1. 26 Jul, 2013 4 commits
    • Will Deacon's avatar
      ARM: 7791/1: a.out: remove partial a.out support · acfdd4b1
      Will Deacon authored
      a.out support on ARM requires that argc, argv and envp are passed in
      r0-r2 respectively, which requires hacking load_aout_binary to
      prevent argc being clobbered by the return code. Whilst mainline kernels
      do set the registers up in start_thread, the aout loader has never
      carried the hack in mainline.
      
      Initialising the registers in this way actually goes against the libc
      expectations for ELF binaries, where argc, argv and envp are passed on
      the stack, with r0 being used to hold a pointer to an exit function for
      cleaning up after the dynamic linker if required. If the pointer is
      NULL, then it is ignored. When execing an ELF binary, Linux currently
      zeroes r0, then sets it to argc and then finally clobbers it with the
      return value of the execve syscall, so we actually end up with:
      
      	r0 = 0
      	stack[0] = argc
      	r1 = stack[1] = argv
      	r2 = stack[2] = envp
      
      libc treats r1 and r2 as undefined. The clobbering of r0 by sys_execve
      works for user-spawned threads, but when executing an ELF binary from a
      kernel thread (via call_usermodehelper), the execve is performed on the
      ret_from_fork path, which restores r0 from the saved pt_regs, resulting
      in argc being presented to the C library. This has horrible consequences
      when the application exits, since we have an exit function registered
      using argc, resulting in a jump to hyperspace.
      
      This patch solves the problem by removing the partial a.out support from
      arch/arm/ altogether.
      
      Cc: <stable@vger.kernel.org>
      Cc: Ashish Sangwan <ashishsangwan2@gmail.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      acfdd4b1
    • Catalin Marinas's avatar
      ARM: 7790/1: Fix deferred mm switch on VIVT processors · bdae73cd
      Catalin Marinas authored
      As of commit b9d4d42a (ARM: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW on
      pre-ARMv6 CPUs), the mm switching on VIVT processors is done in the
      finish_arch_post_lock_switch() function to avoid whole cache flushing
      with interrupts disabled. The need for deferred mm switch is stored as a
      thread flag (TIF_SWITCH_MM). However, with preemption enabled, we can
      have another thread switch before finish_arch_post_lock_switch(). If the
      new thread has the same mm as the previous 'next' thread, the scheduler
      will not call switch_mm() and the TIF_SWITCH_MM flag won't be set for
      the new thread.
      
      This patch moves the switch pending flag to the mm_context_t structure
      since this is specific to the mm rather than thread.
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Reported-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Tested-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Cc: <stable@vger.kernel.org> # 3.5+
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      bdae73cd
    • Fabio Estevam's avatar
      ARM: 7789/1: Do not run dummy_flush_tlb_a15_erratum() on non-Cortex-A15 · 1f49856b
      Fabio Estevam authored
      Commit 93dc6887 (ARM: 7684/1: errata: Workaround for Cortex-A15 erratum 798181 (TLBI/DSB operations)) causes the following undefined instruction error on a mx53 (Cortex-A8):
      
      Internal error: Oops - undefined instruction: 0 [#1] SMP ARM
      CPU: 0 PID: 275 Comm: modprobe Not tainted 3.11.0-rc2-next-20130722-00009-g9b0f371 #881
      task: df46cc00 ti: df48e000 task.ti: df48e000
      PC is at check_and_switch_context+0x17c/0x4d0
      LR is at check_and_switch_context+0xdc/0x4d0
      
      This problem happens because check_and_switch_context() calls dummy_flush_tlb_a15_erratum() without checking if we are really running on a Cortex-A15 or not.
      
      To avoid this issue, only call dummy_flush_tlb_a15_erratum() inside
      check_and_switch_context() if erratum_a15_798181() returns true, which means that we are really running on a Cortex-A15.
      Signed-off-by: default avatarFabio Estevam <fabio.estevam@freescale.com>
      Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Reviewed-by: default avatarRoger Quadros <rogerq@ti.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      1f49856b
    • Mark Rutland's avatar
      ARM: 7787/1: virt: ensure visibility of __boot_cpu_mode · 8fbac214
      Mark Rutland authored
      Secondary CPUs write to __boot_cpu_mode with caches disabled, and thus a
      cached value of __boot_cpu_mode may be incoherent with that in memory.
      This could lead to a failure to detect mismatched boot modes.
      
      This patch adds flushing to ensure that writes by secondaries to
      __boot_cpu_mode are made visible before we test against it.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Acked-by: default avatarDave Martin <Dave.Martin@arm.com>
      Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Cc: Christoffer Dall <cdall@cs.columbia.edu>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      8fbac214
  2. 22 Jul, 2013 5 commits
    • Tetsuyuki Kobayashi's avatar
      ARM: 7788/1: elf: fix lpae hwcap feature reporting in proc/cpuinfo · ab8d46c0
      Tetsuyuki Kobayashi authored
      Commit a469abd0 ("ARM: elf: add new hwcap for identifying atomic
      ldrd/strd instructions") added a new hwcap to identify LPAE on CPUs
      which support it. Whilst the hwcap data is correct, the string reported
      in /proc/cpuinfo actually matches on HWCAP_VFPD32, which was missing
      an entry in the string table.
      
      This patch fixes this problem by adding a "vfpd32" string at the correct
      offset, preventing us from falsely advertising LPAE on CPUs which do not
      support it.
      
      [will: added commit message]
      Acked-by: default avatarWill Deacon <will.deacon@arm.com>
      Tested-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarTetsuyuki Kobayashi <koba@kmckk.co.jp>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      ab8d46c0
    • Mark Rutland's avatar
      ARM: 7786/1: hyp: fix macro parameterisation · b60d5db6
      Mark Rutland authored
      Currently, compare_cpu_mode_with_primary uses a mixture of macro
      arguments and hardcoded registers, and does so incorrectly, as it
      stores (__boot_cpu_mode_offset | BOOT_CPU_MODE_MISMATCH) to
      (__boot_cpu_mode + &__boot_cpu_mode_offset), which could corrupt an
      arbitrary portion of memory.
      
      This patch fixes up compare_cpu_mode_with_primary to use the macro
      arguments, correctly updating __boot_cpu_mode.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Acked-by: default avatarDave Martin <Dave.Martin@arm.com>
      Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Cc: Christoffer Dall <cdall@cs.columbia.edu>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      b60d5db6
    • Russell King's avatar
      ARM: 7785/1: mm: restrict early_alloc to section-aligned memory · c65b7e98
      Russell King authored
      When map_lowmem() runs, and processes a memory bank whose start or end
      is not section-aligned, memory must be allocated to store the 2nd-level
      page tables. Those allocations are made by calling memblock_alloc().
      
      At this point, the only memory that is free *and* mapped is memory which
      has already been mapped by map_lowmem() itself. For this reason, we must
      calculate the first point at which map_lowmem() will need to allocate
      memory, and set the memblock allocation limit to a lower address, so that
      memblock_alloc() is guaranteed to return memory that is already mapped.
      
      This patch enhances sanity_check_meminfo() to calculate that memory
      address, and pass it to memblock_set_current_limit(), rather than just
      assuming the limit is arm_lowmem_limit.
      
      The algorithm applied is:
      
      * Default memblock_limit to arm_lowmem_limit in the absence of any other
        limit; arm_lowmem_limit is the highest memory that is mapped by
        map_lowmem().
      
      * While walking the list of memblocks, if the start of a block is not
        aligned, 2nd-level page tables will need to be allocated to map the
        first few pages of the block. Hence, the memblock_limit must be before
        the start of the block.
      
      * Similarly, if the end of any block is not aligned, 2nd-level page
        tables will need to be allocated to map the last few pages of the
        block. Hence, the memblock_limit must point at the end of the block,
        rounded down to section-alignment.
      
      * The memory blocks are assumed to be sorted in address order, so the
        first unaligned block start or end is used to set the limit.
      
      With this algorithm, the start or end of almost any bank can be non-
      section-aligned. The only exception is that the start of bank 0 must
      be section-aligned, since otherwise memory would need to be allocated
      when mapping the start of bank 0, which occurs before any free memory
      is mapped.
      
      [swarren, wrote commit description, rewrote calculation of memblock_limit]
      Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      c65b7e98
    • Will Deacon's avatar
      ARM: 7784/1: mm: ensure SMP alternates assemble to exactly 4 bytes with Thumb-2 · bf3f0f33
      Will Deacon authored
      Commit ae8a8b95 ("ARM: 7691/1: mm: kill unused TLB_CAN_READ_FROM_L1_CACHE
      and use ALT_SMP instead") added early function returns for page table
      cache flushing operations on ARMv7 SMP CPUs.
      
      Unfortunately, when targetting Thumb-2, these `mov pc, lr' sequences
      assemble to 2 bytes which can lead to corruption of the instruction
      stream after code patching.
      
      This patch fixes the alternates to use wide (32-bit) instructions for
      Thumb-2, therefore ensuring that the patching code works correctly.
      
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      bf3f0f33
    • Russell King's avatar
      ARM: document DEBUG_UNCOMPRESS Kconfig option · b6992fa9
      Russell King authored
      This non-user visible option lacked any kind of documentation.  This
      is quite common for non-user visible options; certian people can't
      understand the point of documenting such options with help text.
      
      However, here we have a case in point: developers don't understand the
      option either, as they were thinking that when the option is not set,
      the decompressor should produce no output what so ever.  This is
      incorrect, as the purpose of this option is to control whether a
      multiplatform kernel uses the kernel debugging macros to produce
      output or not.
      
      So let's document this via help rather than commentry to prevent others
      falling into this misunderstanding.
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      b6992fa9
  3. 21 Jul, 2013 5 commits
    • Linus Torvalds's avatar
      Linux 3.11-rc2 · 3b2f64d0
      Linus Torvalds authored
      3b2f64d0
    • Linus Torvalds's avatar
      Merge tag 'acpi-video-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · ea45ea70
      Linus Torvalds authored
      Pull ACPI video support fixes from Rafael Wysocki:
       "I'm sending a separate pull request for this as it may be somewhat
        controversial.  The breakage addressed here is not really new and the
        fixes may not satisfy all users of the affected systems, but we've had
        so much back and forth dance in this area over the last several weeks
        that I think it's time to actually make some progress.
      
        The source of the problem is that about a year ago we started to tell
        BIOSes that we're compatible with Windows 8, which we really need to
        do, because some systems shipping with Windows 8 are tested with it
        and nothing else, so if we tell their BIOSes that we aren't compatible
        with Windows 8, we expose our users to untested BIOS/AML code paths.
      
        However, as it turns out, some Windows 8-specific AML code paths are
        not tested either, because Windows 8 actually doesn't use the ACPI
        methods containing them, so if we declare Windows 8 compatibility and
        attempt to use those ACPI methods, things break.  That occurs mostly
        in the backlight support area where in particular the _BCM and _BQC
        methods are plain unusable on some systems if the OS declares Windows
        8 compatibility.
      
        [ The additional twist is that they actually become usable if the OS
          says it is not compatible with Windows 8, but that may cause
          problems to show up elsewhere ]
      
        Investigation carried out by Matthew Garrett indicates that what
        Windows 8 does about backlight is to leave backlight control up to
        individual graphics drivers.  At least there's evidence that it does
        that if the Intel graphics driver is used, so we've decided to follow
        Windows 8 in that respect and allow i915 to control backlight (Daniel
        likes that part).
      
        The first commit from Aaron Lu makes ACPICA export the variable from
        which we can infer whether or not the BIOS believes that we are
        compatible with Windows 8.
      
        The second commit from Matthew Garrett prepares the ACPI video driver
        by making it initialize the ACPI backlight even if it is not going to
        be used afterward (that is needed for backlight control to work on
        Thinkpads).
      
        The third commit implements the actual workaround making i915 take
        over backlight control if the firmware thinks it's dealing with
        Windows 8 and is based on the work of multiple developers, including
        Matthew Garrett, Chun-Yi Lee, Seth Forshee, and Aaron Lu.
      
        The final commit from Aaron Lu makes us follow Windows 8 by informing
        the firmware through the _DOS method that it should not carry out
        automatic brightness changes, so that brightness can be controlled by
        GUI.
      
        Hopefully, this approach will allow us to avoid using blacklists of
        systems that should not declare Windows 8 compatibility just to avoid
        backlight control problems in the future.
      
         - Change from Aaron Lu makes ACPICA export a variable which can be
           used by driver code to determine whether or not the BIOS believes
           that we are compatible with Windows 8.
      
         - Change from Matthew Garrett makes the ACPI video driver initialize
           the ACPI backlight even if it is not going to be used afterward
           (that is needed for backlight control to work on Thinkpads).
      
         - Fix from Rafael J Wysocki implements Windows 8 backlight support
           workaround making i915 take over bakclight control if the firmware
           thinks it's dealing with Windows 8.  Based on the work of multiple
           developers including Matthew Garrett, Chun-Yi Lee, Seth Forshee,
           and Aaron Lu.
      
         - Fix from Aaron Lu makes the kernel follow Windows 8 by informing
           the firmware through the _DOS method that it should not carry out
           automatic brightness changes, so that brightness can be controlled
           by GUI"
      
      * tag 'acpi-video-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
        ACPI / video: no automatic brightness changes by win8-compatible firmware
        ACPI / video / i915: No ACPI backlight if firmware expects Windows 8
        ACPI / video: Always call acpi_video_init_brightness() on init
        ACPICA: expose OSI version
      ea45ea70
    • Linus Torvalds's avatar
      Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 90db76e8
      Linus Torvalds authored
      Pull ext[34] tmpfile bugfix from Ted Ts'o:
       "Fix regression caused by commit af51a2ac which added ->tmpfile()
        support (along with a similar fix for ext3)"
      
      * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
        ext3: fix a BUG when opening a file with O_TMPFILE flag
        ext4: fix a BUG when opening a file with O_TMPFILE flag
      90db76e8
    • Zheng Liu's avatar
      ext3: fix a BUG when opening a file with O_TMPFILE flag · dda5690d
      Zheng Liu authored
      When we try to open a file with O_TMPFILE flag, we will trigger a bug.
      The root cause is that in ext4_orphan_add() we check ->i_nlink == 0 and
      this check always fails because we set ->i_nlink = 1 in
      inode_init_always().  We can use the following program to trigger it:
      
      int main(int argc, char *argv[])
      {
      	int fd;
      
      	fd = open(argv[1], O_TMPFILE, 0666);
      	if (fd < 0) {
      		perror("open ");
      		return -1;
      	}
      	close(fd);
      	return 0;
      }
      
      The oops message looks like this:
      
      kernel: kernel BUG at fs/ext3/namei.c:1992!
      kernel: invalid opcode: 0000 [#1] SMP
      kernel: Modules linked in: ext4 jbd2 crc16 cpufreq_ondemand ipv6 dm_mirror dm_region_hash dm_log dm_mod parport_pc parport serio_raw sg dcdbas pcspkr i2c_i801 ehci_pci ehci_hcd button acpi_cpufreq mperf e1000e ptp pps_core ttm drm_kms_helper drm hwmon i2c_algo_bit i2c_core ext3 jbd sd_mod ahci libahci libata scsi_mod uhci_hcd
      kernel: CPU: 0 PID: 2882 Comm: tst_tmpfile Not tainted 3.11.0-rc1+ #4
      kernel: Hardware name: Dell Inc. OptiPlex 780 /0V4W66, BIOS A05 08/11/2010
      kernel: task: ffff880112d30050 ti: ffff8801124d4000 task.ti: ffff8801124d4000
      kernel: RIP: 0010:[<ffffffffa00db5ae>] [<ffffffffa00db5ae>] ext3_orphan_add+0x6a/0x1eb [ext3]
      kernel: RSP: 0018:ffff8801124d5cc8  EFLAGS: 00010202
      kernel: RAX: 0000000000000000 RBX: ffff880111510128 RCX: ffff8801114683a0
      kernel: RDX: 0000000000000000 RSI: ffff880111510128 RDI: ffff88010fcf65a8
      kernel: RBP: ffff8801124d5d18 R08: 0080000000000000 R09: ffffffffa00d3b7f
      kernel: R10: ffff8801114683a0 R11: ffff8801032a2558 R12: 0000000000000000
      kernel: R13: ffff88010fcf6800 R14: ffff8801032a2558 R15: ffff8801115100d8
      kernel: FS:  00007f5d172b5700(0000) GS:ffff880117c00000(0000) knlGS:0000000000000000
      kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
      kernel: CR2: 00007f5d16df15d0 CR3: 0000000110b1d000 CR4: 00000000000407f0
      kernel: Stack:
      kernel: 000000000000000c ffff8801048a7dc8 ffff8801114685a8 ffffffffa00b80d7
      kernel: ffff8801124d5e38 ffff8801032a2558 ffff88010ce24d68 0000000000000000
      kernel: ffff88011146b300 ffff8801124d5d44 ffff8801124d5d78 ffffffffa00db7e1
      kernel: Call Trace:
      kernel: [<ffffffffa00b80d7>] ? journal_start+0x8c/0xbd [jbd]
      kernel: [<ffffffffa00db7e1>] ext3_tmpfile+0xb2/0x13b [ext3]
      kernel: [<ffffffff821076f8>] path_openat+0x11f/0x5e7
      kernel: [<ffffffff821c86b4>] ? list_del+0x11/0x30
      kernel: [<ffffffff82065fa2>] ?  __dequeue_entity+0x33/0x38
      kernel: [<ffffffff82107cd5>] do_filp_open+0x3f/0x8d
      kernel: [<ffffffff82112532>] ? __alloc_fd+0x50/0x102
      kernel: [<ffffffff820f9296>] do_sys_open+0x13b/0x1cd
      kernel: [<ffffffff820f935c>] SyS_open+0x1e/0x20
      kernel: [<ffffffff82398c02>] system_call_fastpath+0x16/0x1b
      kernel: Code: 39 c7 0f 85 67 01 00 00 0f b7 03 25 00 f0 00 00 3d 00 40 00 00 74 18 3d 00 80 00 00 74 11 3d 00 a0 00 00 74 0a 83 7b 48 00 74 04 <0f> 0b eb fe 49 8b 85 50 03 00 00 4c 89 f6 48 c7 c7 c0 99 0e a0
      kernel: RIP  [<ffffffffa00db5ae>] ext3_orphan_add+0x6a/0x1eb [ext3]
      kernel: RSP <ffff8801124d5cc8>
      
      Here we couldn't call clear_nlink() directly because in d_tmpfile() we
      will call inode_dec_link_count() to decrease ->i_nlink.  So this commit
      tries to call d_tmpfile() before ext4_orphan_add() to fix this problem.
      Signed-off-by: default avatarZheng Liu <wenqing.lz@taobao.com>
      Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      Cc: Jan Kara <jack@suse.cz>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      dda5690d
    • Zheng Liu's avatar
      ext4: fix a BUG when opening a file with O_TMPFILE flag · e94bd349
      Zheng Liu authored
      When we try to open a file with O_TMPFILE flag, we will trigger a bug.
      The root cause is that in ext4_orphan_add() we check ->i_nlink == 0 and
      this check always fails because we set ->i_nlink = 1 in
      inode_init_always().  We can use the following program to trigger it:
      
      int main(int argc, char *argv[])
      {
      	int fd;
      
      	fd = open(argv[1], O_TMPFILE, 0666);
      	if (fd < 0) {
      		perror("open ");
      		return -1;
      	}
      	close(fd);
      	return 0;
      }
      
      The oops message looks like this:
      
      kernel BUG at fs/ext4/namei.c:2572!
      invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
      Modules linked in: dlci bridge stp hidp cmtp kernelcapi l2tp_ppp l2tp_netlink l2tp_core sctp libcrc32c rfcomm tun fuse nfnetli
      nk can_raw ipt_ULOG can_bcm x25 scsi_transport_iscsi ipx p8023 p8022 appletalk phonet psnap vmw_vsock_vmci_transport af_key vmw_vmci rose vsock atm can netrom ax25 af_rxrpc ir
      da pppoe pppox ppp_generic slhc bluetooth nfc rfkill rds caif_socket caif crc_ccitt af_802154 llc2 llc snd_hda_codec_realtek snd_hda_intel snd_hda_codec serio_raw snd_pcm pcsp
      kr edac_core snd_page_alloc snd_timer snd soundcore r8169 mii sr_mod cdrom pata_atiixp radeon backlight drm_kms_helper ttm
      CPU: 1 PID: 1812571 Comm: trinity-child2 Not tainted 3.11.0-rc1+ #12
      Hardware name: Gigabyte Technology Co., Ltd. GA-MA78GM-S2H/GA-MA78GM-S2H, BIOS F12a 04/23/2010
      task: ffff88007dfe69a0 ti: ffff88010f7b6000 task.ti: ffff88010f7b6000
      RIP: 0010:[<ffffffff8125ce69>]  [<ffffffff8125ce69>] ext4_orphan_add+0x299/0x2b0
      RSP: 0018:ffff88010f7b7cf8  EFLAGS: 00010202
      RAX: 0000000000000000 RBX: ffff8800966d3020 RCX: 0000000000000000
      RDX: 0000000000000000 RSI: ffff88007dfe70b8 RDI: 0000000000000001
      RBP: ffff88010f7b7d40 R08: ffff880126a3c4e0 R09: ffff88010f7b7ca0
      R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801271fd668
      R13: ffff8800966d2f78 R14: ffff88011d7089f0 R15: ffff88007dfe69a0
      FS:  00007f70441a3740(0000) GS:ffff88012a800000(0000) knlGS:00000000f77c96c0
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 0000000002834000 CR3: 0000000107964000 CR4: 00000000000007e0
      DR0: 0000000000780000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
      Stack:
       0000000000002000 00000020810b6dde 0000000000000000 ffff88011d46db00
       ffff8800966d3020 ffff88011d7089f0 ffff88009c7f4c10 ffff88010f7b7f2c
       ffff88007dfe69a0 ffff88010f7b7da8 ffffffff8125cfac ffff880100000004
      Call Trace:
       [<ffffffff8125cfac>] ext4_tmpfile+0x12c/0x180
       [<ffffffff811cba78>] path_openat+0x238/0x700
       [<ffffffff8100afc4>] ? native_sched_clock+0x24/0x80
       [<ffffffff811cc647>] do_filp_open+0x47/0xa0
       [<ffffffff811db73f>] ? __alloc_fd+0xaf/0x200
       [<ffffffff811ba2e4>] do_sys_open+0x124/0x210
       [<ffffffff81010725>] ? syscall_trace_enter+0x25/0x290
       [<ffffffff811ba3ee>] SyS_open+0x1e/0x20
       [<ffffffff816ca8d4>] tracesys+0xdd/0xe2
       [<ffffffff81001001>] ? start_thread_common.constprop.6+0x1/0xa0
      Code: 04 00 00 00 89 04 24 31 c0 e8 c4 77 04 00 e9 43 fe ff ff 66 25 00 d0 66 3d 00 80 0f 84 0e fe ff ff 83 7b 48 00 0f 84 04 fe ff ff <0f> 0b 49 8b 8c 24 50 07 00 00 e9 88 fe ff ff 0f 1f 84 00 00 00
      
      Here we couldn't call clear_nlink() directly because in d_tmpfile() we
      will call inode_dec_link_count() to decrease ->i_nlink.  So this commit
      tries to call d_tmpfile() before ext4_orphan_add() to fix this problem.
      Reported-by: default avatarDave Jones <davej@redhat.com>
      Signed-off-by: default avatarZheng Liu <wenqing.lz@taobao.com>
      Tested-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Tested-by: default avatarDave Jones <davej@redhat.com>
      Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      Acked-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      e94bd349
  4. 20 Jul, 2013 7 commits
    • Linus Torvalds's avatar
      Merge tag 'staging-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging · f6a0d9d5
      Linus Torvalds authored
      Pull staging tree fixes from Greg KH:
       "Here are a few iio driver fixes for 3.11-rc2.  They are still spread
        across drivers/iio and drivers/staging/iio so they are coming in
        through this tree.
      
        I've also removed the drivers/staging/csr/ driver as the developers
        who originally sent it to me have moved on to other companies, and CSR
        still will not send us the specs for the device, making the driver
        pretty much obsolete and impossible to fix up.  Deleting it now
        prevents people from sending in lots of tiny codingsyle fixes that
        will never go anywhere.
      
        It also helps to offset the large lustre filesystem merge that
        happened in 3.11-rc1 in the overall 3.11.0 diffstat.  :)"
      
      * tag 'staging-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
        staging: csr: remove driver
        iio: lps331ap: Fix wrong in_pressure_scale output value
        iio staging: fix lis3l02dq, read error handling
        staging:iio:ad7291: add missing .driver_module to struct iio_info
        iio: ti_am335x_adc: add missing .driver_module to struct iio_info
        iio: mxs-lradc: Remove useless check in read_raw
        iio: mxs-lradc: Fix misuse of iio->trig
        iio: inkern: fix iio_convert_raw_to_processed_unlocked
        iio: Fix iio_channel_has_info
        iio:trigger: device_unregister->device_del to avoid double free
        iio: dac: ad7303: fix error return code in ad7303_probe()
      f6a0d9d5
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · 36231d25
      Linus Torvalds authored
      Pull vfs fixes from Al Viro:
       "The sget() one is a long-standing bug and will need to go into -stable
        (in fact, it had been originally caught in RHEL6), the other two are
        3.11-only"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
        vfs: constify dentry parameter in d_count()
        livelock avoidance in sget()
        allow O_TMPFILE to work with O_WRONLY
      36231d25
    • Linus Torvalds's avatar
      Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 19bf1c2c
      Linus Torvalds authored
      Pull ext4 bugfixes from Ted Ts'o:
       "Fixes for 3.11-rc2, sent at 5pm, in the professoinal style.  :-)"
      
      I'm not sure I like this new level of "professionalism".
      9-5, people, 9-5.
      
      * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
        ext4: call ext4_es_lru_add() after handling cache miss
        ext4: yield during large unlinks
        ext4: make the extent_status code more robust against ENOMEM failures
        ext4: simplify calculation of blocks to free on error
        ext4: fix error handling in ext4_ext_truncate()
      19bf1c2c
    • Linus Torvalds's avatar
      Merge tag 'nfs-for-3.11-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs · 3be542d4
      Linus Torvalds authored
      Pull NFS client bugfixes from Trond Myklebust:
       - Fix a regression against NFSv4 FreeBSD servers when creating a new
         file
       - Fix another regression in rpc_client_register()
      
      * tag 'nfs-for-3.11-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
        NFSv4: Fix a regression against the FreeBSD server
        SUNRPC: Fix another issue with rpc_client_register()
      3be542d4
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-next · 90290c4e
      Linus Torvalds authored
      Pull btrfs fixes from Josef Bacik:
       "I'm playing the role of Chris Mason this week while he's on vacation.
        There are a few critical fixes for btrfs here, all regressions and
        have been tested well"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-next:
        Btrfs: fix wrong write offset when replacing a device
        Btrfs: re-add root to dead root list if we stop dropping it
        Btrfs: fix lock leak when resuming snapshot deletion
        Btrfs: update drop progress before stopping snapshot dropping
      90290c4e
    • Peng Tao's avatar
      vfs: constify dentry parameter in d_count() · 24924a20
      Peng Tao authored
      so that it can be used in places like d_compare/d_hash
      without causing a compiler warning.
      Signed-off-by: default avatarPeng Tao <tao.peng@emc.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      24924a20
    • Al Viro's avatar
      livelock avoidance in sget() · acfec9a5
      Al Viro authored
      Eric Sandeen has found a nasty livelock in sget() - take a mount(2) about
      to fail.  The superblock is on ->fs_supers, ->s_umount is held exclusive,
      ->s_active is 1.  Along comes two more processes, trying to mount the same
      thing; sget() in each is picking that superblock, bumping ->s_count and
      trying to grab ->s_umount.  ->s_active is 3 now.  Original mount(2)
      finally gets to deactivate_locked_super() on failure; ->s_active is 2,
      superblock is still ->fs_supers because shutdown will *not* happen until
      ->s_active hits 0.  ->s_umount is dropped and now we have two processes
      chasing each other:
      s_active = 2, A acquired ->s_umount, B blocked
      A sees that the damn thing is stillborn, does deactivate_locked_super()
      s_active = 1, A drops ->s_umount, B gets it
      A restarts the search and finds the same superblock.  And bumps it ->s_active.
      s_active = 2, B holds ->s_umount, A blocked on trying to get it
      ... and we are in the earlier situation with A and B switched places.
      
      The root cause, of course, is that ->s_active should not grow until we'd
      got MS_BORN.  Then failing ->mount() will have deactivate_locked_super()
      shut the damn thing down.  Fortunately, it's easy to do - the key point
      is that grab_super() is called only for superblocks currently on ->fs_supers,
      so it can bump ->s_count and grab ->s_umount first, then check MS_BORN and
      bump ->s_active; we must never increment ->s_count for superblocks past
      ->kill_sb(), but grab_super() is never called for those.
      
      The bug is pretty old; we would've caught it by now, if not for accidental
      exclusion between sget() for block filesystems; the things like cgroup or
      e.g. mtd-based filesystems don't have anything of that sort, so they get
      bitten.  The right way to deal with that is obviously to fix sget()...
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      acfec9a5
  5. 19 Jul, 2013 19 commits