1. 09 Apr, 2019 1 commit
    • Linus Torvalds's avatar
      Merge tag 'xtensa-20190408' of git://github.com/jcmvbkbc/linux-xtensa · 10d43397
      Linus Torvalds authored
      Pull xtensa fixes from Max Filippov:
      
       - fix syscall number passed to trace_sys_exit
      
       - fix syscall number initialization in start_thread
      
       - fix level interpretation in the return_address
      
       - fix format string warning in init_pmd
      
      * tag 'xtensa-20190408' of git://github.com/jcmvbkbc/linux-xtensa:
        xtensa: fix format string warning in init_pmd
        xtensa: fix return_address
        xtensa: fix initialization of pt_regs::syscall in start_thread
        xtensa: use actual syscall number in do_syscall_trace_leave
      10d43397
  2. 08 Apr, 2019 3 commits
  3. 07 Apr, 2019 15 commits
    • Linus Torvalds's avatar
      Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc · d8491223
      Linus Torvalds authored
      Pull ARM SoC fixes from Olof Johansson:
       "A collection of fixes from the last few weeks. Most of them are
        smaller tweaks and fixes to DT and hardware descriptions for boards.
        Some of the more significant ones are:
      
         - eMMC and RGMII stability tweaks for rk3288
      
         - DDC fixes for Rock PI 4
      
         - Audio fixes for two TI am335x eval boards
      
         - D_CAN clock fix for am335x
      
         - Compilation fixes for clang
      
         - !HOTPLUG_CPU compilation fix for one of the new platforms this
           release (milbeaut)
      
         - A revert of a gpio fix for nomadik that instead was fixed in the
           gpio subsystem
      
         - Whitespace fix for the DT JSON schema (no tabs allowed)"
      
      * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (25 commits)
        ARM: milbeaut: fix build with !CONFIG_HOTPLUG_CPU
        ARM: iop: don't use using 64-bit DMA masks
        ARM: orion: don't use using 64-bit DMA masks
        Revert "ARM: dts: nomadik: Fix polarity of SPI CS"
        dt-bindings: cpu: Fix JSON schema
        arm/mach-at91/pm : fix possible object reference leak
        ARM: dts: at91: Fix typo in ISC_D0 on PC9
        ARM: dts: Fix dcan clkctrl clock for am3
        reset: meson-audio-arb: Fix missing .owner setting of reset_controller_dev
        dt-bindings: reset: meson-g12a: Add missing USB2 PHY resets
        ARM: dts: rockchip: Remove #address/#size-cells from rk3288-veyron gpio-keys
        ARM: dts: rockchip: Remove #address/#size-cells from rk3288 mipi_dsi
        ARM: dts: rockchip: Fix gpu opp node names for rk3288
        ARM: dts: am335x-evmsk: Correct the regulators for the audio codec
        ARM: dts: am335x-evm: Correct the regulators for the audio codec
        ARM: OMAP2+: add missing of_node_put after of_device_is_available
        ARM: OMAP1: ams-delta: Fix broken GPIO ID allocation
        arm64: dts: stratix10: add the sysmgr-syscon property from the gmac's
        arm64: dts: rockchip: fix rk3328 sdmmc0 write errors
        arm64: dts: rockchip: fix rk3328 rgmii high tx error rate
        ...
      d8491223
    • Linus Torvalds's avatar
      Merge tag 'for-linus-20190407' of git://git.kernel.dk/linux-block · 429fba10
      Linus Torvalds authored
      Pull block fixes from Jens Axboe:
      
       - Fixups for the pf/pcd queue handling (YueHaibing)
      
       - Revert of the three direct issue changes as they have been proven to
         cause an issue with dm-mpath (Bart)
      
       - Plug rq_count reset fix (Dongli)
      
       - io_uring double free in fileset registration error handling (me)
      
       - Make null_blk handle bad numa node passed in (John)
      
       - BFQ ifdef fix (Konstantin)
      
       - Flush queue leak fix (Shenghui)
      
       - Plug trace fix (Yufen)
      
      * tag 'for-linus-20190407' of git://git.kernel.dk/linux-block:
        xsysace: Fix error handling in ace_setup
        null_blk: prevent crash from bad home_node value
        block: Revert v5.0 blk_mq_request_issue_directly() changes
        paride/pcd: Fix potential NULL pointer dereference and mem leak
        blk-mq: do not reset plug->rq_count before the list is sorted
        paride/pf: Fix potential NULL pointer dereference
        io_uring: fix double free in case of fileset regitration failure
        blk-mq: add trace block plug and unplug for multiple queues
        block: use blk_free_flush_queue() to free hctx->fq in blk_mq_init_hctx
        block/bfq: fix ifdef for CONFIG_BFQ_GROUP_IOSCHED=y
      429fba10
    • Arnd Bergmann's avatar
      ARM: milbeaut: fix build with !CONFIG_HOTPLUG_CPU · 9a8f3203
      Arnd Bergmann authored
      When HOTPLUG_CPU is disabled, some fields in the smp operations
      are not available or needed:
      
      arch/arm/mach-milbeaut/platsmp.c:90:3: error: field designator 'cpu_die' does not refer to any field in type
            'struct smp_operations'
              .cpu_die                = m10v_cpu_die,
               ^
      arch/arm/mach-milbeaut/platsmp.c:91:3: error: field designator 'cpu_kill' does not refer to any field in type
            'struct smp_operations'
              .cpu_kill               = m10v_cpu_kill,
               ^
      
      Hide them in an #ifdef like the other platforms do.
      
      Fixes: 9fb29c73 ("ARM: milbeaut: Add basic support for Milbeaut m10v SoC")
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      9a8f3203
    • Arnd Bergmann's avatar
      ARM: iop: don't use using 64-bit DMA masks · 2125801c
      Arnd Bergmann authored
      clang warns about statically defined DMA masks from the DMA_BIT_MASK
      macro with length 64:
      
       arch/arm/mach-iop13xx/setup.c:303:35: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
       static u64 iop13xx_adma_dmamask = DMA_BIT_MASK(64);
                                        ^~~~~~~~~~~~~~~~
       include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK'
       #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
                                                            ^ ~~~
      
      The ones in iop shouldn't really be 64 bit masks, so changing them
      to what the driver can support avoids the warning.
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      2125801c
    • Arnd Bergmann's avatar
      ARM: orion: don't use using 64-bit DMA masks · cd92d74d
      Arnd Bergmann authored
      clang warns about statically defined DMA masks from the DMA_BIT_MASK
      macro with length 64:
      
      arch/arm/plat-orion/common.c:625:29: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
                      .coherent_dma_mask      = DMA_BIT_MASK(64),
                                                ^~~~~~~~~~~~~~~~
      include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK'
       #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
      
      The ones in orion shouldn't really be 64 bit masks, so changing them
      to what the driver can support avoids the warning.
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      cd92d74d
    • Olof Johansson's avatar
      Revert "ARM: dts: nomadik: Fix polarity of SPI CS" · fbe8758f
      Olof Johansson authored
      This reverts commit fa946356.
      
      Per Linus Walleij:
      
      Dear ARM SoC maintainers,
      
      can you please revert this patch. It was the wrong solution to the
      wrong problem, and I must have acted in stress. Andrey fixed the
      real bug in a proper way in these commits:
      
      commit e5545c94
      "gpio: of: Check propname before applying "cs-gpios" quirks"
      commit 7ce40277
      "gpio: of: Check for "spi-cs-high" in child instead of parent node"
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      fbe8758f
    • Olof Johansson's avatar
      Merge tag 'omap-for-v5.1/fixes-signed' of... · c983f102
      Olof Johansson authored
      Merge tag 'omap-for-v5.1/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into arm/fixes
      
      Fixes for omaps for v5.1-rc cycle
      
      Few small fixes for omap variants:
      
      - Fix ams-delta gpio IDs
      - Add missing of_node_put for omapdss platform init code
      - Fix unconfigured audio regulators for two am335x boards
      - Fix use of wrong offset for am335x d_can clocks
      
      * tag 'omap-for-v5.1/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
        ARM: dts: Fix dcan clkctrl clock for am3
        ARM: dts: am335x-evmsk: Correct the regulators for the audio codec
        ARM: dts: am335x-evm: Correct the regulators for the audio codec
        ARM: OMAP2+: add missing of_node_put after of_device_is_available
        ARM: OMAP1: ams-delta: Fix broken GPIO ID allocation
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      c983f102
    • Olof Johansson's avatar
      Merge tag 'at91-5.1-fixes' of... · fccf5166
      Olof Johansson authored
      Merge tag 'at91-5.1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/at91/linux into arm/fixes
      
      AT91 fixes for 5.1
      
      - fix a typo in sama5d2 pinmuxing which concerns the ISC data 0 signal
      - fix a kobject reference leak
      
      * tag 'at91-5.1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/at91/linux:
        arm/mach-at91/pm : fix possible object reference leak
        ARM: dts: at91: Fix typo in ISC_D0 on PC9
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      fccf5166
    • Olof Johansson's avatar
      Merge tag 'v5.1-rockchip-dtfixes-1' of... · a9708285
      Olof Johansson authored
      Merge tag 'v5.1-rockchip-dtfixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip into arm/fixes
      
      Fixes for dtc warnings, fixes for ethernet transfers on rk3328,
      sd-card related fixes on both rk3328 ans rk3288-tinker and a
      regulator fix on rock64 and making ddc actually work on the
      Rock PI 4 due to missing the ddc bus.
      
      * tag 'v5.1-rockchip-dtfixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip:
        ARM: dts: rockchip: Remove #address/#size-cells from rk3288-veyron gpio-keys
        ARM: dts: rockchip: Remove #address/#size-cells from rk3288 mipi_dsi
        ARM: dts: rockchip: Fix gpu opp node names for rk3288
        arm64: dts: rockchip: fix rk3328 sdmmc0 write errors
        arm64: dts: rockchip: fix rk3328 rgmii high tx error rate
        ARM: dts: rockchip: Fix SD card detection on rk3288-tinker
        arm64: dts: rockchip: Fix vcc_host1_5v GPIO polarity on rk3328-rock64
        ARM: dts: rockchip: fix rk3288 cpu opp node reference
        arm64: dts: rockchip: add DDC bus on Rock Pi 4
        arm64: dts: rockchip: fix rk3328-roc-cc gmac2io tx/rx_delay
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      a9708285
    • Olof Johansson's avatar
      Merge tag 'stratix10_fix_for_v5.1' of... · 3e372088
      Olof Johansson authored
      Merge tag 'stratix10_fix_for_v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux into arm/fixes
      
      arm64: dts: stratix10: fix emac loading warning
      - Add missing "altr,sysmgr-syscon" property to all gmac nodes
      
      * tag 'stratix10_fix_for_v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux:
        arm64: dts: stratix10: add the sysmgr-syscon property from the gmac's
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      3e372088
    • Olof Johansson's avatar
      Merge tag 'reset-fixes-for-v5.1' of git://git.pengutronix.de/pza/linux into arm/fixes · 57683e45
      Olof Johansson authored
      Reset controller fixes for v5.1
      
      This tag adds missing USB PHY reset lines to the Meson G12A reset
      controller header and fixes the Meson Audio ARB driver to prevent
      module unloading while it is in use.
      
      * tag 'reset-fixes-for-v5.1' of git://git.pengutronix.de/pza/linux:
        reset: meson-audio-arb: Fix missing .owner setting of reset_controller_dev
        dt-bindings: reset: meson-g12a: Add missing USB2 PHY resets
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      57683e45
    • Maxime Ripard's avatar
      dt-bindings: cpu: Fix JSON schema · ac0722f2
      Maxime Ripard authored
      Commit fd73403a ("dt-bindings: arm: Add SMP enable-method for
      Milbeaut") added support for a new cpu enable-method, but did so using
      tabulations to ident. This is however invalid in the syntax, and resulted
      in a failure when trying to use that schemas for validation.
      
      Use spaces instead of tabs to indent to fix this.
      
      Fixes: fd73403a ("dt-bindings: arm: Add SMP enable-method for Milbeaut")
      Signed-off-by: default avatarMaxime Ripard <maxime.ripard@bootlin.com>
      Reviewed-by: default avatarRob Herring <robh@kernel.org>
      Acked-by: default avatarSugaya Taichi <sugaya.taichi@socionext.com>
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      ac0722f2
    • Linus Torvalds's avatar
      Merge tag 'for-linus-5.1b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip · 3b046891
      Linus Torvalds authored
      Pull xen fixes from Juergen Gross:
       "One minor fix and a small cleanup for the xen privcmd driver"
      
      * tag 'for-linus-5.1b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
        xen: Prevent buffer overflow in privcmd ioctl
        xen: use struct_size() helper in kzalloc()
      3b046891
    • Linus Torvalds's avatar
      Merge tag 'mtd/fixes-for-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux · 82331a70
      Linus Torvalds authored
      Pull MTD fix from Richard Weinberger:
       "A single fix for a possible infinite loop in the cfi_cmdset_0002
        driver"
      
      * tag 'mtd/fixes-for-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
        mtd: cfi: fix deadloop in cfi_cmdset_0002.c do_write_buffer
      82331a70
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · eccc58cb
      Linus Torvalds authored
      Pull SCSI fixes from James Bottomley:
       "Five small fixes. Four in three drivers: qedi, lpfc and storvsc. The
        final one is labelled core, but merely adds a dh rdac entry for Lenovo
        systems"
      
      * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
        scsi: lpfc: Fix missing wakeups on abort threads
        scsi: storvsc: Reduce default ring buffer size to 128 Kbytes
        scsi: storvsc: Fix calculation of sub-channel count
        scsi: core: add new RDAC LENOVO/DE_Series device
        scsi: qedi: remove declaration of nvm_image from stack
      eccc58cb
  4. 06 Apr, 2019 21 commits
    • Linus Torvalds's avatar
      Merge branch 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux · faac51dd
      Linus Torvalds authored
      Pull i2c fix from Wolfram Sang:
       "A simple but wanted driver bugfix"
      
      * 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
        i2c: imx: don't leak the i2c adapter on error
      faac51dd
    • Linus Torvalds's avatar
      Merge branch 'parisc-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux · 373c3925
      Linus Torvalds authored
      Pull parisc fixes from Helge Deller:
       "A 32-bit boot regression fix introduced in the merge window, a QEMU
        detection fix and two fixes by Sven regarding ptrace & kprobes"
      
      * 'parisc-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
        parisc: Detect QEMU earlier in boot process
        parisc: also set iaoq_b in instruction_pointer_set()
        parisc: regs_return_value() should return gpr28
        Revert: parisc: Use F_EXTEND() macro in iosapic code
      373c3925
    • Helge Deller's avatar
      parisc: Detect QEMU earlier in boot process · d006e95b
      Helge Deller authored
      While adding LASI support to QEMU, I noticed that the QEMU detection in
      the kernel happens much too late. For example, when a LASI chip is found
      by the kernel, it registers the LASI LED driver as well.  But when we
      run on QEMU it makes sense to avoid spending unnecessary CPU cycles, so
      we need to access the running_on_QEMU flag earlier than before.
      
      This patch now makes the QEMU detection the fist task of the Linux
      kernel by moving it to where the kernel enters the C-coding.
      
      Fixes: 310d8278 ("parisc: qemu idle sleep support")
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Cc: stable@vger.kernel.org # v4.14+
      d006e95b
    • Sven Schnelle's avatar
      parisc: also set iaoq_b in instruction_pointer_set() · f324fa58
      Sven Schnelle authored
      When setting the instruction pointer on PA-RISC we also need
      to set the back of the instruction queue to the new offset, otherwise
      we will execute on instruction from the new location, and jumping
      back to the old location stored in iaoq_b.
      Signed-off-by: default avatarSven Schnelle <svens@stackframe.org>
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Fixes: 75ebedf1 ("parisc: Add HAVE_REGS_AND_STACK_ACCESS_API feature")
      Cc: stable@vger.kernel.org # 4.19+
      f324fa58
    • Sven Schnelle's avatar
      parisc: regs_return_value() should return gpr28 · 45efd871
      Sven Schnelle authored
      While working on kretprobes for PA-RISC I was wondering while the
      kprobes sanity test always fails on kretprobes. This is caused by
      returning gpr20 instead of gpr28.
      Signed-off-by: default avatarSven Schnelle <svens@stackframe.org>
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Cc: stable@vger.kernel.org # 4.14+
      45efd871
    • Helge Deller's avatar
      Revert: parisc: Use F_EXTEND() macro in iosapic code · c2f8d7cb
      Helge Deller authored
      Revert parts of commit 97d7e2e3 ("parisc: Use F_EXTEND() macro in
      iosapic code"). It breaks booting the 32-bit kernel on some machines.
      Reported-by: default avatarSven Schnelle <svens@stackframe.org>
      Tested-by: default avatarSven Schnelle <svens@stackframe.org>
      Fixes: 97d7e2e3 ("parisc: Use F_EXTEND() macro in iosapic code")
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      c2f8d7cb
    • Kirill Smelkov's avatar
      fs: stream_open - opener for stream-like files so that read and write can run... · 10dce8af
      Kirill Smelkov authored
      fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock
      
      Commit 9c225f26 ("vfs: atomic f_pos accesses as per POSIX") added
      locking for file.f_pos access and in particular made concurrent read and
      write not possible - now both those functions take f_pos lock for the
      whole run, and so if e.g. a read is blocked waiting for data, write will
      deadlock waiting for that read to complete.
      
      This caused regression for stream-like files where previously read and
      write could run simultaneously, but after that patch could not do so
      anymore. See e.g. commit 581d21a2 ("xenbus: fix deadlock on writes
      to /proc/xen/xenbus") which fixes such regression for particular case of
      /proc/xen/xenbus.
      
      The patch that added f_pos lock in 2014 did so to guarantee POSIX thread
      safety for read/write/lseek and added the locking to file descriptors of
      all regular files. In 2014 that thread-safety problem was not new as it
      was already discussed earlier in 2006.
      
      However even though 2006'th version of Linus's patch was adding f_pos
      locking "only for files that are marked seekable with FMODE_LSEEK (thus
      avoiding the stream-like objects like pipes and sockets)", the 2014
      version - the one that actually made it into the tree as 9c225f26 -
      is doing so irregardless of whether a file is seekable or not.
      
      See
      
          https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/
          https://lwn.net/Articles/180387
          https://lwn.net/Articles/180396
      
      for historic context.
      
      The reason that it did so is, probably, that there are many files that
      are marked non-seekable, but e.g. their read implementation actually
      depends on knowing current position to correctly handle the read. Some
      examples:
      
      	kernel/power/user.c		snapshot_read
      	fs/debugfs/file.c		u32_array_read
      	fs/fuse/control.c		fuse_conn_waiting_read + ...
      	drivers/hwmon/asus_atk0110.c	atk_debugfs_ggrp_read
      	arch/s390/hypfs/inode.c		hypfs_read_iter
      	...
      
      Despite that, many nonseekable_open users implement read and write with
      pure stream semantics - they don't depend on passed ppos at all. And for
      those cases where read could wait for something inside, it creates a
      situation similar to xenbus - the write could be never made to go until
      read is done, and read is waiting for some, potentially external, event,
      for potentially unbounded time -> deadlock.
      
      Besides xenbus, there are 14 such places in the kernel that I've found
      with semantic patch (see below):
      
      	drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write()
      	drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write()
      	drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write()
      	drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write()
      	net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write()
      	drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write()
      	drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write()
      	drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write()
      	net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write()
      	drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write()
      	drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write()
      	drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write()
      	drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write()
      	drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write()
      
      In addition to the cases above another regression caused by f_pos
      locking is that now FUSE filesystems that implement open with
      FOPEN_NONSEEKABLE flag, can no longer implement bidirectional
      stream-like files - for the same reason as above e.g. read can deadlock
      write locking on file.f_pos in the kernel.
      
      FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990 ("fuse:
      implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp
      in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and
      write routines not depending on current position at all, and with both
      read and write being potentially blocking operations:
      
      See
      
          https://github.com/libfuse/osspd
          https://lwn.net/Articles/308445
      
          https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406
          https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477
          https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510
      
      Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as
      "somewhat pipe-like files ..." with read handler not using offset.
      However that test implements only read without write and cannot exercise
      the deadlock scenario:
      
          https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131
          https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163
          https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216
      
      I've actually hit the read vs write deadlock for real while implementing
      my FUSE filesystem where there is /head/watch file, for which open
      creates separate bidirectional socket-like stream in between filesystem
      and its user with both read and write being later performed
      simultaneously. And there it is semantically not easy to split the
      stream into two separate read-only and write-only channels:
      
          https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169
      
      Let's fix this regression. The plan is:
      
      1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS -
         doing so would break many in-kernel nonseekable_open users which
         actually use ppos in read/write handlers.
      
      2. Add stream_open() to kernel to open stream-like non-seekable file
         descriptors. Read and write on such file descriptors would never use
         nor change ppos. And with that property on stream-like files read and
         write will be running without taking f_pos lock - i.e. read and write
         could be running simultaneously.
      
      3. With semantic patch search and convert to stream_open all in-kernel
         nonseekable_open users for which read and write actually do not
         depend on ppos and where there is no other methods in file_operations
         which assume @offset access.
      
      4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via
         steam_open if that bit is present in filesystem open reply.
      
         It was tempting to change fs/fuse/ open handler to use stream_open
         instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but
         grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE,
         and in particular GVFS which actually uses offset in its read and
         write handlers
      
      	https://codesearch.debian.net/search?q=-%3Enonseekable+%3D
      	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080
      	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346
      	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481
      
         so if we would do such a change it will break a real user.
      
      5. Add stream_open and FOPEN_STREAM handling to stable kernels starting
         from v3.14+ (the kernel where 9c225f26 first appeared).
      
         This will allow to patch OSSPD and other FUSE filesystems that
         provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE
         in their open handler and this way avoid the deadlock on all kernel
         versions. This should work because fs/fuse/ ignores unknown open
         flags returned from a filesystem and so passing FOPEN_STREAM to a
         kernel that is not aware of this flag cannot hurt. In turn the kernel
         that is not aware of FOPEN_STREAM will be < v3.14 where just
         FOPEN_NONSEEKABLE is sufficient to implement streams without read vs
         write deadlock.
      
      This patch adds stream_open, converts /proc/xen/xenbus to it and adds
      semantic patch to automatically locate in-kernel places that are either
      required to be converted due to read vs write deadlock, or that are just
      safe to be converted because read and write do not use ppos and there
      are no other funky methods in file_operations.
      
      Regarding semantic patch I've verified each generated change manually -
      that it is correct to convert - and each other nonseekable_open instance
      left - that it is either not correct to convert there, or that it is not
      converted due to current stream_open.cocci limitations.
      
      The script also does not convert files that should be valid to convert,
      but that currently have .llseek = noop_llseek or generic_file_llseek for
      unknown reason despite file being opened with nonseekable_open (e.g.
      drivers/input/mousedev.c)
      
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yongzhi Pan <panyongzhi@gmail.com>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Miklos Szeredi <miklos@szeredi.hu>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Julia Lawall <Julia.Lawall@lip6.fr>
      Cc: Nikolaus Rath <Nikolaus@rath.org>
      Cc: Han-Wen Nienhuys <hanwen@google.com>
      Signed-off-by: Kirill Smelkov's avatarKirill Smelkov <kirr@nexedi.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      10dce8af
    • Guenter Roeck's avatar
      xsysace: Fix error handling in ace_setup · 47b16820
      Guenter Roeck authored
      If xace hardware reports a bad version number, the error handling code
      in ace_setup() calls put_disk(), followed by queue cleanup. However, since
      the disk data structure has the queue pointer set, put_disk() also
      cleans and releases the queue. This results in blk_cleanup_queue()
      accessing an already released data structure, which in turn may result
      in a crash such as the following.
      
      [   10.681671] BUG: Kernel NULL pointer dereference at 0x00000040
      [   10.681826] Faulting instruction address: 0xc0431480
      [   10.682072] Oops: Kernel access of bad area, sig: 11 [#1]
      [   10.682251] BE PAGE_SIZE=4K PREEMPT Xilinx Virtex440
      [   10.682387] Modules linked in:
      [   10.682528] CPU: 0 PID: 1 Comm: swapper Tainted: G        W         5.0.0-rc6-next-20190218+ #2
      [   10.682733] NIP:  c0431480 LR: c043147c CTR: c0422ad8
      [   10.682863] REGS: cf82fbe0 TRAP: 0300   Tainted: G        W          (5.0.0-rc6-next-20190218+)
      [   10.683065] MSR:  00029000 <CE,EE,ME>  CR: 22000222  XER: 00000000
      [   10.683236] DEAR: 00000040 ESR: 00000000
      [   10.683236] GPR00: c043147c cf82fc90 cf82ccc0 00000000 00000000 00000000 00000002 00000000
      [   10.683236] GPR08: 00000000 00000000 c04310bc 00000000 22000222 00000000 c0002c54 00000000
      [   10.683236] GPR16: 00000000 00000001 c09aa39c c09021b0 c09021dc 00000007 c0a68c08 00000000
      [   10.683236] GPR24: 00000001 ced6d400 ced6dcf0 c0815d9c 00000000 00000000 00000000 cedf0800
      [   10.684331] NIP [c0431480] blk_mq_run_hw_queue+0x28/0x114
      [   10.684473] LR [c043147c] blk_mq_run_hw_queue+0x24/0x114
      [   10.684602] Call Trace:
      [   10.684671] [cf82fc90] [c043147c] blk_mq_run_hw_queue+0x24/0x114 (unreliable)
      [   10.684854] [cf82fcc0] [c04315bc] blk_mq_run_hw_queues+0x50/0x7c
      [   10.685002] [cf82fce0] [c0422b24] blk_set_queue_dying+0x30/0x68
      [   10.685154] [cf82fcf0] [c0423ec0] blk_cleanup_queue+0x34/0x14c
      [   10.685306] [cf82fd10] [c054d73c] ace_probe+0x3dc/0x508
      [   10.685445] [cf82fd50] [c052d740] platform_drv_probe+0x4c/0xb8
      [   10.685592] [cf82fd70] [c052abb0] really_probe+0x20c/0x32c
      [   10.685728] [cf82fda0] [c052ae58] driver_probe_device+0x68/0x464
      [   10.685877] [cf82fdc0] [c052b500] device_driver_attach+0xb4/0xe4
      [   10.686024] [cf82fde0] [c052b5dc] __driver_attach+0xac/0xfc
      [   10.686161] [cf82fe00] [c0528428] bus_for_each_dev+0x80/0xc0
      [   10.686314] [cf82fe30] [c0529b3c] bus_add_driver+0x144/0x234
      [   10.686457] [cf82fe50] [c052c46c] driver_register+0x88/0x15c
      [   10.686610] [cf82fe60] [c09de288] ace_init+0x4c/0xac
      [   10.686742] [cf82fe80] [c0002730] do_one_initcall+0xac/0x330
      [   10.686888] [cf82fee0] [c09aafd0] kernel_init_freeable+0x34c/0x478
      [   10.687043] [cf82ff30] [c0002c6c] kernel_init+0x18/0x114
      [   10.687188] [cf82ff40] [c000f2f0] ret_from_kernel_thread+0x14/0x1c
      [   10.687349] Instruction dump:
      [   10.687435] 3863ffd4 4bfffd70 9421ffd0 7c0802a6 93c10028 7c9e2378 93e1002c 38810008
      [   10.687637] 7c7f1b78 90010034 4bfffc25 813f008c <81290040> 75290100 4182002c 80810008
      [   10.688056] ---[ end trace 13c9ff51d41b9d40 ]---
      
      Fix the problem by setting the disk queue pointer to NULL before calling
      put_disk(). A more comprehensive fix might be to rearrange the code
      to check the hardware version before initializing data structures,
      but I don't know if this would have undesirable side effects, and
      it would increase the complexity of backporting the fix to older kernels.
      
      Fixes: 74489a91 ("Add support for Xilinx SystemACE CompactFlash interface")
      Acked-by: default avatarMichal Simek <michal.simek@xilinx.com>
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      47b16820
    • John Pittman's avatar
      null_blk: prevent crash from bad home_node value · 7ff684a6
      John Pittman authored
      At module load, if the selected home_node value is greater than
      the available numa nodes, the system will crash in
      __alloc_pages_nodemask() due to a bad paging request.  Prevent this
      user error crash by detecting the bad value, logging an error, and
      setting g_home_node back to the default of NUMA_NO_NODE.
      Signed-off-by: default avatarJohn Pittman <jpittman@redhat.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      7ff684a6
    • Linus Torvalds's avatar
      Merge tag 'rtc-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux · be76865d
      Linus Torvalds authored
      Pull RTC fixes from Alexandre Belloni:
      
       - Various alarm fixes for da9063, cros-ec and sh
      
       - sd3078 manufacturer name fix as this was introduced this cycle
      
      * tag 'rtc-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
        rtc: da9063: set uie_unsupported when relevant
        rtc: sd3078: fix manufacturer name
        rtc: sh: Fix invalid alarm warning for non-enabled alarm
        rtc: cros-ec: Fail suspend/resume if wake IRQ can't be configured
      be76865d
    • Laurentiu Tudor's avatar
      i2c: imx: don't leak the i2c adapter on error · 3ace6891
      Laurentiu Tudor authored
      Make sure to free the i2c adapter on the error exit path.
      Signed-off-by: default avatarLaurentiu Tudor <laurentiu.tudor@nxp.com>
      Reviewed-by: default avatarMukesh Ojha <mojha@codeaurora.org>
      Reviewed-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
      Fixes: e1ab9a46 ("i2c: imx: improve the error handling in i2c_imx_dma_request()")
      Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
      3ace6891
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · f654f0fc
      Linus Torvalds authored
      Merge misc fixes from Andrew Morton:
       "14 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>:
        kernel/sysctl.c: fix out-of-bounds access when setting file-max
        mm/util.c: fix strndup_user() comment
        sh: fix multiple function definition build errors
        MAINTAINERS: add maintainer and replacing reviewer ARM/NUVOTON NPCM
        MAINTAINERS: fix bad pattern in ARM/NUVOTON NPCM
        mm: writeback: use exact memcg dirty counts
        psi: clarify the units used in pressure files
        mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()
        hugetlbfs: fix memory leak for resv_map
        mm: fix vm_fault_t cast in VM_FAULT_GET_HINDEX()
        lib/lzo: fix bugs for very short or empty input
        include/linux/bitrev.h: fix constant bitrev
        kmemleak: powerpc: skip scanning holes in the .bss section
        lib/string.c: implement a basic bcmp
      f654f0fc
    • Will Deacon's avatar
      kernel/sysctl.c: fix out-of-bounds access when setting file-max · 9002b214
      Will Deacon authored
      Commit 32a5ad9c ("sysctl: handle overflow for file-max") hooked up
      min/max values for the file-max sysctl parameter via the .extra1 and
      .extra2 fields in the corresponding struct ctl_table entry.
      
      Unfortunately, the minimum value points at the global 'zero' variable,
      which is an int.  This results in a KASAN splat when accessed as a long
      by proc_doulongvec_minmax on 64-bit architectures:
      
        | BUG: KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax+0x5d8/0x6a0
        | Read of size 8 at addr ffff2000133d1c20 by task systemd/1
        |
        | CPU: 0 PID: 1 Comm: systemd Not tainted 5.1.0-rc3-00012-g40b114779944 #2
        | Hardware name: linux,dummy-virt (DT)
        | Call trace:
        |  dump_backtrace+0x0/0x228
        |  show_stack+0x14/0x20
        |  dump_stack+0xe8/0x124
        |  print_address_description+0x60/0x258
        |  kasan_report+0x140/0x1a0
        |  __asan_report_load8_noabort+0x18/0x20
        |  __do_proc_doulongvec_minmax+0x5d8/0x6a0
        |  proc_doulongvec_minmax+0x4c/0x78
        |  proc_sys_call_handler.isra.19+0x144/0x1d8
        |  proc_sys_write+0x34/0x58
        |  __vfs_write+0x54/0xe8
        |  vfs_write+0x124/0x3c0
        |  ksys_write+0xbc/0x168
        |  __arm64_sys_write+0x68/0x98
        |  el0_svc_common+0x100/0x258
        |  el0_svc_handler+0x48/0xc0
        |  el0_svc+0x8/0xc
        |
        | The buggy address belongs to the variable:
        |  zero+0x0/0x40
        |
        | Memory state around the buggy address:
        |  ffff2000133d1b00: 00 00 00 00 00 00 00 00 fa fa fa fa 04 fa fa fa
        |  ffff2000133d1b80: fa fa fa fa 04 fa fa fa fa fa fa fa 04 fa fa fa
        | >ffff2000133d1c00: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
        |                                ^
        |  ffff2000133d1c80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00
        |  ffff2000133d1d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      
      Fix the splat by introducing a unsigned long 'zero_ul' and using that
      instead.
      
      Link: http://lkml.kernel.org/r/20190403153409.17307-1-will.deacon@arm.com
      Fixes: 32a5ad9c ("sysctl: handle overflow for file-max")
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Acked-by: default avatarChristian Brauner <christian@brauner.io>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Cc: Matteo Croce <mcroce@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9002b214
    • Andrew Morton's avatar
      mm/util.c: fix strndup_user() comment · e9145521
      Andrew Morton authored
      The kerneldoc misdescribes strndup_user()'s return value.
      
      Cc: Dan Carpenter <dan.carpenter@oracle.com>
      Cc: Timur Tabi <timur@freescale.com>
      Cc: Mihai Caraman <mihai.caraman@freescale.com>
      Cc: Kumar Gala <galak@kernel.crashing.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e9145521
    • Randy Dunlap's avatar
      sh: fix multiple function definition build errors · acaf892e
      Randy Dunlap authored
      Many of the sh CPU-types have their own plat_irq_setup() and
      arch_init_clk_ops() functions, so these same (empty) functions in
      arch/sh/boards/of-generic.c are not needed and cause build errors.
      
      If there is some case where these empty functions are needed, they can
      be retained by marking them as "__weak" while at the same time making
      builds that do not need them succeed.
      
      Fixes these build errors:
      
      arch/sh/boards/of-generic.o: In function `plat_irq_setup':
      (.init.text+0x134): multiple definition of `plat_irq_setup'
      arch/sh/kernel/cpu/sh2/setup-sh7619.o:(.init.text+0x30): first defined here
      arch/sh/boards/of-generic.o: In function `arch_init_clk_ops':
      (.init.text+0x118): multiple definition of `arch_init_clk_ops'
      arch/sh/kernel/cpu/sh2/clock-sh7619.o:(.init.text+0x0): first defined here
      
      Link: http://lkml.kernel.org/r/9ee4e0c5-f100-86a2-bd4d-1d3287ceab31@infradead.orgSigned-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
      Reported-by: default avatarkbuild test robot <lkp@intel.com>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Rich Felker <dalias@libc.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      acaf892e
    • Tomer Maimon's avatar
      MAINTAINERS: add maintainer and replacing reviewer ARM/NUVOTON NPCM · 803cfadc
      Tomer Maimon authored
      Add Tali Perry as Nuvoton NPCM maintainer, replace Brendan Higgins
      Nuvoton NPCM reviewer with Benjamin Fair.
      
      Link: http://lkml.kernel.org/r/20190328235752.334462-2-tmaimon77@gmail.comSigned-off-by: default avatarTomer Maimon <tmaimon77@gmail.com>
      Reviewed-by: default avatarBrendan Higgins <brendanhiggins@google.com>
      Reviewed-by: default avatarBenjamin Fair <benjaminfair@google.com>
      Reviewed-by: default avatarMukesh Ojha <mojha@codeaurora.org>
      Cc: Joe Perches <joe@perches.com>
      Cc: Avi Fishman <avifishman70@gmail.com>
      Cc: Patrick Venture <venture@google.com>
      Cc: Nancy Yuen <yuenn@google.com>
      Cc: Tali Perry <tali.perry1@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      803cfadc
    • Tomer Maimon's avatar
      MAINTAINERS: fix bad pattern in ARM/NUVOTON NPCM · 166dbd93
      Tomer Maimon authored
      In the process of upstreaming architecture support for ARM/NUVOTON NPCM
      include/dt-bindings/clock/nuvoton,npcm7xx-clks.h was renamed
      include/dt-bindings/clock/nuvoton,npcm7xx-clock.h without updating
      MAINTAINERS.  This updates the MAINTAINERS pattern to match the new name
      of this file.
      
      Link: http://lkml.kernel.org/r/20190328235752.334462-1-tmaimon77@gmail.com
      Fixes: 6a498e06 ("MAINTAINERS: Add entry for the Nuvoton NPCM architecture")
      Signed-off-by: default avatarBrendan Higgins <brendanhiggins@google.com>
      Signed-off-by: default avatarTomer Maimon <tmaimon77@gmail.com>
      Reported-by: default avatarJoe Perches <joe@perches.com>
      Reviewed-by: default avatarBenjamin Fair <benjaminfair@google.com>
      Cc: Avi Fishman <avifishman70@gmail.com>
      Cc: Mukesh Ojha <mojha@codeaurora.org>
      Cc: Nancy Yuen <yuenn@google.com>
      Cc: Patrick Venture <venture@google.com>
      Cc: Tali Perry <tali.perry1@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      166dbd93
    • Greg Thelen's avatar
      mm: writeback: use exact memcg dirty counts · 0b3d6e6f
      Greg Thelen authored
      Since commit a983b5eb ("mm: memcontrol: fix excessive complexity in
      memory.stat reporting") memcg dirty and writeback counters are managed
      as:
      
       1) per-memcg per-cpu values in range of [-32..32]
      
       2) per-memcg atomic counter
      
      When a per-cpu counter cannot fit in [-32..32] it's flushed to the
      atomic.  Stat readers only check the atomic.  Thus readers such as
      balance_dirty_pages() may see a nontrivial error margin: 32 pages per
      cpu.
      
      Assuming 100 cpus:
         4k x86 page_size:  13 MiB error per memcg
        64k ppc page_size: 200 MiB error per memcg
      
      Considering that dirty+writeback are used together for some decisions the
      errors double.
      
      This inaccuracy can lead to undeserved oom kills.  One nasty case is
      when all per-cpu counters hold positive values offsetting an atomic
      negative value (i.e.  per_cpu[*]=32, atomic=n_cpu*-32).
      balance_dirty_pages() only consults the atomic and does not consider
      throttling the next n_cpu*32 dirty pages.  If the file_lru is in the
      13..200 MiB range then there's absolutely no dirty throttling, which
      burdens vmscan with only dirty+writeback pages thus resorting to oom
      kill.
      
      It could be argued that tiny containers are not supported, but it's more
      subtle.  It's the amount the space available for file lru that matters.
      If a container has memory.max-200MiB of non reclaimable memory, then it
      will also suffer such oom kills on a 100 cpu machine.
      
      The following test reliably ooms without this patch.  This patch avoids
      oom kills.
      
        $ cat test
        mount -t cgroup2 none /dev/cgroup
        cd /dev/cgroup
        echo +io +memory > cgroup.subtree_control
        mkdir test
        cd test
        echo 10M > memory.max
        (echo $BASHPID > cgroup.procs && exec /memcg-writeback-stress /foo)
        (echo $BASHPID > cgroup.procs && exec dd if=/dev/zero of=/foo bs=2M count=100)
      
        $ cat memcg-writeback-stress.c
        /*
         * Dirty pages from all but one cpu.
         * Clean pages from the non dirtying cpu.
         * This is to stress per cpu counter imbalance.
         * On a 100 cpu machine:
         * - per memcg per cpu dirty count is 32 pages for each of 99 cpus
         * - per memcg atomic is -99*32 pages
         * - thus the complete dirty limit: sum of all counters 0
         * - balance_dirty_pages() only sees atomic count -99*32 pages, which
         *   it max()s to 0.
         * - So a workload can dirty -99*32 pages before balance_dirty_pages()
         *   cares.
         */
        #define _GNU_SOURCE
        #include <err.h>
        #include <fcntl.h>
        #include <sched.h>
        #include <stdlib.h>
        #include <stdio.h>
        #include <sys/stat.h>
        #include <sys/sysinfo.h>
        #include <sys/types.h>
        #include <unistd.h>
      
        static char *buf;
        static int bufSize;
      
        static void set_affinity(int cpu)
        {
        	cpu_set_t affinity;
      
        	CPU_ZERO(&affinity);
        	CPU_SET(cpu, &affinity);
        	if (sched_setaffinity(0, sizeof(affinity), &affinity))
        		err(1, "sched_setaffinity");
        }
      
        static void dirty_on(int output_fd, int cpu)
        {
        	int i, wrote;
      
        	set_affinity(cpu);
        	for (i = 0; i < 32; i++) {
        		for (wrote = 0; wrote < bufSize; ) {
        			int ret = write(output_fd, buf+wrote, bufSize-wrote);
        			if (ret == -1)
        				err(1, "write");
        			wrote += ret;
        		}
        	}
        }
      
        int main(int argc, char **argv)
        {
        	int cpu, flush_cpu = 1, output_fd;
        	const char *output;
      
        	if (argc != 2)
        		errx(1, "usage: output_file");
      
        	output = argv[1];
        	bufSize = getpagesize();
        	buf = malloc(getpagesize());
        	if (buf == NULL)
        		errx(1, "malloc failed");
      
        	output_fd = open(output, O_CREAT|O_RDWR);
        	if (output_fd == -1)
        		err(1, "open(%s)", output);
      
        	for (cpu = 0; cpu < get_nprocs(); cpu++) {
        		if (cpu != flush_cpu)
        			dirty_on(output_fd, cpu);
        	}
      
        	set_affinity(flush_cpu);
        	if (fsync(output_fd))
        		err(1, "fsync(%s)", output);
        	if (close(output_fd))
        		err(1, "close(%s)", output);
        	free(buf);
        }
      
      Make balance_dirty_pages() and wb_over_bg_thresh() work harder to
      collect exact per memcg counters.  This avoids the aforementioned oom
      kills.
      
      This does not affect the overhead of memory.stat, which still reads the
      single atomic counter.
      
      Why not use percpu_counter? memcg already handles cpus going offline, so
      no need for that overhead from percpu_counter.  And the percpu_counter
      spinlocks are more heavyweight than is required.
      
      It probably also makes sense to use exact dirty and writeback counters
      in memcg oom reports.  But that is saved for later.
      
      Link: http://lkml.kernel.org/r/20190329174609.164344-1-gthelen@google.comSigned-off-by: default avatarGreg Thelen <gthelen@google.com>
      Reviewed-by: default avatarRoman Gushchin <guro@fb.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@kernel.org>
      Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: <stable@vger.kernel.org>	[4.16+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0b3d6e6f
    • Waiman Long's avatar
      psi: clarify the units used in pressure files · be87ab0a
      Waiman Long authored
      The output of the PSI files show a bunch of numbers with no unit.  The
      psi.txt documentation file also does not indicate what units are used.
      One can only find out by looking at the source code.  The units are
      percentage for the averages and useconds for the total.  Make the
      information easier to find by documenting the units in psi.txt.
      
      Link: http://lkml.kernel.org/r/20190402193810.3450-1-longman@redhat.comSigned-off-by: default avatarWaiman Long <longman@redhat.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      be87ab0a
    • Aneesh Kumar K.V's avatar
      mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd() · c6f3c5ee
      Aneesh Kumar K.V authored
      With some architectures like ppc64, set_pmd_at() cannot cope with a
      situation where there is already some (different) valid entry present.
      
      Use pmdp_set_access_flags() instead to modify the pfn which is built to
      deal with modifying existing PMD entries.
      
      This is similar to commit cae85cb8 ("mm/memory.c: fix modifying of
      page protection by insert_pfn()")
      
      We also do similar update w.r.t insert_pfn_pud eventhough ppc64 don't
      support pud pfn entries now.
      
      Without this patch we also see the below message in kernel log "BUG:
      non-zero pgtables_bytes on freeing mm:"
      
      Link: http://lkml.kernel.org/r/20190402115125.18803-1-aneesh.kumar@linux.ibm.comSigned-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Reported-by: default avatarChandan Rajendra <chandan@linux.ibm.com>
      Reviewed-by: default avatarJan Kara <jack@suse.cz>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c6f3c5ee
    • Mike Kravetz's avatar
      hugetlbfs: fix memory leak for resv_map · 58b6e5e8
      Mike Kravetz authored
      When mknod is used to create a block special file in hugetlbfs, it will
      allocate an inode and kmalloc a 'struct resv_map' via resv_map_alloc().
      inode->i_mapping->private_data will point the newly allocated resv_map.
      However, when the device special file is opened bd_acquire() will set
      inode->i_mapping to bd_inode->i_mapping.  Thus the pointer to the
      allocated resv_map is lost and the structure is leaked.
      
      Programs to reproduce:
              mount -t hugetlbfs nodev hugetlbfs
              mknod hugetlbfs/dev b 0 0
              exec 30<> hugetlbfs/dev
              umount hugetlbfs/
      
      resv_map structures are only needed for inodes which can have associated
      page allocations.  To fix the leak, only allocate resv_map for those
      inodes which could possibly be associated with page allocations.
      
      Link: http://lkml.kernel.org/r/20190401213101.16476-1-mike.kravetz@oracle.comSigned-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reported-by: default avatarYufen Yu <yuyufen@huawei.com>
      Suggested-by: default avatarYufen Yu <yuyufen@huawei.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      58b6e5e8