page-flags-layout.h              |  2 +-
 include/net/flow_offload.h                     |  2 +-
 kernel/async.c                                 |  4 ++--
 kernel/audit.c                                 |  2 +-
 kernel/debug/kdb/kdb_io.c                      |  2 +-
 kernel/dma/debug.c                             |  2 +-
 kernel/events/core.c                           |  2 +-
 kernel/events/uprobes.c                        |  2 +-
 kernel/exit.c                                  |  2 +-
 kernel/futex.c                                 | 14 +++++++-------
 kernel/locking/lockdep.c                       | 16 ++++++++--------
 kernel/trace/ring_buffer.c                     |  2 +-
 lib/radix-tree.c                               |  2 +-
 lib/test_lockup.c                              |  2 +-
 mm/frontswap.c                                 |  2 +-
 mm/ksm.c                                       |  2 +-
 mm/memcontrol.c                                |  2 +-
 mm/memory.c                                    |  2 +-
 mm/mempolicy.c                                 |  4 ++--
 mm/page_alloc.c                                |  2 +-
 mm/percpu.c                                    |  2 +-
 mm/slub.c                                      |  4 ++--
 mm/swap.c                                      |  4 ++--
 net/dccp/options.c                             |  2 +-
 net/ipv4/netfilter/nf_socket_ipv4.c            |  6 +++---
 net/ipv6/ip6_flowlabel.c                       |  2 +-
 net/ipv6/netfilter/nf_socket_ipv6.c            |  2 +-
 net/netfilter/nf_conntrack_ftp.c               |  2 +-
 net/netfilter/nfnetlink_log.c                  |  2 +-
 net/netfilter/nfnetlink_queue.c                |  4 ++--
 net/sched/cls_flow.c                           |  2 +-
 net/sched/sch_cake.c                           |  2 +-
 net/sched/sch_cbq.c                            |  2 +-
 net/sched/sch_fq_codel.c                       |  2 +-
 net/sched/sch_fq_pie.c                         |  2 +-
 net/sched/sch_hfsc.c                           |  2 +-
 net/sched/sch_htb.c                            |  2 +-
 net/sched/sch_sfq.c                            |  2 +-
 net/sunrpc/svcsock.c                           |  4 ++--
 net/sunrpc/xprtsock.c                          | 10 +++++-----
 net/tls/tls_sw.c                               |  2 +-
 scripts/checkpatch.pl                          | 18 ++++++------------
 sound/core/control_compat.c                    |  2 +-
 sound/isa/sb/sb16_csp.c                        |  2 +-
 sound/usb/endpoint.c                           |  2 +-
 tools/include/linux/compiler.h                 |  2 --
 tools/virtio/linux/kernel.h                    |  2 --
 195 files changed, 310 insertions(+), 328 deletions(-)

--
2.25.1

--
You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200603233203.1695403-1-keescook%40chromium.org.