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  1. 07 May, 2013 15 commits
  3. 17 Apr, 2013 1 commit
    • Vineet Gupta's avatar
      ARC: [kbuild] Avoid DTB rebuilds if DTS are untouched · a89516b3
      Vineet Gupta authored 
      Currently, for every ARC kernel build I see the following:

--------------->8-----------------
  DTB    arch/arc/boot/dts/angel4.dtb.S
  AS      arch/arc/boot/dts/angel4.dtb.o
  LD      arch/arc/boot/dts/built-in.o
rm arch/arc/boot/dts/angel4.dtb.S        <-- forces rebuild next iter
  CHK     kernel/config_data.h
--------------->8-----------------

This is because *.dts.S is intermediate file in dtb generation and is by
default deleted by make which needs a ".SECONDARY" hint to NOT do so.

This could have ideally been done in scripts/Makefile.lib - for benefit
of all, however .SECONDARY doesn't seem to work with wildcards.

Thanks to Stephen for suggesting .SECONDARY (vs .PRECIOUS) and making
that work using a non wildcard version in arch makefile.

Thanks to James Hogan for pointing out that *.dtb.S now needs to be
added to clean-files
Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
      a89516b3
  5. 09 Apr, 2013 12 commits
  7. 08 Apr, 2013 9 commits
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sfr/next-fixes · f011a08c
      Linus Torvalds authored 
      Pull powerpc bugfix from Stephen Rothwell:
 "A single BUG_ON fix for a condition that could happen for machines
  with certain hardware installed."

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sfr/next-fixes:
  powerpc: pSeries_lpar_hpte_remove fails from Adjunct partition being performed before the ANDCOND test
      f011a08c
    • Christian Ruppert's avatar
      ARC: Add implicit compiler barrier to raw_local_irq* functions · 79e5f05e
      Christian Ruppert authored 
      ARC irqsave/restore macros were missing the compiler barrier, causing a
stale load in irq-enabled region be used in irq-safe region, despite
being changed, because the register holding the value was still live.

The problem manifested as random crashes in timer code when stress
testing ARCLinux (3.9-rc3) on a !SMP && !PREEMPT_COUNT

Here's the exact sequence which caused this:
 (0). tv1[x] <----> t1 <---> t2
 (1). mod_timer(t1) interrupted after it calls timer_pending()
 (2). mod_timer(t2) completes
 (3). mod_timer(t1) resumes but messes up the list
 (4). __runt_timers( ) uses bogus timer_list entry / crashes in
      timer->function

Essentially mod_timer() was racing against itself and while the spinlock
serialized the tv1[] timer link list, timer_pending() called outside the
spinlock, cached timer link list element in a register.
With low register pressure (and a deep register file), lack of barrier
in raw_local_irqsave() as well as preempt_disable (!PREEMPT_COUNT
version), there was nothing to force gcc to reload across the spinlock,
causing a stale value in reg be used for link list manipulation - ensuing
a corruption.

ARcompact disassembly which shows the culprit generated code:

mod_timer:
    push_s blink
    mov_s r13,r0	# timer, timer
..
    ###### timer_pending( )
    ld_s r3,[r13]       # <------ <variable>.entry.next LOADED
    brne r3, 0, @.L163

.L163:
..
    ###### spin_lock_irq( )
    lr  r5, [status32]  # flags
    bic r4, r5, 6       # temp, flags,
    and.f 0, r5, 6      # flags,
    flag.nz r4

    ###### detach_if_pending( ) begins

    tst_s r3,r3  <--------------
			# timer_pending( ) checks timer->entry.next
                        # r3 is NOT reloaded by gcc, using stale value
    beq.d @.L169
    mov.eq r0,0

    #####  detach_timer( ): __list_del( )

    ld r4,[r13,4]    	# <variable>.entry.prev, D.31439
    st r4,[r3,4]     	# <variable>.prev, D.31439
    st r3,[r4]       	# <variable>.next, D.30246

We initially tried to fix this by adding barrier() to preempt_* macros
for !PREEMPT_COUNT but Linus clarified that it was anything but wrong.
http://www.spinics.net/lists/kernel/msg1512709.html

[vgupta: updated commitlog]

Reported-by/Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Debugged-by/Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      79e5f05e
    • Linus Torvalds's avatar
      Merge tag 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev · f465d40d
      Linus Torvalds authored 
      Pull libata fixes from Jeff Garzik:
 "The HDIO_DRIVE_* fix is really the biggie.

  1) Fix ATAPI regression, noticed mainly on tape drives, due to a
     commit which mistakenly changed an 'int' return type to a 'bool'.
     Broken by commit 4dce8ba9 ("libata: Use 'bool' return value for
     ata_id_XXX")

  2) Add Slimtype DVD A DS8A8SH ATAPI quirk

  3) ata_piix: Intel Haswell platform quirk

  4) Avoid DMA'ing to stack buffer, when obtaining DEVSLP timings.  IMO
     a mild regression, given that libata previously did not DMA to a
     stack buffer.  Broken by commit commit 803739d2 ("[libata]
     replace sata_settings with devslp_timing")

  5) Fix regression impacting SMART and smartd, broken by commit
     84a9a8cd ("[libata] Set proper SK when CK_COND is set")"

* tag 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [libata] Fix HDIO_DRIVE_* ioctl() Linux 3.9 regression
  libata: fix DMA to stack in reading devslp_timing parameters
  ata_piix: Fix DVD not dectected at some Haswell platforms
  libata: Set max sector to 65535 for Slimtype DVD A DS8A8SH drive
  libata: Use integer return value for atapi_command_packet_set
      f465d40d
    • Linus Torvalds's avatar
      Merge tag 'trace-fixes-3.9-rc6' of... · 5f2f280f
      Linus Torvalds authored 
      Merge tag 'trace-fixes-3.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "This includes three fixes.  Two fix features added in 3.9 and one
  fixes a long time minor bug.

  The first patch fixes a race that can happen if the user switches from
  the irqsoff tracer to another tracer.  If a irqs off latency is
  detected, it will try to use the snapshot buffer, but the new tracer
  wont have it allocated.  There's a nasty warning that gets printed and
  the trace is ignored.  Nothing crashes, just a nasty WARN_ON is shown.

  The second patch fixes an issue where if the sysctl is used to disable
  and enable function tracing, it can put the function tracing into an
  unstable state.

  The third patch fixes an issue with perf using the function tracer.
  An update was done, where the stub function could be called during the
  perf function tracing, and that stub function wont have the "control"
  flag set and cause a nasty warning when running perf."

* tag 'trace-fixes-3.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Do not call stub functions in control loop
  ftrace: Consistently restore trace function on sysctl enabling
  tracing: Fix race with update_max_tr_single and changing tracers
      5f2f280f
    • Steven Rostedt (Red Hat)'s avatar
      ftrace: Do not call stub functions in control loop · 395b97a3
      Steven Rostedt (Red Hat) authored 
      The function tracing control loop used by perf spits out a warning
if the called function is not a control function. This is because
the control function references a per cpu allocated data structure
on struct ftrace_ops that is not allocated for other types of
functions.

commit 0a016409 "ftrace: Optimize the function tracer list loop"

Had an optimization done to all function tracing loops to optimize
for a single registered ops. Unfortunately, this allows for a slight
race when tracing starts or ends, where the stub function might be
called after the current registered ops is removed. In this case we
get the following dump:

root# perf stat -e ftrace:function sleep 1
[   74.339105] WARNING: at include/linux/ftrace.h:209 ftrace_ops_control_func+0xde/0xf0()
[   74.349522] Hardware name: PRIMERGY RX200 S6
[   74.357149] Modules linked in: sg igb iTCO_wdt ptp pps_core iTCO_vendor_support i7core_edac dca lpc_ich i2c_i801 coretemp edac_core crc32c_intel mfd_core ghash_clmulni_intel dm_multipath acpi_power_meter pcspk
r microcode vhost_net tun macvtap macvlan nfsd kvm_intel kvm auth_rpcgss nfs_acl lockd sunrpc uinput xfs libcrc32c sd_mod crc_t10dif sr_mod cdrom mgag200 i2c_algo_bit drm_kms_helper ttm qla2xxx mptsas ahci drm li
bahci scsi_transport_sas mptscsih libata scsi_transport_fc i2c_core mptbase scsi_tgt dm_mirror dm_region_hash dm_log dm_mod
[   74.446233] Pid: 1377, comm: perf Tainted: G        W    3.9.0-rc1 #1
[   74.453458] Call Trace:
[   74.456233]  [<ffffffff81062e3f>] warn_slowpath_common+0x7f/0xc0
[   74.462997]  [<ffffffff810fbc60>] ? rcu_note_context_switch+0xa0/0xa0
[   74.470272]  [<ffffffff811041a2>] ? __unregister_ftrace_function+0xa2/0x1a0
[   74.478117]  [<ffffffff81062e9a>] warn_slowpath_null+0x1a/0x20
[   74.484681]  [<ffffffff81102ede>] ftrace_ops_control_func+0xde/0xf0
[   74.491760]  [<ffffffff8162f400>] ftrace_call+0x5/0x2f
[   74.497511]  [<ffffffff8162f400>] ? ftrace_call+0x5/0x2f
[   74.503486]  [<ffffffff8162f400>] ? ftrace_call+0x5/0x2f
[   74.509500]  [<ffffffff810fbc65>] ? synchronize_sched+0x5/0x50
[   74.516088]  [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[   74.522268]  [<ffffffff810fbc65>] ? synchronize_sched+0x5/0x50
[   74.528837]  [<ffffffff811041a2>] ? __unregister_ftrace_function+0xa2/0x1a0
[   74.536696]  [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[   74.542878]  [<ffffffff8162402d>] ? mutex_lock+0x1d/0x50
[   74.548869]  [<ffffffff81105c67>] unregister_ftrace_function+0x27/0x50
[   74.556243]  [<ffffffff8111eadf>] perf_ftrace_event_register+0x9f/0x140
[   74.563709]  [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[   74.569887]  [<ffffffff8162402d>] ? mutex_lock+0x1d/0x50
[   74.575898]  [<ffffffff8111e94e>] perf_trace_destroy+0x2e/0x50
[   74.582505]  [<ffffffff81127ba9>] tp_perf_event_destroy+0x9/0x10
[   74.589298]  [<ffffffff811295d0>] free_event+0x70/0x1a0
[   74.595208]  [<ffffffff8112a579>] perf_event_release_kernel+0x69/0xa0
[   74.602460]  [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[   74.608667]  [<ffffffff8112a640>] put_event+0x90/0xc0
[   74.614373]  [<ffffffff8112a740>] perf_release+0x10/0x20
[   74.620367]  [<ffffffff811a3044>] __fput+0xf4/0x280
[   74.625894]  [<ffffffff811a31de>] ____fput+0xe/0x10
[   74.631387]  [<ffffffff81083697>] task_work_run+0xa7/0xe0
[   74.637452]  [<ffffffff81014981>] do_notify_resume+0x71/0xb0
[   74.643843]  [<ffffffff8162fa92>] int_signal+0x12/0x17

To fix this a new ftrace_ops flag is added that denotes the ftrace_list_end
ftrace_ops stub as just that, a stub. This flag is now checked in the
control loop and the function is not called if the flag is set.

Thanks to Jovi for not just reporting the bug, but also pointing out
where the bug was in the code.

Link: http://lkml.kernel.org/r/514A8855.7090402@redhat.com
Link: http://lkml.kernel.org/r/1364377499-1900-15-git-send-email-jovi.zhangwei@huawei.comTested-by: default avatarWANG Chao <chaowang@redhat.com>
Reported-by: default avatarWANG Chao <chaowang@redhat.com>
Reported-by: default avatarzhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      395b97a3
    • Jan Kiszka's avatar
      ftrace: Consistently restore trace function on sysctl enabling · 5000c418
      Jan Kiszka authored 
      If we reenable ftrace via syctl, we currently set ftrace_trace_function
based on the previous simplistic algorithm. This is inconsistent with
what update_ftrace_function does. So better call that helper instead.

Link: http://lkml.kernel.org/r/5151D26F.1070702@siemens.com

Cc: stable@vger.kernel.org
Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      5000c418
    • Steven Rostedt (Red Hat)'s avatar
      tracing: Fix race with update_max_tr_single and changing tracers · 2930e04d
      Steven Rostedt (Red Hat) authored 
      The commit 34600f0e "tracing: Fix race with max_tr and changing tracers"
fixed the updating of the main buffers with the race of changing
tracers, but left out the fix to the updating of just a per cpu buffer.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      2930e04d
    • Michael Wolf's avatar
      powerpc: pSeries_lpar_hpte_remove fails from Adjunct partition being performed... · 9fb26401
      Michael Wolf authored 
      powerpc: pSeries_lpar_hpte_remove fails from Adjunct partition being performed before the ANDCOND test

Some versions of pHyp will perform the adjunct partition test before the
ANDCOND test.  The result of this is that H_RESOURCE can be returned and
cause the BUG_ON condition to occur. The HPTE is not removed.  So add a
check for H_RESOURCE, it is ok if this HPTE is not removed as
pSeries_lpar_hpte_remove is looking for an HPTE to remove and not a
specific HPTE to remove.  So it is ok to just move on to the next slot
and try again.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarMichael Wolf <mjw@linux.vnet.ibm.com>
Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
      9fb26401
    • Linus Torvalds's avatar
      Linux 3.9-rc6 · 31880c37
      Linus Torvalds authored
      31880c37
  9. 07 Apr, 2013 3 commits
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