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mxc_hdmi: save & restore xres_virtual/yres_virtual with (re)applying … #23

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merged 2 commits into from
Oct 20, 2015

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mk01
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@mk01 mk01 commented Oct 19, 2015

…screen modes.

  • mxc_hdmi_set_mode() is restoring previous mode from saved structure which doesn't
    contain virtual dimensions (double/triple buffer).
  • this reallocates fb mem to one page and makes page flipping not work
  • restoring setup + mxc_hdmi_notify_fb() ensures proper allocations again

@mk01
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mk01 commented Oct 19, 2015

@linux4kix

wait please with any action, I forgot there is zeroing previous_mode in cable_disconnected now.

…arest_mode()

    is no longer usable (it is not considering various vmodes at all). add own function
mxc_fb_find_nearest_mode().
@mk01 mk01 force-pushed the 3.14-1.0.x-mx6-sr branch 2 times, most recently from 98af674 to e5ac91e Compare October 19, 2015 23:20
…screen modes.

- mxc_hdmi_set_mode() is restoring previous mode from saved structure which doesn't
contain virtual dimensions (double/triple buffer).
- this reallocates fb mem to one page and makes page flipping not work
- restoring setup + mxc_hdmi_notify_fb() ensures proper allocations again
@mk01
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mk01 commented Oct 19, 2015

@linux4kix

take a look. this is something what works, although I don't like it much.
open to suggestions.

linux4kix added a commit that referenced this pull request Oct 20, 2015
mxc_hdmi: save & restore xres_virtual/yres_virtual with (re)applying …
@linux4kix linux4kix merged commit 12c2973 into SolidRun:3.14-1.0.x-mx6-sr Oct 20, 2015
vpeter4 pushed a commit to vpeter4/linux-fslc that referenced this pull request Oct 22, 2015
Upstream-commit: de0e35e

state->buf_dma not being initialized can cause try_buf_map_to_sec4_sg
to try to free unallocated DMA memory:

caam_jr ffe301000.jr: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x000000002eb15068] [size=0 bytes]
WARNING: at lib/dma-debug.c:1080
Modules linked in: caamhash(+) [last unloaded: caamhash]
CPU: 0 PID: 1387 Comm: cryptomgr_test Tainted: G        W     3.16.0-rc1 SolidRun#23
task: eed24e90 ti: eebd0000 task.ti: eebd0000
NIP: c02889fc LR: c02889fc CTR: c02d7020
REGS: eebd1a50 TRAP: 0700   Tainted: G        W      (3.16.0-rc1)
MSR: 00029002 <CE,EE,ME>  CR: 44042082  XER: 00000000

GPR00: c02889fc eebd1b00 eed24e90 0000008d c1de3478 c1de382c 00000000 00029002
GPR08: 00000007 00000000 01660000 00000000 24042082 00000000 c07a1900 eeda2a40
GPR16: 005d62a0 c078ad4c 00000000 eeb15068 c07e1e10 c0da1180 00029002 c0d97408
GPR24: c62497a0 00000014 eebd1b5 00000000 c078ad4c ee130210 00000000 2eb15068
NIP [c02889fc] check_unmap+0x8ac/0xab0
LR [c02889fc] check_unmap+0x8ac/0xab0
Call Trace:
[eebd1b00] [c02889fc] check_unmap+0x8ac/0xab0 (unreliable)
--- Exception: 0 at   (null)
    LR =   (null)
[eebd1b50] [c0288c78] debug_dma_unmap_page+0x78/0x90 (unreliable)
[eebd1bd0] [f956f738] ahash_final_ctx+0x6d8/0x7b0 [caamhash]
[eebd1c30] [c022ff4c] __test_hash+0x2ac/0x6c0
[eebd1de0] [c0230388] test_hash+0x28/0xb0
[eebd1e00] [c02304a4] alg_test_hash+0x94/0xc0
[eebd1e20] [c022fa94] alg_test+0x114/0x2e0
[eebd1ea0] [c022cd1c] cryptomgr_test+0x4c/0x60
[eebd1eb0] [c00497a4] kthread+0xc4/0xe0
[eebd1f40] [c000f2fc] ret_from_kernel_thread+0x5c/0x64
Instruction dump:
41de01c8 80a9002c 2f850000 40fe0008 80a90008 80fa0018 3c60c06d 811a001c
3863f4a4 813a0020 815a0024 4830cd01 <0fe00000> 81340048 2f890000 40feff48

Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Conflicts:
	drivers/crypto/caam/caamhash.c
linux4kix pushed a commit that referenced this pull request Jan 26, 2016
Mike Galbraith captered the following:
| >#11 [ffff88017b243e90] _raw_spin_lock at ffffffff815d2596
| >#12 [ffff88017b243e90] rt_mutex_trylock at ffffffff815d15be
| >#13 [ffff88017b243eb0] get_next_timer_interrupt at ffffffff81063b42
| >#14 [ffff88017b243f00] tick_nohz_stop_sched_tick at ffffffff810bd1fd
| >#15 [ffff88017b243f70] tick_nohz_irq_exit at ffffffff810bd7d2
| >#16 [ffff88017b243f90] irq_exit at ffffffff8105b02d
| >#17 [ffff88017b243fb0] reschedule_interrupt at ffffffff815db3dd
| >--- <IRQ stack> ---
| >#18 [ffff88017a2a9bc8] reschedule_interrupt at ffffffff815db3dd
| >    [exception RIP: task_blocks_on_rt_mutex+51]
| >#19 [ffff88017a2a9ce0] rt_spin_lock_slowlock at ffffffff815d183c
| >#20 [ffff88017a2a9da0] lock_timer_base.isra.35 at ffffffff81061cbf
| >#21 [ffff88017a2a9dd0] schedule_timeout at ffffffff815cf1ce
| >#22 [ffff88017a2a9e50] rcu_gp_kthread at ffffffff810f9bbb
| >#23 [ffff88017a2a9ed0] kthread at ffffffff810796d5
| >#24 [ffff88017a2a9f50] ret_from_fork at ffffffff815da04c

lock_timer_base() does a try_lock() which deadlocks on the waiter lock
not the lock itself.
This patch takes the waiter_lock with trylock so it should work from interrupt
context as well. If the fastpath doesn't work and the waiter_lock itself is
taken then it seems that the lock itself taken.
This patch also adds "rt_spin_unlock_after_trylock_in_irq" to keep lockdep
happy. If we managed to take the wait_lock in the first place we should also
be able to take it in the unlock path.

Cc: stable-rt@vger.kernel.org
Reported-by: Mike Galbraith <bitbucket@online.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
linux4kix pushed a commit that referenced this pull request Jan 26, 2016
Since we replaced msleep() by hrtimer I see now and then (rarely) this:

| [....] Waiting for /dev to be fully populated...
| =====================================
| [ BUG: udevd/229 still has locks held! ]
| 3.12.11-rt17 #23 Not tainted
| -------------------------------------
| 1 lock held by udevd/229:
|  #0:  (&type->i_mutex_dir_key#2){+.+.+.}, at: lookup_slow+0x28/0x98
|
| stack backtrace:
| CPU: 0 PID: 229 Comm: udevd Not tainted 3.12.11-rt17 #23
| (unwind_backtrace+0x0/0xf8) from (show_stack+0x10/0x14)
| (show_stack+0x10/0x14) from (dump_stack+0x74/0xbc)
| (dump_stack+0x74/0xbc) from (do_nanosleep+0x120/0x160)
| (do_nanosleep+0x120/0x160) from (hrtimer_nanosleep+0x90/0x110)
| (hrtimer_nanosleep+0x90/0x110) from (cpu_chill+0x30/0x38)
| (cpu_chill+0x30/0x38) from (dentry_kill+0x158/0x1ec)
| (dentry_kill+0x158/0x1ec) from (dput+0x74/0x15c)
| (dput+0x74/0x15c) from (lookup_real+0x4c/0x50)
| (lookup_real+0x4c/0x50) from (__lookup_hash+0x34/0x44)
| (__lookup_hash+0x34/0x44) from (lookup_slow+0x38/0x98)
| (lookup_slow+0x38/0x98) from (path_lookupat+0x208/0x7fc)
| (path_lookupat+0x208/0x7fc) from (filename_lookup+0x20/0x60)
| (filename_lookup+0x20/0x60) from (user_path_at_empty+0x50/0x7c)
| (user_path_at_empty+0x50/0x7c) from (user_path_at+0x14/0x1c)
| (user_path_at+0x14/0x1c) from (vfs_fstatat+0x48/0x94)
| (vfs_fstatat+0x48/0x94) from (SyS_stat64+0x14/0x30)
| (SyS_stat64+0x14/0x30) from (ret_fast_syscall+0x0/0x48)

For now I see no better way but to disable the freezer the sleep the period.

Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
jnettlet pushed a commit that referenced this pull request Mar 23, 2018
commit 6ac5a11 upstream.

Xtensa memory initialization code frees high memory pages without
checking whether they are in the reserved memory regions or not. That
results in invalid value of totalram_pages and duplicate page usage by
CMA and highmem. It produces a bunch of BUGs at startup looking like
this:

BUG: Bad page state in process swapper  pfn:70800
page:be60c000 count:0 mapcount:-127 mapping:  (null) index:0x1
flags: 0x80000000()
raw: 80000000 00000000 00000001 ffffff80 00000000 be60c014 be60c014 0000000a
page dumped because: nonzero mapcount
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Tainted: G    B            4.16.0-rc1-00015-g7928b2cbe55b-dirty #23
Stack:
 bd839d33 00000000 00000018 ba97b64c a106578c bd839d70 be60c000 00000000
 a1378054 bd86a000 00000003 ba97b64c a1066166 bd839da0 be60c000 ffe00000
 a1066b58 bd839dc0 be504000 00000000 000002f4 bd838000 00000000 0000001e
Call Trace:
 [<a1065734>] bad_page+0xac/0xd0
 [<a106578c>] free_pages_check_bad+0x34/0x4c
 [<a1066166>] __free_pages_ok+0xae/0x14c
 [<a1066b58>] __free_pages+0x30/0x64
 [<a1365de5>] init_cma_reserved_pageblock+0x35/0x44
 [<a13682dc>] cma_init_reserved_areas+0xf4/0x148
 [<a10034b8>] do_one_initcall+0x80/0xf8
 [<a1361c16>] kernel_init_freeable+0xda/0x13c
 [<a125b59d>] kernel_init+0x9/0xd0
 [<a1004304>] ret_from_kernel_thread+0xc/0x18

Only free high memory pages that are not reserved.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jnettlet pushed a commit that referenced this pull request Mar 23, 2018
commit b9c97c6 upstream.

If m88d3103 chip ID is not recognized, the device is not initialized.

However, it returns from probe without any error, causing this OOPS:

[    7.689289] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[    7.689297] pgd = 7b0bd7a7
[    7.689302] [00000000] *pgd=00000000
[    7.689318] Internal error: Oops: 80000005 [#1] SMP ARM
[    7.689322] Modules linked in: dvb_usb_dvbsky(+) m88ds3103 dvb_usb_v2 dvb_core videobuf2_vmalloc videobuf2_memops videobuf2_core crc32_arm_ce videodev media
[    7.689358] CPU: 3 PID: 197 Comm: systemd-udevd Not tainted 4.15.0-mcc+ #23
[    7.689361] Hardware name: BCM2835
[    7.689367] PC is at 0x0
[    7.689382] LR is at m88ds3103_attach+0x194/0x1d0 [m88ds3103]
[    7.689386] pc : [<00000000>]    lr : [<bf0ae1ec>]    psr: 60000013
[    7.689391] sp : ed8e5c20  ip : ed8c1e00  fp : ed8945c0
[    7.689395] r10: ed894000  r9 : ed894378  r8 : eda736c0
[    7.689400] r7 : ed894070  r6 : ed8e5c44  r5 : bf0bb040  r4 : eda77600
[    7.689405] r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : eda77600
[    7.689412] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[    7.689417] Control: 10c5383d  Table: 2d8e806a  DAC: 00000051
[    7.689423] Process systemd-udevd (pid: 197, stack limit = 0xe9dbfb63)
[    7.689428] Stack: (0xed8e5c20 to 0xed8e6000)
[    7.689439] 5c20: ed853a80 eda73640 ed894000 ed8942c0 ed853a80 bf0b9e98 ed894070 bf0b9f10
[    7.689449] 5c40: 00000000 00000000 bf08c17c c08dfc50 00000000 00000000 00000000 00000000
[    7.689459] 5c60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    7.689468] 5c80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    7.689479] 5ca0: 00000000 00000000 ed8945c0 ed8942c0 ed894000 ed894830 bf0b9e98 00000000
[    7.689490] 5cc0: ed894378 bf0a3cb4 bf0bc3b0 0000533b ed920540 00000000 00000034 bf0a6434
[    7.689500] 5ce0: ee952070 ed826600 bf0a7038 bf0a2dd8 00000001 bf0a6768 bf0a2f90 ed8943c0
[    7.689511] 5d00: 00000000 c08eca68 ed826620 ed826620 00000000 ee952070 bf0bc034 ee952000
[    7.689521] 5d20: ed826600 bf0bb080 ffffffed c0aa9e9c c0aa9dac ed826620 c16edf6c c168c2c8
[    7.689531] 5d40: c16edf70 00000000 bf0bc034 0000000d 00000000 c08e268c bf0bb080 ed826600
[    7.689541] 5d60: bf0bc034 ed826654 ed826620 bf0bc034 c164c8bc 00000000 00000001 00000000
[    7.689553] 5d80: 00000028 c08e2948 00000000 bf0bc034 c08e2848 c08e0778 ee9f0a58 ed88bab4
[    7.689563] 5da0: bf0bc034 ed90ba80 c168c1f0 c08e1934 bf0bb3bc c17045ac bf0bc034 c164c8bc
[    7.689574] 5dc0: bf0bc034 bf0bb3bc ed91f564 c08e34ec bf0bc000 c164c8bc bf0bc034 c0aa8dc4
[    7.689584] 5de0: ffffe000 00000000 bf0bf000 ed91f600 ed91f564 c03021e4 00000001 00000000
[    7.689595] 5e00: c166e040 8040003f ed853a80 bf0bc448 00000000 c1678174 ed853a80 f0f22000
[    7.689605] 5e20: f0f21fff 8040003f 014000c0 ed91e700 ed91e700 c16d8e68 00000001 ed91e6c0
[    7.689615] 5e40: bf0bc400 00000001 bf0bc400 ed91f564 00000001 00000000 00000028 c03c9a24
[    7.689625] 5e60: 00000001 c03c8c94 ed8e5f50 ed8e5f50 00000001 bf0bc400 ed91f540 c03c8cb0
[    7.689637] 5e80: bf0bc40c 00007fff bf0bc400 c03c60b0 00000000 bf0bc448 00000028 c0e09684
[    7.689647] 5ea0: 00000002 bf0bc530 c1234bf8 bf0bc5dc bf0bc514 c10ebbe8 ffffe000 bf000000
[    7.689657] 5ec0: 00011538 00000000 ed8e5f48 00000000 00000000 00000000 00000000 00000000
[    7.689666] 5ee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    7.689676] 5f00: 00000000 00000000 7fffffff 00000000 00000013 b6e55a18 0000017b c0309104
[    7.689686] 5f20: ed8e4000 00000000 00510af0 c03c9430 7fffffff 00000000 00000003 00000000
[    7.689697] 5f40: 00000000 f0f0f000 00011538 00000000 f0f107b0 f0f0f000 00011538 f0f1fdb8
[    7.689707] 5f60: f0f1fbe8 f0f1b974 00004000 000041e0 bf0bc3d0 00000001 00000000 000024c4
[    7.689717] 5f80: 0000002d 0000002e 00000019 00000000 00000010 00000000 16894000 00000000
[    7.689727] 5fa0: 00000000 c0308f20 16894000 00000000 00000013 b6e55a18 00000000 b6e5652c
[    7.689737] 5fc0: 16894000 00000000 00000000 0000017b 00020000 00508110 00000000 00510af0
[    7.689748] 5fe0: bef68948 bef68938 b6e4d3d0 b6d32590 60000010 00000013 00000000 00000000
[    7.689790] [<bf0ae1ec>] (m88ds3103_attach [m88ds3103]) from [<bf0b9f10>] (dvbsky_s960c_attach+0x78/0x280 [dvb_usb_dvbsky])
[    7.689821] [<bf0b9f10>] (dvbsky_s960c_attach [dvb_usb_dvbsky]) from [<bf0a3cb4>] (dvb_usbv2_probe+0xa3c/0x1024 [dvb_usb_v2])
[    7.689849] [<bf0a3cb4>] (dvb_usbv2_probe [dvb_usb_v2]) from [<c0aa9e9c>] (usb_probe_interface+0xf0/0x2a8)
[    7.689869] [<c0aa9e9c>] (usb_probe_interface) from [<c08e268c>] (driver_probe_device+0x2f8/0x4b4)
[    7.689881] [<c08e268c>] (driver_probe_device) from [<c08e2948>] (__driver_attach+0x100/0x11c)
[    7.689895] [<c08e2948>] (__driver_attach) from [<c08e0778>] (bus_for_each_dev+0x4c/0x9c)
[    7.689909] [<c08e0778>] (bus_for_each_dev) from [<c08e1934>] (bus_add_driver+0x1c0/0x264)
[    7.689919] [<c08e1934>] (bus_add_driver) from [<c08e34ec>] (driver_register+0x78/0xf4)
[    7.689931] [<c08e34ec>] (driver_register) from [<c0aa8dc4>] (usb_register_driver+0x70/0x134)
[    7.689946] [<c0aa8dc4>] (usb_register_driver) from [<c03021e4>] (do_one_initcall+0x44/0x168)
[    7.689963] [<c03021e4>] (do_one_initcall) from [<c03c9a24>] (do_init_module+0x64/0x1f4)
[    7.689979] [<c03c9a24>] (do_init_module) from [<c03c8cb0>] (load_module+0x20a0/0x25c8)
[    7.689993] [<c03c8cb0>] (load_module) from [<c03c9430>] (SyS_finit_module+0xb4/0xec)
[    7.690007] [<c03c9430>] (SyS_finit_module) from [<c0308f20>] (ret_fast_syscall+0x0/0x54)
[    7.690018] Code: bad PC value

This may happen on normal circumstances, if, for some reason, the demod
hangs and start returning an invalid chip ID:

[   10.394395] m88ds3103 3-0068: Unknown device. Chip_id=00

So, change the logic to cause probe to fail with -ENODEV, preventing
the OOPS.

Detected while testing DVB MMAP patches on Raspberry Pi 3 with
DVBSky S960CI.

Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jnettlet pushed a commit that referenced this pull request Apr 13, 2018
commit 7688f2c upstream.

The attempt to join multicast group without ensuring that CMA device
exists will lead to the following crash reported by syzkaller.

[   64.076794] BUG: KASAN: null-ptr-deref in rdma_join_multicast+0x26e/0x12c0
[   64.076797] Read of size 8 at addr 00000000000000b0 by task join/691
[   64.076797]
[   64.076800] CPU: 1 PID: 691 Comm: join Not tainted 4.16.0-rc1-00219-gb97853b65b93 #23
[   64.076802] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-proj4
[   64.076803] Call Trace:
[   64.076809]  dump_stack+0x5c/0x77
[   64.076817]  kasan_report+0x163/0x380
[   64.085859]  ? rdma_join_multicast+0x26e/0x12c0
[   64.086634]  rdma_join_multicast+0x26e/0x12c0
[   64.087370]  ? rdma_disconnect+0xf0/0xf0
[   64.088579]  ? __radix_tree_replace+0xc3/0x110
[   64.089132]  ? node_tag_clear+0x81/0xb0
[   64.089606]  ? idr_alloc_u32+0x12e/0x1a0
[   64.090517]  ? __fprop_inc_percpu_max+0x150/0x150
[   64.091768]  ? tracing_record_taskinfo+0x10/0xc0
[   64.092340]  ? idr_alloc+0x76/0xc0
[   64.092951]  ? idr_alloc_u32+0x1a0/0x1a0
[   64.093632]  ? ucma_process_join+0x23d/0x460
[   64.094510]  ucma_process_join+0x23d/0x460
[   64.095199]  ? ucma_migrate_id+0x440/0x440
[   64.095696]  ? futex_wake+0x10b/0x2a0
[   64.096159]  ucma_join_multicast+0x88/0xe0
[   64.096660]  ? ucma_process_join+0x460/0x460
[   64.097540]  ? _copy_from_user+0x5e/0x90
[   64.098017]  ucma_write+0x174/0x1f0
[   64.098640]  ? ucma_resolve_route+0xf0/0xf0
[   64.099343]  ? rb_erase_cached+0x6c7/0x7f0
[   64.099839]  __vfs_write+0xc4/0x350
[   64.100622]  ? perf_syscall_enter+0xe4/0x5f0
[   64.101335]  ? kernel_read+0xa0/0xa0
[   64.103525]  ? perf_sched_cb_inc+0xc0/0xc0
[   64.105510]  ? syscall_exit_register+0x2a0/0x2a0
[   64.107359]  ? __switch_to+0x351/0x640
[   64.109285]  ? fsnotify+0x899/0x8f0
[   64.111610]  ? fsnotify_unmount_inodes+0x170/0x170
[   64.113876]  ? __fsnotify_update_child_dentry_flags+0x30/0x30
[   64.115813]  ? ring_buffer_record_is_on+0xd/0x20
[   64.117824]  ? __fget+0xa8/0xf0
[   64.119869]  vfs_write+0xf7/0x280
[   64.122001]  SyS_write+0xa1/0x120
[   64.124213]  ? SyS_read+0x120/0x120
[   64.126644]  ? SyS_read+0x120/0x120
[   64.128563]  do_syscall_64+0xeb/0x250
[   64.130732]  entry_SYSCALL_64_after_hwframe+0x21/0x86
[   64.132984] RIP: 0033:0x7f5c994ade99
[   64.135699] RSP: 002b:00007f5c99b97d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   64.138740] RAX: ffffffffffffffda RBX: 00000000200001e4 RCX: 00007f5c994ade99
[   64.141056] RDX: 00000000000000a0 RSI: 00000000200001c0 RDI: 0000000000000015
[   64.143536] RBP: 00007f5c99b97ec0 R08: 0000000000000000 R09: 0000000000000000
[   64.146017] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5c99b97fc0
[   64.148608] R13: 0000000000000000 R14: 00007fff660e1c40 R15: 00007f5c99b989c0
[   64.151060]
[   64.153703] Disabling lock debugging due to kernel taint
[   64.156032] BUG: unable to handle kernel NULL pointer dereference at 00000000000000b0
[   64.159066] IP: rdma_join_multicast+0x26e/0x12c0
[   64.161451] PGD 80000001d0298067 P4D 80000001d0298067 PUD 1dea39067 PMD 0
[   64.164442] Oops: 0000 [#1] SMP KASAN PTI
[   64.166817] CPU: 1 PID: 691 Comm: join Tainted: G    B 4.16.0-rc1-00219-gb97853b65b93 #23
[   64.170004] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-proj4
[   64.174985] RIP: 0010:rdma_join_multicast+0x26e/0x12c0
[   64.177246] RSP: 0018:ffff8801c8207860 EFLAGS: 00010282
[   64.179901] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff94789522
[   64.183344] RDX: 1ffffffff2d50fa5 RSI: 0000000000000297 RDI: 0000000000000297
[   64.186237] RBP: ffff8801c8207a50 R08: 0000000000000000 R09: ffffed0039040ea7
[   64.189328] R10: 0000000000000001 R11: ffffed0039040ea6 R12: 0000000000000000
[   64.192634] R13: 0000000000000000 R14: ffff8801e2022800 R15: ffff8801d4ac2400
[   64.196105] FS:  00007f5c99b98700(0000) GS:ffff8801e5d00000(0000) knlGS:0000000000000000
[   64.199211] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   64.202046] CR2: 00000000000000b0 CR3: 00000001d1c48004 CR4: 00000000003606a0
[   64.205032] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   64.208221] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   64.211554] Call Trace:
[   64.213464]  ? rdma_disconnect+0xf0/0xf0
[   64.216124]  ? __radix_tree_replace+0xc3/0x110
[   64.219337]  ? node_tag_clear+0x81/0xb0
[   64.222140]  ? idr_alloc_u32+0x12e/0x1a0
[   64.224422]  ? __fprop_inc_percpu_max+0x150/0x150
[   64.226588]  ? tracing_record_taskinfo+0x10/0xc0
[   64.229763]  ? idr_alloc+0x76/0xc0
[   64.232186]  ? idr_alloc_u32+0x1a0/0x1a0
[   64.234505]  ? ucma_process_join+0x23d/0x460
[   64.237024]  ucma_process_join+0x23d/0x460
[   64.240076]  ? ucma_migrate_id+0x440/0x440
[   64.243284]  ? futex_wake+0x10b/0x2a0
[   64.245302]  ucma_join_multicast+0x88/0xe0
[   64.247783]  ? ucma_process_join+0x460/0x460
[   64.250841]  ? _copy_from_user+0x5e/0x90
[   64.253878]  ucma_write+0x174/0x1f0
[   64.257008]  ? ucma_resolve_route+0xf0/0xf0
[   64.259877]  ? rb_erase_cached+0x6c7/0x7f0
[   64.262746]  __vfs_write+0xc4/0x350
[   64.265537]  ? perf_syscall_enter+0xe4/0x5f0
[   64.267792]  ? kernel_read+0xa0/0xa0
[   64.270358]  ? perf_sched_cb_inc+0xc0/0xc0
[   64.272575]  ? syscall_exit_register+0x2a0/0x2a0
[   64.275367]  ? __switch_to+0x351/0x640
[   64.277700]  ? fsnotify+0x899/0x8f0
[   64.280530]  ? fsnotify_unmount_inodes+0x170/0x170
[   64.283156]  ? __fsnotify_update_child_dentry_flags+0x30/0x30
[   64.286182]  ? ring_buffer_record_is_on+0xd/0x20
[   64.288749]  ? __fget+0xa8/0xf0
[   64.291136]  vfs_write+0xf7/0x280
[   64.292972]  SyS_write+0xa1/0x120
[   64.294965]  ? SyS_read+0x120/0x120
[   64.297474]  ? SyS_read+0x120/0x120
[   64.299751]  do_syscall_64+0xeb/0x250
[   64.301826]  entry_SYSCALL_64_after_hwframe+0x21/0x86
[   64.304352] RIP: 0033:0x7f5c994ade99
[   64.306711] RSP: 002b:00007f5c99b97d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   64.309577] RAX: ffffffffffffffda RBX: 00000000200001e4 RCX: 00007f5c994ade99
[   64.312334] RDX: 00000000000000a0 RSI: 00000000200001c0 RDI: 0000000000000015
[   64.315783] RBP: 00007f5c99b97ec0 R08: 0000000000000000 R09: 0000000000000000
[   64.318365] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5c99b97fc0
[   64.320980] R13: 0000000000000000 R14: 00007fff660e1c40 R15: 00007f5c99b989c0
[   64.323515] Code: e8 e8 79 08 ff 4c 89 ff 45 0f b6 a7 b8 01 00 00 e8 68 7c 08 ff 49 8b 1f 4d 89 e5 49 c1 e4 04 48 8
[   64.330753] RIP: rdma_join_multicast+0x26e/0x12c0 RSP: ffff8801c8207860
[   64.332979] CR2: 00000000000000b0
[   64.335550] ---[ end trace 0c00c17a408849c1 ]---

Reported-by: <syzbot+e6aba77967bd72cbc9d6@syzkaller.appspotmail.com>
Fixes: c8f6a36 ("RDMA/cma: Add multicast communication support")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jnettlet pushed a commit that referenced this pull request Sep 4, 2018
Retry loops on RT might loop forever when the modifying side was
preempted. Add cpu_chill() to replace cpu_relax(). cpu_chill()
defaults to cpu_relax() for non RT. On RT it puts the looping task to
sleep for a tick so the preempted task can make progress.

Steven Rostedt changed it to use a hrtimer instead of msleep():
|
|Ulrich Obergfell pointed out that cpu_chill() calls msleep() which is woken
|up by the ksoftirqd running the TIMER softirq. But as the cpu_chill() is
|called from softirq context, it may block the ksoftirqd() from running, in
|which case, it may never wake up the msleep() causing the deadlock.
|
|I checked the vmcore, and irq/74-qla2xxx is stuck in the msleep() call,
|running on CPU 8. The one ksoftirqd that is stuck, happens to be the one that
|runs on CPU 8, and it is blocked on a lock held by irq/74-qla2xxx. As that
|ksoftirqd is the one that will wake up irq/74-qla2xxx, and it happens to be
|blocked on a lock that irq/74-qla2xxx holds, we have our deadlock.
|
|The solution is not to convert the cpu_chill() back to a cpu_relax() as that
|will re-create a possible live lock that the cpu_chill() fixed earlier, and may
|also leave this bug open on other softirqs. The fix is to remove the
|dependency on ksoftirqd from cpu_chill(). That is, instead of calling
|msleep() that requires ksoftirqd to wake it up, use the
|hrtimer_nanosleep() code that does the wakeup from hard irq context.
|
||Looks to be the lock of the block softirq. I don't have the core dump
||anymore, but from what I could tell the ksoftirqd was blocked on the
||block softirq lock, where the block softirq handler did a msleep
||(called by the qla2xxx interrupt handler).
||
||Looking at trigger_softirq() in block/blk-softirq.c, it can do a
||smp_callfunction() to another cpu to run the block softirq. If that
||happens to be the cpu where the qla2xx irq handler is doing the block
||softirq and is in a middle of a msleep(), I believe the ksoftirqd will
||try to run the softirq. If it does that, then BOOM, it's deadlocked
||because the ksoftirqd will never run the timer softirq either.
|
||I should have also stated that it was only one lock that was involved.
||But the lock owner was doing a msleep() that requires a wakeup by
||ksoftirqd to continue. If ksoftirqd happens to be blocked on a lock
||held by the msleep() caller, then you have your deadlock.
||
||It's best not to have any softirqs going to sleep requiring another
||softirq to wake it up. Note, if we ever require a timer softirq to do a
||cpu_chill() it will most definitely hit this deadlock.

+ bigeasy: add PF_NOFREEZE:
| [....] Waiting for /dev to be fully populated...
| =====================================
| [ BUG: udevd/229 still has locks held! ]
| 3.12.11-rt17 #23 Not tainted
| -------------------------------------
| 1 lock held by udevd/229:
|  #0:  (&type->i_mutex_dir_key#2){+.+.+.}, at: lookup_slow+0x28/0x98
|
| stack backtrace:
| CPU: 0 PID: 229 Comm: udevd Not tainted 3.12.11-rt17 #23
| (unwind_backtrace+0x0/0xf8) from (show_stack+0x10/0x14)
| (show_stack+0x10/0x14) from (dump_stack+0x74/0xbc)
| (dump_stack+0x74/0xbc) from (do_nanosleep+0x120/0x160)
| (do_nanosleep+0x120/0x160) from (hrtimer_nanosleep+0x90/0x110)
| (hrtimer_nanosleep+0x90/0x110) from (cpu_chill+0x30/0x38)
| (cpu_chill+0x30/0x38) from (dentry_kill+0x158/0x1ec)
| (dentry_kill+0x158/0x1ec) from (dput+0x74/0x15c)
| (dput+0x74/0x15c) from (lookup_real+0x4c/0x50)
| (lookup_real+0x4c/0x50) from (__lookup_hash+0x34/0x44)
| (__lookup_hash+0x34/0x44) from (lookup_slow+0x38/0x98)
| (lookup_slow+0x38/0x98) from (path_lookupat+0x208/0x7fc)
| (path_lookupat+0x208/0x7fc) from (filename_lookup+0x20/0x60)
| (filename_lookup+0x20/0x60) from (user_path_at_empty+0x50/0x7c)
| (user_path_at_empty+0x50/0x7c) from (user_path_at+0x14/0x1c)
| (user_path_at+0x14/0x1c) from (vfs_fstatat+0x48/0x94)
| (vfs_fstatat+0x48/0x94) from (SyS_stat64+0x14/0x30)
| (SyS_stat64+0x14/0x30) from (ret_fast_syscall+0x0/0x48)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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