Commit graph

27840 commits

Author SHA1 Message Date
Linus Torvalds 864af0d40c Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "11 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kvm, mm: account shadow page tables to kmemcg
  zswap: re-check zswap_is_full() after do zswap_shrink()
  include/linux/eventfd.h: include linux/errno.h
  mm: fix vma_is_anonymous() false-positives
  mm: use vma_init() to initialize VMAs on stack and data segments
  mm: introduce vma_init()
  mm: fix exports that inadvertently make put_page() EXPORT_SYMBOL_GPL
  ipc/sem.c: prevent queue.status tearing in semop
  mm: disallow mappings that conflict for devm_memremap_pages()
  kasan: only select SLUB_DEBUG with SYSFS=y
  delayacct: fix crash in delayacct_blkio_end() after delayacct init failure
2018-07-27 10:30:47 -07:00
Linus Torvalds 3ebb6fb03d Various fixes to the tracing infrastructure:
- Fix double free when the reg() call fails in event_trigger_callback()
 
  - Fix anomoly of snapshot causing tracing_on flag to change
 
  - Add selftest to test snapshot and tracing_on affecting each other
 
  - Fix setting of tracepoint flag on error that prevents probes from
    being deleted.
 
  - Fix another possible double free that is similar to event_trigger_callback()
 
  - Quiet a gcc warning of a false positive unused variable
 
  - Fix crash of partial exposed task->comm to trace events
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCW1pToBQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qijEAQCzqQsnlO6YBCYajRBq2wFaM7J6tVnJ
 LxLZlVE8lJlHZQD/YpyGOPq98CB81BfQV7RA/CAVd4RZAhTjldDgGyfL/QI=
 =wU8I
 -----END PGP SIGNATURE-----

Merge tag 'trace-v4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Various fixes to the tracing infrastructure:

   - Fix double free when the reg() call fails in
     event_trigger_callback()

   - Fix anomoly of snapshot causing tracing_on flag to change

   - Add selftest to test snapshot and tracing_on affecting each other

   - Fix setting of tracepoint flag on error that prevents probes from
     being deleted.

   - Fix another possible double free that is similar to
     event_trigger_callback()

   - Quiet a gcc warning of a false positive unused variable

   - Fix crash of partial exposed task->comm to trace events"

* tag 'trace-v4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  kthread, tracing: Don't expose half-written comm when creating kthreads
  tracing: Quiet gcc warning about maybe unused link variable
  tracing: Fix possible double free in event_enable_trigger_func()
  tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure
  selftests/ftrace: Add snapshot and tracing_on test case
  ring_buffer: tracing: Inherit the tracing setting to next ring buffer
  tracing: Fix double free of event_trigger_data
2018-07-27 09:50:33 -07:00
Kirill A. Shutemov 027232da7c mm: introduce vma_init()
Not all VMAs allocated with vm_area_alloc().  Some of them allocated on
stack or in data segment.

The new helper can be use to initialize VMA properly regardless where it
was allocated.

Link: http://lkml.kernel.org/r/20180724121139.62570-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Dan Williams 31c5bda3a6 mm: fix exports that inadvertently make put_page() EXPORT_SYMBOL_GPL
Commit e763848843 ("mm: introduce MEMORY_DEVICE_FS_DAX and
CONFIG_DEV_PAGEMAP_OPS") added two EXPORT_SYMBOL_GPL() symbols, but
these symbols are required by the inlined put_page(), thus accidentally
making put_page() a GPL export only.  This breaks OpenAFS (at least).

Mark them EXPORT_SYMBOL() instead.

Link: http://lkml.kernel.org/r/153128611970.2928.11310692420711601254.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: e763848843 ("mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Joe Gorse <jhgorse@gmail.com>
Reported-by: John Hubbard <jhubbard@nvidia.com>
Tested-by: Joe Gorse <jhgorse@gmail.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Mark Vitale <mvitale@sinenomine.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Dave Jiang 15d36fecd0 mm: disallow mappings that conflict for devm_memremap_pages()
When pmem namespaces created are smaller than section size, this can
cause an issue during removal and gpf was observed:

  general protection fault: 0000 1 SMP PTI
  CPU: 36 PID: 3941 Comm: ndctl Tainted: G W 4.14.28-1.el7uek.x86_64 #2
  task: ffff88acda150000 task.stack: ffffc900233a4000
  RIP: 0010:__put_page+0x56/0x79
  Call Trace:
    devm_memremap_pages_release+0x155/0x23a
    release_nodes+0x21e/0x260
    devres_release_all+0x3c/0x48
    device_release_driver_internal+0x15c/0x207
    device_release_driver+0x12/0x14
    unbind_store+0xba/0xd8
    drv_attr_store+0x27/0x31
    sysfs_kf_write+0x3f/0x46
    kernfs_fop_write+0x10f/0x18b
    __vfs_write+0x3a/0x16d
    vfs_write+0xb2/0x1a1
    SyS_write+0x55/0xb9
    do_syscall_64+0x79/0x1ae
    entry_SYSCALL_64_after_hwframe+0x3d/0x0

Add code to check whether we have a mapping already in the same section
and prevent additional mappings from being created if that is the case.

Link: http://lkml.kernel.org/r/152909478401.50143.312364396244072931.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Snild Dolkow 3e536e222f kthread, tracing: Don't expose half-written comm when creating kthreads
There is a window for racing when printing directly to task->comm,
allowing other threads to see a non-terminated string. The vsnprintf
function fills the buffer, counts the truncated chars, then finally
writes the \0 at the end.

	creator                     other
	vsnprintf:
	  fill (not terminated)
	  count the rest            trace_sched_waking(p):
	  ...                         memcpy(comm, p->comm, TASK_COMM_LEN)
	  write \0

The consequences depend on how 'other' uses the string. In our case,
it was copied into the tracing system's saved cmdlines, a buffer of
adjacent TASK_COMM_LEN-byte buffers (note the 'n' where 0 should be):

	crash-arm64> x/1024s savedcmd->saved_cmdlines | grep 'evenk'
	0xffffffd5b3818640:     "irq/497-pwr_evenkworker/u16:12"

...and a strcpy out of there would cause stack corruption:

	[224761.522292] Kernel panic - not syncing: stack-protector:
	    Kernel stack is corrupted in: ffffff9bf9783c78

	crash-arm64> kbt | grep 'comm\|trace_print_context'
	#6  0xffffff9bf9783c78 in trace_print_context+0x18c(+396)
	      comm (char [16]) =  "irq/497-pwr_even"

	crash-arm64> rd 0xffffffd4d0e17d14 8
	ffffffd4d0e17d14:  2f71726900000000 5f7277702d373934   ....irq/497-pwr_
	ffffffd4d0e17d24:  726f776b6e657665 3a3631752f72656b   evenkworker/u16:
	ffffffd4d0e17d34:  f9780248ff003231 cede60e0ffffff9b   12..H.x......`..
	ffffffd4d0e17d44:  cede60c8ffffffd4 00000fffffffffd4   .....`..........

The workaround in e09e28671 (use strlcpy in __trace_find_cmdline) was
likely needed because of this same bug.

Solved by vsnprintf:ing to a local buffer, then using set_task_comm().
This way, there won't be a window where comm is not terminated.

Link: http://lkml.kernel.org/r/20180726071539.188015-1-snild@sony.com

Cc: stable@vger.kernel.org
Fixes: bc0c38d139 ("ftrace: latency tracer infrastructure")
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Snild Dolkow <snild@sony.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-26 09:59:33 -04:00
Steven Rostedt (VMware) 2519c1bbe3 tracing: Quiet gcc warning about maybe unused link variable
Commit 57ea2a34ad ("tracing/kprobes: Fix trace_probe flags on
enable_trace_kprobe() failure") added an if statement that depends on another
if statement that gcc doesn't see will initialize the "link" variable and
gives the warning:

 "warning: 'link' may be used uninitialized in this function"

It is really a false positive, but to quiet the warning, and also to make
sure that it never actually is used uninitialized, initialize the "link"
variable to NULL and add an if (!WARN_ON_ONCE(!link)) where the compiler
thinks it could be used uninitialized.

Cc: stable@vger.kernel.org
Fixes: 57ea2a34ad ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 22:33:50 -04:00
Steven Rostedt (VMware) 15cc78644d tracing: Fix possible double free in event_enable_trigger_func()
There was a case that triggered a double free in event_trigger_callback()
due to the called reg() function freeing the trigger_data and then it
getting freed again by the error return by the caller. The solution there
was to up the trigger_data ref count.

Code inspection found that event_enable_trigger_func() has the same issue,
but is not as easy to trigger (requires harder to trigger failures). It
needs to be solved slightly different as it needs more to clean up when the
reg() function fails.

Link: http://lkml.kernel.org/r/20180725124008.7008e586@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 7862ad1846 ("tracing: Add 'enable_event' and 'disable_event' event trigger commands")
Reivewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 21:25:16 -04:00
Artem Savkov 57ea2a34ad tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure
If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe
it returns an error, but does not unset the tp flags it set previously.
This results in a probe being considered enabled and failures like being
unable to remove the probe through kprobe_events file since probes_open()
expects every probe to be disabled.

Link: http://lkml.kernel.org/r/20180725102826.8300-1-asavkov@redhat.com
Link: http://lkml.kernel.org/r/20180725142038.4765-1-asavkov@redhat.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 41a7dd420c ("tracing/kprobes: Support ftrace_event_file base multibuffer")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 11:41:08 -04:00
Masami Hiramatsu 73c8d89455 ring_buffer: tracing: Inherit the tracing setting to next ring buffer
Maintain the tracing on/off setting of the ring_buffer when switching
to the trace buffer snapshot.

Taking a snapshot is done by swapping the backup ring buffer
(max_tr_buffer). But since the tracing on/off setting is defined
by the ring buffer, when swapping it, the tracing on/off setting
can also be changed. This causes a strange result like below:

  /sys/kernel/debug/tracing # cat tracing_on
  1
  /sys/kernel/debug/tracing # echo 0 > tracing_on
  /sys/kernel/debug/tracing # cat tracing_on
  0
  /sys/kernel/debug/tracing # echo 1 > snapshot
  /sys/kernel/debug/tracing # cat tracing_on
  1
  /sys/kernel/debug/tracing # echo 1 > snapshot
  /sys/kernel/debug/tracing # cat tracing_on
  0

We don't touch tracing_on, but snapshot changes tracing_on
setting each time. This is an anomaly, because user doesn't know
that each "ring_buffer" stores its own tracing-enable state and
the snapshot is done by swapping ring buffers.

Link: http://lkml.kernel.org/r/153149929558.11274.11730609978254724394.stgit@devbox

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Hiraku Toyooka <hiraku.toyooka@cybertrust.co.jp>
Cc: stable@vger.kernel.org
Fixes: debdd57f51 ("tracing: Make a snapshot feature available from userspace")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ Updated commit log and comment in the code ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 10:29:41 -04:00
Steven Rostedt (VMware) 1863c38725 tracing: Fix double free of event_trigger_data
Running the following:

 # cd /sys/kernel/debug/tracing
 # echo 500000 > buffer_size_kb
[ Or some other number that takes up most of memory ]
 # echo snapshot > events/sched/sched_switch/trigger

Triggers the following bug:

 ------------[ cut here ]------------
 kernel BUG at mm/slub.c:296!
 invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
 CPU: 6 PID: 6878 Comm: bash Not tainted 4.18.0-rc6-test+ #1066
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 RIP: 0010:kfree+0x16c/0x180
 Code: 05 41 0f b6 72 51 5b 5d 41 5c 4c 89 d7 e9 ac b3 f8 ff 48 89 d9 48 89 da 41 b8 01 00 00 00 5b 5d 41 5c 4c 89 d6 e9 f4 f3 ff ff <0f> 0b 0f 0b 48 8b 3d d9 d8 f9 00 e9 c1 fe ff ff 0f 1f 40 00 0f 1f
 RSP: 0018:ffffb654436d3d88 EFLAGS: 00010246
 RAX: ffff91a9d50f3d80 RBX: ffff91a9d50f3d80 RCX: ffff91a9d50f3d80
 RDX: 00000000000006a4 RSI: ffff91a9de5a60e0 RDI: ffff91a9d9803500
 RBP: ffffffff8d267c80 R08: 00000000000260e0 R09: ffffffff8c1a56be
 R10: fffff0d404543cc0 R11: 0000000000000389 R12: ffffffff8c1a56be
 R13: ffff91a9d9930e18 R14: ffff91a98c0c2890 R15: ffffffff8d267d00
 FS:  00007f363ea64700(0000) GS:ffff91a9de580000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055c1cacc8e10 CR3: 00000000d9b46003 CR4: 00000000001606e0
 Call Trace:
  event_trigger_callback+0xee/0x1d0
  event_trigger_write+0xfc/0x1a0
  __vfs_write+0x33/0x190
  ? handle_mm_fault+0x115/0x230
  ? _cond_resched+0x16/0x40
  vfs_write+0xb0/0x190
  ksys_write+0x52/0xc0
  do_syscall_64+0x5a/0x160
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 RIP: 0033:0x7f363e16ab50
 Code: 73 01 c3 48 8b 0d 38 83 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 79 db 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e e3 01 00 48 89 04 24
 RSP: 002b:00007fff9a4c6378 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f363e16ab50
 RDX: 0000000000000009 RSI: 000055c1cacc8e10 RDI: 0000000000000001
 RBP: 000055c1cacc8e10 R08: 00007f363e435740 R09: 00007f363ea64700
 R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000009
 R13: 0000000000000001 R14: 00007f363e4345e0 R15: 00007f363e4303c0
 Modules linked in: ip6table_filter ip6_tables snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device i915 snd_pcm snd_timer i2c_i801 snd soundcore i2c_algo_bit drm_kms_helper
86_pkg_temp_thermal video kvm_intel kvm irqbypass wmi e1000e
 ---[ end trace d301afa879ddfa25 ]---

The cause is because the register_snapshot_trigger() call failed to
allocate the snapshot buffer, and then called unregister_trigger()
which freed the data that was passed to it. Then on return to the
function that called register_snapshot_trigger(), as it sees it
failed to register, it frees the trigger_data again and causes
a double free.

By calling event_trigger_init() on the trigger_data (which only ups
the reference counter for it), and then event_trigger_free() afterward,
the trigger_data would not get freed by the registering trigger function
as it would only up and lower the ref count for it. If the register
trigger function fails, then the event_trigger_free() called after it
will free the trigger data normally.

Link: http://lkml.kernel.org/r/20180724191331.738eb819@gandalf.local.home

Cc: stable@vger.kerne.org
Fixes: 93e31ffbf4 ("tracing: Add 'snapshot' event trigger command")
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 10:29:24 -04:00
Linus Torvalds 0723090656 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Handle stations tied to AP_VLANs properly during mac80211 hw
    reconfig. From Manikanta Pubbisetty.

 2) Fix jump stack depth validation in nf_tables, from Taehee Yoo.

 3) Fix quota handling in aRFS flow expiration of mlx5 driver, from Eran
    Ben Elisha.

 4) Exit path handling fix in powerpc64 BPF JIT, from Daniel Borkmann.

 5) Use ptr_ring_consume_bh() in page pool code, from Tariq Toukan.

 6) Fix cached netdev name leak in nf_tables, from Florian Westphal.

 7) Fix memory leaks on chain rename, also from Florian Westphal.

 8) Several fixes to DCTCP congestion control ACK handling, from Yuchunk
    Cheng.

 9) Missing rcu_read_unlock() in CAIF protocol code, from Yue Haibing.

10) Fix link local address handling with VRF, from David Ahern.

11) Don't clobber 'err' on a successful call to __skb_linearize() in
    skb_segment(). From Eric Dumazet.

12) Fix vxlan fdb notification races, from Roopa Prabhu.

13) Hash UDP fragments consistently, from Paolo Abeni.

14) If TCP receives lots of out of order tiny packets, we do really
    silly stuff. Make the out-of-order queue ending more robust to this
    kind of behavior, from Eric Dumazet.

15) Don't leak netlink dump state in nf_tables, from Florian Westphal.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (76 commits)
  net: axienet: Fix double deregister of mdio
  qmi_wwan: fix interface number for DW5821e production firmware
  ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull
  bnx2x: Fix invalid memory access in rss hash config path.
  net/mlx4_core: Save the qpn from the input modifier in RST2INIT wrapper
  r8169: restore previous behavior to accept BIOS WoL settings
  cfg80211: never ignore user regulatory hint
  sock: fix sg page frag coalescing in sk_alloc_sg
  netfilter: nf_tables: move dumper state allocation into ->start
  tcp: add tcp_ooo_try_coalesce() helper
  tcp: call tcp_drop() from tcp_data_queue_ofo()
  tcp: detect malicious patterns in tcp_collapse_ofo_queue()
  tcp: avoid collapses in tcp_prune_queue() if possible
  tcp: free batches of packets in tcp_prune_ofo_queue()
  ip: hash fragments consistently
  ipv6: use fib6_info_hold_safe() when necessary
  can: xilinx_can: fix power management handling
  can: xilinx_can: fix incorrect clear of non-processed interrupts
  can: xilinx_can: fix RX overflow interrupt not being enabled
  can: xilinx_can: keep only 1-2 frames in TX FIFO to fix TX accounting
  ...
2018-07-24 17:31:47 -07:00
Linus Torvalds 48b1db7c7a Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Two fixes: a stop-machine preemption fix and a SCHED_DEADLINE fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix switched_from_dl() warning
  stop_machine: Disable preemption when waking two stopper threads
2018-07-21 17:21:34 -07:00
Linus Torvalds 490fc05386 mm: make vm_area_alloc() initialize core fields
Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.

The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 15:24:03 -07:00
Linus Torvalds 95faf6992d mm: make vm_area_dup() actually copy the old vma data
.. and re-initialize th eanon_vma_chain head.

This removes some boiler-plate from the users, and also makes it clear
why it didn't need use the 'zalloc()' version.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 14:48:45 -07:00
Linus Torvalds 3928d4f5ee mm: use helper functions for allocating and freeing vm_area structs
The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.

We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.

Right now those functions are literally just wrappers around the
kmem_cache_*() calls.  This is a purely mechanical conversion:

    # new vma:
    kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()

    # copy old vma
    kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)

    # free vma
    kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)

to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 13:48:51 -07:00
Martin KaFai Lau 36fc3c8c28 bpf: btf: Clean up BTF_INT_BITS() in uapi btf.h
This patch shrinks the BTF_INT_BITS() mask.  The current
btf_int_check_meta() ensures the nr_bits of an integer
cannot exceed 64.  Hence, it is mostly an uapi cleanup.

The actual btf usage (i.e. seq_show()) is also modified
to use u8 instead of u16.  The verification (e.g. btf_int_check_meta())
path stays as is to deal with invalid BTF situation.

Fixes: 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-20 10:25:48 +02:00
Linus Torvalds 024ddc0ce1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Lots of fixes, here goes:

   1) NULL deref in qtnfmac, from Gustavo A. R. Silva.

   2) Kernel oops when fw download fails in rtlwifi, from Ping-Ke Shih.

   3) Lost completion messages in AF_XDP, from Magnus Karlsson.

   4) Correct bogus self-assignment in rhashtable, from Rishabh
      Bhatnagar.

   5) Fix regression in ipv6 route append handling, from David Ahern.

   6) Fix masking in __set_phy_supported(), from Heiner Kallweit.

   7) Missing module owner set in x_tables icmp, from Florian Westphal.

   8) liquidio's timeouts are HZ dependent, fix from Nicholas Mc Guire.

   9) Link setting fixes for sh_eth and ravb, from Vladimir Zapolskiy.

  10) Fix NULL deref when using chains in act_csum, from Davide Caratti.

  11) XDP_REDIRECT needs to check if the interface is up and whether the
      MTU is sufficient. From Toshiaki Makita.

  12) Net diag can do a double free when killing TCP_NEW_SYN_RECV
      connections, from Lorenzo Colitti.

  13) nf_defrag in ipv6 can unnecessarily hold onto dst entries for a
      full minute, delaying device unregister. From Eric Dumazet.

  14) Update MAC entries in the correct order in ixgbe, from Alexander
      Duyck.

  15) Don't leave partial mangles bpf program in jit_subprogs, from
      Daniel Borkmann.

  16) Fix pfmemalloc SKB state propagation, from Stefano Brivio.

  17) Fix ACK handling in DCTCP congestion control, from Yuchung Cheng.

  18) Use after free in tun XDP_TX, from Toshiaki Makita.

  19) Stale ipv6 header pointer in ipv6 gre code, from Prashant Bhole.

  20) Don't reuse remainder of RX page when XDP is set in mlx4, from
      Saeed Mahameed.

  21) Fix window probe handling of TCP rapair sockets, from Stefan
      Baranoff.

  22) Missing socket locking in smc_ioctl(), from Ursula Braun.

  23) IPV6_ILA needs DST_CACHE, from Arnd Bergmann.

  24) Spectre v1 fix in cxgb3, from Gustavo A. R. Silva.

  25) Two spots in ipv6 do a rol32() on a hash value but ignore the
      result. Fixes from Colin Ian King"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (176 commits)
  tcp: identify cryptic messages as TCP seq # bugs
  ptp: fix missing break in switch
  hv_netvsc: Fix napi reschedule while receive completion is busy
  MAINTAINERS: Drop inactive Vitaly Bordug's email
  net: cavium: Add fine-granular dependencies on PCI
  net: qca_spi: Fix log level if probe fails
  net: qca_spi: Make sure the QCA7000 reset is triggered
  net: qca_spi: Avoid packet drop during initial sync
  ipv6: fix useless rol32 call on hash
  ipv6: sr: fix useless rol32 call on hash
  net: sched: Using NULL instead of plain integer
  net: usb: asix: replace mii_nway_restart in resume path
  net: cxgb3_main: fix potential Spectre v1
  lib/rhashtable: consider param->min_size when setting initial table size
  net/smc: reset recv timeout after clc handshake
  net/smc: add error handling for get_user()
  net/smc: optimize consumer cursor updates
  net/nfc: Avoid stalls when nfc_alloc_send_skb() returned NULL.
  ipv6: ila: select CONFIG_DST_CACHE
  net: usb: rtl8150: demote allmulti message to dev_dbg()
  ...
2018-07-18 19:32:54 -07:00
Linus Torvalds 3c53776e29 Mark HI and TASKLET softirq synchronous
Way back in 4.9, we committed 4cd13c21b2 ("softirq: Let ksoftirqd do
its job"), and ever since we've had small nagging issues with it.  For
example, we've had:

  1ff688209e ("watchdog: core: make sure the watchdog_worker is not deferred")
  8d5755b3f7 ("watchdog: softdog: fire watchdog even if softirqs do not get to run")
  217f697436 ("net: busy-poll: allow preemption in sk_busy_loop()")

all of which worked around some of the effects of that commit.

The DVB people have also complained that the commit causes excessive USB
URB latencies, which seems to be due to the USB code using tasklets to
schedule USB traffic.  This seems to be an issue mainly when already
living on the edge, but waiting for ksoftirqd to handle it really does
seem to cause excessive latencies.

Now Hanna Hawa reports that this issue isn't just limited to USB URB and
DVB, but also causes timeout problems for the Marvell SoC team:

 "I'm facing kernel panic issue while running raid 5 on sata disks
  connected to Macchiatobin (Marvell community board with Armada-8040
  SoC with 4 ARMv8 cores of CA72) Raid 5 built with Marvell DMA engine
  and async_tx mechanism (ASYNC_TX_DMA [=y]); the DMA driver (mv_xor_v2)
  uses a tasklet to clean the done descriptors from the queue"

The latency problem causes a panic:

  mv_xor_v2 f0400000.xor: dma_sync_wait: timeout!
  Kernel panic - not syncing: async_tx_quiesce: DMA error waiting for transaction

We've discussed simply just reverting the original commit entirely, and
also much more involved solutions (with per-softirq threads etc).  This
patch is intentionally stupid and fairly limited, because the issue
still remains, and the other solutions either got sidetracked or had
other issues.

We should probably also consider the timer softirqs to be synchronous
and not be delayed to ksoftirqd (since they were the issue with the
earlier watchdog problems), but that should be done as a separate patch.
This does only the tasklet cases.

Reported-and-tested-by: Hanna Hawa <hannah@marvell.com>
Reported-and-tested-by: Josef Griebichler <griebichler.josef@gmx.at>
Reported-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-17 11:12:43 -07:00
Juri Lelli e117cb52bd sched/deadline: Fix switched_from_dl() warning
Mark noticed that syzkaller is able to reliably trigger the following warning:

  dl_rq->running_bw > dl_rq->this_bw
  WARNING: CPU: 1 PID: 153 at kernel/sched/deadline.c:124 switched_from_dl+0x454/0x608
  Kernel panic - not syncing: panic_on_warn set ...

  CPU: 1 PID: 153 Comm: syz-executor253 Not tainted 4.18.0-rc3+ #29
  Hardware name: linux,dummy-virt (DT)
  Call trace:
   dump_backtrace+0x0/0x458
   show_stack+0x20/0x30
   dump_stack+0x180/0x250
   panic+0x2dc/0x4ec
   __warn_printk+0x0/0x150
   report_bug+0x228/0x2d8
   bug_handler+0xa0/0x1a0
   brk_handler+0x2f0/0x568
   do_debug_exception+0x1bc/0x5d0
   el1_dbg+0x18/0x78
   switched_from_dl+0x454/0x608
   __sched_setscheduler+0x8cc/0x2018
   sys_sched_setattr+0x340/0x758
   el0_svc_naked+0x30/0x34

syzkaller reproducer runs a bunch of threads that constantly switch
between DEADLINE and NORMAL classes while interacting through futexes.

The splat above is caused by the fact that if a DEADLINE task is setattr
back to NORMAL while in non_contending state (blocked on a futex -
inactive timer armed), its contribution to running_bw is not removed
before sub_rq_bw() gets called (!task_on_rq_queued() branch) and the
latter sees running_bw > this_bw.

Fix it by removing a task contribution from running_bw if the task is
not queued and in non_contending state while switched to a different
class.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Reviewed-by: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20180711072948.27061-1-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:47:33 +02:00
Isaac J. Manjarres 9fb8d5dc4b stop_machine: Disable preemption when waking two stopper threads
When cpu_stop_queue_two_works() begins to wake the stopper threads, it does
so without preemption disabled, which leads to the following race
condition:

The source CPU calls cpu_stop_queue_two_works(), with cpu1 as the source
CPU, and cpu2 as the destination CPU. When adding the stopper threads to
the wake queue used in this function, the source CPU stopper thread is
added first, and the destination CPU stopper thread is added last.

When wake_up_q() is invoked to wake the stopper threads, the threads are
woken up in the order that they are queued in, so the source CPU's stopper
thread is woken up first, and it preempts the thread running on the source
CPU.

The stopper thread will then execute on the source CPU, disable preemption,
and begin executing multi_cpu_stop(), and wait for an ack from the
destination CPU's stopper thread, with preemption still disabled. Since the
worker thread that woke up the stopper thread on the source CPU is affine
to the source CPU, and preemption is disabled on the source CPU, that
thread will never run to dequeue the destination CPU's stopper thread from
the wake queue, and thus, the destination CPU's stopper thread will never
run, causing the source CPU's stopper thread to wait forever, and stall.

Disable preemption when waking the stopper threads in
cpu_stop_queue_two_works().

Fixes: 0b26351b91 ("stop_machine, sched: Fix migrate_swap() vs. active_balance() deadlock")
Co-Developed-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Co-Developed-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: matt@codeblueprint.co.uk
Cc: bigeasy@linutronix.de
Cc: gregkh@linuxfoundation.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1530655334-4601-1-git-send-email-isaacm@codeaurora.org
2018-07-15 12:12:45 +02:00
Linus Torvalds 3951dbf232 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
 "A clocksource driver fix and a revert"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: arm_arch_timer: Set arch_mem_timer cpumask to cpu_possible_mask
  Revert "tick: Prefer a lower rating device only if it's CPU local device"
2018-07-13 13:36:36 -07:00
Linus Torvalds ae4ea3975d Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull rseq fixes from Ingo Molnar:
 "Various rseq ABI fixes and cleanups: use get_user()/put_user(),
  validate parameters and use proper uapi types, etc"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq/selftests: cleanup: Update comment above rseq_prepare_unload
  rseq: Remove unused types_32_64.h uapi header
  rseq: uapi: Declare rseq_cs field as union, update includes
  rseq: uapi: Update uapi comments
  rseq: Use get_user/put_user rather than __get_user/__put_user
  rseq: Use __u64 for rseq_cs fields, validate user inputs
2018-07-13 12:50:42 -07:00
Linus Torvalds 35a84f34cf Joel Fernandes asked to add a feature in tracing that Android had its
own patch internally for. I took it back in 4.13. Now he realizes that
 he had a mistake, and swapped the values from what Android had. This
 means that the old Android tools will break when using a new kernel
 that has the new feature on it.
 
 The options are:
 
  1. To swap it back to what Android wants.
  2. Add a command line option or something to do the swap
  3. Just let Android carry a patch that swaps it back
 
 Since it requires setting a tracing option to enable this anyway,
 I doubt there are other users of this than Android. Thus, I've
 decided to take option 1. If someone else is actually depending on the
 order that is in the kernel, then we will have to revert this change
 and go to option 2 or 3.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCW0ib3BQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qpH2APwJb1C72w6/QF9QK8I7HWzK3BN+9KuK
 xfJA+58HXzu7SgD+IXzhXW9tODU+sWbYr9cVOyj2ad6p8CYNDkPlVAJulwM=
 =XJE5
 -----END PGP SIGNATURE-----

Merge tag 'trace-v4.18-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixlet from Steven Rostedt:
 "Joel Fernandes asked to add a feature in tracing that Android had its
  own patch internally for. I took it back in 4.13. Now he realizes that
  he had a mistake, and swapped the values from what Android had. This
  means that the old Android tools will break when using a new kernel
  that has the new feature on it.

  The options are:

   1. To swap it back to what Android wants.
   2. Add a command line option or something to do the swap
   3. Just let Android carry a patch that swaps it back

  Since it requires setting a tracing option to enable this anyway, I
  doubt there are other users of this than Android. Thus, I've decided
  to take option 1. If someone else is actually depending on the order
  that is in the kernel, then we will have to revert this change and go
  to option 2 or 3"

* tag 'trace-v4.18-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Reorder display of TGID to be after PID
2018-07-13 11:40:11 -07:00
Joel Fernandes (Google) f8494fa3dd tracing: Reorder display of TGID to be after PID
Currently ftrace displays data in trace output like so:

                                       _-----=> irqs-off
                                      / _----=> need-resched
                                     | / _---=> hardirq/softirq
                                     || / _--=> preempt-depth
                                     ||| /     delay
            TASK-PID   CPU    TGID   ||||    TIMESTAMP  FUNCTION
               | |       |      |    ||||       |         |
            bash-1091  [000] ( 1091) d..2    28.313544: sched_switch:

However Android's trace visualization tools expect a slightly different
format due to an out-of-tree patch patch that was been carried for a
decade, notice that the TGID and CPU fields are reversed:

                                       _-----=> irqs-off
                                      / _----=> need-resched
                                     | / _---=> hardirq/softirq
                                     || / _--=> preempt-depth
                                     ||| /     delay
            TASK-PID    TGID   CPU   ||||    TIMESTAMP  FUNCTION
               | |        |      |   ||||       |         |
            bash-1091  ( 1091) [002] d..2    64.965177: sched_switch:

From kernel v4.13 onwards, during which TGID was introduced, tracing
with systrace on all Android kernels will break (most Android kernels
have been on 4.9 with Android patches, so this issues hasn't been seen
yet). From v4.13 onwards things will break.

The chrome browser's tracing tools also embed the systrace viewer which
uses the legacy TGID format and updates to that are known to be
difficult to make.

Considering this, I suggest we make this change to the upstream kernel
and backport it to all Android kernels. I believe this feature is merged
recently enough into the upstream kernel that it shouldn't be a problem.
Also logically, IMO it makes more sense to group the TGID with the
TASK-PID and the CPU after these.

Link: http://lkml.kernel.org/r/20180626000822.113931-1-joel@joelfernandes.org

Cc: jreck@google.com
Cc: tkjos@google.com
Cc: stable@vger.kernel.org
Fixes: 441dae8f2f ("tracing: Add support for display of tgid in trace output")
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-12 19:56:25 -04:00
Daniel Borkmann c7a8978432 bpf: don't leave partial mangled prog in jit_subprogs error path
syzkaller managed to trigger the following bug through fault injection:

  [...]
  [  141.043668] verifier bug. No program starts at insn 3
  [  141.044648] WARNING: CPU: 3 PID: 4072 at kernel/bpf/verifier.c:1613
                 get_callee_stack_depth kernel/bpf/verifier.c:1612 [inline]
  [  141.044648] WARNING: CPU: 3 PID: 4072 at kernel/bpf/verifier.c:1613
                 fixup_call_args kernel/bpf/verifier.c:5587 [inline]
  [  141.044648] WARNING: CPU: 3 PID: 4072 at kernel/bpf/verifier.c:1613
                 bpf_check+0x525e/0x5e60 kernel/bpf/verifier.c:5952
  [  141.047355] CPU: 3 PID: 4072 Comm: a.out Not tainted 4.18.0-rc4+ #51
  [  141.048446] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),BIOS 1.10.2-1 04/01/2014
  [  141.049877] Call Trace:
  [  141.050324]  __dump_stack lib/dump_stack.c:77 [inline]
  [  141.050324]  dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
  [  141.050950]  ? dump_stack_print_info.cold.2+0x52/0x52 lib/dump_stack.c:60
  [  141.051837]  panic+0x238/0x4e7 kernel/panic.c:184
  [  141.052386]  ? add_taint.cold.5+0x16/0x16 kernel/panic.c:385
  [  141.053101]  ? __warn.cold.8+0x148/0x1ba kernel/panic.c:537
  [  141.053814]  ? __warn.cold.8+0x117/0x1ba kernel/panic.c:530
  [  141.054506]  ? get_callee_stack_depth kernel/bpf/verifier.c:1612 [inline]
  [  141.054506]  ? fixup_call_args kernel/bpf/verifier.c:5587 [inline]
  [  141.054506]  ? bpf_check+0x525e/0x5e60 kernel/bpf/verifier.c:5952
  [  141.055163]  __warn.cold.8+0x163/0x1ba kernel/panic.c:538
  [  141.055820]  ? get_callee_stack_depth kernel/bpf/verifier.c:1612 [inline]
  [  141.055820]  ? fixup_call_args kernel/bpf/verifier.c:5587 [inline]
  [  141.055820]  ? bpf_check+0x525e/0x5e60 kernel/bpf/verifier.c:5952
  [...]

What happens in jit_subprogs() is that kcalloc() for the subprog func
buffer is failing with NULL where we then bail out. Latter is a plain
return -ENOMEM, and this is definitely not okay since earlier in the
loop we are walking all subprogs and temporarily rewrite insn->off to
remember the subprog id as well as insn->imm to temporarily point the
call to __bpf_call_base + 1 for the initial JIT pass. Thus, bailing
out in such state and handing this over to the interpreter is troublesome
since later/subsequent e.g. find_subprog() lookups are based on wrong
insn->imm.

Therefore, once we hit this point, we need to jump to out_free path
where we undo all changes from earlier loop, so that interpreter can
work on unmodified insn->{off,imm}.

Another point is that should find_subprog() fail in jit_subprogs() due
to a verifier bug, then we also should not simply defer the program to
the interpreter since also here we did partial modifications. Instead
we should just bail out entirely and return an error to the user who is
trying to load the program.

Fixes: 1c2a088a66 ("bpf: x64: add JIT support for multi-function programs")
Reported-by: syzbot+7d427828b2ea6e592804@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-12 14:00:54 -07:00
Okash Khawaja b65f370d06 bpf: btf: Fix bitfield extraction for big endian
When extracting bitfield from a number, btf_int_bits_seq_show() builds
a mask and accesses least significant byte of the number in a way
specific to little-endian. This patch fixes that by checking endianness
of the machine and then shifting left and right the unneeded bits.

Thanks to Martin Lau for the help in navigating potential pitfalls when
dealing with endianess and for the final solution.

Fixes: b00b8daec8 ("bpf: btf: Add pretty print capability for data with BTF type info")
Signed-off-by: Okash Khawaja <osk@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:36:08 +02:00
Linus Torvalds c25c74b747 This fixes a memory leak in the kprobe code.
-----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCW0ZhphQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qlxwAP4jKOp86ljtdqHSlh9mOHChnvwdMprQ
 kaQ82WiamGikIwD/Vo/6ynsVl5eYMDO2VQSv6W1DHmhV9I/KgdqcQBl8jAk=
 =RF9o
 -----END PGP SIGNATURE-----

Merge tag 'trace-v4.18-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull kprobe fix from Steven Rostedt:
 "This fixes a memory leak in the kprobe code"

* tag 'trace-v4.18-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/kprobe: Release kprobe print_fmt properly
2018-07-11 13:03:51 -07:00
Jiri Olsa 0fc8c3581d tracing/kprobe: Release kprobe print_fmt properly
We don't release tk->tp.call.print_fmt when destroying
local uprobe. Also there's missing print_fmt kfree in
create_local_trace_kprobe error path.

Link: http://lkml.kernel.org/r/20180709141906.2390-1-jolsa@kernel.org

Cc: stable@vger.kernel.org
Fixes: e12f03d703 ("perf/core: Implement the 'perf_kprobe' PMU")
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-11 15:50:52 -04:00
Mathieu Desnoyers ec9c82e03a rseq: uapi: Declare rseq_cs field as union, update includes
Declaring the rseq_cs field as a union between __u64 and two __u32
allows both 32-bit and 64-bit kernels to read the full __u64, and
therefore validate that a 32-bit user-space cleared the upper 32
bits, thus ensuring a consistent behavior between native 32-bit
kernels and 32-bit compat tasks on 64-bit kernels.

Check that the rseq_cs value read is < TASK_SIZE.

The asm/byteorder.h header needs to be included by rseq.h, now
that it is not using linux/types_32_64.h anymore.

Considering that only __32 and __u64 types are declared in linux/rseq.h,
the linux/types.h header should always be included for both kernel and
user-space code: including stdint.h is just for u64 and u32, which are
not used in this header at all.

Use copy_from_user()/clear_user() to interact with a 64-bit field,
because arm32 does not implement 64-bit __get_user, and ppc32 does not
64-bit get_user. Considering that the rseq_cs pointer does not need to
be loaded/stored with single-copy atomicity from the kernel anymore, we
can simply use copy_from_user()/clear_user().

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Paul Turner <pjt@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Chris Lameter <cl@linux.com>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180709195155.7654-5-mathieu.desnoyers@efficios.com
2018-07-10 22:18:52 +02:00
Mathieu Desnoyers 0fb9a1abc8 rseq: uapi: Update uapi comments
Update rseq uapi header comments to reflect that user-space need to do
thread-local loads/stores from/to the struct rseq fields.

As a consequence of this added requirement, the kernel does not need
to perform loads/stores with single-copy atomicity.

Update the comment associated to the "flags" fields to describe
more accurately that it's only useful to facilitate single-stepping
through rseq critical sections with debuggers.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Paul Turner <pjt@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Chris Lameter <cl@linux.com>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180709195155.7654-4-mathieu.desnoyers@efficios.com
2018-07-10 22:18:52 +02:00
Mathieu Desnoyers 8f28177014 rseq: Use get_user/put_user rather than __get_user/__put_user
__get_user()/__put_user() is used to read values for address ranges that
were already checked with access_ok() on rseq registration.

It has been recognized that __get_user/__put_user are optimizing the
wrong thing. Replace them by get_user/put_user across rseq instead.

If those end up showing up in benchmarks, the proper approach would be to
use user_access_begin() / unsafe_{get,put}_user() / user_access_end()
anyway.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Paul Turner <pjt@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Chris Lameter <cl@linux.com>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/20180709195155.7654-3-mathieu.desnoyers@efficios.com
2018-07-10 22:18:52 +02:00
Mathieu Desnoyers e96d71359e rseq: Use __u64 for rseq_cs fields, validate user inputs
Change the rseq ABI so rseq_cs start_ip, post_commit_offset and abort_ip
fields are seen as 64-bit fields by both 32-bit and 64-bit kernels rather
that ignoring the 32 upper bits on 32-bit kernels. This ensures we have a
consistent behavior for a 32-bit binary executed on 32-bit kernels and in
compat mode on 64-bit kernels.

Validating the value of abort_ip field to be below TASK_SIZE ensures the
kernel don't return to an invalid address when returning to userspace
after an abort. I don't fully trust each architecture code to consistently
deal with invalid return addresses.

Validating the value of the start_ip and post_commit_offset fields
prevents overflow on arithmetic performed on those values, used to
check whether abort_ip is within the rseq critical section.

If validation fails, the process is killed with a segmentation fault.

When the signature encountered before abort_ip does not match the expected
signature, return -EINVAL rather than -EPERM to be consistent with other
input validation return codes from rseq_get_rseq_cs().

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Paul Turner <pjt@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Chris Lameter <cl@linux.com>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180709195155.7654-2-mathieu.desnoyers@efficios.com
2018-07-10 22:18:51 +02:00
Sudeep Holla 5b5ccbc2b0 Revert "tick: Prefer a lower rating device only if it's CPU local device"
This reverts commit 1332a90558.

The original issue was not because of incorrect checking of cpumask for
both new and old tick device. It was incorrectly analysed was due to the
misunderstanding of the comment and misinterpretation of the return value
from tick_check_preferred. The main issue is with the clockevent driver
that sets the cpumask to cpu_all_mask instead of cpu_possible_mask.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1531151136-18297-1-git-send-email-sudeep.holla@arm.com
2018-07-10 22:12:47 +02:00
Linus Torvalds 6fb2489d7f Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:

 - The hopefully final fix for the reported race problems in
   kthread_parkme(). The previous attempt still left a hole and was
   partially wrong.

 - Plug a race in the remote tick mechanism which triggers a warning
   about updates not being done correctly. That's a false positive if
   the race condition is hit as the remote CPU is idle. Plug it by
   checking the condition again when holding run queue lock.

 - Fix a bug in the utilization estimation of a run queue which causes
   the estimation to be 0 when a run queue is throttled.

 - Advance the global expiration of the period timer when the timer is
   restarted after a idle period. Otherwise the expiry time is stale and
   the timer fires prematurely.

 - Cure the drift between the bandwidth timer and the runqueue
   accounting, which leads to bogus throttling of runqueues

 - Place the call to cpufreq_update_util() correctly so the function
   will observe the correct number of running RT tasks and not a stale
   one.

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kthread, sched/core: Fix kthread_parkme() (again...)
  sched/util_est: Fix util_est_dequeue() for throttled cfs_rq
  sched/fair: Advance global expiration when period timer is restarted
  sched/fair: Fix bandwidth timer clock drift condition
  sched/rt: Fix call to cpufreq_update_util()
  sched/nohz: Skip remote tick on idle task entirely
2018-07-08 12:41:23 -07:00
Toshiaki Makita d8d7218ad8 xdp: XDP_REDIRECT should check IFF_UP and MTU
Otherwise we end up with attempting to send packets from down devices
or to send oversized packets, which may cause unexpected driver/device
behaviour. Generic XDP has already done this check, so reuse the logic
in native XDP.

Fixes: 814abfabef ("xdp: add bpf_redirect helper function")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-07 15:25:35 -07:00
John Fastabend 0ea488ff8d bpf: sockmap, convert bpf_compute_data_pointers to bpf_*_sk_skb
In commit

  'bpf: bpf_compute_data uses incorrect cb structure' (8108a77515)

we added the routine bpf_compute_data_end_sk_skb() to compute the
correct data_end values, but this has since been lost. In kernel
v4.14 this was correct and the above patch was applied in it
entirety. Then when v4.14 was merged into v4.15-rc1 net-next tree
we lost the piece that renamed bpf_compute_data_pointers to the
new function bpf_compute_data_end_sk_skb. This was done here,

e1ea2f9856 ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net")

When it conflicted with the following rename patch,

6aaae2b6c4 ("bpf: rename bpf_compute_data_end into bpf_compute_data_pointers")

Finally, after a refactor I thought even the function
bpf_compute_data_end_sk_skb() was no longer needed and it was
erroneously removed.

However, we never reverted the sk_skb_convert_ctx_access() usage of
tcp_skb_cb which had been committed and survived the merge conflict.
Here we fix this by adding back the helper and *_data_end_sk_skb()
usage. Using the bpf_skc_data_end mapping is not correct because it
expects a qdisc_skb_cb object but at the sock layer this is not the
case. Even though it happens to work here because we don't overwrite
any data in-use at the socket layer and the cb structure is cleared
later this has potential to create some subtle issues. But, even
more concretely the filter.c access check uses tcp_skb_cb.

And by some act of chance though,

struct bpf_skb_data_end {
        struct qdisc_skb_cb        qdisc_cb;             /*     0    28 */

        /* XXX 4 bytes hole, try to pack */

        void *                     data_meta;            /*    32     8 */
        void *                     data_end;             /*    40     8 */

        /* size: 48, cachelines: 1, members: 3 */
        /* sum members: 44, holes: 1, sum holes: 4 */
        /* last cacheline: 48 bytes */
};

and then tcp_skb_cb,

struct tcp_skb_cb {
	[...]
                struct {
                        __u32      flags;                /*    24     4 */
                        struct sock * sk_redir;          /*    32     8 */
                        void *     data_end;             /*    40     8 */
                } bpf;                                   /*          24 */
        };

So when we use offset_of() to track down the byte offset we get 40 in
either case and everything continues to work. Fix this mess and use
correct structures its unclear how long this might actually work for
until someone moves the structs around.

Reported-by: Martin KaFai Lau <kafai@fb.com>
Fixes: e1ea2f9856 ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net")
Fixes: 6aaae2b6c4 ("bpf: rename bpf_compute_data_end into bpf_compute_data_pointers")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-07 15:19:30 -07:00
John Fastabend 7ebc14d507 bpf: sockmap, consume_skb in close path
Currently, when a sock is closed and the bpf_tcp_close() callback is
used we remove memory but do not free the skb. Call consume_skb() if
the skb is attached to the buffer.

Reported-by: syzbot+d464d2c20c717ef5a6a8@syzkaller.appspotmail.com
Fixes: 1aa12bdf1b ("bpf: sockmap, add sock close() hook to remove socks")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-07 15:19:30 -07:00
John Fastabend 99ba2b5aba bpf: sockhash, disallow bpf_tcp_close and update in parallel
After latest lock updates there is no longer anything preventing a
close and recvmsg call running in parallel. Additionally, we can
race update with close if we close a socket and simultaneously update
if via the BPF userspace API (note the cgroup ops are already run
with sock_lock held).

To resolve this take sock_lock in close and update paths.

Reported-by: syzbot+b680e42077a0d7c9a0c4@syzkaller.appspotmail.com
Fixes: e9db4ef6bf ("bpf: sockhash fix omitted bucket lock in sock_close")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-07 15:19:30 -07:00
John Fastabend 1d1ef005db bpf: sockmap, hash table is RCU so readers do not need locks
This removes locking from readers of RCU hash table. Its not
necessary.

Fixes: 8111038444 ("bpf: sockmap, add hash map support")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-07 15:16:58 -07:00
John Fastabend 547b3aa451 bpf: sockmap, error path can not release psock in multi-map case
The current code, in the error path of sock_hash_ctx_update_elem,
checks if the sock has a psock in the user data and if so decrements
the reference count of the psock. However, if the error happens early
in the error path we may have never incremented the psock reference
count and if the psock exists because the sock is in another map then
we may inadvertently decrement the reference count.

Fix this by making the error path only call smap_release_sock if the
error happens after the increment.

Reported-by: syzbot+d464d2c20c717ef5a6a8@syzkaller.appspotmail.com
Fixes: 8111038444 ("bpf: sockmap, add hash map support")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-07 15:16:58 -07:00
Linus Torvalds 97f4e14229 While cleaning out my INBOX, I found a few patches that were lost
in the noise. These are minor bug fixes and clean ups. Those include:
 
  - Avoiding a string overflow
  - Code that didn't match the comment (but should)
  - A small code optimization (use of a conditional)
  - Quieting printf warnings
  - Nuking unused code
  - Fixing function graph interrupt annotation
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCWz7ARhQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qmMqAQDTS7uvFLRR603WXyOazX6Y7FeiYFWp
 MUUZjnbG9u0bawEAulW53AM0OL3EAAaZKtPi8VtsT+uktR1GIynXrp+yoww=
 =yQDv
 -----END PGP SIGNATURE-----

Merge tag 'trace-v4.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes and cleanups from Steven Rostedt:
 "While cleaning out my INBOX, I found a few patches that were lost in
  the noise. These are minor bug fixes and clean ups. Those include:

   - avoid a string overflow

   - code that didn't match the comment (but should)

   - a small code optimization (use of a conditional)

   - quiet printf warnings

   - nuke unused code

   - fix function graph interrupt annotation"

* tag 'trace-v4.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix missing return symbol in function_graph output
  ftrace: Nuke clear_ftrace_function
  tracing: Use __printf markup to silence compiler
  tracing: Optimize trace_buffer_iter() logic
  tracing: Make create_filter() code match the comments
  tracing: Avoid string overflow
2018-07-05 19:29:07 -07:00
Changbin Du 1fe4293f4b tracing: Fix missing return symbol in function_graph output
The function_graph tracer does not show the interrupt return marker for the
leaf entry. On leaf entries, we see an unbalanced interrupt marker (the
interrupt was entered, but nevern left).

Before:
 1)               |  SyS_write() {
 1)               |    __fdget_pos() {
 1)   0.061 us    |      __fget_light();
 1)   0.289 us    |    }
 1)               |    vfs_write() {
 1)   0.049 us    |      rw_verify_area();
 1) + 15.424 us   |      __vfs_write();
 1)   ==========> |
 1)   6.003 us    |      smp_apic_timer_interrupt();
 1)   0.055 us    |      __fsnotify_parent();
 1)   0.073 us    |      fsnotify();
 1) + 23.665 us   |    }
 1) + 24.501 us   |  }

After:
 0)               |  SyS_write() {
 0)               |    __fdget_pos() {
 0)   0.052 us    |      __fget_light();
 0)   0.328 us    |    }
 0)               |    vfs_write() {
 0)   0.057 us    |      rw_verify_area();
 0)               |      __vfs_write() {
 0)   ==========> |
 0)   8.548 us    |      smp_apic_timer_interrupt();
 0)   <========== |
 0) + 36.507 us   |      } /* __vfs_write */
 0)   0.049 us    |      __fsnotify_parent();
 0)   0.066 us    |      fsnotify();
 0) + 50.064 us   |    }
 0) + 50.952 us   |  }

Link: http://lkml.kernel.org/r/1517413729-20411-1-git-send-email-changbin.du@intel.com

Cc: stable@vger.kernel.org
Fixes: f8b755ac8e ("tracing/function-graph-tracer: Output arrows signal on hardirq call/return")
Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-03 18:47:11 -04:00
Yisheng Xie 5ccba64a56 ftrace: Nuke clear_ftrace_function
clear_ftrace_function is not used outside of ftrace.c and is not help to
use a function, so nuke it per Steve's suggestion.

Link: http://lkml.kernel.org/r/1517537689-34947-1-git-send-email-xieyisheng1@huawei.com

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-03 18:33:19 -04:00
Mathieu Malaterre 26b68dd2f4 tracing: Use __printf markup to silence compiler
Silence warnings (triggered at W=1) by adding relevant __printf attributes.

  CC      kernel/trace/trace.o
kernel/trace/trace.c: In function ‘__trace_array_vprintk’:
kernel/trace/trace.c:2979:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
  len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args);
  ^~~
  AR      kernel/trace/built-in.o

Link: http://lkml.kernel.org/r/20180308205843.27447-1-malat@debian.org

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-03 18:32:04 -04:00
yuan linyu f26808ba72 tracing: Optimize trace_buffer_iter() logic
Simplify and optimize the logic in trace_buffer_iter() to use a conditional
operation instead of an if conditional.

Link: http://lkml.kernel.org/r/20180408113631.3947-1-cugyly@163.com

Signed-off-by: yuan linyu <Linyu.Yuan@alcatel-sbell.com.cn>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-03 18:23:33 -04:00
Steven Rostedt (VMware) f90658725b tracing: Make create_filter() code match the comments
The comment in create_filter() states that the passed in filter pointer
(filterp) will either be NULL or contain an error message stating why the
filter failed. But it also expects the filter pointer to point to NULL when
passed in. If it is not, the function create_filter_start() will warn and
return an error message without updating the filter pointer. This is not
what the comment states.

As we always expect the pointer to point to NULL, if it is not, trigger a
WARN_ON(), set it to NULL, and then continue the path as the rest will work
as the comment states. Also update the comment to state it must point to
NULL.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-03 18:14:40 -04:00
Arnd Bergmann cf4d418e65 tracing: Avoid string overflow
'err' is used as a NUL-terminated string, but using strncpy() with the length
equal to the buffer size may result in lack of the termination:

kernel/trace/trace_events_hist.c: In function 'hist_err_event':
kernel/trace/trace_events_hist.c:396:3: error: 'strncpy' specified bound 256 equals destination size [-Werror=stringop-truncation]
   strncpy(err, var, MAX_FILTER_STR_VAL);

This changes it to use the safer strscpy() instead.

Link: http://lkml.kernel.org/r/20180328140920.2842153-1-arnd@arndb.de

Cc: stable@vger.kernel.org
Fixes: f404da6e1d ("tracing: Add 'last error' error facility for hist triggers")
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-03 18:14:39 -04:00
Mauricio Vasquez B ed2b82c03d bpf: hash map: decrement counter on error
Decrement the number of elements in the map in case the allocation
of a new node fails.

Fixes: 6c90598174 ("bpf: pre-allocate hash map elements")
Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-03 23:26:28 +02:00
Peter Zijlstra 1cef1150ef kthread, sched/core: Fix kthread_parkme() (again...)
Gaurav reports that commit:

  85f1abe001 ("kthread, sched/wait: Fix kthread_parkme() completion issue")

isn't working for him. Because of the following race:

> controller Thread                               CPUHP Thread
> takedown_cpu
> kthread_park
> kthread_parkme
> Set KTHREAD_SHOULD_PARK
>                                                 smpboot_thread_fn
>                                                 set Task interruptible
>
>
> wake_up_process
>  if (!(p->state & state))
>                 goto out;
>
>                                                 Kthread_parkme
>                                                 SET TASK_PARKED
>                                                 schedule
>                                                 raw_spin_lock(&rq->lock)
> ttwu_remote
> waiting for __task_rq_lock
>                                                 context_switch
>
>                                                 finish_lock_switch
>
>
>
>                                                 Case TASK_PARKED
>                                                 kthread_park_complete
>
>
> SET Running

Furthermore, Oleg noticed that the whole scheduler TASK_PARKED
handling is buggered because the TASK_DEAD thing is done with
preemption disabled, the current code can still complete early on
preemption :/

So basically revert that earlier fix and go with a variant of the
alternative mentioned in the commit. Promote TASK_PARKED to special
state to avoid the store-store issue on task->state leading to the
WARN in kthread_unpark() -> __kthread_bind().

But in addition, add wait_task_inactive() to kthread_park() to ensure
the task really is PARKED when we return from kthread_park(). This
avoids the whole kthread still gets migrated nonsense -- although it
would be really good to get this done differently.

Reported-by: Gaurav Kohli <gkohli@codeaurora.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 85f1abe001 ("kthread, sched/wait: Fix kthread_parkme() completion issue")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-03 09:17:30 +02:00