1. 20 Apr, 2016 4 commits
    • Takashi Iwai's avatar
      ALSA: timer: Use mod_timer() for rearming the system timer · f0c3c0e1
      Takashi Iwai authored
      commit 4a07083e upstream.
      
      ALSA system timer backend stops the timer via del_timer() without sync
      and leaves del_timer_sync() at the close instead.  This is because of
      the restriction by the design of ALSA timer: namely, the stop callback
      may be called from the timer handler, and calling the sync shall lead
      to a hangup.  However, this also triggers a kernel BUG() when the
      timer is rearmed immediately after stopping without sync:
       kernel BUG at kernel/time/timer.c:966!
       Call Trace:
        <IRQ>
        [<ffffffff8239c94e>] snd_timer_s_start+0x13e/0x1a0
        [<ffffffff8239e1f4>] snd_timer_interrupt+0x504/0xec0
        [<ffffffff8122fca0>] ? debug_check_no_locks_freed+0x290/0x290
        [<ffffffff8239ec64>] snd_timer_s_function+0xb4/0x120
        [<ffffffff81296b72>] call_timer_fn+0x162/0x520
        [<ffffffff81296add>] ? call_timer_fn+0xcd/0x520
        [<ffffffff8239ebb0>] ? snd_timer_interrupt+0xec0/0xec0
        ....
      
      It's the place where add_timer() checks the pending timer.  It's clear
      that this may happen after the immediate restart without sync in our
      cases.
      
      So, the workaround here is just to use mod_timer() instead of
      add_timer().  This looks like a band-aid fix, but it's a right move,
      as snd_timer_interrupt() takes care of the continuous rearm of timer.
      Reported-by: default avatarJiri Slaby <jslaby@suse.cz>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f0c3c0e1
    • Helge Deller's avatar
      parisc: Fix kernel crash with reversed copy_from_user() · 7b5b3bf5
      Helge Deller authored
      commit ef72f311 upstream.
      
      The kernel module testcase (lib/test_user_copy.c) exhibited a kernel
      crash on parisc if the parameters for copy_from_user were reversed
      ("illegal reversed copy_to_user" testcase).
      
      Fix this potential crash by checking the fault handler if the faulting
      address is in the exception table.
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Cc: Kees Cook <keescook@chromium.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7b5b3bf5
    • Helge Deller's avatar
      parisc: Avoid function pointers for kernel exception routines · e2e26bf7
      Helge Deller authored
      commit e3893027 upstream.
      
      We want to avoid the kernel module loader to create function pointers
      for the kernel fixup routines of get_user() and put_user(). Changing
      the external reference from function type to int type fixes this.
      
      This unbreaks exception handling for get_user() and put_user() when
      called from a kernel module.
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e2e26bf7
    • Guenter Roeck's avatar
      hwmon: (max1111) Return -ENODEV from max1111_read_channel if not instantiated · a0132681
      Guenter Roeck authored
      commit 3c2e2266 upstream.
      
      arm:pxa_defconfig can result in the following crash if the max1111 driver
      is not instantiated.
      
      Unhandled fault: page domain fault (0x01b) at 0x00000000
      pgd = c0004000
      [00000000] *pgd=00000000
      Internal error: : 1b [#1] PREEMPT ARM
      Modules linked in:
      CPU: 0 PID: 300 Comm: kworker/0:1 Not tainted 4.5.0-01301-g1701f680 #10
      Hardware name: SHARP Akita
      Workqueue: events sharpsl_charge_toggle
      task: c390a000 ti: c391e000 task.ti: c391e000
      PC is at max1111_read_channel+0x20/0x30
      LR is at sharpsl_pm_pxa_read_max1111+0x2c/0x3c
      pc : [<c03aaab0>]    lr : [<c0024b50>]    psr: 20000013
      ...
      [<c03aaab0>] (max1111_read_channel) from [<c0024b50>]
      					(sharpsl_pm_pxa_read_max1111+0x2c/0x3c)
      [<c0024b50>] (sharpsl_pm_pxa_read_max1111) from [<c00262e0>]
      					(spitzpm_read_devdata+0x5c/0xc4)
      [<c00262e0>] (spitzpm_read_devdata) from [<c0024094>]
      					(sharpsl_check_battery_temp+0x78/0x110)
      [<c0024094>] (sharpsl_check_battery_temp) from [<c0024f9c>]
      					(sharpsl_charge_toggle+0x48/0x110)
      [<c0024f9c>] (sharpsl_charge_toggle) from [<c004429c>]
      					(process_one_work+0x14c/0x48c)
      [<c004429c>] (process_one_work) from [<c0044618>] (worker_thread+0x3c/0x5d4)
      [<c0044618>] (worker_thread) from [<c004a238>] (kthread+0xd0/0xec)
      [<c004a238>] (kthread) from [<c000a670>] (ret_from_fork+0x14/0x24)
      
      This can occur because the SPI controller driver (SPI_PXA2XX) is built as
      module and thus not necessarily loaded. While building SPI_PXA2XX into the
      kernel would make the problem disappear, it appears prudent to ensure that
      the driver is instantiated before accessing its data structures.
      
      Cc: Arnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a0132681
  2. 12 Apr, 2016 36 commits