linux-stable.git/lib, branch v4.14.80

test_bpf: Fix testing with CONFIG_BPF_JIT_ALWAYS_ON=y on other arches

2018-11-04T13:52:43+00:00

[ Upstream commit 52fda36d63bfc8c8e8ae5eda8eb5ac6f52cd67ed ]

Function bpf_fill_maxinsns11 is designed to not be able to be JITed on
x86_64. So, it fails when CONFIG_BPF_JIT_ALWAYS_ON=y, and
commit 09584b406742 ("bpf: fix selftests/bpf test_kmod.sh failure when
CONFIG_BPF_JIT_ALWAYS_ON=y") makes sure that failure is detected on that
case.

However, it does not fail on other architectures, which have a different
JIT compiler design. So, test_bpf has started to fail to load on those.

After this fix, test_bpf loads fine on both x86_64 and ppc64el.

Fixes: 09584b406742 ("bpf: fix selftests/bpf test_kmod.sh failure when CONFIG_BPF_JIT_ALWAYS_ON=y")
Signed-off-by: Thadeu Lima de Souza Cascardo 
Reviewed-by: Yonghong Song 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Sasha Levin

scsi: klist: Make it safe to use klists in atomic context

2018-10-04T00:00:48+00:00

[ Upstream commit 624fa7790f80575a4ec28fbdb2034097dc18d051 ]

In the scsi_transport_srp implementation it cannot be avoided to
iterate over a klist from atomic context when using the legacy block
layer instead of blk-mq. Hence this patch that makes it safe to use
klists in atomic context. This patch avoids that lockdep reports the
following:

WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&(&k->k_lock)->rlock);
                               local_irq_disable();
                               lock(&(&q->__queue_lock)->rlock);
                               lock(&(&k->k_lock)->rlock);
  
    lock(&(&q->__queue_lock)->rlock);

stack backtrace:
Workqueue: kblockd blk_timeout_work
Call Trace:
 dump_stack+0xa4/0xf5
 check_usage+0x6e6/0x700
 __lock_acquire+0x185d/0x1b50
 lock_acquire+0xd2/0x260
 _raw_spin_lock+0x32/0x50
 klist_next+0x47/0x190
 device_for_each_child+0x8e/0x100
 srp_timed_out+0xaf/0x1d0 [scsi_transport_srp]
 scsi_times_out+0xd4/0x410 [scsi_mod]
 blk_rq_timed_out+0x36/0x70
 blk_timeout_work+0x1b5/0x220
 process_one_work+0x4fe/0xad0
 worker_thread+0x63/0x5a0
 kthread+0x1c1/0x1e0
 ret_from_fork+0x24/0x30

See also commit c9ddf73476ff ("scsi: scsi_transport_srp: Fix shost to
rport translation").

Signed-off-by: Bart Van Assche 
Cc: Martin K. Petersen 
Cc: James Bottomley 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rhashtable: add schedule points

2018-09-19T20:43:45+00:00

Rehashing and destroying large hash table takes a lot of time,
and happens in process context. It is safe to add cond_resched()
in rhashtable_rehash_table() and rhashtable_free_and_destroy()

Signed-off-by: Eric Dumazet 
Acked-by: Herbert Xu 
Signed-off-by: David S. Miller 
(cherry picked from commit ae6da1f503abb5a5081f9f6c4a6881de97830f3e)
Signed-off-by: Greg Kroah-Hartman

debugobjects: Make stack check warning more informative

2018-09-15T07:45:35+00:00

commit fc91a3c4c27acdca0bc13af6fbb68c35cfd519f2 upstream.

While debugging an issue debugobject tracking warned about an annotation
issue of an object on stack. It turned out that the issue was due to the
object in concern being on a different stack which was due to another
issue.

Thomas suggested to print the pointers and the location of the stack for
the currently running task. This helped to figure out that the object was
on the wrong stack.

As this is general useful information for debugging similar issues, make
the error message more informative by printing the pointers.

[ tglx: Massaged changelog ]

Signed-off-by: Joel Fernandes (Google) 
Signed-off-by: Thomas Gleixner 
Acked-by: Waiman Long 
Acked-by: Yang Shi 
Cc: kernel-team@android.com
Cc: Arnd Bergmann 
Cc: astrachan@google.com
Link: https://lkml.kernel.org/r/20180723212531.202328-1-joel@joelfernandes.org
Signed-off-by: Greg Kroah-Hartman

printk/nmi: Prevent deadlock when accessing the main log buffer in NMI

2018-09-05T07:26:35+00:00

commit 03fc7f9c99c1e7ae2925d459e8487f1a6f199f79 upstream.

The commit 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI
when logbuf_lock is available") brought back the possible deadlocks
in printk() and NMI.

The check of logbuf_lock is done only in printk_nmi_enter() to prevent
mixed output. But another CPU might take the lock later, enter NMI, and:

      + Both NMIs might be serialized by yet another lock, for example,
	the one in nmi_cpu_backtrace().

      + The other CPU might get stopped in NMI, see smp_send_stop()
	in panic().

The only safe solution is to use trylock when storing the message
into the main log-buffer. It might cause reordering when some lines
go to the main lock buffer directly and others are delayed via
the per-CPU buffer. It means that it is not useful in general.

This patch replaces the problematic NMI deferred context with NMI
direct context. It can be used to mark a code that might produce
many messages in NMI and the risk of losing them is more critical
than problems with eventual reordering.

The context is then used when dumping trace buffers on oops. It was
the primary motivation for the original fix. Also the reordering is
even smaller issue there because some traces have their own time stamps.

Finally, nmi_cpu_backtrace() need not longer be serialized because
it will always us the per-CPU buffers again.

Fixes: 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI when logbuf_lock is available")
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180627142028.11259-1-pmladek@suse.com
To: Steven Rostedt 
Cc: Peter Zijlstra 
Cc: Tetsuo Handa 
Cc: Sergey Senozhatsky 
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Acked-by: Sergey Senozhatsky 
Signed-off-by: Petr Mladek 
Signed-off-by: Greg Kroah-Hartman

ioremap: Update pgtable free interfaces with addr

2018-08-17T19:01:11+00:00

commit 785a19f9d1dd8a4ab2d0633be4656653bd3de1fc upstream.

The following kernel panic was observed on ARM64 platform due to a stale
TLB entry.

 1. ioremap with 4K size, a valid pte page table is set.
 2. iounmap it, its pte entry is set to 0.
 3. ioremap the same address with 2M size, update its pmd entry with
    a new value.
 4. CPU may hit an exception because the old pmd entry is still in TLB,
    which leads to a kernel panic.

Commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page
table") has addressed this panic by falling to pte mappings in the above
case on ARM64.

To support pmd mappings in all cases, TLB purge needs to be performed
in this case on ARM64.

Add a new arg, 'addr', to pud_free_pmd_page() and pmd_free_pte_page()
so that TLB purge can be added later in seprate patches.

[toshi.kani@hpe.com: merge changes, rewrite patch description]
Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Signed-off-by: Chintan Pandya 
Signed-off-by: Toshi Kani 
Signed-off-by: Thomas Gleixner 
Cc: mhocko@suse.com
Cc: akpm@linux-foundation.org
Cc: hpa@zytor.com
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon 
Cc: Joerg Roedel 
Cc: stable@vger.kernel.org
Cc: Andrew Morton 
Cc: Michal Hocko 
Cc: "H. Peter Anvin" 
Cc: 
Link: https://lkml.kernel.org/r/20180627141348.21777-3-toshi.kani@hpe.com
Signed-off-by: Greg Kroah-Hartman

lib/rhashtable: consider param->min_size when setting initial table size

2018-07-25T09:25:09+00:00

[ Upstream commit 107d01f5ba10f4162c38109496607eb197059064 ]

rhashtable_init() currently does not take into account the user-passed
min_size parameter unless param->nelem_hint is set as well. As such,
the default size (number of buckets) will always be HASH_DEFAULT_SIZE
even if the smallest allowed size is larger than that. Remediate this
by unconditionally calling into rounded_hashtable_size() and handling
things accordingly.

Signed-off-by: Davidlohr Bueso 
Acked-by: Herbert Xu 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

lib/vsprintf: Remove atomic-unsafe support for %pCr

2018-07-03T09:24:48+00:00

commit 666902e42fd8344b923c02dc5b0f37948ff4f225 upstream.

"%pCr" formats the current rate of a clock, and calls clk_get_rate().
The latter obtains a mutex, hence it must not be called from atomic
context.

Remove support for this rarely-used format, as vsprintf() (and e.g.
printk()) must be callable from any context.

Any remaining out-of-tree users will start seeing the clock's name
printed instead of its rate.

Reported-by: Jia-Ju Bai 
Fixes: 900cca2944254edd ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks")
Link: http://lkml.kernel.org/r/1527845302-12159-5-git-send-email-geert+renesas@glider.be
To: Jia-Ju Bai 
To: Jonathan Corbet 
To: Michael Turquette 
To: Stephen Boyd 
To: Zhang Rui 
To: Eduardo Valentin 
To: Eric Anholt 
To: Stefan Wahren 
To: Greg Kroah-Hartman 
Cc: Sergey Senozhatsky 
Cc: Petr Mladek 
Cc: Linus Torvalds 
Cc: Steven Rostedt 
Cc: linux-doc@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Geert Uytterhoeven 
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Petr Mladek 
Signed-off-by: Greg Kroah-Hartman

lib/test_kmod.c: fix limit check on number of test devices created

2018-05-30T05:52:14+00:00

[ Upstream commit ac68b1b3b9c73e652dc7ce0585672e23c5a2dca4 ]

As reported by Dan the parentheses is in the wrong place, and since
unlikely() call returns either 0 or 1 it's never less than zero.  The
second issue is that signed integer overflows like "INT_MAX + 1" are
undefined behavior.

Since num_test_devs represents the number of devices, we want to stop
prior to hitting the max, and not rely on the wrap arround at all.  So
just cap at num_test_devs + 1, prior to assigning a new device.

Link: http://lkml.kernel.org/r/20180224030046.24238-1-mcgrof@kernel.org
Fixes: d9c6a72d6fa2 ("kmod: add test driver to stress test the module loader")
Reported-by: Dan Carpenter 
Signed-off-by: Luis R. Rodriguez 
Acked-by: Kees Cook 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

idr: fix invalid ptr dereference on item delete

2018-05-30T05:51:49+00:00

commit 7a4deea1aa8bddfed4ef1b35fc2b6732563d8ad5 upstream.

If the radix tree underlying the IDR happens to be full and we attempt
to remove an id which is larger than any id in the IDR, we will call
__radix_tree_delete() with an uninitialised 'slot' pointer, at which
point anything could happen.  This was easiest to hit with a single
entry at id 0 and attempting to remove a non-0 id, but it could have
happened with 64 entries and attempting to remove an id >= 64.

Roman said:

  The syzcaller test boils down to opening /dev/kvm, creating an
  eventfd, and calling a couple of KVM ioctls. None of this requires
  superuser. And the result is dereferencing an uninitialized pointer
  which is likely a crash. The specific path caught by syzbot is via
  KVM_HYPERV_EVENTD ioctl which is new in 4.17. But I guess there are
  other user-triggerable paths, so cc:stable is probably justified.

Matthew added:

  We have around 250 calls to idr_remove() in the kernel today. Many of
  them pass an ID which is embedded in the object they're removing, so
  they're safe. Picking a few likely candidates:

  drivers/firewire/core-cdev.c looks unsafe; the ID comes from an ioctl.
  drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c is similar
  drivers/atm/nicstar.c could be taken down by a handcrafted packet

Link: http://lkml.kernel.org/r/20180518175025.GD6361@bombadil.infradead.org
Fixes: 0a835c4f090a ("Reimplement IDR and IDA using the radix tree")
Reported-by: 
Debugged-by: Roman Kagan 
Signed-off-by: Matthew Wilcox 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman