1. 11 Nov, 2016 6 commits
    • Sean Young's avatar
      dib0700: fix nec repeat handling · ba13e98f
      Sean Young authored
      When receiving a nec repeat, ensure the correct scancode is repeated
      rather than a random value from the stack.  This removes the need for
      the bogus uninitialized_var() and also fixes the warnings:
      
          drivers/media/usb/dvb-usb/dib0700_core.c: In function ‘dib0700_rc_urb_completion’:
          drivers/media/usb/dvb-usb/dib0700_core.c:679: warning: ‘protocol’ may be used uninitialized in this function
      
      [sean addon: So after writing the patch and submitting it, I've bought the
                   hardware on ebay. Without this patch you get random scancodes
                   on nec repeats, which the patch indeed fixes.]
      Signed-off-by: default avatarSean Young <sean@mess.org>
      Tested-by: default avatarSean Young <sean@mess.org>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ba13e98f
    • Arnd Bergmann's avatar
      s390: pci: don't print uninitialized data for debugging · 92dfffee
      Arnd Bergmann authored
      gcc correctly warns about an incorrect use of the 'pa' variable in case
      we pass an empty scatterlist to __s390_dma_map_sg:
      
        arch/s390/pci/pci_dma.c: In function '__s390_dma_map_sg':
        arch/s390/pci/pci_dma.c:309:13: warning: 'pa' may be used uninitialized in this function [-Wmaybe-uninitialized]
      
      This adds a bogus initialization to the function to sanitize the debug
      output.  I would have preferred a solution without the initialization,
      but I only got the report from the kbuild bot after turning on the
      warning again, and didn't manage to reproduce it myself.
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Acked-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
      Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      92dfffee
    • Arnd Bergmann's avatar
      nios2: fix timer initcall return value · 069013a9
      Arnd Bergmann authored
      When called more than twice, the nios2_time_init() function return an
      uninitialized value, as detected by gcc -Wmaybe-uninitialized
      
        arch/nios2/kernel/time.c: warning: 'ret' may be used uninitialized in this function
      
      This makes it return '0' here, matching the comment above the function.
      Acked-by: default avatarLey Foon Tan <lftan@altera.com>
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      069013a9
    • Arnd Bergmann's avatar
      x86: apm: avoid uninitialized data · 3a6d8676
      Arnd Bergmann authored
      apm_bios_call() can fail, and return a status in its argument structure.
      If that status however is zero during a call from
      apm_get_power_status(), we end up using data that may have never been
      set, as reported by "gcc -Wmaybe-uninitialized":
      
        arch/x86/kernel/apm_32.c: In function ‘apm’:
        arch/x86/kernel/apm_32.c:1729:17: error: ‘bx’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
        arch/x86/kernel/apm_32.c:1835:5: error: ‘cx’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
        arch/x86/kernel/apm_32.c:1730:17: note: ‘cx’ was declared here
        arch/x86/kernel/apm_32.c:1842:27: error: ‘dx’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
        arch/x86/kernel/apm_32.c:1731:17: note: ‘dx’ was declared here
      
      This changes the function to return "APM_NO_ERROR" here, which makes the
      code more robust to broken BIOS versions, and avoids the warning.
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Reviewed-by: default avatarJiri Kosina <jkosina@suse.cz>
      Reviewed-by: default avatarLuis R. Rodriguez <mcgrof@kernel.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3a6d8676
    • Arnd Bergmann's avatar
      NFSv4.1: work around -Wmaybe-uninitialized warning · e84efa32
      Arnd Bergmann authored
      A bugfix introduced a harmless gcc warning in nfs4_slot_seqid_in_use if
      we enable -Wmaybe-uninitialized again:
      
        fs/nfs/nfs4session.c:203:54: error: 'cur_seq' may be used uninitialized in this function [-Werror=maybe-uninitialized]
      
      gcc is not smart enough to conclude that the IS_ERR/PTR_ERR pair results
      in a nonzero return value here.  Using PTR_ERR_OR_ZERO() instead makes
      this clear to the compiler.
      
      Fixes: e09c978a ("NFSv4.1: Fix Oopsable condition in server callback races")
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e84efa32
    • Arnd Bergmann's avatar
      Kbuild: enable -Wmaybe-uninitialized warning for "make W=1" · a76bcf55
      Arnd Bergmann authored
      Traditionally, we have always had warnings about uninitialized variables
      enabled, as this is part of -Wall, and generally a good idea [1], but it
      also always produced false positives, mainly because this is a variation
      of the halting problem and provably impossible to get right in all cases
      [2].
      
      Various people have identified cases that are particularly bad for false
      positives, and in commit e74fc973 ("Turn off -Wmaybe-uninitialized
      when building with -Os"), I turned off the warning for any build that
      was done with CC_OPTIMIZE_FOR_SIZE.  This drastically reduced the number
      of false positive warnings in the default build but unfortunately had
      the side effect of turning the warning off completely in 'allmodconfig'
      builds, which in turn led to a lot of warnings (both actual bugs, and
      remaining false positives) to go in unnoticed.
      
      With commit 877417e6 ("Kbuild: change CC_OPTIMIZE_FOR_SIZE
      definition") enabled the warning again for allmodconfig builds in v4.7
      and in v4.8-rc1, I had finally managed to address all warnings I get in
      an ARM allmodconfig build and most other maybe-uninitialized warnings
      for ARM randconfig builds.
      
      However, commit 6e8d666e ("Disable "maybe-uninitialized" warning
      globally") was merged at the same time and disabled it completely for
      all configurations, because of false-positive warnings on x86 that I had
      not addressed until then.  This caused a lot of actual bugs to get
      merged into mainline, and I sent several dozen patches for these during
      the v4.9 development cycle.  Most of these are actual bugs, some are for
      correct code that is safe because it is only called under external
      constraints that make it impossible to run into the case that gcc sees,
      and in a few cases gcc is just stupid and finds something that can
      obviously never happen.
      
      I have now done a few thousand randconfig builds on x86 and collected
      all patches that I needed to address every single warning I got (I can
      provide the combined patch for the other warnings if anyone is
      interested), so I hope we can get the warning back and let people catch
      the actual bugs earlier.
      
      This reverts the change to disable the warning completely and for now
      brings it back at the "make W=1" level, so we can get it merged into
      mainline without introducing false positives.  A follow-up patch enables
      it on all levels unless some configuration option turns it off because
      of false-positives.
      
      Link: https://rusty.ozlabs.org/?p=232 [1]
      Link: https://gcc.gnu.org/wiki/Better_Uninitialized_Warnings [2]
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a76bcf55
  2. 09 Nov, 2016 3 commits
    • Linus Torvalds's avatar
      Merge tag 'sound-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound · 27bcd37e
      Linus Torvalds authored
      Pull sound fixes from Takashi Iwai:
       "This became a largish pull-request, as we've got a bunch of pending
        ASoC fixes at this time. One noticeable change is the removal of error
        directive in uapi/sound/asoc.h. We found that the API has been already
        used on Chromebooks, so we need to support it even now.
      
        A slight big LOC is found in Qualcomm lpass driver, but the rest are
        all small and easy fixes for ASoC drivers (sti, sun4i, Realtek codecs,
        Intel, tas571x, etc) in addition to the patches to harden the ALSA
        core proc file accesses"
      
      * tag 'sound-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (26 commits)
        ALSA: info: Return error for invalid read/write
        ALSA: info: Limit the proc text input size
        ASoC: samsung: spdif: Fix DMA filter initialization
        ASoC: sun4i-codec: Enable bus clock after getting GPIO
        ASoC: lpass-cpu: add module licence and description
        ASoC: lpass-platform: Fix broken pcm data usage
        ASoC: sun4i-codec: return error code instead of NULL when create_card fails
        ASoC: hdmi-codec: Fix hdmi_of_xlate_dai_name when #sound-dai-cells = <0>
        ASoC: samsung: get access to DMA engine early to defer probe properly
        ASoC: da7219: Connect output enable register to DAIOUT
        ASoC: Intel: Skylake: Fix to turn off hdmi power on probe failure
        ASoC: sti-sas: enable fast io for regmap
        ASoC: sti: fix channel status update after playback start
        ASoC: PXA: Brownstone needs I2C
        ASoC: Intel: Skylake: Always acquire runtime pm ref on unload
        ASoC: Intel: Atom: add terminate entry for dmi_system_id tables
        ASoC: rt298: fix jack type detect error
        ASoC: rt5663: fix a debug statement
        ASoC: cs4270: fix DAPM stream name mismatch
        ASoC: Intel: haswell depends on sst-firmware
        ...
      27bcd37e
    • Linus Torvalds's avatar
      Merge tag 'for-linus-4.9-rc4-ofs-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux · 3c6106da
      Linus Torvalds authored
      Pull orangefs fix from Mike Marshall:
       "We recently refactored the Orangefs debugfs code. The refactor seemed
        to trigger dan.carpenter@oracle.com's static tester to find a possible
        double-free in the code.
      
        While designing the fix we saw a condition under which the buffer
        being freed could also be overflowed.
      
        We also realized how to rebuild the related debugfs file's "contents"
        (a string) without deleting and re-creating the file.
      
        This fix should eliminate the possible double-free, the potential
        overflow and improve code readability"
      
      * tag 'for-linus-4.9-rc4-ofs-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
        orangefs: clean up debugfs
      3c6106da
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux · ae67e87f
      Linus Torvalds authored
      Pull s390 fixes from Martin Schwidefsky:
       "Two bug fixes
      
         - a memory alignment fix in the s390 only hypfs code
      
         - a fix for the generic percpu code that caused ftrace to break on
           s390. This is not relevant for x86 but for all architectures that
           use the generic percpu code"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
        percpu: use notrace variant of preempt_disable/preempt_enable
        s390/hypfs: Use get_free_page() instead of kmalloc to ensure page alignment
      ae67e87f
  3. 08 Nov, 2016 9 commits
    • Linus Torvalds's avatar
      Merge tag 'iommu-fixes-v4.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu · e3a00f68
      Linus Torvalds authored
      Pull IOMMU fixes from Joerg Roedel:
      
       - Four patches from Robin Murphy fix several issues with the recently
         merged generic DT-bindings support for arm-smmu drivers
      
       - A fix for a dead-lock issue in the VT-d driver, which shows up on
         iommu hotplug
      
      * tag 'iommu-fixes-v4.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
        iommu/vt-d: Fix dead-locks in disable_dmar_iommu() path
        iommu/arm-smmu: Fix out-of-bounds dereference
        iommu/arm-smmu: Check that iommu_fwspecs are ours
        iommu/arm-smmu: Don't inadvertently reject multiple SMMUv3s
        iommu/arm-smmu: Work around ARM DMA configuration
      e3a00f68
    • Joerg Roedel's avatar
      iommu/vt-d: Fix dead-locks in disable_dmar_iommu() path · bea64033
      Joerg Roedel authored
      It turns out that the disable_dmar_iommu() code-path tried
      to get the device_domain_lock recursivly, which will
      dead-lock when this code runs on dmar removal. Fix both
      code-paths that could lead to the dead-lock.
      
      Fixes: 55d94043 ('iommu/vt-d: Get rid of domain->iommu_lock')
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      bea64033
    • Robin Murphy's avatar
      iommu/arm-smmu: Fix out-of-bounds dereference · 8c82d6ec
      Robin Murphy authored
      When we iterate a master's config entries, what we generally care
      about is the entry's stream map index, rather than the entry index
      itself, so it's nice to have the iterator automatically assign the
      former from the latter. Unfortunately, booting with KASAN reveals
      the oversight that using a simple comma operator results in the
      entry index being dereferenced before being checked for validity,
      so we always access one element past the end of the fwspec array.
      
      Flip things around so that the check always happens before the index
      may be dereferenced.
      
      Fixes: adfec2e7 ("iommu/arm-smmu: Convert to iommu_fwspec")
      Reported-by: default avatarMark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
      Acked-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      8c82d6ec
    • Robin Murphy's avatar
      iommu/arm-smmu: Check that iommu_fwspecs are ours · 3c117b54
      Robin Murphy authored
      We seem to have forgotten to check that iommu_fwspecs actually belong to
      us before we go ahead and dereference their private data. Oops.
      
      Fixes: 021bb842 ("iommu/arm-smmu: Wire up generic configuration support")
      Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      3c117b54
    • Robin Murphy's avatar
      iommu/arm-smmu: Don't inadvertently reject multiple SMMUv3s · ec615f43
      Robin Murphy authored
      We now delay installing our per-bus iommu_ops until we know an SMMU has
      successfully probed, as they don't serve much purpose beforehand, and
      doing so also avoids fights between multiple IOMMU drivers in a single
      kernel. However, the upshot of passing the return value of bus_set_iommu()
      back from our probe function is that if there happens to be more than
      one SMMUv3 device in a system, the second and subsequent probes will
      wind up returning -EBUSY to the driver core and getting torn down again.
      
      Avoid re-setting ops if ours are already installed, so that any genuine
      failures stand out.
      
      Fixes: 08d4ca2a ("iommu/arm-smmu: Support non-PCI devices with SMMUv3")
      CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
      CC: Hanjun Guo <hanjun.guo@linaro.org>
      Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      ec615f43
    • Robin Murphy's avatar
      iommu/arm-smmu: Work around ARM DMA configuration · fba4f8e5
      Robin Murphy authored
      The 32-bit ARM DMA configuration code predates the IOMMU core's default
      domain functionality, and instead relies on allocating its own domains
      and attaching any devices using the generic IOMMU binding to them.
      Unfortunately, it does this relatively early on in the creation of the
      device, before we've seen our add_device callback, which leads us to
      attempt to operate on a half-configured master.
      
      To avoid a crash, check for this situation on attach, but refuse to
      play, as there's nothing we can do. This at least allows VFIO to keep
      working for people who update their 32-bit DTs to the generic binding,
      albeit with a few (innocuous) warnings from the DMA layer on boot.
      Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      fba4f8e5
    • Takashi Iwai's avatar
      ALSA: info: Return error for invalid read/write · 6809cd68
      Takashi Iwai authored
      Currently the ALSA proc handler allows read or write even if the proc
      file were write-only or read-only.  It's mostly harmless, does thing
      but allocating memory and ignores the input/output.  But it doesn't
      tell user about the invalid use, and it's confusing and inconsistent
      in comparison with other proc files.
      
      This patch adds some sanity checks and let the proc handler returning
      an -EIO error when the invalid read/write is performed.
      
      Cc: <stable@vger.kernel.org> # v4.2+
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      6809cd68
    • Takashi Iwai's avatar
      ALSA: info: Limit the proc text input size · 027a9fe6
      Takashi Iwai authored
      The ALSA proc handler allows currently the write in the unlimited size
      until kmalloc() fails.  But basically the write is supposed to be only
      for small inputs, mostly for one line inputs, and we don't have to
      handle too large sizes at all.  Since the kmalloc error results in the
      kernel warning, it's better to limit the size beforehand.
      
      This patch adds the limit of 16kB, which must be large enough for the
      currently existing code.
      
      Cc: stable@vger.kernel.org # v4.2+
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      027a9fe6
    • Heiko Carstens's avatar
      percpu: use notrace variant of preempt_disable/preempt_enable · 7f8d61f0
      Heiko Carstens authored
      Commit 345ddcc8 ("ftrace: Have set_ftrace_pid use the bitmap like
      events do") added a couple of this_cpu_read calls to the ftrace code.
      
      On x86 this is not a problem, since it has single instructions to read
      percpu data. Other architectures which use the generic variant now
      have additional preempt_disable and preempt_enable calls in the core
      ftrace code. This may lead to recursive calls and in result to a dead
      machine, e.g. if preemption and debugging options are enabled.
      
      To fix this use the notrace variant of preempt_disable and
      preempt_enable within the generic percpu code.
      Reported-and-bisected-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
      Tested-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
      Fixes: 345ddcc8 ("ftrace: Have set_ftrace_pid use the bitmap like events do")
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      7f8d61f0
  4. 07 Nov, 2016 5 commits
  5. 06 Nov, 2016 1 commit
    • Guenter Roeck's avatar
      openrisc: Define __ro_after_init to avoid crash · 2c7a5c5c
      Guenter Roeck authored
      openrisc qemu tests fail with the following crash.
      
      Unable to handle kernel access at virtual address 0xc0300c34
      
      Oops#: 0001
      CPU #: 0
         PC: c016c710    SR: 0000ae67    SP: c1017e04
         GPR00: 00000000 GPR01: c1017e04 GPR02: c0300c34 GPR03: c0300c34
         GPR04: 00000000 GPR05: c0300cb0 GPR06: c0300c34 GPR07: 000000ff
         GPR08: c107f074 GPR09: c0199ef4 GPR10: c1016000 GPR11: 00000000
         GPR12: 00000000 GPR13: c107f044 GPR14: c0473774 GPR15: 07ce0000
         GPR16: 00000000 GPR17: c107ed8a GPR18: 00009600 GPR19: c107f044
         GPR20: c107ee74 GPR21: 00000003 GPR22: c0473770 GPR23: 00000033
         GPR24: 000000bf GPR25: 00000019 GPR26: c046400c GPR27: 00000001
         GPR28: c0464028 GPR29: c1018000 GPR30: 00000006 GPR31: ccf37483
           RES: 00000000 oGPR11: ffffffff
           Process swapper (pid: 1, stackpage=c1001960)
      
           Stack: Stack dump [0xc1017cf8]:
           sp + 00: 0xc1017e04
           sp + 04: 0xc0300c34
           sp + 08: 0xc0300c34
           sp + 12: 0x00000000
      ...
      
      Bisect points to commit d2ec3f77 ("pty: make ptmx file ops read-only
      after init"). Fix by defining __ro_after_init for the openrisc
      architecture, similar to parisc.
      
      Fixes: d2ec3f77 ("pty: make ptmx file ops read-only after init")
      Cc: Kees Cook <keescook@chromium.org>
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Acked-by: default avatarStafford Horne <shorne@gmail.com>
      2c7a5c5c
  6. 05 Nov, 2016 16 commits