Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[SQUASHME] ASoC: Intel: fix Kconfig typos #21

Merged
merged 1 commit into from
Jul 3, 2018

Conversation

plbossart
Copy link
Member

Fix ASoC: Intel: select relevant machine drivers for SOF
s/INTEL_SKL/INTEL_SKYLAKE

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

Fix ASoC: Intel: select relevant machine drivers for SOF
s/INTEL_SKL/INTEL_SKYLAKE

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
@plbossart plbossart merged commit f9ab80f into thesofproject:topic/sof-dev Jul 3, 2018
cujomalainey pushed a commit to cujomalainey/linux that referenced this pull request Sep 18, 2018
commit a5ba1d9 upstream.

We have reports of the following crash:

    PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0"
    #0 [ffff88085c6db710] machine_kexec at ffffffff81046239
    #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248
    #2 [ffff88085c6db830] oops_end at ffffffff81008ae7
    #3 [ffff88085c6db860] no_context at ffffffff81050b8f
    thesofproject#4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75
    thesofproject#5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83
    thesofproject#6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e
    thesofproject#7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c
    thesofproject#8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122
    [exception RIP: uart_put_char+149]
    RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006
    RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081
    RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120
    RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320
    R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000
    R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
    thesofproject#9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544
    thesofproject#10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c
    thesofproject#11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b
    thesofproject#12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2
    thesofproject#13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b
    thesofproject#14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a
    thesofproject#15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016
    thesofproject#16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194
    thesofproject#17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a
    thesofproject#18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2
    thesofproject#19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d
    thesofproject#20 [ffff88085c6dbeb0] kthread at ffffffff81096384
    thesofproject#21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f​

after slogging through some dissasembly:

ffffffff814b6720 <uart_put_char>:
ffffffff814b6720:	55                   	push   %rbp
ffffffff814b6721:	48 89 e5             	mov    %rsp,%rbp
ffffffff814b6724:	48 83 ec 20          	sub    $0x20,%rsp
ffffffff814b6728:	48 89 1c 24          	mov    %rbx,(%rsp)
ffffffff814b672c:	4c 89 64 24 08       	mov    %r12,0x8(%rsp)
ffffffff814b6731:	4c 89 6c 24 10       	mov    %r13,0x10(%rsp)
ffffffff814b6736:	4c 89 74 24 18       	mov    %r14,0x18(%rsp)
ffffffff814b673b:	e8 b0 8e 58 00       	callq  ffffffff81a3f5f0 <mcount>
ffffffff814b6740:	4c 8b a7 88 02 00 00 	mov    0x288(%rdi),%r12
ffffffff814b6747:	45 31 ed             	xor    %r13d,%r13d
ffffffff814b674a:	41 89 f6             	mov    %esi,%r14d
ffffffff814b674d:	49 83 bc 24 70 01 00 	cmpq   $0x0,0x170(%r12)
ffffffff814b6754:	00 00
ffffffff814b6756:	49 8b 9c 24 80 01 00 	mov    0x180(%r12),%rbx
ffffffff814b675d:	00
ffffffff814b675e:	74 2f                	je     ffffffff814b678f <uart_put_char+0x6f>
ffffffff814b6760:	48 89 df             	mov    %rbx,%rdi
ffffffff814b6763:	e8 a8 67 58 00       	callq  ffffffff81a3cf10 <_raw_spin_lock_irqsave>
ffffffff814b6768:	41 8b 8c 24 78 01 00 	mov    0x178(%r12),%ecx
ffffffff814b676f:	00
ffffffff814b6770:	89 ca                	mov    %ecx,%edx
ffffffff814b6772:	f7 d2                	not    %edx
ffffffff814b6774:	41 03 94 24 7c 01 00 	add    0x17c(%r12),%edx
ffffffff814b677b:	00
ffffffff814b677c:	81 e2 ff 0f 00 00    	and    $0xfff,%edx
ffffffff814b6782:	75 23                	jne    ffffffff814b67a7 <uart_put_char+0x87>
ffffffff814b6784:	48 89 c6             	mov    %rax,%rsi
ffffffff814b6787:	48 89 df             	mov    %rbx,%rdi
ffffffff814b678a:	e8 e1 64 58 00       	callq  ffffffff81a3cc70 <_raw_spin_unlock_irqrestore>
ffffffff814b678f:	44 89 e8             	mov    %r13d,%eax
ffffffff814b6792:	48 8b 1c 24          	mov    (%rsp),%rbx
ffffffff814b6796:	4c 8b 64 24 08       	mov    0x8(%rsp),%r12
ffffffff814b679b:	4c 8b 6c 24 10       	mov    0x10(%rsp),%r13
ffffffff814b67a0:	4c 8b 74 24 18       	mov    0x18(%rsp),%r14
ffffffff814b67a5:	c9                   	leaveq
ffffffff814b67a6:	c3                   	retq
ffffffff814b67a7:	49 8b 94 24 70 01 00 	mov    0x170(%r12),%rdx
ffffffff814b67ae:	00
ffffffff814b67af:	48 63 c9             	movslq %ecx,%rcx
ffffffff814b67b2:	41 b5 01             	mov    $0x1,%r13b
ffffffff814b67b5:	44 88 34 0a          	mov    %r14b,(%rdx,%rcx,1)
ffffffff814b67b9:	41 8b 94 24 78 01 00 	mov    0x178(%r12),%edx
ffffffff814b67c0:	00
ffffffff814b67c1:	83 c2 01             	add    $0x1,%edx
ffffffff814b67c4:	81 e2 ff 0f 00 00    	and    $0xfff,%edx
ffffffff814b67ca:	41 89 94 24 78 01 00 	mov    %edx,0x178(%r12)
ffffffff814b67d1:	00
ffffffff814b67d2:	eb b0                	jmp    ffffffff814b6784 <uart_put_char+0x64>
ffffffff814b67d4:	66 66 66 2e 0f 1f 84 	data32 data32 nopw %cs:0x0(%rax,%rax,1)
ffffffff814b67db:	00 00 00 00 00

for our build, this is crashing at:

    circ->buf[circ->head] = c;

Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf)
protected by the "per-port mutex", which based on uart_port_check() is
state->port.mutex. Indeed, the lock acquired in uart_put_char() is
uport->lock, i.e. not the same lock.

Anyway, since the lock is not acquired, if uart_shutdown() is called, the
last chunk of that function may release state->xmit.buf before its assigned
to null, and cause the race above.

To fix it, let's lock uport->lock when allocating/deallocating
state->xmit.buf in addition to the per-port mutex.

v2: switch to locking uport->lock on allocation/deallocation instead of
    locking the per-port mutex in uart_put_char. Note that since
    uport->lock is a spin lock, we have to switch the allocation to
    GFP_ATOMIC.
v3: move the allocation outside the lock, so we can switch back to
    GFP_KERNEL

Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
keyonjie pushed a commit that referenced this pull request Oct 22, 2018
pid_task() dereferences rcu protected tasks array.
But there is no rcu_read_lock() in shutdown_umh() routine so that
rcu_read_lock() is needed.
get_pid_task() is wrapper function of pid_task. it holds rcu_read_lock()
then calls pid_task(). if task isn't NULL, it increases reference count
of task.

test commands:
   %modprobe bpfilter
   %modprobe -rv bpfilter

splat looks like:
[15102.030932] =============================
[15102.030957] WARNING: suspicious RCU usage
[15102.030985] 4.19.0-rc7+ #21 Not tainted
[15102.031010] -----------------------------
[15102.031038] kernel/pid.c:330 suspicious rcu_dereference_check() usage!
[15102.031063]
	       other info that might help us debug this:

[15102.031332]
	       rcu_scheduler_active = 2, debug_locks = 1
[15102.031363] 1 lock held by modprobe/1570:
[15102.031389]  #0: 00000000580ef2b0 (bpfilter_lock){+.+.}, at: stop_umh+0x13/0x52 [bpfilter]
[15102.031552]
               stack backtrace:
[15102.031583] CPU: 1 PID: 1570 Comm: modprobe Not tainted 4.19.0-rc7+ #21
[15102.031607] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 07/08/2015
[15102.031628] Call Trace:
[15102.031676]  dump_stack+0xc9/0x16b
[15102.031723]  ? show_regs_print_info+0x5/0x5
[15102.031801]  ? lockdep_rcu_suspicious+0x117/0x160
[15102.031855]  pid_task+0x134/0x160
[15102.031900]  ? find_vpid+0xf0/0xf0
[15102.032017]  shutdown_umh.constprop.1+0x1e/0x53 [bpfilter]
[15102.032055]  stop_umh+0x46/0x52 [bpfilter]
[15102.032092]  __x64_sys_delete_module+0x47e/0x570
[ ... ]

Fixes: d2ba09c ("net: add skeleton of bpfilter kernel module")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
plbossart pushed a commit that referenced this pull request Dec 11, 2018
xt_rateest_net_exit() was added to check whether rules are flushed
successfully. but ->net_exit() callback is called earlier than
->destroy() callback.
So that ->net_exit() callback can't check that.

test commands:
   %ip netns add vm1
   %ip netns exec vm1 iptables -t mangle -I PREROUTING -p udp \
	   --dport 1111 -j RATEEST --rateest-name ap \
	   --rateest-interval 250ms --rateest-ewma 0.5s
   %ip netns del vm1

splat looks like:
[  668.813518] WARNING: CPU: 0 PID: 87 at net/netfilter/xt_RATEEST.c:210 xt_rateest_net_exit+0x210/0x340 [xt_RATEEST]
[  668.813518] Modules linked in: xt_RATEEST xt_tcpudp iptable_mangle bpfilter ip_tables x_tables
[  668.813518] CPU: 0 PID: 87 Comm: kworker/u4:2 Not tainted 4.19.0-rc7+ #21
[  668.813518] Workqueue: netns cleanup_net
[  668.813518] RIP: 0010:xt_rateest_net_exit+0x210/0x340 [xt_RATEEST]
[  668.813518] Code: 00 48 8b 85 30 ff ff ff 4c 8b 23 80 38 00 0f 85 24 01 00 00 48 8b 85 30 ff ff ff 4d 85 e4 4c 89 a5 58 ff ff ff c6 00 f8 74 b2 <0f> 0b 48 83 c3 08 4c 39 f3 75 b0 48 b8 00 00 00 00 00 fc ff df 49
[  668.813518] RSP: 0018:ffff8801156c73f8 EFLAGS: 00010282
[  668.813518] RAX: ffffed0022ad8e85 RBX: ffff880118928e98 RCX: 5db8012a00000000
[  668.813518] RDX: ffff8801156c7428 RSI: 00000000cb1d185f RDI: ffff880115663b74
[  668.813518] RBP: ffff8801156c74d0 R08: ffff8801156633c0 R09: 1ffff100236440be
[  668.813518] R10: 0000000000000001 R11: ffffed002367d852 R12: ffff880115142b08
[  668.813518] R13: 1ffff10022ad8e81 R14: ffff880118928ea8 R15: dffffc0000000000
[  668.813518] FS:  0000000000000000(0000) GS:ffff88011b200000(0000) knlGS:0000000000000000
[  668.813518] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  668.813518] CR2: 0000563aa69f4f28 CR3: 0000000105a16000 CR4: 00000000001006f0
[  668.813518] Call Trace:
[  668.813518]  ? unregister_netdevice_many+0xe0/0xe0
[  668.813518]  ? xt_rateest_net_init+0x2c0/0x2c0 [xt_RATEEST]
[  668.813518]  ? default_device_exit+0x1ca/0x270
[  668.813518]  ? remove_proc_entry+0x1cd/0x390
[  668.813518]  ? dev_change_net_namespace+0xd00/0xd00
[  668.813518]  ? __init_waitqueue_head+0x130/0x130
[  668.813518]  ops_exit_list.isra.10+0x94/0x140
[  668.813518]  cleanup_net+0x45b/0x900
[  668.813518]  ? net_drop_ns+0x110/0x110
[  668.813518]  ? swapgs_restore_regs_and_return_to_usermode+0x3c/0x80
[  668.813518]  ? save_trace+0x300/0x300
[  668.813518]  ? lock_acquire+0x196/0x470
[  668.813518]  ? lock_acquire+0x196/0x470
[  668.813518]  ? process_one_work+0xb60/0x1de0
[  668.813518]  ? _raw_spin_unlock_irq+0x29/0x40
[  668.813518]  ? _raw_spin_unlock_irq+0x29/0x40
[  668.813518]  ? __lock_acquire+0x4500/0x4500
[  668.813518]  ? __lock_is_held+0xb4/0x140
[  668.813518]  process_one_work+0xc13/0x1de0
[  668.813518]  ? pwq_dec_nr_in_flight+0x3c0/0x3c0
[  668.813518]  ? set_load_weight+0x270/0x270
[ ... ]

Fixes: 3427b2a ("netfilter: make xt_rateest hash table per net")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
plbossart pushed a commit that referenced this pull request Dec 18, 2018
Remove no_pcm check to invoke pcm_new() for backend dai-links
too. This fixes crash in hdmi codec driver during hdmi_codec_startup()
while accessing chmap_info struct. chmap_info struct memory is
allocated in pcm_new() of hdmi codec driver which is not invoked
in case of DPCM when hdmi codec driver is part of backend dai-link.

Below is the crash stack:

[   61.635493] Unable to handle kernel NULL pointer dereference at virtual address 00000018
..
[   61.666696]   CM = 0, WnR = 1
[   61.669778] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffc0d6633000
[   61.676526] [0000000000000018] *pgd=0000000153fc8003, *pud=0000000153fc8003, *pmd=0000000000000000
[   61.685793] Internal error: Oops: 96000046 [#1] PREEMPT SMP
[   61.722955] CPU: 7 PID: 2238 Comm: aplay Not tainted 4.14.72 #21
..
[   61.740269] PC is at hdmi_codec_startup+0x124/0x164
[   61.745308] LR is at hdmi_codec_startup+0xe4/0x164

Signed-off-by: Rohit kumar <rohitkr@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit de17f14)
plbossart pushed a commit that referenced this pull request Jan 3, 2019
Remove no_pcm check to invoke pcm_new() for backend dai-links
too. This fixes crash in hdmi codec driver during hdmi_codec_startup()
while accessing chmap_info struct. chmap_info struct memory is
allocated in pcm_new() of hdmi codec driver which is not invoked
in case of DPCM when hdmi codec driver is part of backend dai-link.

Below is the crash stack:

[   61.635493] Unable to handle kernel NULL pointer dereference at virtual address 00000018
..
[   61.666696]   CM = 0, WnR = 1
[   61.669778] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffc0d6633000
[   61.676526] [0000000000000018] *pgd=0000000153fc8003, *pud=0000000153fc8003, *pmd=0000000000000000
[   61.685793] Internal error: Oops: 96000046 [#1] PREEMPT SMP
[   61.722955] CPU: 7 PID: 2238 Comm: aplay Not tainted 4.14.72 #21
..
[   61.740269] PC is at hdmi_codec_startup+0x124/0x164
[   61.745308] LR is at hdmi_codec_startup+0xe4/0x164

Signed-off-by: Rohit kumar <rohitkr@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit de17f14)
plbossart pushed a commit that referenced this pull request Feb 13, 2019
Remove no_pcm check to invoke pcm_new() for backend dai-links
too. This fixes crash in hdmi codec driver during hdmi_codec_startup()
while accessing chmap_info struct. chmap_info struct memory is
allocated in pcm_new() of hdmi codec driver which is not invoked
in case of DPCM when hdmi codec driver is part of backend dai-link.

Below is the crash stack:

[   61.635493] Unable to handle kernel NULL pointer dereference at virtual address 00000018
..
[   61.666696]   CM = 0, WnR = 1
[   61.669778] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffc0d6633000
[   61.676526] [0000000000000018] *pgd=0000000153fc8003, *pud=0000000153fc8003, *pmd=0000000000000000
[   61.685793] Internal error: Oops: 96000046 [#1] PREEMPT SMP
[   61.722955] CPU: 7 PID: 2238 Comm: aplay Not tainted 4.14.72 #21
..
[   61.740269] PC is at hdmi_codec_startup+0x124/0x164
[   61.745308] LR is at hdmi_codec_startup+0xe4/0x164

Signed-off-by: Rohit kumar <rohitkr@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit de17f14)
naveen-manohar pushed a commit to naveen-manohar/linux that referenced this pull request Mar 14, 2019
Remove no_pcm check to invoke pcm_new() for backend dai-links
too. This fixes crash in hdmi codec driver during hdmi_codec_startup()
while accessing chmap_info struct. chmap_info struct memory is
allocated in pcm_new() of hdmi codec driver which is not invoked
in case of DPCM when hdmi codec driver is part of backend dai-link.

Below is the crash stack:

[   61.635493] Unable to handle kernel NULL pointer dereference at virtual address 00000018
..
[   61.666696]   CM = 0, WnR = 1
[   61.669778] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffc0d6633000
[   61.676526] [0000000000000018] *pgd=0000000153fc8003, *pud=0000000153fc8003, *pmd=0000000000000000
[   61.685793] Internal error: Oops: 96000046 [thesofproject#1] PREEMPT SMP
[   61.722955] CPU: 7 PID: 2238 Comm: aplay Not tainted 4.14.72 thesofproject#21
..
[   61.740269] PC is at hdmi_codec_startup+0x124/0x164
[   61.745308] LR is at hdmi_codec_startup+0xe4/0x164

Signed-off-by: Rohit kumar <rohitkr@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit de17f14)

BUG=b:110025789
TEST=Test Audio use cases for GLK with full SOF patch series applied.

Change-Id: I13b12e904ff589ea67f84e4ce1c9889669eb016a
Signed-off-by: smit shah <smit.shah@intel.corp-partner.google.com>
ranj063 pushed a commit to ranj063/linux that referenced this pull request Mar 31, 2019
Remove no_pcm check to invoke pcm_new() for backend dai-links
too. This fixes crash in hdmi codec driver during hdmi_codec_startup()
while accessing chmap_info struct. chmap_info struct memory is
allocated in pcm_new() of hdmi codec driver which is not invoked
in case of DPCM when hdmi codec driver is part of backend dai-link.

Below is the crash stack:

[   61.635493] Unable to handle kernel NULL pointer dereference at virtual address 00000018
..
[   61.666696]   CM = 0, WnR = 1
[   61.669778] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffc0d6633000
[   61.676526] [0000000000000018] *pgd=0000000153fc8003, *pud=0000000153fc8003, *pmd=0000000000000000
[   61.685793] Internal error: Oops: 96000046 [#1] PREEMPT SMP
[   61.722955] CPU: 7 PID: 2238 Comm: aplay Not tainted 4.14.72 thesofproject#21
..
[   61.740269] PC is at hdmi_codec_startup+0x124/0x164
[   61.745308] LR is at hdmi_codec_startup+0xe4/0x164

Signed-off-by: Rohit kumar <rohitkr@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit de17f14)
plbossart pushed a commit that referenced this pull request Apr 11, 2019
Eric has reported on OpenWrt's bug tracking system[1], that he's not
able to use USB devices on his WNDR3400v2 device after the boot, until
he turns on GPIO #21 manually through sysfs.

1. https://bugs.openwrt.org/index.php?do=details&task_id=2170

Cc: Rafał Miłecki <zajec5@gmail.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Reported-by: Eric Bohlman <ericbohlman@gmail.com>
Tested-by: Eric Bohlman <ericbohlman@gmail.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Signed-off-by: Paul Burton <paul.burton@mips.com>
fredoh9 pushed a commit to fredoh9/linux that referenced this pull request Jun 1, 2019
af_inet sets sock->sk to NULL which trips strparser over:

BUG: kernel NULL pointer dereference, address: 0000000000000012
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 7 PID: 0 Comm: swapper/7 Not tainted 5.2.0-rc1-00139-g14629453a6d3 thesofproject#21
RIP: 0010:tcp_peek_len+0x10/0x60
RSP: 0018:ffffc02e41c54b98 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff9cf924c4e030 RCX: 0000000000000051
RDX: 0000000000000000 RSI: 000000000000000c RDI: ffff9cf97128f480
RBP: ffff9cf9365e0300 R08: ffff9cf94fe7d2c0 R09: 0000000000000000
R10: 000000000000036b R11: ffff9cf939735e00 R12: ffff9cf91ad9ae40
R13: ffff9cf924c4e000 R14: ffff9cf9a8fcbaae R15: 0000000000000020
FS: 0000000000000000(0000) GS:ffff9cf9af7c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000012 CR3: 000000013920a003 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
 <IRQ>
 strp_data_ready+0x48/0x90
 tls_data_ready+0x22/0xd0 [tls]
 tcp_rcv_established+0x569/0x620
 tcp_v4_do_rcv+0x127/0x1e0
 tcp_v4_rcv+0xad7/0xbf0
 ip_protocol_deliver_rcu+0x2c/0x1c0
 ip_local_deliver_finish+0x41/0x50
 ip_local_deliver+0x6b/0xe0
 ? ip_protocol_deliver_rcu+0x1c0/0x1c0
 ip_rcv+0x52/0xd0
 ? ip_rcv_finish_core.isra.20+0x380/0x380
 __netif_receive_skb_one_core+0x7e/0x90
 netif_receive_skb_internal+0x42/0xf0
 napi_gro_receive+0xed/0x150
 nfp_net_poll+0x7a2/0xd30 [nfp]
 ? kmem_cache_free_bulk+0x286/0x310
 net_rx_action+0x149/0x3b0
 __do_softirq+0xe3/0x30a
 ? handle_irq_event_percpu+0x6a/0x80
 irq_exit+0xe8/0xf0
 do_IRQ+0x85/0xd0
 common_interrupt+0xf/0xf
 </IRQ>
RIP: 0010:cpuidle_enter_state+0xbc/0x450

To avoid this issue set sock->sk after sk_prot->close.
My grepping and testing did not discover any code which
would depend on the current behaviour.

Fixes: c46234e ("tls: RX path for ktls")
Reported-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
plbossart pushed a commit that referenced this pull request Aug 12, 2019
A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
plbossart pushed a commit that referenced this pull request Aug 12, 2019
Without this patch, the MAP_SYNC test case will cause a print_bad_pte
warning on arm64 as follows:

[   25.542693] BUG: Bad page map in process mapdax333 pte:2e8000448800f53 pmd:41ff5f003
[   25.546360] page:ffff7e0010220000 refcount:1 mapcount:-1 mapping:ffff8003e29c7440 index:0x0
[   25.550281] ext4_dax_aops
[   25.550282] name:"__aaabbbcccddd__"
[   25.551553] flags: 0x3ffff0000001002(referenced|reserved)
[   25.555802] raw: 03ffff0000001002 ffff8003dfffa908 0000000000000000 ffff8003e29c7440
[   25.559446] raw: 0000000000000000 0000000000000000 00000001fffffffe 0000000000000000
[   25.563075] page dumped because: bad pte
[   25.564938] addr:0000ffffbe05b000 vm_flags:208000fb anon_vma:0000000000000000 mapping:ffff8003e29c7440 index:0
[   25.574272] file:__aaabbbcccddd__ fault:ext4_dax_fault mmmmap:ext4_file_mmap readpage:0x0
[   25.578799] CPU: 1 PID: 1180 Comm: mapdax333 Not tainted 5.2.0+ #21
[   25.581702] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[   25.585624] Call trace:
[   25.587008]  dump_backtrace+0x0/0x178
[   25.588799]  show_stack+0x24/0x30
[   25.590328]  dump_stack+0xa8/0xcc
[   25.591901]  print_bad_pte+0x18c/0x218
[   25.593628]  unmap_page_range+0x778/0xc00
[   25.595506]  unmap_single_vma+0x94/0xe8
[   25.597304]  unmap_vmas+0x90/0x108
[   25.598901]  unmap_region+0xc0/0x128
[   25.600566]  __do_munmap+0x284/0x3f0
[   25.602245]  __vm_munmap+0x78/0xe0
[   25.603820]  __arm64_sys_munmap+0x34/0x48
[   25.605709]  el0_svc_common.constprop.0+0x78/0x168
[   25.607956]  el0_svc_handler+0x34/0x90
[   25.609698]  el0_svc+0x8/0xc
[...]

The root cause is in _vm_normal_page, without the PTE_SPECIAL bit,
the return value will be incorrectly set to pfn_to_page(pfn) instead
of NULL. Besides, this patch also rewrite the pmd_mkdevmap to avoid
setting PTE_SPECIAL for pmd

The MAP_SYNC test case is as follows(Provided by Yibo Cai)
$#include <stdio.h>
$#include <string.h>
$#include <unistd.h>
$#include <sys/file.h>
$#include <sys/mman.h>

$#ifndef MAP_SYNC
$#define MAP_SYNC 0x80000
$#endif

/* mount -o dax /dev/pmem0 /mnt */
$#define F "/mnt/__aaabbbcccddd__"

int main(void)
{
    int fd;
    char buf[4096];
    void *addr;

    if ((fd = open(F, O_CREAT|O_TRUNC|O_RDWR, 0644)) < 0) {
        perror("open1");
        return 1;
    }

    if (write(fd, buf, 4096) != 4096) {
        perror("lseek");
        return 1;
    }

    addr = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_SYNC, fd, 0);
    if (addr == MAP_FAILED) {
        perror("mmap");
        printf("did you mount with '-o dax'?\n");
        return 1;
    }

    memset(addr, 0x55, 4096);

    if (munmap(addr, 4096) == -1) {
        perror("munmap");
        return 1;
    }

    close(fd);

    return 0;
}

Fixes: 73b20c8 ("arm64: mm: implement pte_devmap support")
Reported-by: Yibo Cai <Yibo.Cai@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Robin Murphy <Robin.Murphy@arm.com>
Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
plbossart pushed a commit that referenced this pull request Dec 20, 2019
Some QPs (e.g. XRC QP) are not tracked in kernel, in this case they have
an invalid res and should not be bound to any dynamically-allocated
counter in auto mode.

This fixes below call trace:
BUG: kernel NULL pointer dereference, address: 0000000000000390
PGD 80000001a7233067 P4D 80000001a7233067 PUD 1a7215067 PMD 0
Oops: 0000 [#1] SMP PTI
CPU: 2 PID: 24822 Comm: ibv_xsrq_pingpo Not tainted 5.4.0-rc5+ #21
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014
RIP: 0010:rdma_counter_bind_qp_auto+0x142/0x270 [ib_core]
Code: e1 48 85 c0 48 89 c2 0f 84 bc 00 00 00 49 8b 06 48 39 42 48 75 d6 40 3a aa 90 00 00 00 75 cd 49 8b 86 00 01 00 00 48 8b 4a 28 <8b> 80 90 03 00 00 39 81 90 03 00 00 75 b4 85 c0 74 b0 48 8b 04 24
RSP: 0018:ffffc900003f39c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff88820020ec00 RSI: 0000000000000004 RDI: ffffffffffffffc0
RBP: 0000000000000001 R08: ffff888224149ff0 R09: ffffc900003f3968
R10: ffffffffffffffff R11: ffff8882249c5848 R12: ffffffffffffffff
R13: ffff88821d5aca50 R14: ffff8881f7690800 R15: ffff8881ff890000
FS:  00007fe53a3e1740(0000) GS:ffff888237b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000390 CR3: 00000001a7292006 CR4: 00000000003606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 _ib_modify_qp+0x3a4/0x3f0 [ib_core]
 ? lookup_get_idr_uobject.part.8+0x23/0x40 [ib_uverbs]
 modify_qp+0x322/0x3e0 [ib_uverbs]
 ib_uverbs_modify_qp+0x43/0x70 [ib_uverbs]
 ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xb1/0xf0 [ib_uverbs]
 ib_uverbs_run_method+0x6be/0x760 [ib_uverbs]
 ? uverbs_disassociate_api+0xd0/0xd0 [ib_uverbs]
 ib_uverbs_cmd_verbs+0x18d/0x3a0 [ib_uverbs]
 ? get_acl+0x1a/0x120
 ? __alloc_pages_nodemask+0x15d/0x2c0
 ib_uverbs_ioctl+0xa7/0x110 [ib_uverbs]
 do_vfs_ioctl+0xa5/0x610
 ksys_ioctl+0x60/0x90
 __x64_sys_ioctl+0x16/0x20
 do_syscall_64+0x48/0x110
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 99fa331 ("RDMA/counter: Add "auto" configuration mode support")
Signed-off-by: Mark Zhang <markz@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Ido Kalir <idok@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Link: https://lore.kernel.org/r/20191212091214.315005-2-leon@kernel.org
Signed-off-by: Doug Ledford <dledford@redhat.com>
jason77-wang pushed a commit to jason77-wang/linux-1 that referenced this pull request Apr 10, 2020
When experimenting with bpf_send_signal() helper in our production
environment (5.2 based), we experienced a deadlock in NMI mode:
   thesofproject#5 [ffffc9002219f770] queued_spin_lock_slowpath at ffffffff8110be24
   thesofproject#6 [ffffc9002219f770] _raw_spin_lock_irqsave at ffffffff81a43012
   thesofproject#7 [ffffc9002219f780] try_to_wake_up at ffffffff810e7ecd
   thesofproject#8 [ffffc9002219f7e0] signal_wake_up_state at ffffffff810c7b55
   thesofproject#9 [ffffc9002219f7f0] __send_signal at ffffffff810c8602
  thesofproject#10 [ffffc9002219f830] do_send_sig_info at ffffffff810ca31a
  thesofproject#11 [ffffc9002219f868] bpf_send_signal at ffffffff8119d227
  thesofproject#12 [ffffc9002219f988] bpf_overflow_handler at ffffffff811d4140
  thesofproject#13 [ffffc9002219f9e0] __perf_event_overflow at ffffffff811d68cf
  thesofproject#14 [ffffc9002219fa10] perf_swevent_overflow at ffffffff811d6a09
  thesofproject#15 [ffffc9002219fa38] ___perf_sw_event at ffffffff811e0f47
  thesofproject#16 [ffffc9002219fc30] __schedule at ffffffff81a3e04d
  thesofproject#17 [ffffc9002219fc90] schedule at ffffffff81a3e219
  thesofproject#18 [ffffc9002219fca0] futex_wait_queue_me at ffffffff8113d1b9
  thesofproject#19 [ffffc9002219fcd8] futex_wait at ffffffff8113e529
  thesofproject#20 [ffffc9002219fdf0] do_futex at ffffffff8113ffbc
  thesofproject#21 [ffffc9002219fec0] __x64_sys_futex at ffffffff81140d1c
  thesofproject#22 [ffffc9002219ff38] do_syscall_64 at ffffffff81002602
  thesofproject#23 [ffffc9002219ff50] entry_SYSCALL_64_after_hwframe at ffffffff81c00068

The above call stack is actually very similar to an issue
reported by Commit eac9153 ("bpf/stackmap: Fix deadlock with
rq_lock in bpf_get_stack()") by Song Liu. The only difference is
bpf_send_signal() helper instead of bpf_get_stack() helper.

The above deadlock is triggered with a perf_sw_event.
Similar to Commit eac9153, the below almost identical reproducer
used tracepoint point sched/sched_switch so the issue can be easily caught.
  /* stress_test.c */
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/mman.h>
  #include <pthread.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>

  #define THREAD_COUNT 1000
  char *filename;
  void *worker(void *p)
  {
        void *ptr;
        int fd;
        char *pptr;

        fd = open(filename, O_RDONLY);
        if (fd < 0)
                return NULL;
        while (1) {
                struct timespec ts = {0, 1000 + rand() % 2000};

                ptr = mmap(NULL, 4096 * 64, PROT_READ, MAP_PRIVATE, fd, 0);
                usleep(1);
                if (ptr == MAP_FAILED) {
                        printf("failed to mmap\n");
                        break;
                }
                munmap(ptr, 4096 * 64);
                usleep(1);
                pptr = malloc(1);
                usleep(1);
                pptr[0] = 1;
                usleep(1);
                free(pptr);
                usleep(1);
                nanosleep(&ts, NULL);
        }
        close(fd);
        return NULL;
  }

  int main(int argc, char *argv[])
  {
        void *ptr;
        int i;
        pthread_t threads[THREAD_COUNT];

        if (argc < 2)
                return 0;

        filename = argv[1];

        for (i = 0; i < THREAD_COUNT; i++) {
                if (pthread_create(threads + i, NULL, worker, NULL)) {
                        fprintf(stderr, "Error creating thread\n");
                        return 0;
                }
        }

        for (i = 0; i < THREAD_COUNT; i++)
                pthread_join(threads[i], NULL);
        return 0;
  }
and the following command:
  1. run `stress_test /bin/ls` in one windown
  2. hack bcc trace.py with the following change:
     --- a/tools/trace.py
     +++ b/tools/trace.py
     @@ -513,6 +513,7 @@ BPF_PERF_OUTPUT(%s);
              __data.tgid = __tgid;
              __data.pid = __pid;
              bpf_get_current_comm(&__data.comm, sizeof(__data.comm));
     +        bpf_send_signal(10);
      %s
      %s
              %s.perf_submit(%s, &__data, sizeof(__data));
  3. in a different window run
     ./trace.py -p $(pidof stress_test) t:sched:sched_switch

The deadlock can be reproduced in our production system.

Similar to Song's fix, the fix is to delay sending signal if
irqs is disabled to avoid deadlocks involving with rq_lock.
With this change, my above stress-test in our production system
won't cause deadlock any more.

I also implemented a scale-down version of reproducer in the
selftest (a subsequent commit). With latest bpf-next,
it complains for the following potential deadlock.
  [   32.832450] -> thesofproject#1 (&p->pi_lock){-.-.}:
  [   32.833100]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.833696]        task_rq_lock+0x2c/0xa0
  [   32.834182]        task_sched_runtime+0x59/0xd0
  [   32.834721]        thread_group_cputime+0x250/0x270
  [   32.835304]        thread_group_cputime_adjusted+0x2e/0x70
  [   32.835959]        do_task_stat+0x8a7/0xb80
  [   32.836461]        proc_single_show+0x51/0xb0
  ...
  [   32.839512] -> #0 (&(&sighand->siglock)->rlock){....}:
  [   32.840275]        __lock_acquire+0x1358/0x1a20
  [   32.840826]        lock_acquire+0xc7/0x1d0
  [   32.841309]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.841916]        __lock_task_sighand+0x79/0x160
  [   32.842465]        do_send_sig_info+0x35/0x90
  [   32.842977]        bpf_send_signal+0xa/0x10
  [   32.843464]        bpf_prog_bc13ed9e4d3163e3_send_signal_tp_sched+0x465/0x1000
  [   32.844301]        trace_call_bpf+0x115/0x270
  [   32.844809]        perf_trace_run_bpf_submit+0x4a/0xc0
  [   32.845411]        perf_trace_sched_switch+0x10f/0x180
  [   32.846014]        __schedule+0x45d/0x880
  [   32.846483]        schedule+0x5f/0xd0
  ...

  [   32.853148] Chain exists of:
  [   32.853148]   &(&sighand->siglock)->rlock --> &p->pi_lock --> &rq->lock
  [   32.853148]
  [   32.854451]  Possible unsafe locking scenario:
  [   32.854451]
  [   32.855173]        CPU0                    CPU1
  [   32.855745]        ----                    ----
  [   32.856278]   lock(&rq->lock);
  [   32.856671]                                lock(&p->pi_lock);
  [   32.857332]                                lock(&rq->lock);
  [   32.857999]   lock(&(&sighand->siglock)->rlock);

  Deadlock happens on CPU0 when it tries to acquire &sighand->siglock
  but it has been held by CPU1 and CPU1 tries to grab &rq->lock
  and cannot get it.

  This is not exactly the callstack in our production environment,
  but sympotom is similar and both locks are using spin_lock_irqsave()
  to acquire the lock, and both involves rq_lock. The fix to delay
  sending signal when irq is disabled also fixed this issue.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200304191104.2796501-1-yhs@fb.com
cujomalainey pushed a commit to cujomalainey/linux that referenced this pull request Apr 23, 2020
[ Upstream commit 1bc7896 ]

When experimenting with bpf_send_signal() helper in our production
environment (5.2 based), we experienced a deadlock in NMI mode:
   thesofproject#5 [ffffc9002219f770] queued_spin_lock_slowpath at ffffffff8110be24
   thesofproject#6 [ffffc9002219f770] _raw_spin_lock_irqsave at ffffffff81a43012
   thesofproject#7 [ffffc9002219f780] try_to_wake_up at ffffffff810e7ecd
   thesofproject#8 [ffffc9002219f7e0] signal_wake_up_state at ffffffff810c7b55
   thesofproject#9 [ffffc9002219f7f0] __send_signal at ffffffff810c8602
  thesofproject#10 [ffffc9002219f830] do_send_sig_info at ffffffff810ca31a
  thesofproject#11 [ffffc9002219f868] bpf_send_signal at ffffffff8119d227
  thesofproject#12 [ffffc9002219f988] bpf_overflow_handler at ffffffff811d4140
  thesofproject#13 [ffffc9002219f9e0] __perf_event_overflow at ffffffff811d68cf
  thesofproject#14 [ffffc9002219fa10] perf_swevent_overflow at ffffffff811d6a09
  thesofproject#15 [ffffc9002219fa38] ___perf_sw_event at ffffffff811e0f47
  thesofproject#16 [ffffc9002219fc30] __schedule at ffffffff81a3e04d
  thesofproject#17 [ffffc9002219fc90] schedule at ffffffff81a3e219
  thesofproject#18 [ffffc9002219fca0] futex_wait_queue_me at ffffffff8113d1b9
  thesofproject#19 [ffffc9002219fcd8] futex_wait at ffffffff8113e529
  thesofproject#20 [ffffc9002219fdf0] do_futex at ffffffff8113ffbc
  thesofproject#21 [ffffc9002219fec0] __x64_sys_futex at ffffffff81140d1c
  thesofproject#22 [ffffc9002219ff38] do_syscall_64 at ffffffff81002602
  thesofproject#23 [ffffc9002219ff50] entry_SYSCALL_64_after_hwframe at ffffffff81c00068

The above call stack is actually very similar to an issue
reported by Commit eac9153 ("bpf/stackmap: Fix deadlock with
rq_lock in bpf_get_stack()") by Song Liu. The only difference is
bpf_send_signal() helper instead of bpf_get_stack() helper.

The above deadlock is triggered with a perf_sw_event.
Similar to Commit eac9153, the below almost identical reproducer
used tracepoint point sched/sched_switch so the issue can be easily caught.
  /* stress_test.c */
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/mman.h>
  #include <pthread.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>

  #define THREAD_COUNT 1000
  char *filename;
  void *worker(void *p)
  {
        void *ptr;
        int fd;
        char *pptr;

        fd = open(filename, O_RDONLY);
        if (fd < 0)
                return NULL;
        while (1) {
                struct timespec ts = {0, 1000 + rand() % 2000};

                ptr = mmap(NULL, 4096 * 64, PROT_READ, MAP_PRIVATE, fd, 0);
                usleep(1);
                if (ptr == MAP_FAILED) {
                        printf("failed to mmap\n");
                        break;
                }
                munmap(ptr, 4096 * 64);
                usleep(1);
                pptr = malloc(1);
                usleep(1);
                pptr[0] = 1;
                usleep(1);
                free(pptr);
                usleep(1);
                nanosleep(&ts, NULL);
        }
        close(fd);
        return NULL;
  }

  int main(int argc, char *argv[])
  {
        void *ptr;
        int i;
        pthread_t threads[THREAD_COUNT];

        if (argc < 2)
                return 0;

        filename = argv[1];

        for (i = 0; i < THREAD_COUNT; i++) {
                if (pthread_create(threads + i, NULL, worker, NULL)) {
                        fprintf(stderr, "Error creating thread\n");
                        return 0;
                }
        }

        for (i = 0; i < THREAD_COUNT; i++)
                pthread_join(threads[i], NULL);
        return 0;
  }
and the following command:
  1. run `stress_test /bin/ls` in one windown
  2. hack bcc trace.py with the following change:
#     --- a/tools/trace.py
#     +++ b/tools/trace.py
     @@ -513,6 +513,7 @@ BPF_PERF_OUTPUT(%s);
              __data.tgid = __tgid;
              __data.pid = __pid;
              bpf_get_current_comm(&__data.comm, sizeof(__data.comm));
     +        bpf_send_signal(10);
      %s
      %s
              %s.perf_submit(%s, &__data, sizeof(__data));
  3. in a different window run
     ./trace.py -p $(pidof stress_test) t:sched:sched_switch

The deadlock can be reproduced in our production system.

Similar to Song's fix, the fix is to delay sending signal if
irqs is disabled to avoid deadlocks involving with rq_lock.
With this change, my above stress-test in our production system
won't cause deadlock any more.

I also implemented a scale-down version of reproducer in the
selftest (a subsequent commit). With latest bpf-next,
it complains for the following potential deadlock.
  [   32.832450] -> #1 (&p->pi_lock){-.-.}:
  [   32.833100]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.833696]        task_rq_lock+0x2c/0xa0
  [   32.834182]        task_sched_runtime+0x59/0xd0
  [   32.834721]        thread_group_cputime+0x250/0x270
  [   32.835304]        thread_group_cputime_adjusted+0x2e/0x70
  [   32.835959]        do_task_stat+0x8a7/0xb80
  [   32.836461]        proc_single_show+0x51/0xb0
  ...
  [   32.839512] -> #0 (&(&sighand->siglock)->rlock){....}:
  [   32.840275]        __lock_acquire+0x1358/0x1a20
  [   32.840826]        lock_acquire+0xc7/0x1d0
  [   32.841309]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.841916]        __lock_task_sighand+0x79/0x160
  [   32.842465]        do_send_sig_info+0x35/0x90
  [   32.842977]        bpf_send_signal+0xa/0x10
  [   32.843464]        bpf_prog_bc13ed9e4d3163e3_send_signal_tp_sched+0x465/0x1000
  [   32.844301]        trace_call_bpf+0x115/0x270
  [   32.844809]        perf_trace_run_bpf_submit+0x4a/0xc0
  [   32.845411]        perf_trace_sched_switch+0x10f/0x180
  [   32.846014]        __schedule+0x45d/0x880
  [   32.846483]        schedule+0x5f/0xd0
  ...

  [   32.853148] Chain exists of:
  [   32.853148]   &(&sighand->siglock)->rlock --> &p->pi_lock --> &rq->lock
  [   32.853148]
  [   32.854451]  Possible unsafe locking scenario:
  [   32.854451]
  [   32.855173]        CPU0                    CPU1
  [   32.855745]        ----                    ----
  [   32.856278]   lock(&rq->lock);
  [   32.856671]                                lock(&p->pi_lock);
  [   32.857332]                                lock(&rq->lock);
  [   32.857999]   lock(&(&sighand->siglock)->rlock);

  Deadlock happens on CPU0 when it tries to acquire &sighand->siglock
  but it has been held by CPU1 and CPU1 tries to grab &rq->lock
  and cannot get it.

  This is not exactly the callstack in our production environment,
  but sympotom is similar and both locks are using spin_lock_irqsave()
  to acquire the lock, and both involves rq_lock. The fix to delay
  sending signal when irq is disabled also fixed this issue.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200304191104.2796501-1-yhs@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cujomalainey pushed a commit to cujomalainey/linux that referenced this pull request Oct 26, 2020
[ Upstream commit e24c644 ]

I compiled with AddressSanitizer and I had these memory leaks while I
was using the tep_parse_format function:

    Direct leak of 28 byte(s) in 4 object(s) allocated from:
        #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe)
        #1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985
        #2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140
        #3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206
        thesofproject#4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291
        thesofproject#5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299
        thesofproject#6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849
        thesofproject#7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161
        thesofproject#8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207
        thesofproject#9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786
        thesofproject#10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285
        thesofproject#11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369
        thesofproject#12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335
        thesofproject#13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389
        thesofproject#14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431
        thesofproject#15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251
        thesofproject#16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284
        thesofproject#17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593
        thesofproject#18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727
        thesofproject#19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048
        thesofproject#20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127
        thesofproject#21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152
        thesofproject#22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252
        thesofproject#23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347
        thesofproject#24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461
        thesofproject#25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673
        thesofproject#26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)

The token variable in the process_dynamic_array_len function is
allocated in the read_expect_type function, but is not freed before
calling the read_token function.

Free the token variable before calling read_token in order to plug the
leak.

Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/linux-trace-devel/20200730150236.5392-1-pduplessis@efficios.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
fredoh9 pushed a commit to fredoh9/linux that referenced this pull request Nov 19, 2020
This fix is for a failure that occurred in the DWARF unwind perf test.

Stack unwinders may probe memory when looking for frames.

Memory sanitizer will poison and track uninitialized memory on the
stack, and on the heap if the value is copied to the heap.

This can lead to false memory sanitizer failures for the use of an
uninitialized value.

Avoid this problem by removing the poison on the copied stack.

The full msan failure with track origins looks like:

==2168==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    thesofproject#4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    thesofproject#5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    thesofproject#6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    thesofproject#7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    thesofproject#8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    thesofproject#9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    thesofproject#10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    thesofproject#11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    thesofproject#12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    thesofproject#13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    thesofproject#14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    thesofproject#15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    thesofproject#16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    thesofproject#17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    thesofproject#18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    thesofproject#19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    thesofproject#20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    thesofproject#21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    thesofproject#22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    thesofproject#23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22
    #1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13
    #2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    thesofproject#4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    thesofproject#5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    thesofproject#6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    thesofproject#7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    thesofproject#8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    thesofproject#9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    thesofproject#10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    thesofproject#11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    thesofproject#12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    thesofproject#13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    thesofproject#14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    thesofproject#15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    thesofproject#16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    thesofproject#17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    thesofproject#18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    thesofproject#19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    thesofproject#20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    thesofproject#21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    thesofproject#22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    thesofproject#23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    thesofproject#24 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    thesofproject#4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    thesofproject#5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    thesofproject#6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    thesofproject#7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    thesofproject#8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    thesofproject#9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    thesofproject#10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    thesofproject#11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    thesofproject#12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    thesofproject#13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    thesofproject#14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    thesofproject#15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    thesofproject#16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    thesofproject#17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    thesofproject#18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    thesofproject#19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    thesofproject#20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    thesofproject#21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    thesofproject#22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    thesofproject#23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10
    #1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13
    #2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18
    #3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    thesofproject#4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    thesofproject#5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    thesofproject#6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    thesofproject#7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    thesofproject#8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    thesofproject#9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    thesofproject#10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    thesofproject#11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    thesofproject#12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    thesofproject#13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    thesofproject#14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    thesofproject#15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    thesofproject#16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    thesofproject#17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    thesofproject#18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    thesofproject#19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    thesofproject#20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    thesofproject#21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    thesofproject#22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    thesofproject#23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    thesofproject#24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    thesofproject#25 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3
    #1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2
    #2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9
    #3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6
    thesofproject#4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    thesofproject#5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    thesofproject#6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    thesofproject#7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    thesofproject#8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    thesofproject#9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    thesofproject#10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    thesofproject#11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    thesofproject#12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    thesofproject#13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    thesofproject#14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    thesofproject#15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    thesofproject#16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    thesofproject#17 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events'
    #0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445

SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: clang-built-linux@googlegroups.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandeep Dasgupta <sdasgup@google.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201113182053.754625-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
ujfalusi pushed a commit that referenced this pull request Aug 17, 2021
When using kprobe on powerpc booke series processor, Oops happens
as show bellow:

/ # echo "p:myprobe do_nanosleep" > /sys/kernel/debug/tracing/kprobe_events
/ # echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable
/ # sleep 1
[   50.076730] Oops: Exception in kernel mode, sig: 5 [#1]
[   50.077017] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500
[   50.077221] Modules linked in:
[   50.077462] CPU: 0 PID: 77 Comm: sleep Not tainted 5.14.0-rc4-00022-g251a1524293d #21
[   50.077887] NIP:  c0b9c4e0 LR: c00ebecc CTR: 00000000
[   50.078067] REGS: c3883de0 TRAP: 0700   Not tainted (5.14.0-rc4-00022-g251a1524293d)
[   50.078349] MSR:  00029000 <CE,EE,ME>  CR: 24000228  XER: 20000000
[   50.078675]
[   50.078675] GPR00: c00ebdf0 c3883e90 c313e300 c3883ea0 00000001 00000000 c3883ecc 00000001
[   50.078675] GPR08: c100598c c00ea250 00000004 00000000 24000222 102490c2 bff4180c 101e60d4
[   50.078675] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f 10240000 00500000
[   50.078675] GPR24: 00000002 00000000 c3883ea0 00000001 00000000 0000c350 3b9b8d50 00000000
[   50.080151] NIP [c0b9c4e0] do_nanosleep+0x0/0x190
[   50.080352] LR [c00ebecc] hrtimer_nanosleep+0x14c/0x1e0
[   50.080638] Call Trace:
[   50.080801] [c3883e90] [c00ebdf0] hrtimer_nanosleep+0x70/0x1e0 (unreliable)
[   50.081110] [c3883f00] [c00ec004] sys_nanosleep_time32+0xa4/0x110
[   50.081336] [c3883f40] [c001509c] ret_from_syscall+0x0/0x28
[   50.081541] --- interrupt: c00 at 0x100a4d08
[   50.081749] NIP:  100a4d08 LR: 101b5234 CTR: 00000003
[   50.081931] REGS: c3883f50 TRAP: 0c00   Not tainted (5.14.0-rc4-00022-g251a1524293d)
[   50.082183] MSR:  0002f902 <CE,EE,PR,FP,ME>  CR: 24000222  XER: 00000000
[   50.082457]
[   50.082457] GPR00: 000000a2 bf980040 1024b4d0 bf980084 bf980084 64000000 00555345 fefefeff
[   50.082457] GPR08: 7f7f7f7f 101e0000 00000069 00000003 28000422 102490c2 bff4180c 101e60d4
[   50.082457] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f 10240000 00500000
[   50.082457] GPR24: 00000002 bf9803f4 10240000 00000000 00000000 100039e0 00000000 102444e8
[   50.083789] NIP [100a4d08] 0x100a4d08
[   50.083917] LR [101b5234] 0x101b5234
[   50.084042] --- interrupt: c00
[   50.084238] Instruction dump:
[   50.084483] 4bfffc40 60000000 60000000 60000000 9421fff0 39400402 914200c0 38210010
[   50.084841] 4bfffc20 00000000 00000000 00000000 <7fe00008> 7c0802a6 7c892378 93c10048
[   50.085487] ---[ end trace f6fffe98e2fa8f3e ]---
[   50.085678]
Trace/breakpoint trap

There is no real mode for booke arch and the MMU translation is
always on. The corresponding MSR_IS/MSR_DS bit in booke is used
to switch the address space, but not for real mode judgment.

Fixes: 21f8b2f ("powerpc/kprobes: Ignore traps that happened in real mode")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210809023658.218915-1-pulehui@huawei.com
plbossart pushed a commit that referenced this pull request Oct 4, 2021
The id of slv_cnoc_mnoc_cfg node is mistakenly coded as id of
slv_blsp_1.  It causes the following warning on slv_blsp_1 node adding.
Correct the id of slv_cnoc_mnoc_cfg node.

[    1.948180] ------------[ cut here ]------------
[    1.954122] WARNING: CPU: 2 PID: 7 at drivers/interconnect/core.c:962 icc_node_add+0xe4/0xf8
[    1.958994] Modules linked in:
[    1.967399] CPU: 2 PID: 7 Comm: kworker/u16:0 Not tainted 5.14.0-rc6-next-20210818 #21
[    1.970275] Hardware name: Xiaomi Redmi Note 7 (DT)
[    1.978169] Workqueue: events_unbound deferred_probe_work_func
[    1.982945] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    1.988849] pc : icc_node_add+0xe4/0xf8
[    1.995699] lr : qnoc_probe+0x350/0x438
[    1.999519] sp : ffff80001008bb10
[    2.003337] x29: ffff80001008bb10 x28: 000000000000001a x27: ffffb83ddc61ee28
[    2.006818] x26: ffff2fe341d44080 x25: ffff2fe340f3aa80 x24: ffffb83ddc98f0e8
[    2.013938] x23: 0000000000000024 x22: ffff2fe3408b7400 x21: 0000000000000000
[    2.021054] x20: ffff2fe3408b7410 x19: ffff2fe341d44080 x18: 0000000000000010
[    2.028173] x17: ffff2fe3bdd0aac0 x16: 0000000000000281 x15: ffff2fe3400f5528
[    2.035290] x14: 000000000000013f x13: ffff2fe3400f5528 x12: 00000000ffffffea
[    2.042410] x11: ffffb83ddc9109d0 x10: ffffb83ddc8f8990 x9 : ffffb83ddc8f89e8
[    2.049527] x8 : 0000000000017fe8 x7 : c0000000ffffefff x6 : 0000000000000001
[    2.056645] x5 : 0000000000057fa8 x4 : 0000000000000000 x3 : ffffb83ddc9903b0
[    2.063764] x2 : 1a1f6fde34d45500 x1 : ffff2fe340f3a880 x0 : ffff2fe340f3a880
[    2.070882] Call trace:
[    2.077989]  icc_node_add+0xe4/0xf8
[    2.080247]  qnoc_probe+0x350/0x438
[    2.083718]  platform_probe+0x68/0xd8
[    2.087191]  really_probe+0xb8/0x300
[    2.091011]  __driver_probe_device+0x78/0xe0
[    2.094659]  driver_probe_device+0x80/0x110
[    2.098911]  __device_attach_driver+0x90/0xe0
[    2.102818]  bus_for_each_drv+0x78/0xc8
[    2.107331]  __device_attach+0xf0/0x150
[    2.110977]  device_initial_probe+0x14/0x20
[    2.114796]  bus_probe_device+0x9c/0xa8
[    2.118963]  deferred_probe_work_func+0x88/0xc0
[    2.122784]  process_one_work+0x1a4/0x338
[    2.127296]  worker_thread+0x1f8/0x420
[    2.131464]  kthread+0x150/0x160
[    2.135107]  ret_from_fork+0x10/0x20
[    2.138495] ---[ end trace 5eea8768cb620e87 ]---

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Fixes: f80a1d4 ("interconnect: qcom: Add SDM660 interconnect provider driver")
Link: https://lore.kernel.org/r/20210823014003.31391-1-shawn.guo@linaro.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Vamshigopal pushed a commit to Vamshigopal/linux that referenced this pull request Jan 24, 2023
[ Upstream commit 9de255c ]

Commit b743512 ("uio: fix a sleep-in-atomic-context bug in
uio_dmem_genirq_irqcontrol()") started calling disable_irq() without
holding the spinlock because it can sleep. However, that fix introduced
another bug: if interrupt is already disabled and a new disable request
comes in, then the spinlock is not unlocked:

root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0
root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0
root@localhost:~# [   14.851538] BUG: scheduling while atomic: bash/223/0x00000002
[   14.851991] Modules linked in: uio_dmem_genirq uio myfpga(OE) bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper drm snd_pcm ppdev joydev psmouse snd_timer snd e1000fb_sys_fops syscopyarea parport sysfillrect soundcore sysimgblt input_leds pcspkr i2c_piix4 serio_raw floppy evbug qemu_fw_cfg mac_hid pata_acpi ip_tables x_tables autofs4 [last unloaded: parport_pc]
[   14.854206] CPU: 0 PID: 223 Comm: bash Tainted: G           OE      6.0.0-rc7 thesofproject#21
[   14.854786] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[   14.855664] Call Trace:
[   14.855861]  <TASK>
[   14.856025]  dump_stack_lvl+0x4d/0x67
[   14.856325]  dump_stack+0x14/0x1a
[   14.856583]  __schedule_bug.cold+0x4b/0x5c
[   14.856915]  __schedule+0xe81/0x13d0
[   14.857199]  ? idr_find+0x13/0x20
[   14.857456]  ? get_work_pool+0x2d/0x50
[   14.857756]  ? __flush_work+0x233/0x280
[   14.858068]  ? __schedule+0xa95/0x13d0
[   14.858307]  ? idr_find+0x13/0x20
[   14.858519]  ? get_work_pool+0x2d/0x50
[   14.858798]  schedule+0x6c/0x100
[   14.859009]  schedule_hrtimeout_range_clock+0xff/0x110
[   14.859335]  ? tty_write_room+0x1f/0x30
[   14.859598]  ? n_tty_poll+0x1ec/0x220
[   14.859830]  ? tty_ldisc_deref+0x1a/0x20
[   14.860090]  schedule_hrtimeout_range+0x17/0x20
[   14.860373]  do_select+0x596/0x840
[   14.860627]  ? __kernel_text_address+0x16/0x50
[   14.860954]  ? poll_freewait+0xb0/0xb0
[   14.861235]  ? poll_freewait+0xb0/0xb0
[   14.861517]  ? rpm_resume+0x49d/0x780
[   14.861798]  ? common_interrupt+0x59/0xa0
[   14.862127]  ? asm_common_interrupt+0x2b/0x40
[   14.862511]  ? __uart_start.isra.0+0x61/0x70
[   14.862902]  ? __check_object_size+0x61/0x280
[   14.863255]  core_sys_select+0x1c6/0x400
[   14.863575]  ? vfs_write+0x1c9/0x3d0
[   14.863853]  ? vfs_write+0x1c9/0x3d0
[   14.864121]  ? _copy_from_user+0x45/0x70
[   14.864526]  do_pselect.constprop.0+0xb3/0xf0
[   14.864893]  ? do_syscall_64+0x6d/0x90
[   14.865228]  ? do_syscall_64+0x6d/0x90
[   14.865556]  __x64_sys_pselect6+0x76/0xa0
[   14.865906]  do_syscall_64+0x60/0x90
[   14.866214]  ? syscall_exit_to_user_mode+0x2a/0x50
[   14.866640]  ? do_syscall_64+0x6d/0x90
[   14.866972]  ? do_syscall_64+0x6d/0x90
[   14.867286]  ? do_syscall_64+0x6d/0x90
[   14.867626]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...] stripped
[   14.872959]  </TASK>

('myfpga' is a simple 'uio_dmem_genirq' driver I wrote to test this)

The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and
it is used in a similar manner to the "uio_pdrv_genirq" driver with respect
to interrupt configuration and handling. At the time "uio_dmem_genirq" was
introduced, both had the same implementation of the 'uio_info' handlers
irqcontrol() and handler(). Then commit 34cb275 ("UIO: Fix concurrency
issue"), which was only applied to "uio_pdrv_genirq", ended up making them
a little different. That commit, among other things, changed disable_irq()
to disable_irq_nosync() in the implementation of irqcontrol(). The
motivation there was to avoid a deadlock between irqcontrol() and
handler(), since it added a spinlock in the irq handler, and disable_irq()
waits for the completion of the irq handler.

By changing disable_irq() to disable_irq_nosync() in irqcontrol(), we also
avoid the sleeping-while-atomic bug that commit b743512 ("uio: fix a
sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") was trying to
fix. Thus, this fixes the missing unlock in irqcontrol() by importing the
implementation of irqcontrol() handler from the "uio_pdrv_genirq" driver.
In the end, it reverts commit b743512 ("uio: fix a
sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") and change
disable_irq() to disable_irq_nosync().

It is worth noting that this still does not address the concurrency issue
fixed by commit 34cb275 ("UIO: Fix concurrency issue"). It will be
addressed separately in the next commits.

Split out from commit 34cb275 ("UIO: Fix concurrency issue").

Fixes: b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()")
Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Link: https://lore.kernel.org/r/20220930224100.816175-2-rafaelmendsr@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
plbossart pushed a commit that referenced this pull request Jun 16, 2023
The cited commit adds a compeletion to remove dependency on rtnl
lock. But it causes a deadlock for multiple encapsulations:

 crash> bt ffff8aece8a64000
 PID: 1514557  TASK: ffff8aece8a64000  CPU: 3    COMMAND: "tc"
  #0 [ffffa6d14183f368] __schedule at ffffffffb8ba7f45
  #1 [ffffa6d14183f3f8] schedule at ffffffffb8ba8418
  #2 [ffffa6d14183f418] schedule_preempt_disabled at ffffffffb8ba8898
  #3 [ffffa6d14183f428] __mutex_lock at ffffffffb8baa7f8
  #4 [ffffa6d14183f4d0] mutex_lock_nested at ffffffffb8baabeb
  #5 [ffffa6d14183f4e0] mlx5e_attach_encap at ffffffffc0f48c17 [mlx5_core]
  #6 [ffffa6d14183f628] mlx5e_tc_add_fdb_flow at ffffffffc0f39680 [mlx5_core]
  #7 [ffffa6d14183f688] __mlx5e_add_fdb_flow at ffffffffc0f3b636 [mlx5_core]
  #8 [ffffa6d14183f6f0] mlx5e_tc_add_flow at ffffffffc0f3bcdf [mlx5_core]
  #9 [ffffa6d14183f728] mlx5e_configure_flower at ffffffffc0f3c1d1 [mlx5_core]
 #10 [ffffa6d14183f790] mlx5e_rep_setup_tc_cls_flower at ffffffffc0f3d529 [mlx5_core]
 #11 [ffffa6d14183f7a0] mlx5e_rep_setup_tc_cb at ffffffffc0f3d714 [mlx5_core]
 #12 [ffffa6d14183f7b0] tc_setup_cb_add at ffffffffb8931bb8
 #13 [ffffa6d14183f810] fl_hw_replace_filter at ffffffffc0dae901 [cls_flower]
 #14 [ffffa6d14183f8d8] fl_change at ffffffffc0db5c57 [cls_flower]
 #15 [ffffa6d14183f970] tc_new_tfilter at ffffffffb8936047
 #16 [ffffa6d14183fac8] rtnetlink_rcv_msg at ffffffffb88c7c31
 #17 [ffffa6d14183fb50] netlink_rcv_skb at ffffffffb8942853
 #18 [ffffa6d14183fbc0] rtnetlink_rcv at ffffffffb88c1835
 #19 [ffffa6d14183fbd0] netlink_unicast at ffffffffb8941f27
 #20 [ffffa6d14183fc18] netlink_sendmsg at ffffffffb8942245
 #21 [ffffa6d14183fc98] sock_sendmsg at ffffffffb887d482
 #22 [ffffa6d14183fcb8] ____sys_sendmsg at ffffffffb887d81a
 #23 [ffffa6d14183fd38] ___sys_sendmsg at ffffffffb88806e2
 #24 [ffffa6d14183fe90] __sys_sendmsg at ffffffffb88807a2
 #25 [ffffa6d14183ff28] __x64_sys_sendmsg at ffffffffb888080f
 #26 [ffffa6d14183ff38] do_syscall_64 at ffffffffb8b9b6a8
 #27 [ffffa6d14183ff50] entry_SYSCALL_64_after_hwframe at ffffffffb8c0007c
 crash> bt 0xffff8aeb07544000
 PID: 1110766  TASK: ffff8aeb07544000  CPU: 0    COMMAND: "kworker/u20:9"
  #0 [ffffa6d14e6b7bd8] __schedule at ffffffffb8ba7f45
  #1 [ffffa6d14e6b7c68] schedule at ffffffffb8ba8418
  #2 [ffffa6d14e6b7c88] schedule_timeout at ffffffffb8baef88
  #3 [ffffa6d14e6b7d10] wait_for_completion at ffffffffb8ba968b
  #4 [ffffa6d14e6b7d60] mlx5e_take_all_encap_flows at ffffffffc0f47ec4 [mlx5_core]
  #5 [ffffa6d14e6b7da0] mlx5e_rep_update_flows at ffffffffc0f3e734 [mlx5_core]
  #6 [ffffa6d14e6b7df8] mlx5e_rep_neigh_update at ffffffffc0f400bb [mlx5_core]
  #7 [ffffa6d14e6b7e50] process_one_work at ffffffffb80acc9c
  #8 [ffffa6d14e6b7ed0] worker_thread at ffffffffb80ad012
  #9 [ffffa6d14e6b7f10] kthread at ffffffffb80b615d
 #10 [ffffa6d14e6b7f50] ret_from_fork at ffffffffb8001b2f

After the first encap is attached, flow will be added to encap
entry's flows list. If neigh update is running at this time, the
following encaps of the flow can't hold the encap_tbl_lock and
sleep. If neigh update thread is waiting for that flow's init_done,
deadlock happens.

Fix it by holding lock outside of the for loop. If neigh update is
running, prevent encap flows from offloading. Since the lock is held
outside of the for loop, concurrent creation of encap entries is not
allowed. So remove unnecessary wait_for_completion call for res_ready.

Fixes: 95435ad ("net/mlx5e: Only access fully initialized flows in neigh update")
Signed-off-by: Chris Mi <cmi@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
wenliangwu pushed a commit that referenced this pull request Oct 30, 2023
The following processes run into a deadlock. CPU 41 was waiting for CPU 29
to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29
was hung by that spinlock with IRQs disabled.

  PID: 17360    TASK: ffff95c1090c5c40  CPU: 41  COMMAND: "mrdiagd"
  !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0
  !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0
  !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0
   # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0
   # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0
   # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0
   # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0
   # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0
   # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0
   # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0
   #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0
   #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0
   #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0
   #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0
   #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0
   #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0
   #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0
   #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0
   #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0
   #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

  PID: 17355    TASK: ffff95c1090c3d80  CPU: 29  COMMAND: "mrdiagd"
  !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0
  !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0
   # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0
   # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0
   # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0
   # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0
   # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0
   # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0
   # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0
   # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

The lock is used to synchronize different sysfs operations, it doesn't
protect any resource that will be touched by an interrupt. Consequently
it's not required to disable IRQs. Replace the spinlock with a mutex to fix
the deadlock.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Link: https://lore.kernel.org/r/20230828221018.19471-1-junxiao.bi@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
wenliangwu pushed a commit that referenced this pull request Oct 30, 2023
commit 133466c ("net: stmmac: use per-queue 64 bit statistics
where necessary") caused one regression as found by Uwe, the backtrace
looks like:

	INFO: trying to register non-static key.
	The code is fine but needs lockdep annotation, or maybe
	you didn't initialize this object before use?
	turning off the locking correctness validator.
	CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc1-00449-g133466c3bbe1-dirty #21
	Hardware name: STM32 (Device Tree Support)
	 unwind_backtrace from show_stack+0x18/0x1c
	 show_stack from dump_stack_lvl+0x60/0x90
	 dump_stack_lvl from register_lock_class+0x98c/0x99c
	 register_lock_class from __lock_acquire+0x74/0x293c
	 __lock_acquire from lock_acquire+0x134/0x398
	 lock_acquire from stmmac_get_stats64+0x2ac/0x2fc
	 stmmac_get_stats64 from dev_get_stats+0x44/0x130
	 dev_get_stats from rtnl_fill_stats+0x38/0x120
	 rtnl_fill_stats from rtnl_fill_ifinfo+0x834/0x17f4
	 rtnl_fill_ifinfo from rtmsg_ifinfo_build_skb+0xc0/0x144
	 rtmsg_ifinfo_build_skb from rtmsg_ifinfo+0x50/0x88
	 rtmsg_ifinfo from __dev_notify_flags+0xc0/0xec
	 __dev_notify_flags from dev_change_flags+0x50/0x5c
	 dev_change_flags from ip_auto_config+0x2f4/0x1260
	 ip_auto_config from do_one_initcall+0x70/0x35c
	 do_one_initcall from kernel_init_freeable+0x2ac/0x308
	 kernel_init_freeable from kernel_init+0x1c/0x138
	 kernel_init from ret_from_fork+0x14/0x2c

The reason is the rxq|txq_stats structures are not what expected
because stmmac_open() -> __stmmac_open() the structure is overwritten
by "memcpy(&priv->dma_conf, dma_conf, sizeof(*dma_conf));"
This causes the well initialized syncp member of rxq|txq_stats is
overwritten unexpectedly as pointed out by Johannes and Uwe.

Fix this issue by moving rxq|txq_stats back to stmmac_extra_stats. For
SMP cache friendly, we also mark stmmac_txq_stats and stmmac_rxq_stats
as ____cacheline_aligned_in_smp.

Fixes: 133466c ("net: stmmac: use per-queue 64 bit statistics where necessary")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230917165328.3403-1-jszhang@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
bardliao pushed a commit to bardliao/linux that referenced this pull request Aug 22, 2024
In the buffered write path, the dirty page owns the qgroup reserve until
it creates an ordered_extent.

Therefore, any errors that occur before the ordered_extent is created
must free that reservation, or else the space is leaked. The fstest
generic/475 exercises various IO error paths, and is able to trigger
errors in cow_file_range where we fail to get to allocating the ordered
extent. Note that because we *do* clear delalloc, we are likely to
remove the inode from the delalloc list, so the inodes/pages to not have
invalidate/launder called on them in the commit abort path.

This results in failures at the unmount stage of the test that look like:

  BTRFS: error (device dm-8 state EA) in cleanup_transaction:2018: errno=-5 IO failure
  BTRFS: error (device dm-8 state EA) in btrfs_replace_file_extents:2416: errno=-5 IO failure
  BTRFS warning (device dm-8 state EA): qgroup 0/5 has unreleased space, type 0 rsv 28672
  ------------[ cut here ]------------
  WARNING: CPU: 3 PID: 22588 at fs/btrfs/disk-io.c:4333 close_ctree+0x222/0x4d0 [btrfs]
  Modules linked in: btrfs blake2b_generic libcrc32c xor zstd_compress raid6_pq
  CPU: 3 PID: 22588 Comm: umount Kdump: loaded Tainted: G W          6.10.0-rc7-gab56fde445b8 thesofproject#21
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
  RIP: 0010:close_ctree+0x222/0x4d0 [btrfs]
  RSP: 0018:ffffb4465283be00 EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffffa1a1818e1000 RCX: 0000000000000001
  RDX: 0000000000000000 RSI: ffffb4465283bbe0 RDI: ffffa1a19374fcb8
  RBP: ffffa1a1818e13c0 R08: 0000000100028b16 R09: 0000000000000000
  R10: 0000000000000003 R11: 0000000000000003 R12: ffffa1a18ad7972c
  R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  FS:  00007f9168312b80(0000) GS:ffffa1a4afcc0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f91683c9140 CR3: 000000010acaa000 CR4: 00000000000006f0
  Call Trace:
   <TASK>
   ? close_ctree+0x222/0x4d0 [btrfs]
   ? __warn.cold+0x8e/0xea
   ? close_ctree+0x222/0x4d0 [btrfs]
   ? report_bug+0xff/0x140
   ? handle_bug+0x3b/0x70
   ? exc_invalid_op+0x17/0x70
   ? asm_exc_invalid_op+0x1a/0x20
   ? close_ctree+0x222/0x4d0 [btrfs]
   generic_shutdown_super+0x70/0x160
   kill_anon_super+0x11/0x40
   btrfs_kill_super+0x11/0x20 [btrfs]
   deactivate_locked_super+0x2e/0xa0
   cleanup_mnt+0xb5/0x150
   task_work_run+0x57/0x80
   syscall_exit_to_user_mode+0x121/0x130
   do_syscall_64+0xab/0x1a0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f916847a887
  ---[ end trace 0000000000000000 ]---
  BTRFS error (device dm-8 state EA): qgroup reserved space leaked

Cases 2 and 3 in the out_reserve path both pertain to this type of leak
and must free the reserved qgroup data. Because it is already an error
path, I opted not to handle the possible errors in
btrfs_free_qgroup_data.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
bardliao pushed a commit to bardliao/linux that referenced this pull request Dec 20, 2024
…s_lock

For storing a value to a queue attribute, the queue_attr_store function
first freezes the queue (->q_usage_counter(io)) and then acquire
->sysfs_lock. This seems not correct as the usual ordering should be to
acquire ->sysfs_lock before freezing the queue. This incorrect ordering
causes the following lockdep splat which we are able to reproduce always
simply by accessing /sys/kernel/debug file using ls command:

[   57.597146] WARNING: possible circular locking dependency detected
[   57.597154] 6.12.0-10553-gb86545e02e8c thesofproject#20 Tainted: G        W
[   57.597162] ------------------------------------------------------
[   57.597168] ls/4605 is trying to acquire lock:
[   57.597176] c00000003eb56710 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0x58/0xc0
[   57.597200]
               but task is already holding lock:
[   57.597207] c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4
[   57.597226]
               which lock already depends on the new lock.

[   57.597233]
               the existing dependency chain (in reverse order) is:
[   57.597241]
               -> thesofproject#5 (&sb->s_type->i_mutex_key#3){++++}-{4:4}:
[   57.597255]        down_write+0x6c/0x18c
[   57.597264]        start_creating+0xb4/0x24c
[   57.597274]        debugfs_create_dir+0x2c/0x1e8
[   57.597283]        blk_register_queue+0xec/0x294
[   57.597292]        add_disk_fwnode+0x2e4/0x548
[   57.597302]        brd_alloc+0x2c8/0x338
[   57.597309]        brd_init+0x100/0x178
[   57.597317]        do_one_initcall+0x88/0x3e4
[   57.597326]        kernel_init_freeable+0x3cc/0x6e0
[   57.597334]        kernel_init+0x34/0x1cc
[   57.597342]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597350]
               -> #4 (&q->debugfs_mutex){+.+.}-{4:4}:
[   57.597362]        __mutex_lock+0xfc/0x12a0
[   57.597370]        blk_register_queue+0xd4/0x294
[   57.597379]        add_disk_fwnode+0x2e4/0x548
[   57.597388]        brd_alloc+0x2c8/0x338
[   57.597395]        brd_init+0x100/0x178
[   57.597402]        do_one_initcall+0x88/0x3e4
[   57.597410]        kernel_init_freeable+0x3cc/0x6e0
[   57.597418]        kernel_init+0x34/0x1cc
[   57.597426]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597434]
               -> #3 (&q->sysfs_lock){+.+.}-{4:4}:
[   57.597446]        __mutex_lock+0xfc/0x12a0
[   57.597454]        queue_attr_store+0x9c/0x110
[   57.597462]        sysfs_kf_write+0x70/0xb0
[   57.597471]        kernfs_fop_write_iter+0x1b0/0x2ac
[   57.597480]        vfs_write+0x3dc/0x6e8
[   57.597488]        ksys_write+0x84/0x140
[   57.597495]        system_call_exception+0x130/0x360
[   57.597504]        system_call_common+0x160/0x2c4
[   57.597516]
               -> #2 (&q->q_usage_counter(io)thesofproject#21){++++}-{0:0}:
[   57.597530]        __submit_bio+0x5ec/0x828
[   57.597538]        submit_bio_noacct_nocheck+0x1e4/0x4f0
[   57.597547]        iomap_readahead+0x2a0/0x448
[   57.597556]        xfs_vm_readahead+0x28/0x3c
[   57.597564]        read_pages+0x88/0x41c
[   57.597571]        page_cache_ra_unbounded+0x1ac/0x2d8
[   57.597580]        filemap_get_pages+0x188/0x984
[   57.597588]        filemap_read+0x13c/0x4bc
[   57.597596]        xfs_file_buffered_read+0x88/0x17c
[   57.597605]        xfs_file_read_iter+0xac/0x158
[   57.597614]        vfs_read+0x2d4/0x3b4
[   57.597622]        ksys_read+0x84/0x144
[   57.597629]        system_call_exception+0x130/0x360
[   57.597637]        system_call_common+0x160/0x2c4
[   57.597647]
               -> #1 (mapping.invalidate_lock#2){++++}-{4:4}:
[   57.597661]        down_read+0x6c/0x220
[   57.597669]        filemap_fault+0x870/0x100c
[   57.597677]        xfs_filemap_fault+0xc4/0x18c
[   57.597684]        __do_fault+0x64/0x164
[   57.597693]        __handle_mm_fault+0x1274/0x1dac
[   57.597702]        handle_mm_fault+0x248/0x484
[   57.597711]        ___do_page_fault+0x428/0xc0c
[   57.597719]        hash__do_page_fault+0x30/0x68
[   57.597727]        do_hash_fault+0x90/0x35c
[   57.597736]        data_access_common_virt+0x210/0x220
[   57.597745]        _copy_from_user+0xf8/0x19c
[   57.597754]        sel_write_load+0x178/0xd54
[   57.597762]        vfs_write+0x108/0x6e8
[   57.597769]        ksys_write+0x84/0x140
[   57.597777]        system_call_exception+0x130/0x360
[   57.597785]        system_call_common+0x160/0x2c4
[   57.597794]
               -> #0 (&mm->mmap_lock){++++}-{4:4}:
[   57.597806]        __lock_acquire+0x17cc/0x2330
[   57.597814]        lock_acquire+0x138/0x400
[   57.597822]        __might_fault+0x7c/0xc0
[   57.597830]        filldir64+0xe8/0x390
[   57.597839]        dcache_readdir+0x80/0x2d4
[   57.597846]        iterate_dir+0xd8/0x1d4
[   57.597855]        sys_getdents64+0x88/0x2d4
[   57.597864]        system_call_exception+0x130/0x360
[   57.597872]        system_call_common+0x160/0x2c4
[   57.597881]
               other info that might help us debug this:

[   57.597888] Chain exists of:
                 &mm->mmap_lock --> &q->debugfs_mutex --> &sb->s_type->i_mutex_key#3

[   57.597905]  Possible unsafe locking scenario:

[   57.597911]        CPU0                    CPU1
[   57.597917]        ----                    ----
[   57.597922]   rlock(&sb->s_type->i_mutex_key#3);
[   57.597932]                                lock(&q->debugfs_mutex);
[   57.597940]                                lock(&sb->s_type->i_mutex_key#3);
[   57.597950]   rlock(&mm->mmap_lock);
[   57.597958]
                *** DEADLOCK ***

[   57.597965] 2 locks held by ls/4605:
[   57.597971]  #0: c0000000137c12f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0xcc/0x154
[   57.597989]  #1: c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4

Prevent the above lockdep warning by acquiring ->sysfs_lock before
freezing the queue while storing a queue attribute in queue_attr_store
function. Later, we also found[1] another function __blk_mq_update_nr_
hw_queues where we first freeze queue and then acquire the ->sysfs_lock.
So we've also updated lock ordering in __blk_mq_update_nr_hw_queues
function and ensured that in all code paths we follow the correct lock
ordering i.e. acquire ->sysfs_lock before freezing the queue.

[1] https://lore.kernel.org/all/CAFj5m9Ke8+EHKQBs_Nk6hqd=LGXtk4mUxZUN5==ZcCjnZSBwHw@mail.gmail.com/

Reported-by: kjain@linux.ibm.com
Fixes: af28141 ("block: freeze the queue in queue_attr_store")
Tested-by: kjain@linux.ibm.com
Cc: hch@lst.de
Cc: axboe@kernel.dk
Cc: ritesh.list@gmail.com
Cc: ming.lei@redhat.com
Cc: gjoyce@linux.ibm.com
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241210144222.1066229-1-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

1 participant