1. 22 Oct, 2012 5 commits
    • Jiri Slaby's avatar
      TTY: devpts, do not set driver_data · f11afb61
      Jiri Slaby authored
      The goal is to stop setting and using tty->driver_data in devpts code.
      It should be used solely by the driver's code, pty in this case.
      
      Now driver_data are managed only in the pty driver. devpts_pty_new is
      switched to accept what we used to dig out of tty_struct, i.e. device
      node number and index.
      
      This also removes a note about driver_data being set outside of the
      driver.
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Acked-by: default avatarAlan Cox <alan@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f11afb61
    • Jiri Slaby's avatar
      TTY: devpts, return created inode from devpts_pty_new · 162b97cf
      Jiri Slaby authored
      The goal is to stop setting and using tty->driver_data in devpts code.
      It should be used solely by the driver's code, pty in this case.
      
      For the cleanup of layering, we will need the inode created in
      devpts_pty_new to be stored into slave's driver_data. So we convert
      devpts_pty_new to return the inode or an ERR_PTR-encoded error in case
      of failure.
      
      The move of 'inode = new_inode(sb);' from declarators to the code is
      only cosmetical, but it makes the code easier to read.
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Acked-by: default avatarAlan Cox <alan@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      162b97cf
    • Jiri Slaby's avatar
      TTY: devpts, don't care about TTY in devpts_get_tty · 8fcbaa2b
      Jiri Slaby authored
      The goal is to stop setting and using tty->driver_data in devpts code.
      It should be used solely by the driver's code, pty in this case.
      
      First, here we remove TTY from devpts_get_tty and rename it to
      devpts_get_priv. Note we do not remove type safety, we just shift the
      [implicit] (void *) cast one layer up.
      
      index was unused in devpts_get_tty, so remove that from the prototype
      too.
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Acked-by: default avatarAlan Cox <alan@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8fcbaa2b
    • Ivo Sieben's avatar
      tty: prevent unnecessary work queue lock checking on flip buffer copy · cee4ad1e
      Ivo Sieben authored
      When low_latency flag is set the TTY receive flip buffer is copied to the
      line discipline directly instead of using a work queue in the background.
      Therefor only in case a workqueue is actually used for copying data to the
      line discipline we'll have to flush the workqueue.
      
      This prevents unnecessary spin lock/unlock on the workqueue spin lock that
      can cause additional scheduling overhead on a PREEMPT_RT system. On a 200
      MHz AT91SAM9261 processor setup this fixes about 100us of scheduling
      overhead on the TTY read call.
      Signed-off-by: default avatarIvo Sieben <meltedpianoman@gmail.com>
      Acked-by: default avatarAlan Cox <alan@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cee4ad1e
    • Daniel Vetter's avatar
      console: implement lockdep support for console_lock · daee7797
      Daniel Vetter authored
      Dave Airlie recently discovered a locking bug in the fbcon layer,
      where a timer_del_sync (for the blinking cursor) deadlocks with the
      timer itself, since both (want to) hold the console_lock:
      
      https://lkml.org/lkml/2012/8/21/36
      
      Unfortunately the console_lock isn't a plain mutex and hence has no
      lockdep support. Which resulted in a few days wasted of tracking down
      this bug (complicated by the fact that printk doesn't show anything
      when the console is locked) instead of noticing the bug much earlier
      with the lockdep splat.
      
      Hence I've figured I need to fix that for the next deadlock involving
      console_lock - and with kms/drm growing ever more complex locking
      that'll eventually happen.
      
      Now the console_lock has rather funky semantics, so after a quick irc
      discussion with Thomas Gleixner and Dave Airlie I've quickly ditched
      the original idead of switching to a real mutex (since it won't work)
      and instead opted to annotate the console_lock with lockdep
      information manually.
      
      There are a few special cases:
      - The console_lock state is protected by the console_sem, and usually
        grabbed/dropped at _lock/_unlock time. But the suspend/resume code
        drops the semaphore without dropping the console_lock (see
        suspend_console/resume_console). But since the same thread that did
        the suspend will do the resume, we don't need to fix up anything.
      
      - In the printk code there's a special trylock, only used to kick off
        the logbuffer printk'ing in console_unlock. But all that happens
        while lockdep is disable (since printk does a few other evil
        tricks). So no issue there, either.
      
      - The console_lock can also be acquired form irq context (but only
        with a trylock). lockdep already handles that.
      
      This all leaves us with annotating the normal console_lock, _unlock
      and _trylock functions.
      
      And yes, it works - simply unloading a drm kms driver resulted in
      lockdep complaining about the deadlock in fbcon_deinit:
      
      ======================================================
      [ INFO: possible circular locking dependency detected ]
      3.6.0-rc2+ #552 Not tainted
      -------------------------------------------------------
      kms-reload/3577 is trying to acquire lock:
       ((&info->queue)){+.+...}, at: [<ffffffff81058c70>] wait_on_work+0x0/0xa7
      
      but task is already holding lock:
       (console_lock){+.+.+.}, at: [<ffffffff81264686>] bind_con_driver+0x38/0x263
      
      which lock already depends on the new lock.
      
      the existing dependency chain (in reverse order) is:
      
      -> #1 (console_lock){+.+.+.}:
             [<ffffffff81087440>] lock_acquire+0x95/0x105
             [<ffffffff81040190>] console_lock+0x59/0x5b
             [<ffffffff81209cb6>] fb_flashcursor+0x2e/0x12c
             [<ffffffff81057c3e>] process_one_work+0x1d9/0x3b4
             [<ffffffff810584a2>] worker_thread+0x1a7/0x24b
             [<ffffffff8105ca29>] kthread+0x7f/0x87
             [<ffffffff813b1204>] kernel_thread_helper+0x4/0x10
      
      -> #0 ((&info->queue)){+.+...}:
             [<ffffffff81086cb3>] __lock_acquire+0x999/0xcf6
             [<ffffffff81087440>] lock_acquire+0x95/0x105
             [<ffffffff81058cab>] wait_on_work+0x3b/0xa7
             [<ffffffff81058dd6>] __cancel_work_timer+0xbf/0x102
             [<ffffffff81058e33>] cancel_work_sync+0xb/0xd
             [<ffffffff8120a3b3>] fbcon_deinit+0x11c/0x1dc
             [<ffffffff81264793>] bind_con_driver+0x145/0x263
             [<ffffffff81264a45>] unbind_con_driver+0x14f/0x195
             [<ffffffff8126540c>] store_bind+0x1ad/0x1c1
             [<ffffffff8127cbb7>] dev_attr_store+0x13/0x1f
             [<ffffffff8116d884>] sysfs_write_file+0xe9/0x121
             [<ffffffff811145b2>] vfs_write+0x9b/0xfd
             [<ffffffff811147b7>] sys_write+0x3e/0x6b
             [<ffffffff813b0039>] system_call_fastpath+0x16/0x1b
      
      other info that might help us debug this:
      
       Possible unsafe locking scenario:
      
             CPU0                    CPU1
             ----                    ----
        lock(console_lock);
                                     lock((&info->queue));
                                     lock(console_lock);
        lock((&info->queue));
      
       *** DEADLOCK ***
      
      v2: Mark the lockdep_map static, noticed by Jani Nikula.
      
      Cc: Dave Airlie <airlied@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      daee7797
  2. 20 Oct, 2012 9 commits
    • Linus Torvalds's avatar
      Linux 3.7-rc2 · 6f0c0580
      Linus Torvalds authored
      6f0c0580
    • Linus Torvalds's avatar
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64 · 198190a1
      Linus Torvalds authored
      Pull arm64 fixes from Catalin Marinas:
       "Main changes:
         - AArch64 Linux compilation fixes following 3.7-rc1 changes
           (MODULES_USE_ELF_RELA, update_vsyscall() prototype)
         - Unnecessary register setting in start_thread() (thanks to Al Viro)
         - ptrace fixes"
      
      * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
        arm64: fix alignment padding in assembly code
        arm64: ptrace: use HW_BREAKPOINT_EMPTY type for disabled breakpoints
        arm64: ptrace: make structure padding explicit for debug registers
        arm64: No need to set the x0-x2 registers in start_thread()
        arm64: Ignore memory blocks below PHYS_OFFSET
        arm64: Fix the update_vsyscall() prototype
        arm64: Select MODULES_USE_ELF_RELA
        arm64: Remove duplicate inclusion of mmu_context.h in smp.c
      198190a1
    • Marc Zyngier's avatar
      arm64: fix alignment padding in assembly code · aeed41a9
      Marc Zyngier authored
      An interesting effect of using the generic version of linkage.h
      is that the padding is defined in terms of x86 NOPs, which can have
      even more interesting effects when the assembly code looks like this:
      
      ENTRY(func1)
      	mov	x0, xzr
      ENDPROC(func1)
      	// fall through
      ENTRY(func2)
      	mov	x0, #1
      	ret
      ENDPROC(func2)
      
      Admittedly, the code is not very nice. But having code from another
      architecture doesn't look completely sane either.
      
      The fix is to add arm64's version of linkage.h, which causes the insertion
      of proper AArch64 NOPs.
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      aeed41a9
    • Kees Cook's avatar
      use clamp_t in UNAME26 fix · 31fd84b9
      Kees Cook authored
      The min/max call needed to have explicit types on some architectures
      (e.g. mn10300). Use clamp_t instead to avoid the warning:
      
        kernel/sys.c: In function 'override_release':
        kernel/sys.c:1287:10: warning: comparison of distinct pointer types lacks a cast [enabled by default]
      Reported-by: default avatarFengguang Wu <fengguang.wu@intel.com>
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      31fd84b9
    • Linus Torvalds's avatar
      Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 8c1bee68
      Linus Torvalds authored
      Pull perf fixes from Ingo Molnar:
       "Assorted small fixes"
      
      * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        perf python: Properly link with libtraceevent
        perf hists browser: Add back callchain folding symbol
        perf tools: Fix build on sparc.
        perf python: Link with libtraceevent
        perf python: Initialize 'page_size' variable
        tools lib traceevent: Fix missed freeing of subargs in free_arg() in filter
        lib tools traceevent: Add back pevent assignment in __pevent_parse_format()
        perf hists browser: Fix off-by-two bug on the first column
        perf tools: Remove warnings on JIT samples for srcline sort key
        perf tools: Fix segfault when using srcline sort key
        perf: Require exclude_guest to use PEBS - kernel side enforcement
        perf tool: Precise mode requires exclude_guest
      8c1bee68
    • Arnaldo Carvalho de Melo's avatar
      perf python: Properly link with libtraceevent · 45bff41a
      Arnaldo Carvalho de Melo authored
      Namhyung Kim reported that the build fails with:
      
        GEN python/perf.so
        gcc: error: python_ext_build/tmp//../../libtraceevent.a: No such file or directory
        error: command 'gcc' failed with exit status 1
        cp: cannot stat `python_ext_build/lib/perf.so': No such file or directory
        make: *** [python/perf.so] Error 1
      
      We need to propagate the TE_PATH variable to the setup.py file.
      Reported-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Link: http://lkml.kernel.org/n/tip-8umiPbm4sxpknKivbjgykhut@git.kernel.org
      [ Fixed superfluous variable build error. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      45bff41a
    • Ingo Molnar's avatar
      Merge tag 'perf-urgent-for-mingo' of... · a448a031
      Ingo Molnar authored
      Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
      
      Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
      
      * The python binding needs to link with libtraceevent and to initialize
        the 'page_size' variable so that mmaping works again.
      
      * The callchain folding character that appears on the TUI just before
        the overhead had disappeared due to recent changes, add it back.
      
      * Intel PEBS in VT-x context uses the DS address as a guest linear address,
        even though its programmed by the host as a host linear address. This either
        results in guest memory corruption and or the hardware faulting and 'crashing'
        the virtual machine.  Therefore we have to disable PEBS on VT-x enter and
        re-enable on VT-x exit, enforcing a strict exclude_guest.
      
        Kernel side enforcement fix by Peter Zijlstra, tooling side fix by David Ahern.
      
      * Fix build on sparc due to UAPI, fix from David Miller.
      
      * Fixes for the srclike sort key for unresolved symbols and when processing
        samples in JITted code, where we don't have an ELF file, just an special
        symbol table, fixes from Namhyung Kim.
      
      * Fix some leaks in libtraceevent, from Steven Rostedt.
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      a448a031
    • Linus Torvalds's avatar
      Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc · 37820108
      Linus Torvalds authored
      Pull ARM soc fixes from Olof Johansson:
       "A set of fixes and some minor cleanups for -rc2:
      
         - A series from Arnd that fixes warnings in drivers and other code
           included by ARM defconfigs.  Most have been acked by corresponding
           maintainers (and seem quite hard to argue not picking up anyway in
           the few exception cases).
         - A few misc patches from the list for integrator/vt8500/i.MX
         - A batch of fixes to OMAP platforms, fixing:
           - boot problems on beaglebone,
           - regression fixes for local timers
           - clockdomain locking fixes
           - a few boot/sparse warnings
         - For Tegra:
           - Clock rate calculation overflow fix
           - Revert a change that removed timer clocks and a fix for symbol
             name clashes
         - For Renesas:
           - IO accessor / annotation cleanups to remove warnings
         - For Kirkwood/Dove/mvebu:
           - Fixes for device trees for Dove (some minor cleanups, some fixes)
           - Fixes for the mvebu gpio driver
           - Fix build problem for Feroceon due to missing ifdefs
           - Fix lsxl DTS files"
      
      * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
        ARM: kirkwood: fix buttons on lsxl boards
        ARM: kirkwood: fix LEDs names for lsxl boards
        ARM: Kirkwood: fix disabling CACHE_FEROCEON_L2
        gpio: mvebu: Add missing breaks in mvebu_gpio_irq_set_type
        ARM: dove: Add crypto engine to DT
        ARM: dove: Remove watchdog from DT
        ARM: dove: Restructure SoC device tree descriptor
        ARM: dove: Fix clock names of sata and gbe
        ARM: dove: Fix tauros2 device tree init
        ARM: dove: Add pcie clock support
        ARM: OMAP2+: Allow kernel to boot even if GPMC fails to reserve memory
        ARM: OMAP: clockdomain: Fix locking on _clkdm_clk_hwmod_enable / disable
        ARM: s3c: mark s3c2440_clk_add as __init_refok
        spi/s3c64xx: use correct dma_transfer_direction type
        ARM: OMAP4: devices: fixup OMAP4 DMIC platform device error message
        ARM: OMAP2+: clock data: Add dev-id for the omap-gpmc dummy fck
        ARM: OMAP: resolve sparse warning concerning debug_card_init()
        ARM: OMAP4: Fix twd_local_timer_register regression
        ARM: tegra: add tegra_timer clock
        ARM: tegra: rename tegra system timer
        ...
      37820108
    • David Howells's avatar
      MODSIGN: Move the magic string to the end of a module and eliminate the search · caabe240
      David Howells authored
      Emit the magic string that indicates a module has a signature after the
      signature data instead of before it.  This allows module_sig_check() to
      be made simpler and faster by the elimination of the search for the
      magic string.  Instead we just need to do a single memcmp().
      
      This works because at the end of the signature data there is the
      fixed-length signature information block.  This block then falls
      immediately prior to the magic number.
      
      From the contents of the information block, it is trivial to calculate
      the size of the signature data and thus the size of the actual module
      data.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      caabe240
  3. 19 Oct, 2012 26 commits