1. 15 May, 2015 40 commits
    • Leon Yu's avatar
      mm: fix anon_vma->degree underflow in anon_vma endless growing prevention · 2b4396f4
      Leon Yu authored
      commit 3fe89b3e upstream.
      
      I have constantly stumbled upon "kernel BUG at mm/rmap.c:399!" after
      upgrading to 3.19 and had no luck with 4.0-rc1 neither.
      
      So, after looking into new logic introduced by commit 7a3ef208 ("mm:
      prevent endless growth of anon_vma hierarchy"), I found chances are that
      unlink_anon_vmas() is called without incrementing dst->anon_vma->degree
      in anon_vma_clone() due to allocation failure.  If dst->anon_vma is not
      NULL in error path, its degree will be incorrectly decremented in
      unlink_anon_vmas() and eventually underflow when exiting as a result of
      another call to unlink_anon_vmas().  That's how "kernel BUG at
      mm/rmap.c:399!" is triggered for me.
      
      This patch fixes the underflow by dropping dst->anon_vma when allocation
      fails.  It's safe to do so regardless of original value of dst->anon_vma
      because dst->anon_vma doesn't have valid meaning if anon_vma_clone()
      fails.  Besides, callers don't care dst->anon_vma in such case neither.
      
      Also suggested by Michal Hocko, we can clean up vma_adjust() a bit as
      anon_vma_clone() now does the work.
      
      [akpm@linux-foundation.org: tweak comment]
      Fixes: 7a3ef208 ("mm: prevent endless growth of anon_vma hierarchy")
      Signed-off-by: default avatarLeon Yu <chianglungyu@gmail.com>
      Signed-off-by: default avatarKonstantin Khlebnikov <koct9i@gmail.com>
      Reviewed-by: default avatarMichal Hocko <mhocko@suse.cz>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.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>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      2b4396f4
    • Konstantin Khlebnikov's avatar
      mm: fix corner case in anon_vma endless growing prevention · 4cd01168
      Konstantin Khlebnikov authored
      commit b800c91a upstream.
      
      Fix for BUG_ON(anon_vma->degree) splashes in unlink_anon_vmas() ("kernel
      BUG at mm/rmap.c:399!") caused by commit 7a3ef208 ("mm: prevent
      endless growth of anon_vma hierarchy")
      
      Anon_vma_clone() is usually called for a copy of source vma in
      destination argument.  If source vma has anon_vma it should be already
      in dst->anon_vma.  NULL in dst->anon_vma is used as a sign that it's
      called from anon_vma_fork().  In this case anon_vma_clone() finds
      anon_vma for reusing.
      
      Vma_adjust() calls it differently and this breaks anon_vma reusing
      logic: anon_vma_clone() links vma to old anon_vma and updates degree
      counters but vma_adjust() overrides vma->anon_vma right after that.  As
      a result final unlink_anon_vmas() decrements degree for wrong anon_vma.
      
      This patch assigns ->anon_vma before calling anon_vma_clone().
      Signed-off-by: default avatarKonstantin Khlebnikov <koct9i@gmail.com>
      Reported-and-tested-by: default avatarChris Clayton <chris2553@googlemail.com>
      Reported-and-tested-by: default avatarOded Gabbay <oded.gabbay@amd.com>
      Reported-and-tested-by: default avatarChih-Wei Huang <cwhuang@android-x86.org>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Cc: Daniel Forrest <dan.forrest@ssec.wisc.edu>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: stable@vger.kernel.org  # to match back-porting of 7a3ef208Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      4cd01168
    • Konstantin Khlebnikov's avatar
      mm: prevent endless growth of anon_vma hierarchy · f3c423eb
      Konstantin Khlebnikov authored
      commit 7a3ef208 upstream.
      
      Constantly forking task causes unlimited grow of anon_vma chain.  Each
      next child allocates new level of anon_vmas and links vma to all
      previous levels because pages might be inherited from any level.
      
      This patch adds heuristic which decides to reuse existing anon_vma
      instead of forking new one.  It adds counter anon_vma->degree which
      counts linked vmas and directly descending anon_vmas and reuses anon_vma
      if counter is lower than two.  As a result each anon_vma has either vma
      or at least two descending anon_vmas.  In such trees half of nodes are
      leafs with alive vmas, thus count of anon_vmas is no more than two times
      bigger than count of vmas.
      
      This heuristic reuses anon_vmas as few as possible because each reuse
      adds false aliasing among vmas and rmap walker ought to scan more ptes
      when it searches where page is might be mapped.
      
      Link: http://lkml.kernel.org/r/20120816024610.GA5350@evergreen.ssec.wisc.edu
      Fixes: 5beb4930 ("mm: change anon_vma linking to fix multi-process server scalability issue")
      [akpm@linux-foundation.org: fix typo, per Rik]
      Signed-off-by: default avatarKonstantin Khlebnikov <koct9i@gmail.com>
      Reported-by: default avatarDaniel Forrest <dan.forrest@ssec.wisc.edu>
      Tested-by: default avatarMichal Hocko <mhocko@suse.cz>
      Tested-by: default avatarJerome Marchand <jmarchan@redhat.com>
      Reviewed-by: default avatarMichal Hocko <mhocko@suse.cz>
      Reviewed-by: default avatarRik van Riel <riel@redhat.com>
      Cc: <stable@vger.kernel.org>	[2.6.34+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      f3c423eb
    • Heiko Carstens's avatar
      fs/seq_file: fallback to vmalloc allocation · 77167581
      Heiko Carstens authored
      commit 058504ed upstream.
      
      There are a couple of seq_files which use the single_open() interface.
      This interface requires that the whole output must fit into a single
      buffer.
      
      E.g.  for /proc/stat allocation failures have been observed because an
      order-4 memory allocation failed due to memory fragmentation.  In such
      situations reading /proc/stat is not possible anymore.
      
      Therefore change the seq_file code to fallback to vmalloc allocations
      which will usually result in a couple of order-0 allocations and hence
      also work if memory is fragmented.
      
      For reference a call trace where reading from /proc/stat failed:
      
        sadc: page allocation failure: order:4, mode:0x1040d0
        CPU: 1 PID: 192063 Comm: sadc Not tainted 3.10.0-123.el7.s390x #1
        [...]
        Call Trace:
          show_stack+0x6c/0xe8
          warn_alloc_failed+0xd6/0x138
          __alloc_pages_nodemask+0x9da/0xb68
          __get_free_pages+0x2e/0x58
          kmalloc_order_trace+0x44/0xc0
          stat_open+0x5a/0xd8
          proc_reg_open+0x8a/0x140
          do_dentry_open+0x1bc/0x2c8
          finish_open+0x46/0x60
          do_last+0x382/0x10d0
          path_openat+0xc8/0x4f8
          do_filp_open+0x46/0xa8
          do_sys_open+0x114/0x1f0
          sysc_tracego+0x14/0x1a
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Tested-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Ian Kent <raven@themaw.net>
      Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
      Cc: Thorsten Diehl <thorsten.diehl@de.ibm.com>
      Cc: Andrea Righi <andrea@betterlinux.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Stefan Bader <stefan.bader@canonical.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>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      77167581
    • Al Viro's avatar
      seq_file: always clear m->count when we free m->buf · bb1317a3
      Al Viro authored
      commit 801a7605 upstream.
      
      Once we'd freed m->buf, m->count should become zero - we have no valid
      contents reachable via m->buf.
      Reported-by: default avatarCharley (Hao Chuan) Chu <charley.chu@broadcom.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      bb1317a3
    • Heiko Carstens's avatar
      /proc/stat: convert to single_open_size() · a58d83a1
      Heiko Carstens authored
      commit f74373a5 upstream.
      
      These two patches are supposed to "fix" failed order-4 memory
      allocations which have been observed when reading /proc/stat.  The
      problem has been observed on s390 as well as on x86.
      
      To address the problem change the seq_file memory allocations to
      fallback to use vmalloc, so that allocations also work if memory is
      fragmented.
      
      This approach seems to be simpler and less intrusive than changing
      /proc/stat to use an interator.  Also it "fixes" other users as well,
      which use seq_file's single_open() interface.
      
      This patch (of 2):
      
      Use seq_file's single_open_size() to preallocate a buffer that is large
      enough to hold the whole output, instead of open coding it.  Also
      calculate the requested size using the number of online cpus instead of
      possible cpus, since the size of the output only depends on the number
      of online cpus.
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Ian Kent <raven@themaw.net>
      Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
      Cc: Thorsten Diehl <thorsten.diehl@de.ibm.com>
      Cc: Andrea Righi <andrea@betterlinux.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Stefan Bader <stefan.bader@canonical.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>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      a58d83a1
    • Vineet Gupta's avatar
      ARC: signal handling robustify · dcaf4bff
      Vineet Gupta authored
      commit e4140819 upstream.
      
      A malicious signal handler / restorer can DOS the system by fudging the
      user regs saved on stack, causing weird things such as sigreturn returning
      to user mode PC but cpu state still being kernel mode....
      
      Ensure that in sigreturn path status32 always has U bit; any other bogosity
      (gargbage PC etc) will be taken care of by normal user mode exceptions mechanisms.
      
      Reproducer signal handler:
      
          void handle_sig(int signo, siginfo_t *info, void *context)
          {
      	ucontext_t *uc = context;
      	struct user_regs_struct *regs = &(uc->uc_mcontext.regs);
      
      	regs->scratch.status32 = 0;
          }
      
      Before the fix, kernel would go off to weeds like below:
      
          --------->8-----------
          [ARCLinux]$ ./signal-test
          Path: /signal-test
          CPU: 0 PID: 61 Comm: signal-test Not tainted 4.0.0-rc5+ #65
          task: 8f177880 ti: 5ffe6000 task.ti: 8f15c000
      
          [ECR   ]: 0x00220200 => Invalid Write @ 0x00000010 by insn @ 0x00010698
          [EFA   ]: 0x00000010
          [BLINK ]: 0x2007c1ee
          [ERET  ]: 0x10698
          [STAT32]: 0x00000000 :                                   <--------
          BTA: 0x00010680	 SP: 0x5ffe7e48	 FP: 0x00000000
          LPS: 0x20003c6c	LPE: 0x20003c70	LPC: 0x00000000
          ...
          --------->8-----------
      Reported-by: default avatarAlexey Brodkin <abrodkin@synopsys.com>
      Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      dcaf4bff
    • K. Y. Srinivasan's avatar
      Drivers: hv: vmbus: Don't wait after requesting offers · f3c24356
      K. Y. Srinivasan authored
      commit 73cffdb6 upstream.
      
      Don't wait after sending request for offers to the host. This wait is
      unnecessary and simply adds 5 seconds to the boot time.
      Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      f3c24356
    • Andrzej Pietrasiewicz's avatar
      usb: gadget: printer: enqueue printer's response for setup request · 8ea7695e
      Andrzej Pietrasiewicz authored
      commit eb132ccb upstream.
      
      Function-specific setup requests should be handled in such a way, that
      apart from filling in the data buffer, the requests are also actually
      enqueued: if function-specific setup is called from composte_setup(),
      the "usb_ep_queue()" block of code in composite_setup() is skipped.
      
      The printer function lacks this part and it results in e.g. get device id
      requests failing: the host expects some response, the device prepares it
      but does not equeue it for sending to the host, so the host finally asserts
      timeout.
      
      This patch adds enqueueing the prepared responses.
      
      Fixes: 2e87edf4: "usb: gadget: make g_printer use composite"
      Signed-off-by: default avatarAndrzej Pietrasiewicz <andrzej.p@samsung.com>
      Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
      [ported to stable 3.10 and 3.14]
      Signed-off-by: default avatarAndrzej Pietrasiewicz <andrzej.p@samsung.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      8ea7695e
    • Felipe Balbi's avatar
      usb: host: ehci: use new USB_RESUME_TIMEOUT · af80e75e
      Felipe Balbi authored
      commit ea16328f upstream.
      
      Make sure we're using the new macro, so our
      resume signaling will always pass certification.
      Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      af80e75e
    • Felipe Balbi's avatar
      usb: host: oxu210hp: use new USB_RESUME_TIMEOUT · 90575918
      Felipe Balbi authored
      commit 84c0d178 upstream.
      
      Make sure we're using the new macro, so our
      resume signaling will always pass certification.
      Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      90575918
    • Felipe Balbi's avatar
      usb: musb: use new USB_RESUME_TIMEOUT · 8af6ea1b
      Felipe Balbi authored
      commit 309be239 upstream.
      
      Make sure we're using the new macro, so our
      resume signaling will always pass certification.
      
      Based on original work by Bin Liu <Bin Liu <b-liu@ti.com>>
      
      Cc: Bin Liu <b-liu@ti.com>
      Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      8af6ea1b
    • Alex Deucher's avatar
      drm/radeon: add SI DPM quirk for Sapphire R9 270 Dual-X 2G GDDR5 · 459ff94e
      Alex Deucher authored
      commit cd17e02f upstream.
      
      Seems to have problems with high mclks.
      
      bug:
      https://bugs.freedesktop.org/show_bug.cgi?id=76490Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      459ff94e
    • Christoph Hellwig's avatar
      3w-sas: fix command completion race · d5b20f86
      Christoph Hellwig authored
      commit 579d69bc upstream.
      
      The 3w-sas driver needs to tear down the dma mappings before returning
      the command to the midlayer, as there is no guarantee the sglist and
      count are valid after that point.  Also remove the dma mapping helpers
      which have another inherent race due to the request_id index.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Reported-by: default avatarTorsten Luettgert <ml-lkml@enda.eu>
      Tested-by: default avatarBernd Kardatzki <Bernd.Kardatzki@med.uni-tuebingen.de>
      Acked-by: default avatarAdam Radford <aradford@gmail.com>
      Signed-off-by: default avatarJames Bottomley <JBottomley@Odin.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      d5b20f86
    • Christoph Hellwig's avatar
      3w-9xxx: fix command completion race · c5907e12
      Christoph Hellwig authored
      commit 118c855b upstream.
      
      The 3w-9xxx driver needs to tear down the dma mappings before returning
      the command to the midlayer, as there is no guarantee the sglist and
      count are valid after that point.  Also remove the dma mapping helpers
      which have another inherent race due to the request_id index.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Acked-by: default avatarAdam Radford <aradford@gmail.com>
      Signed-off-by: default avatarJames Bottomley <JBottomley@Odin.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      c5907e12
    • Christoph Hellwig's avatar
      3w-xxxx: fix command completion race · a91071e3
      Christoph Hellwig authored
      commit 9cd95546 upstream.
      
      The 3w-xxxx driver needs to tear down the dma mappings before returning
      the command to the midlayer, as there is no guarantee the sglist and
      count are valid after that point.  Also remove the dma mapping helpers
      which have another inherent race due to the request_id index.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Acked-by: default avatarAdam Radford <aradford@gmail.com>
      Signed-off-by: default avatarJames Bottomley <JBottomley@Odin.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      a91071e3
    • Lukas Czerner's avatar
      ext4: fix data corruption caused by unwritten and delayed extents · 50a61d0c
      Lukas Czerner authored
      commit d2dc317d upstream.
      
      Currently it is possible to lose whole file system block worth of data
      when we hit the specific interaction with unwritten and delayed extents
      in status extent tree.
      
      The problem is that when we insert delayed extent into extent status
      tree the only way to get rid of it is when we write out delayed buffer.
      However there is a limitation in the extent status tree implementation
      so that when inserting unwritten extent should there be even a single
      delayed block the whole unwritten extent would be marked as delayed.
      
      At this point, there is no way to get rid of the delayed extents,
      because there are no delayed buffers to write out. So when a we write
      into said unwritten extent we will convert it to written, but it still
      remains delayed.
      
      When we try to write into that block later ext4_da_map_blocks() will set
      the buffer new and delayed and map it to invalid block which causes
      the rest of the block to be zeroed loosing already written data.
      
      For now we can fix this by simply not allowing to set delayed status on
      written extent in the extent status tree. Also add WARN_ON() to make
      sure that we notice if this happens in the future.
      
      This problem can be easily reproduced by running the following xfs_io.
      
      xfs_io -f -c "pwrite -S 0xaa 4096 2048" \
                -c "falloc 0 131072" \
                -c "pwrite -S 0xbb 65536 2048" \
                -c "fsync" /mnt/test/fff
      
      echo 3 > /proc/sys/vm/drop_caches
      xfs_io -c "pwrite -S 0xdd 67584 2048" /mnt/test/fff
      
      This can be theoretically also reproduced by at random by running fsx,
      but it's not very reliable, though on machines with bigger page size
      (like ppc) this can be seen more often (especially xfstest generic/127)
      Signed-off-by: default avatarLukas Czerner <lczerner@redhat.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      50a61d0c
    • Ilya Dryomov's avatar
      rbd: end I/O the entire obj_request on error · 8ed0623b
      Ilya Dryomov authored
      commit 082a75da upstream.
      
      When we end I/O struct request with error, we need to pass
      obj_request->length as @nr_bytes so that the entire obj_request worth
      of bytes is completed.  Otherwise block layer ends up confused and we
      trip on
      
          rbd_assert(more ^ (which == img_request->obj_request_count));
      
      in rbd_img_obj_callback() due to more being true no matter what.  We
      already do it in most cases but we are missing some, in particular
      those where we don't even get a chance to submit any obj_requests, due
      to an early -ENOMEM for example.
      
      A number of obj_request->xferred assignments seem to be redundant but
      I haven't touched any of obj_request->xferred stuff to keep this small
      and isolated.
      
      Cc: Alex Elder <elder@linaro.org>
      Reported-by: default avatarShawn Edwards <lesser.evil@gmail.com>
      Reviewed-by: default avatarSage Weil <sage@redhat.com>
      Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      8ed0623b
    • Ludovic Desroches's avatar
      tty/serial: at91: maxburst was missing for dma transfers · 7a90b15c
      Ludovic Desroches authored
      commit a8d4e016 upstream.
      
      Maxburst was not set when doing the dma slave configuration. This value
      is checked by the recently introduced xdmac. It causes an error when
      doing the slave configuration and so prevents from using dma.
      Signed-off-by: default avatarLudovic Desroches <ludovic.desroches@atmel.com>
      Acked-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      7a90b15c
    • Charles Keepax's avatar
      ASoC: dapm: Enable autodisable on SOC_DAPM_SINGLE_TLV_AUTODISABLE · 76fa87f6
      Charles Keepax authored
      commit a2d97723 upstream.
      
      Correct small copy and paste error where autodisable was not being
      enabled for the SOC_DAPM_SINGLE_TLV_AUTODISABLE control.
      Signed-off-by: default avatarCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      76fa87f6
    • Michal Simek's avatar
      serial: of-serial: Remove device_type = "serial" registration · b2ca4db9
      Michal Simek authored
      commit 6befa9d8 upstream.
      
      Do not probe all serial drivers by of_serial.c which are using
      device_type = "serial"; property. Only drivers which have valid
      compatible strings listed in the driver should be probed.
      
      When PORT_UNKNOWN is setup probe will fail anyway.
      
      Arnd quotation about driver historical background:
      "when I wrote that driver initially, the idea was that it would
      get used as a stub to hook up all other serial drivers but after
      that, the common code learned to create platform devices from DT"
      
      This patch fix the problem with on the system with xilinx_uartps and
      16550a where of_serial failed to register for xilinx_uartps and because
      of irq_dispose_mapping() removed irq_desc. Then when xilinx_uartps was asking
      for irq with request_irq() EINVAL is returned.
      Signed-off-by: default avatarMichal Simek <michal.simek@xilinx.com>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      b2ca4db9
    • Takashi Iwai's avatar
      ALSA: hda - Fix mute-LED fixed mode · 5de7565b
      Takashi Iwai authored
      commit ee52e56e upstream.
      
      The mute-LED mode control has the fixed on/off states that are
      supposed to remain on/off regardless of the master switch.  However,
      this doesn't work actually because the vmaster hook is called in the
      vmaster code itself.
      
      This patch fixes it by calling the hook indirectly after checking the
      mute LED mode.
      Reported-and-tested-by: default avatarPali Rohár <pali.rohar@gmail.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      5de7565b
    • Peter Zubaj's avatar
      ALSA: emu10k1: Emu10k2 32 bit DMA mode · f10cdffd
      Peter Zubaj authored
      commit 7241ea55 upstream.
      
      Looks like audigy emu10k2 (probably emu10k1 - sb live too) support two
      modes for DMA. Second mode is useful for 64 bit os with more then 2 GB
      of ram (fixes problems with big soundfont loading)
      
      1) 32MB from 2 GB address space using 8192 pages (used now as default)
      2) 16MB from 4 GB address space using 4096 pages
      
      Mode is set using HCFG_EXPANDED_MEM flag in HCFG register.
      Also format of emu10k2 page table is then different.
      Signed-off-by: default avatarPeter Zubaj <pzubaj@marticonet.sk>
      Tested-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      f10cdffd
    • Takashi Iwai's avatar
      ALSA: emu10k1: Fix card shortname string buffer overflow · f0462865
      Takashi Iwai authored
      commit d0226082 upstream.
      
      Some models provide too long string for the shortname that has 32bytes
      including the terminator, and it results in a non-terminated string
      exposed to the user-space.  This isn't too critical, though, as the
      string is stopped at the succeeding longname string.
      
      This patch fixes such entries by dropping "SB" prefix (it's enough to
      fit within 32 bytes, so far).  Meanwhile, it also changes strcpy()
      with strlcpy() to make sure that this kind of problem won't happen in
      future, too.
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      f0462865
    • Takashi Iwai's avatar
      ALSA: emux: Fix mutex deadlock in OSS emulation · 3844eb54
      Takashi Iwai authored
      commit 1c94e65c upstream.
      
      The OSS emulation in synth-emux helper has a potential AB/BA deadlock
      at the simultaneous closing and opening:
      
        close ->
          snd_seq_release() ->
            sne_seq_free_client() ->
              snd_seq_delete_all_ports(): takes client->ports_mutex ->
      	  port_delete() ->
      	    snd_emux_unuse(): takes emux->register_mutex
      
        open ->
          snd_seq_oss_open() ->
            snd_emux_open_seq_oss(): takes emux->register_mutex ->
              snd_seq_event_port_attach() ->
      	  snd_seq_create_port(): takes client->ports_mutex
      
      This patch addresses the deadlock by reducing the rance taking
      emux->register_mutex in snd_emux_open_seq_oss().  The lock is needed
      for the refcount handling, so move it locally.  The calls in
      emux_seq.c are already with the mutex, thus they are replaced with the
      version without mutex lock/unlock.
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      3844eb54
    • Takashi Iwai's avatar
      ALSA: emux: Fix mutex deadlock at unloading · 743fd776
      Takashi Iwai authored
      commit 07b0e5d4 upstream.
      
      The emux-synth driver has a possible AB/BA mutex deadlock at unloading
      the emu10k1 driver:
      
        snd_emux_free() ->
          snd_emux_detach_seq(): mutex_lock(&emu->register_mutex) ->
            snd_seq_delete_kernel_client() ->
              snd_seq_free_client(): mutex_lock(&register_mutex)
      
        snd_seq_release() ->
          snd_seq_free_client(): mutex_lock(&register_mutex) ->
            snd_seq_delete_all_ports() ->
              snd_emux_unuse(): mutex_lock(&emu->register_mutex)
      
      Basically snd_emux_detach_seq() doesn't need a protection of
      emu->register_mutex as it's already being unregistered.  So, we can
      get rid of this for avoiding the deadlock.
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      743fd776
    • hujianyang's avatar
      UBI: fix soft lockup in ubi_check_volume() · 359b12b2
      hujianyang authored
      commit 9aa272b4 upstream.
      
      Running mtd-utils/tests/ubi-tests/io_basic.c could cause
      soft lockup or watchdog reset. It is because *updatevol*
      will perform ubi_check_volume() after updating finish
      and this function will full scan the updated lebs if the
      volume is initialized as STATIC_VOLUME.
      
      This patch adds *cond_resched()* in the loop of lebs scan
      to avoid soft lockup.
      
      Helped by Richard Weinberger <richard@nod.at>
      
      [ 2158.067096] INFO: rcu_sched self-detected stall on CPU { 1}  (t=2101 jiffies g=1606 c=1605 q=56)
      [ 2158.172867] CPU: 1 PID: 2073 Comm: io_basic Tainted: G           O 3.10.53 #21
      [ 2158.172898] [<c000f624>] (unwind_backtrace+0x0/0x120) from [<c000c294>] (show_stack+0x10/0x14)
      [ 2158.172918] [<c000c294>] (show_stack+0x10/0x14) from [<c008ac3c>] (rcu_check_callbacks+0x1c0/0x660)
      [ 2158.172936] [<c008ac3c>] (rcu_check_callbacks+0x1c0/0x660) from [<c002b480>] (update_process_times+0x38/0x64)
      [ 2158.172953] [<c002b480>] (update_process_times+0x38/0x64) from [<c005ff38>] (tick_sched_handle+0x54/0x60)
      [ 2158.172966] [<c005ff38>] (tick_sched_handle+0x54/0x60) from [<c00601ac>] (tick_sched_timer+0x44/0x74)
      [ 2158.172978] [<c00601ac>] (tick_sched_timer+0x44/0x74) from [<c003f348>] (__run_hrtimer+0xc8/0x1b8)
      [ 2158.172992] [<c003f348>] (__run_hrtimer+0xc8/0x1b8) from [<c003fd9c>] (hrtimer_interrupt+0x128/0x2a4)
      [ 2158.173007] [<c003fd9c>] (hrtimer_interrupt+0x128/0x2a4) from [<c0246f1c>] (arch_timer_handler_virt+0x28/0x30)
      [ 2158.173022] [<c0246f1c>] (arch_timer_handler_virt+0x28/0x30) from [<c0086214>] (handle_percpu_devid_irq+0x9c/0x124)
      [ 2158.173036] [<c0086214>] (handle_percpu_devid_irq+0x9c/0x124) from [<c0082bd8>] (generic_handle_irq+0x20/0x30)
      [ 2158.173049] [<c0082bd8>] (generic_handle_irq+0x20/0x30) from [<c000969c>] (handle_IRQ+0x64/0x8c)
      [ 2158.173060] [<c000969c>] (handle_IRQ+0x64/0x8c) from [<c0008544>] (gic_handle_irq+0x3c/0x60)
      [ 2158.173074] [<c0008544>] (gic_handle_irq+0x3c/0x60) from [<c02f0f80>] (__irq_svc+0x40/0x50)
      [ 2158.173083] Exception stack(0xc4043c98 to 0xc4043ce0)
      [ 2158.173092] 3c80:                                                       c4043ce4 00000019
      [ 2158.173102] 3ca0: 1f8a865f c050ad10 1f8a864c 00000031 c04b5970 0003ebce 00000000 f3550000
      [ 2158.173113] 3cc0: bf00bc68 00000800 0003ebce c4043ce0 c0186d14 c0186cb8 80000013 ffffffff
      [ 2158.173130] [<c02f0f80>] (__irq_svc+0x40/0x50) from [<c0186cb8>] (read_current_timer+0x4/0x38)
      [ 2158.173145] [<c0186cb8>] (read_current_timer+0x4/0x38) from [<1f8a865f>] (0x1f8a865f)
      [ 2183.927097] BUG: soft lockup - CPU#1 stuck for 22s! [io_basic:2073]
      [ 2184.002229] Modules linked in: nandflash(O) [last unloaded: nandflash]
      Signed-off-by: default avatarWang Kai <morgan.wang@huawei.com>
      Signed-off-by: default avatarhujianyang <hujianyang@huawei.com>
      Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      359b12b2
    • David S. Miller's avatar
      ipv4: Missing sk_nulls_node_init() in ping_unhash(). · 8a9a51ba
      David S. Miller authored
      [ Upstream commit a134f083 ]
      
      If we don't do that, then the poison value is left in the ->pprev
      backlink.
      
      This can cause crashes if we do a disconnect, followed by a connect().
      Tested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Reported-by: default avatarWen Xu <hotdog3645@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      8a9a51ba
    • Sudip Mukherjee's avatar
      staging: panel: fix lcd type · 9767736a
      Sudip Mukherjee authored
      commit 2c20d92d upstream.
      
      the lcd type as defined in the Kconfig is not matching in the code.
      as a result the rs, rw and en pins were getting interchanged.
      Kconfig defines the value of PANEL_LCD to be 1 if we select custom
      configuration but in the code LCD_TYPE_CUSTOM is defined as 5.
      
      my hardware is LCD_TYPE_CUSTOM, but the pins were assigned to it
      as pins of LCD_TYPE_OLD, and it was not working.
      Now values are corrected with referenece to the values defined in
      Kconfig and it is working.
      checked on JHD204A lcd with LCD_TYPE_CUSTOM configuration.
      
      Cc: <stable@vger.kernel.org> # 2.6.32+
      Signed-off-by: default avatarSudip Mukherjee <sudip@vectorindia.org>
      Acked-by: default avatarWilly Tarreau <w@1wt.eu>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      9767736a
    • Kirill A. Shutemov's avatar
      mm: Fix NULL pointer dereference in madvise(MADV_WILLNEED) support · 5f30307e
      Kirill A. Shutemov authored
      commit ee53664b upstream.
      
      Sasha Levin found a NULL pointer dereference that is due to a missing
      page table lock, which in turn is due to the pmd entry in question being
      a transparent huge-table entry.
      
      The code - introduced in commit 1998cc04 ("mm: make
      madvise(MADV_WILLNEED) support swap file prefetch") - correctly checks
      for this situation using pmd_none_or_trans_huge_or_clear_bad(), but it
      turns out that that function doesn't work correctly.
      
      pmd_none_or_trans_huge_or_clear_bad() expected that pmd_bad() would
      trigger if the transparent hugepage bit was set, but it doesn't do that
      if pmd_numa() is also set. Note that the NUMA bit only gets set on real
      NUMA machines, so people trying to reproduce this on most normal
      development systems would never actually trigger this.
      
      Fix it by removing the very subtle (and subtly incorrect) expectation,
      and instead just checking pmd_trans_huge() explicitly.
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Acked-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      [ Additionally remove the now stale test for pmd_trans_huge() inside the
        pmd_bad() case - Linus ]
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      5f30307e
    • Jann Horn's avatar
      fs: take i_mutex during prepare_binprm for set[ug]id executables · 5176b77f
      Jann Horn authored
      commit 8b01fc86 upstream.
      
      This prevents a race between chown() and execve(), where chowning a
      setuid-user binary to root would momentarily make the binary setuid
      root.
      
      This patch was mostly written by Linus Torvalds.
      Signed-off-by: default avatarJann Horn <jann@thejh.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarCharles Williams <ciwillia@brocade.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      5176b77f
    • Junjie Mao's avatar
      driver core: bus: Goto appropriate labels on failure in bus_add_device · 91350acb
      Junjie Mao authored
      commit 1c34203a upstream.
      
      It is not necessary to call device_remove_groups() when device_add_groups()
      fails.
      
      The group added by device_add_groups() should be removed if sysfs_create_link()
      fails.
      
      Fixes: fa6fdb33 ("driver core: bus_type: add dev_groups")
      Signed-off-by: default avatarJunjie Mao <junjie_mao@yeah.net>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      91350acb
    • Dan Carpenter's avatar
      memstick: mspro_block: add missing curly braces · b9935667
      Dan Carpenter authored
      commit 13f6b191 upstream.
      
      Using the indenting we can see the curly braces were obviously intended.
      This is a static checker fix, but my guess is that we don't read enough
      bytes, because we don't calculate "t_len" correctly.
      
      Fixes: f1d82698 ('memstick: use fully asynchronous request processing')
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Cc: Alex Dubov <oakad@yahoo.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      b9935667
    • Nishanth Menon's avatar
      C6x: time: Ensure consistency in __init · ba394ccc
      Nishanth Menon authored
      commit f4831605 upstream.
      
      time_init invokes timer64_init (which is __init annotation)
      since all of these are invoked at init time, lets maintain
      consistency by ensuring time_init is marked appropriately
      as well.
      
      This fixes the following warning with CONFIG_DEBUG_SECTION_MISMATCH=y
      
      WARNING: vmlinux.o(.text+0x3bfc): Section mismatch in reference from the function time_init() to the function .init.text:timer64_init()
      The function time_init() references
      the function __init timer64_init().
      This is often because time_init lacks a __init
      annotation or the annotation of timer64_init is wrong.
      
      Fixes: 546a3954 ("C6X: time management")
      Signed-off-by: default avatarNishanth Menon <nm@ti.com>
      Signed-off-by: default avatarMark Salter <msalter@redhat.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      ba394ccc
    • Vutla, Lokesh's avatar
      crypto: omap-aes - Fix support for unequal lengths · 1b2a7da9
      Vutla, Lokesh authored
      commit 6d7e7e02 upstream.
      
      For cases where total length of an input SGs is not same as
      length of the input data for encryption, omap-aes driver
      crashes. This happens in the case when IPsec is trying to use
      omap-aes driver.
      
      To avoid this, we copy all the pages from the input SG list
      into a contiguous buffer and prepare a single element SG list
      for this buffer with length as the total bytes to crypt, which is
      similar thing that is done in case of unaligned lengths.
      
      Fixes: 6242332f ("crypto: omap-aes - Add support for cases of unaligned lengths")
      Signed-off-by: default avatarLokesh Vutla <lokeshvutla@ti.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      1b2a7da9
    • Nicolas Iooss's avatar
      wl18xx: show rx_frames_per_rates as an array as it really is · dbbf764b
      Nicolas Iooss authored
      commit a3fa71c4 upstream.
      
      In struct wl18xx_acx_rx_rate_stat, rx_frames_per_rates field is an
      array, not a number.  This means WL18XX_DEBUGFS_FWSTATS_FILE can't be
      used to display this field in debugfs (it would display a pointer, not
      the actual data).  Use WL18XX_DEBUGFS_FWSTATS_FILE_ARRAY instead.
      
      This bug has been found by adding a __printf attribute to
      wl1271_format_buffer.  gcc complained about "format '%u' expects
      argument of type 'unsigned int', but argument 5 has type 'u32 *'".
      
      Fixes: c5d94169 ("wl18xx: use new fw stats structures")
      Signed-off-by: default avatarNicolas Iooss <nicolas.iooss_linux@m4x.org>
      Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      dbbf764b
    • mancha security's avatar
      lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VAR · bf0e4b9a
      mancha security authored
      commit 0b053c95 upstream.
      
      OPTIMIZER_HIDE_VAR(), as defined when using gcc, is insufficient to
      ensure protection from dead store optimization.
      
      For the random driver and crypto drivers, calls are emitted ...
      
        $ gdb vmlinux
        (gdb) disassemble memzero_explicit
        Dump of assembler code for function memzero_explicit:
          0xffffffff813a18b0 <+0>:	push   %rbp
          0xffffffff813a18b1 <+1>:	mov    %rsi,%rdx
          0xffffffff813a18b4 <+4>:	xor    %esi,%esi
          0xffffffff813a18b6 <+6>:	mov    %rsp,%rbp
          0xffffffff813a18b9 <+9>:	callq  0xffffffff813a7120 <memset>
          0xffffffff813a18be <+14>:	pop    %rbp
          0xffffffff813a18bf <+15>:	retq
        End of assembler dump.
      
        (gdb) disassemble extract_entropy
        [...]
          0xffffffff814a5009 <+313>:	mov    %r12,%rdi
          0xffffffff814a500c <+316>:	mov    $0xa,%esi
          0xffffffff814a5011 <+321>:	callq  0xffffffff813a18b0 <memzero_explicit>
          0xffffffff814a5016 <+326>:	mov    -0x48(%rbp),%rax
        [...]
      
      ... but in case in future we might use facilities such as LTO, then
      OPTIMIZER_HIDE_VAR() is not sufficient to protect gcc from a possible
      eviction of the memset(). We have to use a compiler barrier instead.
      
      Minimal test example when we assume memzero_explicit() would *not* be
      a call, but would have been *inlined* instead:
      
        static inline void memzero_explicit(void *s, size_t count)
        {
          memset(s, 0, count);
          <foo>
        }
      
        int main(void)
        {
          char buff[20];
      
          snprintf(buff, sizeof(buff) - 1, "test");
          printf("%s", buff);
      
          memzero_explicit(buff, sizeof(buff));
          return 0;
        }
      
      With <foo> := OPTIMIZER_HIDE_VAR():
      
        (gdb) disassemble main
        Dump of assembler code for function main:
        [...]
         0x0000000000400464 <+36>:	callq  0x400410 <printf@plt>
         0x0000000000400469 <+41>:	xor    %eax,%eax
         0x000000000040046b <+43>:	add    $0x28,%rsp
         0x000000000040046f <+47>:	retq
        End of assembler dump.
      
      With <foo> := barrier():
      
        (gdb) disassemble main
        Dump of assembler code for function main:
        [...]
         0x0000000000400464 <+36>:	callq  0x400410 <printf@plt>
         0x0000000000400469 <+41>:	movq   $0x0,(%rsp)
         0x0000000000400471 <+49>:	movq   $0x0,0x8(%rsp)
         0x000000000040047a <+58>:	movl   $0x0,0x10(%rsp)
         0x0000000000400482 <+66>:	xor    %eax,%eax
         0x0000000000400484 <+68>:	add    $0x28,%rsp
         0x0000000000400488 <+72>:	retq
        End of assembler dump.
      
      As can be seen, movq, movq, movl are being emitted inlined
      via memset().
      
      Reference: http://thread.gmane.org/gmane.linux.kernel.cryptoapi/13764/
      Fixes: d4c5efdb ("random: add and use memzero_explicit() for clearing data")
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarmancha security <mancha1@zoho.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Acked-by: default avatarStephan Mueller <smueller@chronox.de>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      bf0e4b9a
    • Sabrina Dubroca's avatar
      e1000: add dummy allocator to fix race condition between mtu change and netpoll · 47cd2dc5
      Sabrina Dubroca authored
      commit 08e83316 upstream.
      
      There is a race condition between e1000_change_mtu's cleanups and
      netpoll, when we change the MTU across jumbo size:
      
      Changing MTU frees all the rx buffers:
          e1000_change_mtu -> e1000_down -> e1000_clean_all_rx_rings ->
              e1000_clean_rx_ring
      
      Then, close to the end of e1000_change_mtu:
          pr_info -> ... -> netpoll_poll_dev -> e1000_clean ->
              e1000_clean_rx_irq -> e1000_alloc_rx_buffers -> e1000_alloc_frag
      
      And when we come back to do the rest of the MTU change:
          e1000_up -> e1000_configure -> e1000_configure_rx ->
              e1000_alloc_jumbo_rx_buffers
      
      alloc_jumbo finds the buffers already != NULL, since data (shared with
      page in e1000_rx_buffer->rxbuf) has been re-alloc'd, but it's garbage,
      or at least not what is expected when in jumbo state.
      
      This results in an unusable adapter (packets don't get through), and a
      NULL pointer dereference on the next call to e1000_clean_rx_ring
      (other mtu change, link down, shutdown):
      
      BUG: unable to handle kernel NULL pointer dereference at           (null)
      IP: [<ffffffff81194d6e>] put_compound_page+0x7e/0x330
      
          [...]
      
      Call Trace:
       [<ffffffff81195445>] put_page+0x55/0x60
       [<ffffffff815d9f44>] e1000_clean_rx_ring+0x134/0x200
       [<ffffffff815da055>] e1000_clean_all_rx_rings+0x45/0x60
       [<ffffffff815df5e0>] e1000_down+0x1c0/0x1d0
       [<ffffffff811e2260>] ? deactivate_slab+0x7f0/0x840
       [<ffffffff815e21bc>] e1000_change_mtu+0xdc/0x170
       [<ffffffff81647050>] dev_set_mtu+0xa0/0x140
       [<ffffffff81664218>] do_setlink+0x218/0xac0
       [<ffffffff814459e9>] ? nla_parse+0xb9/0x120
       [<ffffffff816652d0>] rtnl_newlink+0x6d0/0x890
       [<ffffffff8104f000>] ? kvm_clock_read+0x20/0x40
       [<ffffffff810a2068>] ? sched_clock_cpu+0xa8/0x100
       [<ffffffff81663802>] rtnetlink_rcv_msg+0x92/0x260
      
      By setting the allocator to a dummy version, netpoll can't mess up our
      rx buffers.  The allocator is set back to a sane value in
      e1000_configure_rx.
      
      Fixes: edbbb3ca ("e1000: implement jumbo receive with partial descriptors")
      Signed-off-by: default avatarSabrina Dubroca <sd@queasysnail.net>
      Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      47cd2dc5
    • Calvin Owens's avatar
      ksoftirqd: Enable IRQs and call cond_resched() before poking RCU · 4e75ff4f
      Calvin Owens authored
      commit 28423ad2 upstream.
      
      While debugging an issue with excessive softirq usage, I encountered the
      following note in commit 3e339b5d ("softirq: Use hotplug thread
      infrastructure"):
      
          [ paulmck: Call rcu_note_context_switch() with interrupts enabled. ]
      
      ...but despite this note, the patch still calls RCU with IRQs disabled.
      
      This seemingly innocuous change caused a significant regression in softirq
      CPU usage on the sending side of a large TCP transfer (~1 GB/s): when
      introducing 0.01% packet loss, the softirq usage would jump to around 25%,
      spiking as high as 50%. Before the change, the usage would never exceed 5%.
      
      Moving the call to rcu_note_context_switch() after the cond_sched() call,
      as it was originally before the hotplug patch, completely eliminated this
      problem.
      Signed-off-by: default avatarCalvin Owens <calvinowens@fb.com>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: default avatarMike Galbraith <mgalbraith@suse.de>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      4e75ff4f
    • Al Viro's avatar
      RCU pathwalk breakage when running into a symlink overmounting something · 6e310c82
      Al Viro authored
      commit 3cab989a upstream.
      
      Calling unlazy_walk() in walk_component() and do_last() when we find
      a symlink that needs to be followed doesn't acquire a reference to vfsmount.
      That's fine when the symlink is on the same vfsmount as the parent directory
      (which is almost always the case), but it's not always true - one _can_
      manage to bind a symlink on top of something.  And in such cases we end up
      with excessive mntput().
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      6e310c82