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  1. Mar 30, 2020
    • David Hildenbrand's avatar
      drivers/base/memory.c: indicate all memory blocks as removable · 53cdc1cb
      David Hildenbrand authored
      We see multiple issues with the implementation/interface to compute
      whether a memory block can be offlined (exposed via
      /sys/devices/system/memory/memoryX/removable) and would like to simplify
      it (remove the implementation).
      
      1. It runs basically lockless. While this might be good for performance,
         we see possible races with memory offlining that will require at
         least some sort of locking to fix.
      
      2. Nowadays, more false positives are possible. No arch-specific checks
         are performed that validate if memory offlining will not be denied
         right away (and such check will require locking). For example, arm64
         won't allow to offline any memory block that was added during boot -
         which will imply a very high error rate. Other archs have other
         constraints.
      
      3. The interface is inherently racy. E.g., if a memory block is detected
         to be removable (and was not a false positive at that time), there is
         still no guarantee that offlining will actually succeed. So any
         caller already has to deal with false positives.
      
      4. It is unclear which performance benefit this interface actually
         provides. The introducing commit 5c755e9f ("memory-hotplug: add
         sysfs removable attribute for hotplug memory remove") mentioned
      
      	"A user-level agent must be able to identify which sections
      	 of memory are likely to be removable before attempting the
      	 potentially expensive operation."
      
         However, no actual performance comparison was included.
      
      Known users:
      
       - lsmem: Will group memory blocks based on the "removable" property. [1]
      
       - chmem: Indirect user. It has a RANGE mode where one can specify
                removable ranges identified via lsmem to be offlined. However,
                it also has a "SIZE" mode, which allows a sysadmin to skip the
                manual "identify removable blocks" step. [2]
      
       - powerpc-utils: Uses the "removable" attribute to skip some memory
                blocks right away when trying to find some to offline+remove.
                However, with ballooning enabled, it already skips this
                information completely (because it once resulted in many false
                negatives). Therefore, the implementation can deal with false
                positives properly already. [3]
      
      According to Nathan Fontenot, DLPAR on powerpc is nowadays no longer
      driven from userspace via the drmgr command (powerpc-utils).  Nowadays
      it's managed in the kernel - including onlining/offlining of memory
      blocks - triggered by drmgr writing to /sys/kernel/dlpar.  So the
      affected legacy userspace handling is only active on old kernels.  Only
      very old versions of drmgr on a new kernel (unlikely) might execute
      slower - totally acceptable.
      
      With CONFIG_MEMORY_HOTREMOVE, always indicating "removable" should not
      break any user space tool.  We implement a very bad heuristic now.
      Without CONFIG_MEMORY_HOTREMOVE we cannot offline anything, so report
      "not removable" as before.
      
      Original discussion can be found in [4] ("[PATCH RFC v1] mm:
      is_mem_section_removable() overhaul").
      
      Other users of is_mem_section_removable() will be removed next, so that
      we can remove is_mem_section_removable() completely.
      
      [1] http://man7.org/linux/man-pages/man1/lsmem.1.html
      [2] http://man7.org/linux/man-pages/man8/chmem.8.html
      [3] https://github.com/ibm-power-utilities/powerpc-utils
      [4] https://lkml.kernel.org/r/20200117105759.27905-1-david@redhat.com
      
      Also, this patch probably fixes a crash reported by Steve.
      http://lkml.kernel.org/r/CAPcyv4jpdaNvJ67SkjyUJLBnBnXXQv686BiVW042g03FUmWLXw@mail.gmail.com
      
      
      
      Reported-by: default avatar"Scargall, Steve" <steve.scargall@intel.com>
      Suggested-by: default avatarMichal Hocko <mhocko@kernel.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reviewed-by: default avatarNathan Fontenot <ndfont@gmail.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Karel Zak <kzak@redhat.com>
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/20200128093542.6908-1-david@redhat.com
      
      
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      53cdc1cb
    • Naohiro Aota's avatar
      mm/swapfile.c: move inode_lock out of claim_swapfile · d795a90e
      Naohiro Aota authored
      claim_swapfile() currently keeps the inode locked when it is successful,
      or the file is already swapfile (with -EBUSY).  And, on the other error
      cases, it does not lock the inode.
      
      This inconsistency of the lock state and return value is quite confusing
      and actually causing a bad unlock balance as below in the "bad_swap"
      section of __do_sys_swapon().
      
      This commit fixes this issue by moving the inode_lock() and IS_SWAPFILE
      check out of claim_swapfile().  The inode is unlocked in
      "bad_swap_unlock_inode" section, so that the inode is ensured to be
      unlocked at "bad_swap".  Thus, error handling codes after the locking now
      jumps to "bad_swap_unlock_inode" instead of "bad_swap".
      
          =====================================
          WARNING: bad unlock balance detected!
          5.5.0-rc7+ #176 Not tainted
          -------------------------------------
          swapon/4294 is trying to release lock (&sb->s_type->i_mutex_key) at: __do_sys_swapon+0x94b/0x3550
          but there are no more locks to release!
      
          other info that might help us debug this:
          no locks held by swapon/4294.
      
          stack backtrace:
          CPU: 5 PID: 4294 Comm: swapon Not tainted 5.5.0-rc7-BTRFS-ZNS+ #176
          Hardware name: ASUS All Series/H87-PRO, BIOS 2102 07/29/2014
          Call Trace:
           dump_stack+0xa1/0xea
           print_unlock_imbalance_bug.cold+0x114/0x123
           lock_release+0x562/0xed0
           up_write+0x2d/0x490
           __do_sys_swapon+0x94b/0x3550
           __x64_sys_swapon+0x54/0x80
           do_syscall_64+0xa4/0x4b0
           entry_SYSCALL_64_after_hwframe+0x49/0xbe
          RIP: 0033:0x7f15da0a0dc7
      
      Fixes: 1638045c
      
       ("mm: set S_SWAPFILE on blockdev swap devices")
      Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Tested-by: default avatarQais Youef <qais.yousef@arm.com>
      Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/20200206090132.154869-1-naohiro.aota@wdc.com
      
      
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d795a90e
  2. Mar 29, 2020
  3. Mar 28, 2020
    • Linus Torvalds's avatar
      Merge branch 'parisc-5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux · 69c5eea3
      Linus Torvalds authored
      Pull parsic fix from Helge Deller:
       "Fix a recursive loop when running 'make ARCH=parisc defconfig'"
      
      * 'parisc-5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
        parisc: Fix defconfig selection
      69c5eea3
    • Linus Torvalds's avatar
      Merge tag 'arm-soc-fixes-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc · 32db9f10
      Linus Torvalds authored
      Pull ARM DT and driver fixes from Arnd Bergmann:
       "For the devicetree files, there are a total of 20 patches, almost
        entirely for 32-bit machines:
      
         - The Allwinner/sun9i r40 SoC dtsi file contains a number of issues,
           both for correctness and for style that are addressed in separate
           patches. This causes most of the changed lines of the DT updates
           this time.
      
         - More Allwinner updates fixing the identification of the security
           system on sun8i/A33, a recent regression of the A83t ethernet, and
           a few board specific issues on the TBS-A711 macine.
      
         - Several bug fixes for OMAP dts files, most notably fixing the
           timings for the NAND flash on the Nokia N900 that regressed a while
           ago after the move to configuring them from DT. Some other OMAPs
           now set the correct dma limits on the L3 bus, and a regression fix
           addresses lost Ethernet on dm814x
      
         - One incorrect setting in the newly added Raspberry Pi Zero W that
           may cause issues with the SD card controller.
      
         - A missing property on the bcm2835 firmware node caused incorrect
           DMA settings.
      
         - An old bug on the oxnas platform causing spurious interrupts is
           finally addressed.
      
         - A regression on the Exynos Midas board broke the OLED panel power
           supply.
      
         - The i.MX6 phycore SoM specified the wrong voltage for the SoC, this
           is now set to the values from the datasheet.
      
         - Some 64-bit machines use a deprecated string to identify the PSCI
           firmware.
      
        There are also several small code fixes addressing mostly serious
        issues:
      
         - Fix the sunxi rsb bus access to no longer return incorrect data
           when mixing 8 and 16 bit I/O.
      
         - Fix a suspend/resume regression on the OMAP2+ lcdc from a missing
           quirk in the ti-sysc driver
      
         - Fix a NULL pointer access from a race in the fsl dpio driver
      
         - Fix a v5.5 regression in the exynos-chipid driver that caused an
           invalid error code probing the device on non-exynos platforms
      
         - Fix an out-of-bounds access in the AMD TEE driver"
      
      * tag 'arm-soc-fixes-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (24 commits)
        soc: samsung: chipid: Fix return value on non-Exynos platforms
        arm64: dts: Fix leftover entry-methods for PSCI
        ARM: dts: exynos: Fix regulator node aliasing on Midas-based boards
        ARM: dts: oxnas: Fix clear-mask property
        ARM: dts: bcm283x: Fix vc4's firmware bus DMA limitations
        ARM: dts: omap5: Add bus_dma_limit for L3 bus
        ARM: dts: omap4-droid4: Fix lost touchscreen interrupts
        ARM: dts: dra7: Add bus_dma_limit for L3 bus
        ARM: bcm2835-rpi-zero-w: Add missing pinctrl name
        ARM: dts: sun8i: a33: add the new SS compatible
        dt-bindings: crypto: add new compatible for A33 SS
        ARM: dts: sun8i: r40: Move SPI device nodes based on address order
        ARM: dts: sun8i: r40: Fix register base address for SPI2 and SPI3
        ARM: dts: sun8i: r40: Move AHCI device node based on address order
        ARM: dts: imx6: phycore-som: fix arm and soc minimum voltage
        soc: fsl: dpio: register dpio irq handlers after dpio create
        tee: amdtee: out of bounds read in find_session()
        ARM: dts: N900: fix onenand timings
        bus: ti-sysc: Fix quirk flags for lcdc on am335x
        ARM: dts: Fix dm814x Ethernet by changing to use rgmii-id mode
        ...
      32db9f10
    • Linus Torvalds's avatar
      Merge tag 'riscv-for-linus-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux · 823846c3
      Linus Torvalds authored
      Pull RISC-V fixes from Palmer Dabbelt:
       "Sorry for the last minute patches, but a few things fell through the
        cracks recently. I was on the fence about sending a late pull request
        just for the M-mode fixes, as we don't really have any users, but the
        last patch fixes the build for Fedora which I consider pretty
        important.
      
        Given that the M-mode fixes should be very low risk, I figured it's
        worth sending them along as well.
      
        Thhis passes my standard 'boot in QEMU' test"
      
      * tag 'riscv-for-linus-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
        RISC-V: Move all address space definition macros to one place
        RISC-V: Only select essential drivers for SOC_VIRT config
        riscv: fix the IPI missing issue in nommu mode
        riscv: uaccess should be used in nommu mode
      823846c3
    • Linus Torvalds's avatar
      Merge tag 'devicetree-fixes-for-5.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux · bb36d37e
      Linus Torvalds authored
      Pull Devicetree fix from Rob Herring:
       "A single fix for building dtc with GCC 10"
      
      * tag 'devicetree-fixes-for-5.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
        scripts/dtc: Remove redundant YYLOC global declaration
      bb36d37e
    • Linus Torvalds's avatar
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux · 1fa8cb0b
      Linus Torvalds authored
      Pull arm64 fix from Will Deacon:
       "Fix defconfig build when using Clang's integrated assembler"
      
      * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
        arm64: alternative: fix build with clang integrated assembler
      1fa8cb0b
    • Linus Torvalds's avatar
      Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux · 527630fb
      Linus Torvalds authored
      Pull clk fixes from Stephen Boyd:
       "A handful of clk driver fixes.
      
        Mostly they're around the i.MX drivers fixing the parents of a few
        clks and making KASAN happy with how the message passing code works.
      
        Besides that we have a TI driver fix for the RTC parent and a fix for
        the basic gate type registration functions introduced this release
        where they didn't actually pass the arguments in the right places to
        the multiplexer function down below"
      
      * tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
        clk: imx: Align imx sc clock parent msg structs to 4
        clk: imx: Align imx sc clock msg structs to 4
        clk: Pass correct arguments to __clk_hw_register_gate()
        clk: ti: am43xx: Fix clock parent for RTC clock
        clk: imx8mp: Correct the enet_qos parent clock
        clk: imx8mp: Correct IMX8MP_CLK_HDMI_AXI clock parent
      527630fb
    • Linus Torvalds's avatar
      Merge tag 'drm-fixes-2020-03-27' of git://anongit.freedesktop.org/drm/drm · 7bf8df68
      Linus Torvalds authored
      Pull drm fixes from Dave Airlie:
       "Pretty quiet: some minor sg mapping fixes for 3 drivers, and a single
        oops fix for the scheduler. I'm hoping nobody tries to send me a fixes
        pull today but I'll keep an eye out of the weekend.
      
        radeon/amdgpu/dma-buf:
         - sg list fixes
      
        scheduler:
         - oops fix"
      
      * tag 'drm-fixes-2020-03-27' of git://anongit.freedesktop.org/drm/drm:
        drm/scheduler: fix rare NULL ptr race
        drm/radeon: fix scatter-gather mapping with user pages
        drm/amdgpu: fix scatter-gather mapping with user pages
        drm/prime: use dma length macro when mapping sg
      7bf8df68
  4. Mar 27, 2020
  5. Mar 26, 2020