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Odroidxu4 v4.14 #3

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@mihailescu2m mihailescu2m force-pushed the odroidxu4-4.14.y branch 5 times, most recently from d93a555 to 540f1c6 Compare October 20, 2017 12:14
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patches were already added

mihailescu2m pushed a commit that referenced this pull request Oct 24, 2017
Thomas reported that 'perf buildid-list' gets a SEGFAULT due to NULL
pointer deref when he ran it on a data with namespace events.  It was
because the buildid_id__mark_dso_hit_ops lacks the namespace event
handler and perf_too__fill_default() didn't set it.

  Program received signal SIGSEGV, Segmentation fault.
  0x0000000000000000 in ?? ()
  Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x
  +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x
  +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x
  (gdb) where
  #0  0x0000000000000000 in ?? ()
  #1  0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18,
      evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888,
      tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287
  #2  0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>,
      sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340
  #3  perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470,
      file_offset=file_offset@entry=1136) at util/session.c:1522
  #4  0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>,
      data_offset=<optimized out>, session=0x0) at util/session.c:1899
  #5  perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953
  #6  0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>)
      at builtin-buildid-list.c:83
  #7  cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115
  #8  0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0)
      at perf.c:296
  #9  0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348
  hardkernel#10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392
  hardkernel#11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536
  (gdb)

Fix it by adding a stub event handler for namespace event.

Committer testing:

Further clarifying, plain using 'perf buildid-list' will not end up in a
SEGFAULT when processing a perf.data file with namespace info:

  # perf record -a --namespaces sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 2.024 MB perf.data (1058 samples) ]
  # perf buildid-list | wc -l
  38
  # perf buildid-list | head -5
  e2a171c7b905826fc8494f0711ba76ab6abbd604 /lib/modules/4.14.0-rc3+/build/vmlinux
  874840a02d8f8a31cedd605d0b8653145472ced3 /lib/modules/4.14.0-rc3+/kernel/arch/x86/kvm/kvm-intel.ko
  ea7223776730cd8a22f320040aae4d54312984bc /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/i915/i915.ko
  5961535e6732a8edb7f22b3f148bb2fa2e0be4b9 /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/drm.ko
  f045f54aa78cf1931cc893f78b6cbc52c72a8cb1 /usr/lib64/libc-2.25.so
  #

It is only when one asks for checking what of those entries actually had
samples, i.e. when we use either -H or --with-hits, that we will process
all the PERF_RECORD_ events, and since tools/perf/builtin-buildid-list.c
neither explicitely set a perf_tool.namespaces() callback nor the
default stub was set that we end up, when processing a
PERF_RECORD_NAMESPACE record, causing a SEGFAULT:

  # perf buildid-list -H
  Segmentation fault (core dumped)
  ^C
  #

Reported-and-Tested-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Fixes: f3b3614 ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info")
Link: http://lkml.kernel.org/r/20171017132900.11043-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
mihailescu2m pushed a commit that referenced this pull request Oct 31, 2017
v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN
recovery") extended accessing parent pointer fields of struct
zfcp_erp_action for tracing.  If an erp_action has never been enqueued
before, these parent pointer fields are uninitialized and NULL. Examples
are zfcp objects freshly added to the parent object's children list,
before enqueueing their first recovery subsequently. In
zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action
fields can cause a NULL pointer dereference.  Since the kernel can read
from lowcore on s390, it does not immediately cause a kernel page
fault. Instead it can cause hangs on trying to acquire the wrong
erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl()
                      ^bogus^
while holding already other locks with IRQs disabled.

Real life example from attaching lots of LUNs in parallel on many CPUs:

crash> bt 17723
PID: 17723  TASK: ...               CPU: 25  COMMAND: "zfcperp0.0.1800"
 LOWCORE INFO:
  -psw      : 0x0404300180000000 0x000000000038e424
  -function : _raw_spin_lock_wait_flags at 38e424
...
 #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp]
 #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp]
 #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp]
 #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp]
 #4 [fdde8fe60] kthread at 173550
 #5 [fdde8feb8] kernel_thread_starter at 10add2

zfcp_adapter
 zfcp_port
  zfcp_unit <address>, 0x404040d600000000
  scsi_device NULL, returning early!
zfcp_scsi_dev.status = 0x40000000
0x40000000 ZFCP_STATUS_COMMON_RUNNING

crash> zfcp_unit <address>
struct zfcp_unit {
  erp_action = {
    adapter = 0x0,
    port = 0x0,
    unit = 0x0,
  },
}

zfcp_erp_action is always fully embedded into its container object. Such
container object is never moved in its object tree (only add or delete).
Hence, erp_action parent pointers can never change.

To fix the issue, initialize the erp_action parent pointers before
adding the erp_action container to any list and thus before it becomes
accessible from outside of its initializing function.

In order to also close the time window between zfcp_erp_setup_act()
memsetting the entire erp_action to zero and setting the parent pointers
again, drop the memset and instead explicitly initialize individually
all erp_action fields except for parent pointers. To be extra careful
not to introduce any other unintended side effect, even keep zeroing the
erp_action fields for list and timer. Also double-check with
WARN_ON_ONCE that erp_action parent pointers never change, so we get to
know when we would deviate from previous behavior.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery")
Cc: <stable@vger.kernel.org> #2.6.32+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
mihailescu2m pushed a commit that referenced this pull request Jan 21, 2019
Yonghong Song says:

====================
The previous BTF kind_flag support patch set introduced a bug
for kernel bpffs pretty printing and another bug for bpftool
map pretty printing. If a bitfield struct member offset is
greater than 256 bits, printed value for that struct
member will be incorrect.

- Patch #1 fixed the bug in kernel bpffs pretty printing.
- Patch #2 enhanced the test_btf test case to cover the
           issue exposed by patch #1.
- Patch #3 fixed the bug in bpftool map pretty printing.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
mihailescu2m pushed a commit that referenced this pull request Jan 21, 2019
Taehee Yoo says:

====================
net: bpfilter: fix two bugs in bpfilter

This patches fix two bugs in the bpfilter_umh which are related in
iptables command.

The first patch adds an exit code for UMH process.
This provides an opportunity to cleanup members of the umh_info
to modules which use the UMH.
In order to identify UMH processes, a new flag PF_UMH is added.

The second patch makes the bpfilter_umh use UMH cleanup callback.

The third patch adds re-start routine for the bpfilter_umh.
The bpfilter_umh does not re-start after error occurred.
because there is no re-start routine in the module.

The fourth patch ensures that the bpfilter.ko module will not removed while
it's being used.
The bpfilter.ko is not protected by locks or module reference counter.
Therefore that can be removed while module is being used.
In order to protect that, mutex is used.

The first and second patch are preparation patches for the third and
fourth patch.

TEST #1
   while :
   do
	modprobe bpfilter
	kill -9 <pid of the bpfilter_umh>
	iptables -vnL
   done

TEST #2
   while :
   do
	iptables -I FORWARD -m string --string ap --algo kmp &
	iptables -F &
	modprobe -rv bpfilter &
   done

TEST #3
   while :
   do
	modprobe bpfilter &
	modprobe -rv bpfilter &
   done

The TEST1 makes a failure of iptables command.
This is fixed by the third patch.

The TEST2 makes a panic because of a race condition in the bpfilter_umh
module.
This is fixed by the fourth patch.

The TEST3 makes a double-create UMH process.
This is fixed by the third and fourth patch.

v4 :
 - declare the exit_umh() as static inline
 - check stop flag in the load_umh() to avoid a double-create UMH
v3 :
 - Avoid unnecessary list lookup for non-UMH processes
 - Add a new PF_UMH flag
v2 : add the first and second patch
v1 : Initial patch
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
mihailescu2m pushed a commit that referenced this pull request Jan 28, 2019
We were experiencing a crash similar to the one reported as part of
commit:a5ba1d95e46e ("uart: fix race between uart_put_char() and
uart_shutdown()") in our testbed as well. We continue to observe the same
crash after integrating the commit a5ba1d9 ("uart: fix race between
uart_put_char() and uart_shutdown()")

On reviewing the change, the port lock should be taken prior to checking for
if (!circ->buf) in fn. __uart_put_char and other fns. that update the buffer
uart_state->xmit.

Traceback:

[11/27/2018 06:24:32.4870] Unable to handle kernel NULL pointer dereference
                           at virtual address 0000003b

[11/27/2018 06:24:32.4950] PC is at memcpy+0x48/0x180
[11/27/2018 06:24:32.4950] LR is at uart_write+0x74/0x120
[11/27/2018 06:24:32.4950] pc : [<ffffffc0002e6808>]
                           lr : [<ffffffc0003747cc>] pstate: 000001c5
[11/27/2018 06:24:32.4950] sp : ffffffc076433d30
[11/27/2018 06:24:32.4950] x29: ffffffc076433d30 x28: 0000000000000140
[11/27/2018 06:24:32.4950] x27: ffffffc0009b9d5e x26: ffffffc07ce36580
[11/27/2018 06:24:32.4950] x25: 0000000000000000 x24: 0000000000000140
[11/27/2018 06:24:32.4950] x23: ffffffc000891200 x22: ffffffc01fc34000
[11/27/2018 06:24:32.4950] x21: 0000000000000fff x20: 0000000000000076
[11/27/2018 06:24:32.4950] x19: 0000000000000076 x18: 0000000000000000
[11/27/2018 06:24:32.4950] x17: 000000000047cf08 x16: ffffffc000099e68
[11/27/2018 06:24:32.4950] x15: 0000000000000018 x14: 776d726966205948
[11/27/2018 06:24:32.4950] x13: 50203a6c6974755f x12: 74647075205d3333
[11/27/2018 06:24:32.4950] x11: 3a35323a36203831 x10: 30322f37322f3131
[11/27/2018 06:24:32.4950] x9 : 5b205d303638342e x8 : 746164206f742070
[11/27/2018 06:24:32.4950] x7 : 7520736920657261 x6 : 000000000000003b
[11/27/2018 06:24:32.4950] x5 : 000000000000817a x4 : 0000000000000008
[11/27/2018 06:24:32.4950] x3 : 2f37322f31312a5b x2 : 000000000000006e
[11/27/2018 06:24:32.4950] x1 : ffffffc0009b9cf0 x0 : 000000000000003b

[11/27/2018 06:24:32.4950] CPU2: stopping
[11/27/2018 06:24:32.4950] CPU: 2 PID: 0 Comm: swapper/2 Tainted: P      D    O    4.1.51 #3
[11/27/2018 06:24:32.4950] Hardware name: Broadcom-v8A (DT)
[11/27/2018 06:24:32.4950] Call trace:
[11/27/2018 06:24:32.4950] [<ffffffc0000883b8>] dump_backtrace+0x0/0x150
[11/27/2018 06:24:32.4950] [<ffffffc00008851c>] show_stack+0x14/0x20
[11/27/2018 06:24:32.4950] [<ffffffc0005ee810>] dump_stack+0x90/0xb0
[11/27/2018 06:24:32.4950] [<ffffffc00008e844>] handle_IPI+0x18c/0x1a0
[11/27/2018 06:24:32.4950] [<ffffffc000080c68>] gic_handle_irq+0x88/0x90

Fixes: a5ba1d9 ("uart: fix race between uart_put_char() and uart_shutdown()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Samir Virmani <samir@embedur.com>
Acked-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mihailescu2m pushed a commit that referenced this pull request Feb 4, 2019
Song Liu reported crash in 'perf record':

  > #0  0x0000000000500055 in ordered_events(float, long double,...)(...) ()
  > #1  0x0000000000500196 in ordered_events.reinit ()
  > #2  0x00000000004fe413 in perf_session.process_events ()
  > #3  0x0000000000440431 in cmd_record ()
  > #4  0x00000000004a439f in run_builtin ()
  > #5  0x000000000042b3e5 in main ()"

This can happen when we get out of buffers during event processing.

The subsequent ordered_events__free() call assumes oe->buffer != NULL
and crashes. Add a check to prevent that.

Reported-by: Song Liu <liu.song.a23@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Song Liu <liu.song.a23@gmail.com>
Tested-by: Song Liu <liu.song.a23@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20190117113017.12977-1-jolsa@kernel.org
Fixes: d5ceb62 ("perf ordered_events: Add 'struct ordered_events_buffer' layer")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
mihailescu2m pushed a commit that referenced this pull request Feb 4, 2019
This patch adds quirk VID/PID IDs for the Opus #3 DAP (made by 'The Bit')
in order to enable Native DSD support.

[ NOTE: this could be handled in the generic way with fp->dvd_raw if
  we add 0x10cb to the vendor whitelist, but since 0x10cb shows a
  different vendor name (Erantech), put to the individual entry at
  this time -- tiwai ]

Signed-off-by: Olek Poplavsky <woodenbits@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
mihailescu2m pushed a commit that referenced this pull request Feb 4, 2019
The async_file might be freed before the disassociation has been ended,
causing qp shutdown to use after free on it.

Since uverbs_destroy_ufile_hw is not a fence, it returns if a
disassociation is ongoing in another thread. It has to be written this way
to avoid deadlock. However this means that the ufile FD close cannot
destroy anything that may still be used by an active kref, such as the the
async_file.

To fix that move the kref_put() to be in ib_uverbs_release_file().

 BUG: unable to handle kernel paging request at ffffffffba682787
 PGD bc80e067 P4D bc80e067 PUD bc80f063 PMD 1313df163 PTE 80000000bc682061
 Oops: 0003 [#1] SMP PTI
 CPU: 1 PID: 32410 Comm: bash Tainted: G           OE 4.20.0-rc6+ #3
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:__pv_queued_spin_lock_slowpath+0x1b3/0x2a0
 Code: 98 83 e2 60 49 89 df 48 8b 04 c5 80 18 72 ba 48 8d
		ba 80 32 02 00 ba 00 80 00 00 4c 8d 65 14 41 bd 01 00 00 00 48 01 c7 85
		d2 <48> 89 2f 48 89 fb 74 14 8b 45 08 85 c0 75 42 84 d2 74 6b f3 90 83
 RSP: 0018:ffffc1bbc064fb58 EFLAGS: 00010006
 RAX: ffffffffba65f4e7 RBX: ffff9f209c656c00 RCX: 0000000000000001
 RDX: 0000000000008000 RSI: 0000000000000000 RDI: ffffffffba682787
 RBP: ffff9f217bb23280 R08: 0000000000000001 R09: 0000000000000000
 R10: ffff9f209d2c7800 R11: ffffffffffffffe8 R12: ffff9f217bb23294
 R13: 0000000000000001 R14: 0000000000000000 R15: ffff9f209c656c00
 FS:  00007fac55aad740(0000) GS:ffff9f217bb00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffffffffba682787 CR3: 000000012f8e0000 CR4: 00000000000006e0
 Call Trace:
  _raw_spin_lock_irq+0x27/0x30
  ib_uverbs_release_uevent+0x1e/0xa0 [ib_uverbs]
  uverbs_free_qp+0x7e/0x90 [ib_uverbs]
  destroy_hw_idr_uobject+0x1c/0x50 [ib_uverbs]
  uverbs_destroy_uobject+0x2e/0x180 [ib_uverbs]
  __uverbs_cleanup_ufile+0x73/0x90 [ib_uverbs]
  uverbs_destroy_ufile_hw+0x5d/0x120 [ib_uverbs]
  ib_uverbs_remove_one+0xea/0x240 [ib_uverbs]
  ib_unregister_device+0xfb/0x200 [ib_core]
  mlx5_ib_remove+0x51/0xe0 [mlx5_ib]
  mlx5_remove_device+0xc1/0xd0 [mlx5_core]
  mlx5_unregister_device+0x3d/0xb0 [mlx5_core]
  remove_one+0x2a/0x90 [mlx5_core]
  pci_device_remove+0x3b/0xc0
  device_release_driver_internal+0x16d/0x240
  unbind_store+0xb2/0x100
  kernfs_fop_write+0x102/0x180
  __vfs_write+0x36/0x1a0
  ? __alloc_fd+0xa9/0x170
  ? set_close_on_exec+0x49/0x70
  vfs_write+0xad/0x1a0
  ksys_write+0x52/0xc0
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fac551aac60

Cc: <stable@vger.kernel.org> # 4.2
Fixes: 036b106 ("IB/uverbs: Enable device removal when there are active user space applications")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
mihailescu2m pushed a commit that referenced this pull request Feb 4, 2019
Methods cannot peak into the ufile, the only way to get a ucontext and
hence a device is via the ib_uverbs_get_ucontext() call or inspecing a
locked uobject.

Otherwise during/after disassociation the pointers may be null or free'd.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
 PGD 800000005ece6067 P4D 800000005ece6067 PUD 5ece7067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 0 PID: 10631 Comm: ibv_ud_pingpong Tainted: GW  OE     4.20.0-rc6+ #3
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:ib_uverbs_handler_UVERBS_METHOD_QUERY_PORT+0x53/0x191 [ib_uverbs]
 Code: 80 00 00 00 31 c0 48 8b 47 40 48 8d 5c 24 38 48 8d 6c 24
               08 48 89 df 48 8b 40 08 4c 8b a0 18 03 00 00 31 c0 f3 48 ab 48 89
               ef <49> 83 7c 24 78 00 b1 06 f3 48 ab 0f 84 89 00 00 00 45 31  c9 31 d2
 RSP: 0018:ffffb54802ccfb10 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffffb54802ccfb48 RCX:0000000000000000
 RDX: fffffffffffffffa RSI: ffffb54802ccfcf8 RDI:ffffb54802ccfb18
 RBP: ffffb54802ccfb18 R08: ffffb54802ccfd18 R09:0000000000000000
 R10: 0000000000000000 R11: 00000000000000d0 R12:0000000000000000
 R13: ffffb54802ccfcb0 R14: ffffb54802ccfc48 R15:ffff9f736e0059a0
 FS:  00007f55a6bd7740(0000) GS:ffff9f737ba00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000078 CR3: 0000000064214000 CR4:00000000000006f0
 Call Trace:
  ib_uverbs_cmd_verbs.isra.5+0x94d/0xa60 [ib_uverbs]
  ? copy_port_attr_to_resp+0x120/0x120 [ib_uverbs]
  ? arch_tlb_finish_mmu+0x16/0xc0
  ? tlb_finish_mmu+0x1f/0x30
  ? unmap_region+0xd9/0x120
  ib_uverbs_ioctl+0xbc/0x120 [ib_uverbs]
  do_vfs_ioctl+0xa9/0x620
  ? __do_munmap+0x29f/0x3a0
  ksys_ioctl+0x60/0x90
  __x64_sys_ioctl+0x16/0x20
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f55a62cb567

Fixes: 641d120 ("IB/core: Move query port to ioctl")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
mihailescu2m pushed a commit that referenced this pull request Feb 4, 2019
The vma->vm_mm can become impossible to get before rdma_umap_close() is
called, in this case we must not try to get an mm that is already
undergoing process exit. In this case there is no need to wait for
anything as the VMA will be destroyed by another thread soon and is
already effectively 'unreachable' by userspace.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 PGD 800000012bc50067 P4D 800000012bc50067 PUD 129db5067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 1 PID: 2050 Comm: bash Tainted: G        W  OE 4.20.0-rc6+ #3
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:__rb_erase_color+0xb9/0x280
 Code: 84 17 01 00 00 48 3b 68 10 0f 84 15 01 00 00 48 89
               58 08 48 89 de 48 89 ef 4c 89 e3 e8 90 84 22 00 e9 60 ff ff ff 48 8b 5d
               10 <f6> 03 01 0f 84 9c 00 00 00 48 8b 43 10 48 85 c0 74 09 f6 00 01 0f
 RSP: 0018:ffffbecfc090bab8 EFLAGS: 00010246
 RAX: ffff97616346cf30 RBX: 0000000000000000 RCX: 0000000000000101
 RDX: 0000000000000000 RSI: ffff97623b6ca828 RDI: ffff97621ef10828
 RBP: ffff97621ef10828 R08: ffff97621ef10828 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff97623b6ca838
 R13: ffffffffbb3fef50 R14: ffff97623b6ca828 R15: 0000000000000000
 FS:  00007f7a5c31d740(0000) GS:ffff97623bb00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000011255a000 CR4: 00000000000006e0
 Call Trace:
  unlink_file_vma+0x3b/0x50
  free_pgtables+0xa1/0x110
  exit_mmap+0xca/0x1a0
  ? mlx5_ib_dealloc_pd+0x28/0x30 [mlx5_ib]
  mmput+0x54/0x140
  uverbs_user_mmap_disassociate+0xcc/0x160 [ib_uverbs]
  uverbs_destroy_ufile_hw+0xf7/0x120 [ib_uverbs]
  ib_uverbs_remove_one+0xea/0x240 [ib_uverbs]
  ib_unregister_device+0xfb/0x200 [ib_core]
  mlx5_ib_remove+0x51/0xe0 [mlx5_ib]
  mlx5_remove_device+0xc1/0xd0 [mlx5_core]
  mlx5_unregister_device+0x3d/0xb0 [mlx5_core]
  remove_one+0x2a/0x90 [mlx5_core]
  pci_device_remove+0x3b/0xc0
  device_release_driver_internal+0x16d/0x240
  unbind_store+0xb2/0x100
  kernfs_fop_write+0x102/0x180
  __vfs_write+0x36/0x1a0
  ? __alloc_fd+0xa9/0x170
  ? set_close_on_exec+0x49/0x70
  vfs_write+0xad/0x1a0
  ksys_write+0x52/0xc0
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Cc: <stable@vger.kernel.org> # 4.19
Fixes: 5f9794d ("RDMA/ucontext: Add a core API for mmaping driver IO memory")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
mihailescu2m pushed a commit that referenced this pull request Feb 4, 2019
…l/git/tiwai/sound

Pull sound fixes from Takashi Iwai:
 "Only three fixes.

  The fix for Realtek HD-audio looks lengthy, but it's just a code
  shuffling, and the actual changes are fairly small.

  The rest are a PCM core fix for a long-standing bug that was recently
  scratched by syzkaller, and a trivial USB-audio quirk for DSD support"

* tag 'sound-5.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Fixed hp_pin no value
  ALSA: pcm: Fix tight loop of OSS capture stream
  ALSA: usb-audio: Add Opus #3 to quirks for native DSD support
mihailescu2m pushed a commit that referenced this pull request Feb 4, 2019
When option CONFIG_KASAN is enabled toghether with ftrace, function
ftrace_graph_caller() gets in to a recursion, via functions
kasan_check_read() and kasan_check_write().

 Breakpoint 2, ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
 179             mcount_get_pc             x0    //     function's pc
 (gdb) bt
 #0  ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
 #1  0xffffff90101406c8 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151
 #2  0xffffff90106fd084 in kasan_check_write (p=0xffffffc06c170878, size=4) at ../mm/kasan/common.c:105
 #3  0xffffff90104a2464 in atomic_add_return (v=<optimized out>, i=<optimized out>) at ./include/generated/atomic-instrumented.h:71
 #4  atomic_inc_return (v=<optimized out>) at ./include/generated/atomic-fallback.h:284
 #5  trace_graph_entry (trace=0xffffffc03f5ff380) at ../kernel/trace/trace_functions_graph.c:441
 #6  0xffffff9010481774 in trace_graph_entry_watchdog (trace=<optimized out>) at ../kernel/trace/trace_selftest.c:741
 #7  0xffffff90104a185c in function_graph_enter (ret=<optimized out>, func=<optimized out>, frame_pointer=18446743799894897728, retp=<optimized out>) at ../kernel/trace/trace_functions_graph.c:196
 #8  0xffffff9010140628 in prepare_ftrace_return (self_addr=18446743592948977792, parent=0xffffffc03f5ff418, frame_pointer=18446743799894897728) at ../arch/arm64/kernel/ftrace.c:231
 #9  0xffffff90101406f4 in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182
 Backtrace stopped: previous frame identical to this frame (corrupt stack?)
 (gdb)

Rework so that the kasan implementation isn't traced.

Link: http://lkml.kernel.org/r/20181212183447.15890-1-anders.roxell@linaro.org
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mihailescu2m pushed a commit that referenced this pull request Feb 14, 2019
The H6 main pin controller has four banks of interrupt-triggering pins.
The driver as originally submitted only specified three, but had pin
descriptions referencing a fourth bank. This results in a out-of-bounds
access into .irq_array of struct sunxi_pinctrl. This however did not
result in a crash until v4.20, with commit a66d972 ("devres: Align
data[] to ARCH_KMALLOC_MINALIGN"), which changed the alignment of memory
region returned by devm_kcalloc(). The increase likely moved the
out-of-bounds access into the next, unmapped page.

With KASAN on, the bug is quite clear:

    BUG: KASAN: slab-out-of-bounds in sunxi_pinctrl_init_with_variant+0x49c/0x12b8
    Write of size 4 at addr ffff80002c680280 by task swapper/0/1

    CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc1-00016-gc480a5e6a077 #3
    Hardware name: OrangePi Lite2 (DT)
    Call trace:
     dump_backtrace+0x0/0x220
     show_stack+0x14/0x20
     dump_stack+0xac/0xd4
     print_address_description+0x60/0x25c
     kasan_report+0x14c/0x1ac
     __asan_store4+0x80/0xa0
     sunxi_pinctrl_init_with_variant+0x49c/0x12b8
     h6_pinctrl_probe+0x18/0x20
     platform_drv_probe+0x6c/0xc8
     really_probe+0x244/0x4b0
     driver_probe_device.part.4+0x11c/0x164
     __driver_attach+0x120/0x190
     bus_for_each_dev+0xe8/0x158
     driver_attach+0x30/0x40
     bus_add_driver+0x308/0x318
     driver_register+0xbc/0x1d0
     __platform_driver_register+0x7c/0x88
     h6_pinctrl_driver_init+0x18/0x20
     do_one_initcall+0xd4/0x208
     kernel_init_freeable+0x230/0x2c8
     kernel_init+0x10/0x108
     ret_from_fork+0x10/0x1c

    Allocated by task 1:
     kasan_kmalloc.part.0+0x4c/0x100
     kasan_kmalloc+0xc4/0xe8
     kasan_slab_alloc+0x14/0x20
     __kmalloc_track_caller+0x130/0x238
     devm_kmalloc+0x34/0xd0
     sunxi_pinctrl_init_with_variant+0x1d8/0x12b8
     h6_pinctrl_probe+0x18/0x20
     platform_drv_probe+0x6c/0xc8
     really_probe+0x244/0x4b0
     driver_probe_device.part.4+0x11c/0x164
     __driver_attach+0x120/0x190
     bus_for_each_dev+0xe8/0x158
     driver_attach+0x30/0x40
     bus_add_driver+0x308/0x318
     driver_register+0xbc/0x1d0
     __platform_driver_register+0x7c/0x88
     h6_pinctrl_driver_init+0x18/0x20
     do_one_initcall+0xd4/0x208
     kernel_init_freeable+0x230/0x2c8
     kernel_init+0x10/0x108
     ret_from_fork+0x10/0x1c

    Freed by task 0:
    (stack is not available)

    The buggy address belongs to the object at ffff80002c680080
     which belongs to the cache kmalloc-512 of size 512
    The buggy address is located 0 bytes to the right of
     512-byte region [ffff80002c680080, ffff80002c680280)
    The buggy address belongs to the page:
    page:ffff7e0000b1a000 count:1 mapcount:0 mapping:ffff80002e00c780 index:0xffff80002c683c80 compound_mapcount: 0
    flags: 0x10200(slab|head)
    raw: 0000000000010200 ffff80002e003a10 ffff80002e003a10 ffff80002e00c780
    raw: ffff80002c683c80 0000000000100001 00000001ffffffff 0000000000000000
    page dumped because: kasan: bad access detected

    Memory state around the buggy address:
     ffff80002c680180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     ffff80002c680200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    >ffff80002c680280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
		       ^
     ffff80002c680300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
     ffff80002c680380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Correct the number of IRQ banks so there are no more mismatches.

Fixes: c8a8309 ("pinctrl: sunxi: add support for the Allwinner H6 main pin controller")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
mihailescu2m pushed a commit that referenced this pull request Feb 14, 2019
Lockdep found a potential deadlock between cpu_hotplug_lock, bpf_event_mutex, and cpuctx_mutex:
[   13.007000] WARNING: possible circular locking dependency detected
[   13.007587] 5.0.0-rc3-00018-g2fa53f892422-dirty torvalds#477 Not tainted
[   13.008124] ------------------------------------------------------
[   13.008624] test_progs/246 is trying to acquire lock:
[   13.009030] 0000000094160d1d (tracepoints_mutex){+.+.}, at: tracepoint_probe_register_prio+0x2d/0x300
[   13.009770]
[   13.009770] but task is already holding lock:
[   13.010239] 00000000d663ef86 (bpf_event_mutex){+.+.}, at: bpf_probe_register+0x1d/0x60
[   13.010877]
[   13.010877] which lock already depends on the new lock.
[   13.010877]
[   13.011532]
[   13.011532] the existing dependency chain (in reverse order) is:
[   13.012129]
[   13.012129] -> #4 (bpf_event_mutex){+.+.}:
[   13.012582]        perf_event_query_prog_array+0x9b/0x130
[   13.013016]        _perf_ioctl+0x3aa/0x830
[   13.013354]        perf_ioctl+0x2e/0x50
[   13.013668]        do_vfs_ioctl+0x8f/0x6a0
[   13.014003]        ksys_ioctl+0x70/0x80
[   13.014320]        __x64_sys_ioctl+0x16/0x20
[   13.014668]        do_syscall_64+0x4a/0x180
[   13.015007]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   13.015469]
[   13.015469] -> #3 (&cpuctx_mutex){+.+.}:
[   13.015910]        perf_event_init_cpu+0x5a/0x90
[   13.016291]        perf_event_init+0x1b2/0x1de
[   13.016654]        start_kernel+0x2b8/0x42a
[   13.016995]        secondary_startup_64+0xa4/0xb0
[   13.017382]
[   13.017382] -> #2 (pmus_lock){+.+.}:
[   13.017794]        perf_event_init_cpu+0x21/0x90
[   13.018172]        cpuhp_invoke_callback+0xb3/0x960
[   13.018573]        _cpu_up+0xa7/0x140
[   13.018871]        do_cpu_up+0xa4/0xc0
[   13.019178]        smp_init+0xcd/0xd2
[   13.019483]        kernel_init_freeable+0x123/0x24f
[   13.019878]        kernel_init+0xa/0x110
[   13.020201]        ret_from_fork+0x24/0x30
[   13.020541]
[   13.020541] -> #1 (cpu_hotplug_lock.rw_sem){++++}:
[   13.021051]        static_key_slow_inc+0xe/0x20
[   13.021424]        tracepoint_probe_register_prio+0x28c/0x300
[   13.021891]        perf_trace_event_init+0x11f/0x250
[   13.022297]        perf_trace_init+0x6b/0xa0
[   13.022644]        perf_tp_event_init+0x25/0x40
[   13.023011]        perf_try_init_event+0x6b/0x90
[   13.023386]        perf_event_alloc+0x9a8/0xc40
[   13.023754]        __do_sys_perf_event_open+0x1dd/0xd30
[   13.024173]        do_syscall_64+0x4a/0x180
[   13.024519]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   13.024968]
[   13.024968] -> #0 (tracepoints_mutex){+.+.}:
[   13.025434]        __mutex_lock+0x86/0x970
[   13.025764]        tracepoint_probe_register_prio+0x2d/0x300
[   13.026215]        bpf_probe_register+0x40/0x60
[   13.026584]        bpf_raw_tracepoint_open.isra.34+0xa4/0x130
[   13.027042]        __do_sys_bpf+0x94f/0x1a90
[   13.027389]        do_syscall_64+0x4a/0x180
[   13.027727]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   13.028171]
[   13.028171] other info that might help us debug this:
[   13.028171]
[   13.028807] Chain exists of:
[   13.028807]   tracepoints_mutex --> &cpuctx_mutex --> bpf_event_mutex
[   13.028807]
[   13.029666]  Possible unsafe locking scenario:
[   13.029666]
[   13.030140]        CPU0                    CPU1
[   13.030510]        ----                    ----
[   13.030875]   lock(bpf_event_mutex);
[   13.031166]                                lock(&cpuctx_mutex);
[   13.031645]                                lock(bpf_event_mutex);
[   13.032135]   lock(tracepoints_mutex);
[   13.032441]
[   13.032441]  *** DEADLOCK ***
[   13.032441]
[   13.032911] 1 lock held by test_progs/246:
[   13.033239]  #0: 00000000d663ef86 (bpf_event_mutex){+.+.}, at: bpf_probe_register+0x1d/0x60
[   13.033909]
[   13.033909] stack backtrace:
[   13.034258] CPU: 1 PID: 246 Comm: test_progs Not tainted 5.0.0-rc3-00018-g2fa53f892422-dirty torvalds#477
[   13.034964] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
[   13.035657] Call Trace:
[   13.035859]  dump_stack+0x5f/0x8b
[   13.036130]  print_circular_bug.isra.37+0x1ce/0x1db
[   13.036526]  __lock_acquire+0x1158/0x1350
[   13.036852]  ? lock_acquire+0x98/0x190
[   13.037154]  lock_acquire+0x98/0x190
[   13.037447]  ? tracepoint_probe_register_prio+0x2d/0x300
[   13.037876]  __mutex_lock+0x86/0x970
[   13.038167]  ? tracepoint_probe_register_prio+0x2d/0x300
[   13.038600]  ? tracepoint_probe_register_prio+0x2d/0x300
[   13.039028]  ? __mutex_lock+0x86/0x970
[   13.039337]  ? __mutex_lock+0x24a/0x970
[   13.039649]  ? bpf_probe_register+0x1d/0x60
[   13.039992]  ? __bpf_trace_sched_wake_idle_without_ipi+0x10/0x10
[   13.040478]  ? tracepoint_probe_register_prio+0x2d/0x300
[   13.040906]  tracepoint_probe_register_prio+0x2d/0x300
[   13.041325]  bpf_probe_register+0x40/0x60
[   13.041649]  bpf_raw_tracepoint_open.isra.34+0xa4/0x130
[   13.042068]  ? __might_fault+0x3e/0x90
[   13.042374]  __do_sys_bpf+0x94f/0x1a90
[   13.042678]  do_syscall_64+0x4a/0x180
[   13.042975]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   13.043382] RIP: 0033:0x7f23b10a07f9
[   13.045155] RSP: 002b:00007ffdef42fdd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141
[   13.045759] RAX: ffffffffffffffda RBX: 00007ffdef42ff70 RCX: 00007f23b10a07f9
[   13.046326] RDX: 0000000000000070 RSI: 00007ffdef42fe10 RDI: 0000000000000011
[   13.046893] RBP: 00007ffdef42fdf0 R08: 0000000000000038 R09: 00007ffdef42fe10
[   13.047462] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
[   13.048029] R13: 0000000000000016 R14: 00007f23b1db4690 R15: 0000000000000000

Since tracepoints_mutex will be taken in tracepoint_probe_register/unregister()
there is no need to take bpf_event_mutex too.
bpf_event_mutex is protecting modifications to prog array used in kprobe/perf bpf progs.
bpf_raw_tracepoints don't need to take this mutex.

Fixes: c4f6699 ("bpf: introduce BPF_RAW_TRACEPOINT")
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
mihailescu2m pushed a commit that referenced this pull request Feb 27, 2019
Evaluating page_mapping() on a poisoned page ends up dereferencing junk
and making PF_POISONED_CHECK() considerably crashier than intended:

    Unable to handle kernel NULL pointer dereference at virtual address 0000000000000006
    Mem abort info:
      ESR = 0x96000005
      Exception class = DABT (current EL), IL = 32 bits
      SET = 0, FnV = 0
      EA = 0, S1PTW = 0
    Data abort info:
      ISV = 0, ISS = 0x00000005
      CM = 0, WnR = 0
    user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000c2f6ac38
    [0000000000000006] pgd=0000000000000000, pud=0000000000000000
    Internal error: Oops: 96000005 [#1] PREEMPT SMP
    Modules linked in:
    CPU: 2 PID: 491 Comm: bash Not tainted 5.0.0-rc1+ #1
    Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Dec 17 2018
    pstate: 00000005 (nzcv daif -PAN -UAO)
    pc : page_mapping+0x18/0x118
    lr : __dump_page+0x1c/0x398
    Process bash (pid: 491, stack limit = 0x000000004ebd4ecd)
    Call trace:
     page_mapping+0x18/0x118
     __dump_page+0x1c/0x398
     dump_page+0xc/0x18
     remove_store+0xbc/0x120
     dev_attr_store+0x18/0x28
     sysfs_kf_write+0x40/0x50
     kernfs_fop_write+0x130/0x1d8
     __vfs_write+0x30/0x180
     vfs_write+0xb4/0x1a0
     ksys_write+0x60/0xd0
     __arm64_sys_write+0x18/0x20
     el0_svc_common+0x94/0xf8
     el0_svc_handler+0x68/0x70
     el0_svc+0x8/0xc
    Code: f9400401 d1000422 f240003f 9a801040 (f9400402)
    ---[ end trace cdb5eb5bf435cecb ]---

Fix that by not inspecting the mapping until we've determined that it's
likely to be valid.  Now the above condition still ends up stopping the
kernel, but in the correct manner:

    page:ffffffbf20000000 is uninitialized and poisoned
    raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
    raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
    page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
    ------------[ cut here ]------------
    kernel BUG at ./include/linux/mm.h:1006!
    Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
    Modules linked in:
    CPU: 1 PID: 483 Comm: bash Not tainted 5.0.0-rc1+ #3
    Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Dec 17 2018
    pstate: 40000005 (nZcv daif -PAN -UAO)
    pc : remove_store+0xbc/0x120
    lr : remove_store+0xbc/0x120
    ...

Link: http://lkml.kernel.org/r/03b53ee9d7e76cda4b9b5e1e31eea080db033396.1550071778.git.robin.murphy@arm.com
Fixes: 1c6fb1d ("mm: print more information about mapping in __dump_page")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mihailescu2m pushed a commit that referenced this pull request Nov 7, 2019
8-letter strings representing ARC perf events are stores in two
32-bit registers as ASCII characters like that: "IJMP", "IALL", "IJMPTAK" etc.

And the same order of bytes in the word is used regardless CPU endianness.

Which means in case of big-endian CPU core we need to swap bytes to get
the same order as if it was on little-endian CPU.

Otherwise we're seeing the following error message on boot:
------------------------->8----------------------
ARC perf        : 8 counters (32 bits), 40 conditions, [overflow IRQ support]
sysfs: cannot create duplicate filename '/devices/arc_pct/events/pmji'
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3
Stack Trace:
  arc_unwind_core+0xd4/0xfc
  dump_stack+0x64/0x80
  sysfs_warn_dup+0x46/0x58
  sysfs_add_file_mode_ns+0xb2/0x168
  create_files+0x70/0x2a0
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at kernel/events/core.c:12144 perf_event_sysfs_init+0x70/0xa0
Failed to register pmu: arc_pct, reason -17
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3
Stack Trace:
  arc_unwind_core+0xd4/0xfc
  dump_stack+0x64/0x80
  __warn+0x9c/0xd4
  warn_slowpath_fmt+0x22/0x2c
  perf_event_sysfs_init+0x70/0xa0
---[ end trace a75fb9a9837bd1ec ]---
------------------------->8----------------------

What happens here we're trying to register more than one raw perf event
with the same name "PMJI". Why? Because ARC perf events are 4 to 8 letters
and encoded into two 32-bit words. In this particular case we deal with 2
events:
 * "IJMP____" which counts all jump & branch instructions
 * "IJMPC___" which counts only conditional jumps & branches

Those strings are split in two 32-bit words this way "IJMP" + "____" &
"IJMP" + "C___" correspondingly. Now if we read them swapped due to CPU core
being big-endian then we read "PMJI" + "____" & "PMJI" + "___C".

And since we interpret read array of ASCII letters as a null-terminated string
on big-endian CPU we end up with 2 events of the same name "PMJI".

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
mihailescu2m pushed a commit that referenced this pull request Nov 14, 2019
When lockdep is enabled, plugging Thunderbolt dock on Dominik's laptop
triggers following splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.3.0-rc6+ #1 Tainted: G                T
  ------------------------------------------------------
  pool-/usr/lib/b/1258 is trying to acquire lock:
  000000005ab0ad43 (pci_rescan_remove_lock){+.+.}, at: authorized_store+0xe8/0x210

  but task is already holding lock:
  00000000bfb796b5 (&tb->lock){+.+.}, at: authorized_store+0x7c/0x210

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #1 (&tb->lock){+.+.}:
         __mutex_lock+0xac/0x9a0
         tb_domain_add+0x2d/0x130
         nhi_probe+0x1dd/0x330
         pci_device_probe+0xd2/0x150
         really_probe+0xee/0x280
         driver_probe_device+0x50/0xc0
         bus_for_each_drv+0x84/0xd0
         __device_attach+0xe4/0x150
         pci_bus_add_device+0x4e/0x70
         pci_bus_add_devices+0x2e/0x66
         pci_bus_add_devices+0x59/0x66
         pci_bus_add_devices+0x59/0x66
         enable_slot+0x344/0x450
         acpiphp_check_bridge.part.0+0x119/0x150
         acpiphp_hotplug_notify+0xaa/0x140
         acpi_device_hotplug+0xa2/0x3f0
         acpi_hotplug_work_fn+0x1a/0x30
         process_one_work+0x234/0x580
         worker_thread+0x50/0x3b0
         kthread+0x10a/0x140
         ret_from_fork+0x3a/0x50

  -> #0 (pci_rescan_remove_lock){+.+.}:
         __lock_acquire+0xe54/0x1ac0
         lock_acquire+0xb8/0x1b0
         __mutex_lock+0xac/0x9a0
         authorized_store+0xe8/0x210
         kernfs_fop_write+0x125/0x1b0
         vfs_write+0xc2/0x1d0
         ksys_write+0x6c/0xf0
         do_syscall_64+0x50/0x180
         entry_SYSCALL_64_after_hwframe+0x49/0xbe

  other info that might help us debug this:
   Possible unsafe locking scenario:
         CPU0                    CPU1
         ----                    ----
    lock(&tb->lock);
                                 lock(pci_rescan_remove_lock);
                                 lock(&tb->lock);
    lock(pci_rescan_remove_lock);

   *** DEADLOCK ***
  5 locks held by pool-/usr/lib/b/1258:
   #0: 000000003df1a1ad (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x4d/0x60
   #1: 0000000095a40b02 (sb_writers#6){.+.+}, at: vfs_write+0x185/0x1d0
   #2: 0000000017a7d714 (&of->mutex){+.+.}, at: kernfs_fop_write+0xf2/0x1b0
   #3: 000000004f262981 (kn->count#208){.+.+}, at: kernfs_fop_write+0xfa/0x1b0
   #4: 00000000bfb796b5 (&tb->lock){+.+.}, at: authorized_store+0x7c/0x210

  stack backtrace:
  CPU: 0 PID: 1258 Comm: pool-/usr/lib/b Tainted: G                T 5.3.0-rc6+ #1

On an system using ACPI hotplug the host router gets hotplugged first and then
the firmware starts sending notifications about connected devices so the above
scenario should not happen in reality. However, after taking a second
look at commit a03e828 ("thunderbolt: Serialize PCIe tunnel
creation with PCI rescan") that introduced the locking, I don't think it
is actually correct. It may have cured the symptom but probably the real
root cause was somewhere closer to PCI stack and possibly is already
fixed with recent kernels. I also tried to reproduce the original issue
with the commit reverted but could not.

So to keep lockdep happy and the code bit less complex drop calls to
pci_lock_rescan_remove()/pci_unlock_rescan_remove() in
tb_switch_set_authorized() effectively reverting a03e828.

Link: https://lkml.org/lkml/2019/8/30/513
Fixes: a03e828 ("thunderbolt: Serialize PCIe tunnel creation with PCI rescan")
Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
mihailescu2m pushed a commit that referenced this pull request Nov 27, 2019
Call napi_disable() twice would cause dead lock. There are three situations
may result in the issue.

1. rtl8152_pre_reset() and set_carrier() are run at the same time.
2. Call rtl8152_set_tunable() after rtl8152_close().
3. Call rtl8152_set_ringparam() after rtl8152_close().

For #1, use the same solution as commit 8481141 ("r8152: Re-order
napi_disable in rtl8152_close"). For #2 and #3, add checking the flag
of IFF_UP and using napi_disable/napi_enable during mutex.

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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