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@pull pull bot commented Apr 23, 2020

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bjorn-helgaas and others added 5 commits April 14, 2020 19:16
Some Google Apex Edge TPU devices have a class code of 0
(PCI_CLASS_NOT_DEFINED).  This prevents the PCI core from assigning
resources for the Apex BARs because __dev_sort_resources() ignores
classless devices, host bridges, and IOAPICs.

On x86, firmware typically assigns those resources, so this was not a
problem.  But on some architectures, firmware does *not* assign BARs, and
since the PCI core didn't do it either, the Apex device didn't work
correctly:

  apex 0000:01:00.0: can't enable device: BAR 0 [mem 0x00000000-0x00003fff 64bit pref] not claimed
  apex 0000:01:00.0: error enabling PCI device

f390d08 ("staging: gasket: apex: fixup undefined PCI class") added a
quirk to fix the class code, but it was in the apex driver, and if the
driver was built as a module, it was too late to help.

Move the quirk to the PCI core, where it will always run early enough that
the PCI core will assign resources if necessary.

Link: https://lore.kernel.org/r/CAEzXK1r0Er039iERnc2KJ4jn7ySNUOG9H=Ha8TD8XroVqiZjgg@mail.gmail.com
Fixes: f390d08 ("staging: gasket: apex: fixup undefined PCI class")
Reported-by: Luís Mendes <luis.p.mendes@gmail.com>
Debugged-by: Luís Mendes <luis.p.mendes@gmail.com>
Tested-by: Luis Mendes <luis.p.mendes@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Todd Poynor <toddpoynor@google.com>
Christof Meerwald <cmeerw@cmeerw.org> writes:
> Hi,
>
> this is probably related to commit
> 7a0cf09 (signal: Correct namespace
> fixups of si_pid and si_uid).
>
> With a 5.6.5 kernel I am seeing SIGCHLD signals that don't include a
> properly set si_pid field - this seems to happen for multi-threaded
> child processes.
>
> A simple test program (based on the sample from the signalfd man page):
>
> #include <sys/signalfd.h>
> #include <signal.h>
> #include <unistd.h>
> #include <spawn.h>
> #include <stdlib.h>
> #include <stdio.h>
>
> #define handle_error(msg) \
>     do { perror(msg); exit(EXIT_FAILURE); } while (0)
>
> int main(int argc, char *argv[])
> {
>   sigset_t mask;
>   int sfd;
>   struct signalfd_siginfo fdsi;
>   ssize_t s;
>
>   sigemptyset(&mask);
>   sigaddset(&mask, SIGCHLD);
>
>   if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
>     handle_error("sigprocmask");
>
>   pid_t chldpid;
>   char *chldargv[] = { "./sfdclient", NULL };
>   posix_spawn(&chldpid, "./sfdclient", NULL, NULL, chldargv, NULL);
>
>   sfd = signalfd(-1, &mask, 0);
>   if (sfd == -1)
>     handle_error("signalfd");
>
>   for (;;) {
>     s = read(sfd, &fdsi, sizeof(struct signalfd_siginfo));
>     if (s != sizeof(struct signalfd_siginfo))
>       handle_error("read");
>
>     if (fdsi.ssi_signo == SIGCHLD) {
>       printf("Got SIGCHLD %d %d %d %d\n",
>           fdsi.ssi_status, fdsi.ssi_code,
>           fdsi.ssi_uid, fdsi.ssi_pid);
>       return 0;
>     } else {
>       printf("Read unexpected signal\n");
>     }
>   }
> }
>
>
> and a multi-threaded client to test with:
>
> #include <unistd.h>
> #include <pthread.h>
>
> void *f(void *arg)
> {
>   sleep(100);
> }
>
> int main()
> {
>   pthread_t t[8];
>
>   for (int i = 0; i != 8; ++i)
>   {
>     pthread_create(&t[i], NULL, f, NULL);
>   }
> }
>
> I tried to do a bit of debugging and what seems to be happening is
> that
>
>   /* From an ancestor pid namespace? */
>   if (!task_pid_nr_ns(current, task_active_pid_ns(t))) {
>
> fails inside task_pid_nr_ns because the check for "pid_alive" fails.
>
> This code seems to be called from do_notify_parent and there we
> actually have "tsk != current" (I am assuming both are threads of the
> current process?)

I instrumented the code with a warning and received the following backtrace:
> WARNING: CPU: 0 PID: 777 at kernel/pid.c:501 __task_pid_nr_ns.cold.6+0xc/0x15
> Modules linked in:
> CPU: 0 PID: 777 Comm: sfdclient Not tainted 5.7.0-rc1userns+ #2924
> Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
> RIP: 0010:__task_pid_nr_ns.cold.6+0xc/0x15
> Code: ff 66 90 48 83 ec 08 89 7c 24 04 48 8d 7e 08 48 8d 74 24 04 e8 9a b6 44 00 48 83 c4 08 c3 48 c7 c7 59 9f ac 82 e8 c2 c4 04 00 <0f> 0b e9 3fd
> RSP: 0018:ffffc9000042fbf8 EFLAGS: 00010046
> RAX: 000000000000000c RBX: 0000000000000000 RCX: ffffc9000042faf4
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff81193d29
> RBP: ffffc9000042fc18 R08: 0000000000000000 R09: 0000000000000001
> R10: 000000100f938416 R11: 0000000000000309 R12: ffff8880b941c140
> R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880b941c140
> FS:  0000000000000000(0000) GS:ffff8880bca00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f2e8c0a32e0 CR3: 0000000002e10000 CR4: 00000000000006f0
> Call Trace:
>  send_signal+0x1c8/0x310
>  do_notify_parent+0x50f/0x550
>  release_task.part.21+0x4fd/0x620
>  do_exit+0x6f6/0xaf0
>  do_group_exit+0x42/0xb0
>  get_signal+0x13b/0xbb0
>  do_signal+0x2b/0x670
>  ? __audit_syscall_exit+0x24d/0x2b0
>  ? rcu_read_lock_sched_held+0x4d/0x60
>  ? kfree+0x24c/0x2b0
>  do_syscall_64+0x176/0x640
>  ? trace_hardirqs_off_thunk+0x1a/0x1c
>  entry_SYSCALL_64_after_hwframe+0x49/0xb3

The immediate problem is as Christof noticed that "pid_alive(current) == false".
This happens because do_notify_parent is called from the last thread to exit
in a process after that thread has been reaped.

The bigger issue is that do_notify_parent can be called from any
process that manages to wait on a thread of a multi-threaded process
from wait_task_zombie.  So any logic based upon current for
do_notify_parent is just nonsense, as current can be pretty much
anything.

So change do_notify_parent to call __send_signal directly.

Inspecting the code it appears this problem has existed since the pid
namespace support started handling this case in 2.6.30.  This fix only
backports to 7a0cf09 ("signal: Correct namespace fixups of si_pid and si_uid")
where the problem logic was moved out of __send_signal and into send_signal.

Cc: stable@vger.kernel.org
Fixes: 6588c1e ("signals: SI_USER: Masquerade si_pid when crossing pid ns boundary")
Ref: 921cf9f ("signals: protect cinit from unblocked SIG_DFL signals")
Link: https://lore.kernel.org/lkml/20200419201336.GI22017@edge.cmeerw.net/
Reported-by: Christof Meerwald <cmeerw@cmeerw.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Andy Murray decided to step down as PCI controller reviewer and Rob Herring
is willing to help review PCI controller patches.

Update the respective MAINTAINERS entries to reflect this change.

Link: https://lore.kernel.org/r/20200422150336.10528-1-lorenzo.pieralisi@arm.com
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Andrew Murray <amurray@thegoodpenguin.co.uk>
…rnel/git/helgaas/pci

Pull PCI fixes from Bjorn Helgaas:

 - Workaround Apex TPU class code issue that prevents resource
   assignment (Bjorn Helgaas)

 - Update MAINTAINERS to add Rob Herring for native PCI controller
   drivers (Lorenzo Pieralisi)

* tag 'pci-v5.7-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  MAINTAINERS: Add Rob Herring and remove Andy Murray as PCI reviewers
  PCI: Move Apex Edge TPU class quirk to fix BAR assignment
…/git/ebiederm/user-namespace

Pull SIGCHLD fix from Eric Biederman:
 "Christof Meerwald reported that do_notify_parent has not been
  successfully populating si_pid and si_uid for multi-threaded
  processes.

  This is the one-liner fix. Strictly speaking a one-liner plus
  comment"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Avoid corrupting si_pid and si_uid in do_notify_parent
@pull pull bot added the ⤵️ pull label Apr 23, 2020
@pull pull bot merged commit b4f6332 into ikingye:master Apr 23, 2020
pull bot pushed a commit that referenced this pull request Jul 26, 2020
KASAN report null-ptr-deref error when register_netdev() failed:

KASAN: null-ptr-deref in range [0x00000000000003c0-0x00000000000003c7]
CPU: 2 PID: 422 Comm: ip Not tainted 5.8.0-rc4+ #12
Call Trace:
 ip6gre_init_net+0x4ab/0x580
 ? ip6gre_tunnel_uninit+0x3f0/0x3f0
 ops_init+0xa8/0x3c0
 setup_net+0x2de/0x7e0
 ? rcu_read_lock_bh_held+0xb0/0xb0
 ? ops_init+0x3c0/0x3c0
 ? kasan_unpoison_shadow+0x33/0x40
 ? __kasan_kmalloc.constprop.0+0xc2/0xd0
 copy_net_ns+0x27d/0x530
 create_new_namespaces+0x382/0xa30
 unshare_nsproxy_namespaces+0xa1/0x1d0
 ksys_unshare+0x39c/0x780
 ? walk_process_tree+0x2a0/0x2a0
 ? trace_hardirqs_on+0x4a/0x1b0
 ? _raw_spin_unlock_irq+0x1f/0x30
 ? syscall_trace_enter+0x1a7/0x330
 ? do_syscall_64+0x1c/0xa0
 __x64_sys_unshare+0x2d/0x40
 do_syscall_64+0x56/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

ip6gre_tunnel_uninit() has set 'ign->fb_tunnel_dev' to NULL, later
access to ign->fb_tunnel_dev cause null-ptr-deref. Fix it by saving
'ign->fb_tunnel_dev' to local variable ndev.

Fixes: dafabb6 ("ip6_gre: fix use-after-free in ip6gre_tunnel_lookup()")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
pull bot pushed a commit that referenced this pull request Aug 2, 2020
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
        #4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291
        #5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299
        #6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849
        #7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161
        #8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207
        #9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786
        #10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285
        #11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369
        #12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335
        #13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389
        #14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431
        #15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251
        #16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284
        #17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593
        #18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727
        #19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048
        #20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127
        #21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152
        #22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252
        #23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347
        #24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461
        #25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673
        #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>
pull bot pushed a commit that referenced this pull request Aug 5, 2020
The following deadlock was captured. The first process is holding 'kernfs_mutex'
and hung by io. The io was staging in 'r1conf.pending_bio_list' of raid1 device,
this pending bio list would be flushed by second process 'md127_raid1', but
it was hung by 'kernfs_mutex'. Using sysfs_notify_dirent_safe() to replace
sysfs_notify() can fix it. There were other sysfs_notify() invoked from io
path, removed all of them.

 PID: 40430  TASK: ffff8ee9c8c65c40  CPU: 29  COMMAND: "probe_file"
  #0 [ffffb87c4df37260] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df372f8] schedule at ffffffff9a867f06
  #2 [ffffb87c4df37310] io_schedule at ffffffff9a0c73e6
  #3 [ffffb87c4df37328] __dta___xfs_iunpin_wait_3443 at ffffffffc03a4057 [xfs]
  #4 [ffffb87c4df373a0] xfs_iunpin_wait at ffffffffc03a6c79 [xfs]
  #5 [ffffb87c4df373b0] __dta_xfs_reclaim_inode_3357 at ffffffffc039a46c [xfs]
  #6 [ffffb87c4df37400] xfs_reclaim_inodes_ag at ffffffffc039a8b6 [xfs]
  #7 [ffffb87c4df37590] xfs_reclaim_inodes_nr at ffffffffc039bb33 [xfs]
  #8 [ffffb87c4df375b0] xfs_fs_free_cached_objects at ffffffffc03af0e9 [xfs]
  #9 [ffffb87c4df375c0] super_cache_scan at ffffffff9a287ec7
 #10 [ffffb87c4df37618] shrink_slab at ffffffff9a1efd93
 #11 [ffffb87c4df37700] shrink_node at ffffffff9a1f5968
 #12 [ffffb87c4df37788] do_try_to_free_pages at ffffffff9a1f5ea2
 #13 [ffffb87c4df377f0] try_to_free_mem_cgroup_pages at ffffffff9a1f6445
 #14 [ffffb87c4df37880] try_charge at ffffffff9a26cc5f
 #15 [ffffb87c4df37920] memcg_kmem_charge_memcg at ffffffff9a270f6a
 #16 [ffffb87c4df37958] new_slab at ffffffff9a251430
 #17 [ffffb87c4df379c0] ___slab_alloc at ffffffff9a251c85
 #18 [ffffb87c4df37a80] __slab_alloc at ffffffff9a25635d
 #19 [ffffb87c4df37ac0] kmem_cache_alloc at ffffffff9a251f89
 #20 [ffffb87c4df37b00] alloc_inode at ffffffff9a2a2b10
 #21 [ffffb87c4df37b20] iget_locked at ffffffff9a2a4854
 #22 [ffffb87c4df37b60] kernfs_get_inode at ffffffff9a311377
 #23 [ffffb87c4df37b80] kernfs_iop_lookup at ffffffff9a311e2b
 #24 [ffffb87c4df37ba8] lookup_slow at ffffffff9a290118
 #25 [ffffb87c4df37c10] walk_component at ffffffff9a291e83
 #26 [ffffb87c4df37c78] path_lookupat at ffffffff9a293619
 #27 [ffffb87c4df37cd8] filename_lookup at ffffffff9a2953af
 #28 [ffffb87c4df37de8] user_path_at_empty at ffffffff9a295566
 #29 [ffffb87c4df37e10] vfs_statx at ffffffff9a289787
 #30 [ffffb87c4df37e70] SYSC_newlstat at ffffffff9a289d5d
 #31 [ffffb87c4df37f18] sys_newlstat at ffffffff9a28a60e
 #32 [ffffb87c4df37f28] do_syscall_64 at ffffffff9a003949
 #33 [ffffb87c4df37f50] entry_SYSCALL_64_after_hwframe at ffffffff9aa001ad
     RIP: 00007f617a5f2905  RSP: 00007f607334f838  RFLAGS: 00000246
     RAX: ffffffffffffffda  RBX: 00007f6064044b20  RCX: 00007f617a5f2905
     RDX: 00007f6064044b20  RSI: 00007f6064044b20  RDI: 00007f6064005890
     RBP: 00007f6064044aa0   R8: 0000000000000030   R9: 000000000000011c
     R10: 0000000000000013  R11: 0000000000000246  R12: 00007f606417e6d0
     R13: 00007f6064044aa0  R14: 00007f6064044b10  R15: 00000000ffffffff
     ORIG_RAX: 0000000000000006  CS: 0033  SS: 002b

 PID: 927    TASK: ffff8f15ac5dbd80  CPU: 42  COMMAND: "md127_raid1"
  #0 [ffffb87c4df07b28] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df07bc0] schedule at ffffffff9a867f06
  #2 [ffffb87c4df07bd8] schedule_preempt_disabled at ffffffff9a86825e
  #3 [ffffb87c4df07be8] __mutex_lock at ffffffff9a869bcc
  #4 [ffffb87c4df07ca0] __mutex_lock_slowpath at ffffffff9a86a013
  #5 [ffffb87c4df07cb0] mutex_lock at ffffffff9a86a04f
  #6 [ffffb87c4df07cc8] kernfs_find_and_get_ns at ffffffff9a311d83
  #7 [ffffb87c4df07cf0] sysfs_notify at ffffffff9a314b3a
  #8 [ffffb87c4df07d18] md_update_sb at ffffffff9a688696
  #9 [ffffb87c4df07d98] md_update_sb at ffffffff9a6886d5
 #10 [ffffb87c4df07da8] md_check_recovery at ffffffff9a68ad9c
 #11 [ffffb87c4df07dd0] raid1d at ffffffffc01f0375 [raid1]
 #12 [ffffb87c4df07ea0] md_thread at ffffffff9a680348
 #13 [ffffb87c4df07f08] kthread at ffffffff9a0b8005
 #14 [ffffb87c4df07f50] ret_from_fork at ffffffff9aa00344

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
pull bot pushed a commit that referenced this pull request Aug 11, 2020
This patch is to fix a crash:

 #3 [ffffb6580689f898] oops_end at ffffffffa2835bc2
 #4 [ffffb6580689f8b8] no_context at ffffffffa28766e7
 #5 [ffffb6580689f920] async_page_fault at ffffffffa320135e
    [exception RIP: f2fs_is_compressed_page+34]
    RIP: ffffffffa2ba83a2  RSP: ffffb6580689f9d8  RFLAGS: 00010213
    RAX: 0000000000000001  RBX: fffffc0f50b34bc0  RCX: 0000000000002122
    RDX: 0000000000002123  RSI: 0000000000000c00  RDI: fffffc0f50b34bc0
    RBP: ffff97e815a40178   R8: 0000000000000000   R9: ffff97e83ffc9000
    R10: 0000000000032300  R11: 0000000000032380  R12: ffffb6580689fa38
    R13: fffffc0f50b34bc0  R14: ffff97e825cbd000  R15: 0000000000000c00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #6 [ffffb6580689f9d8] __is_cp_guaranteed at ffffffffa2b7ea98
 #7 [ffffb6580689f9f0] f2fs_submit_page_write at ffffffffa2b81a69
 #8 [ffffb6580689fa30] f2fs_do_write_meta_page at ffffffffa2b99777
 #9 [ffffb6580689fae0] __f2fs_write_meta_page at ffffffffa2b75f1a
 #10 [ffffb6580689fb18] f2fs_sync_meta_pages at ffffffffa2b77466
 #11 [ffffb6580689fc98] do_checkpoint at ffffffffa2b78e46
 #12 [ffffb6580689fd88] f2fs_write_checkpoint at ffffffffa2b79c29
 #13 [ffffb6580689fdd0] f2fs_sync_fs at ffffffffa2b69d95
 #14 [ffffb6580689fe20] sync_filesystem at ffffffffa2ad2574
 #15 [ffffb6580689fe30] generic_shutdown_super at ffffffffa2a9b582
 #16 [ffffb6580689fe48] kill_block_super at ffffffffa2a9b6d1
 #17 [ffffb6580689fe60] kill_f2fs_super at ffffffffa2b6abe1
 #18 [ffffb6580689fea0] deactivate_locked_super at ffffffffa2a9afb6
 #19 [ffffb6580689feb8] cleanup_mnt at ffffffffa2abcad4
 #20 [ffffb6580689fee0] task_work_run at ffffffffa28bca28
 #21 [ffffb6580689ff00] exit_to_usermode_loop at ffffffffa28050b7
 #22 [ffffb6580689ff38] do_syscall_64 at ffffffffa280560e
 #23 [ffffb6580689ff50] entry_SYSCALL_64_after_hwframe at ffffffffa320008c

This occurred when umount f2fs if enable F2FS_FS_COMPRESSION
with F2FS_IO_TRACE. Fixes it by adding IS_IO_TRACED_PAGE to check
validity of pid for page_private.

Signed-off-by: Yu Changchun <yuchangchun1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
pull bot pushed a commit that referenced this pull request Aug 11, 2020
https://bugzilla.kernel.org/show_bug.cgi?id=208565

PID: 257    TASK: ecdd0000  CPU: 0   COMMAND: "init"
  #0 [<c0b420ec>] (__schedule) from [<c0b423c8>]
  #1 [<c0b423c8>] (schedule) from [<c0b459d4>]
  #2 [<c0b459d4>] (rwsem_down_read_failed) from [<c0b44fa0>]
  #3 [<c0b44fa0>] (down_read) from [<c044233c>]
  #4 [<c044233c>] (f2fs_truncate_blocks) from [<c0442890>]
  #5 [<c0442890>] (f2fs_truncate) from [<c044d408>]
  #6 [<c044d408>] (f2fs_evict_inode) from [<c030be18>]
  #7 [<c030be18>] (evict) from [<c030a558>]
  #8 [<c030a558>] (iput) from [<c047c600>]
  #9 [<c047c600>] (f2fs_sync_node_pages) from [<c0465414>]
 #10 [<c0465414>] (f2fs_write_checkpoint) from [<c04575f4>]
 #11 [<c04575f4>] (f2fs_sync_fs) from [<c0441918>]
 #12 [<c0441918>] (f2fs_do_sync_file) from [<c0441098>]
 #13 [<c0441098>] (f2fs_sync_file) from [<c0323fa0>]
 #14 [<c0323fa0>] (vfs_fsync_range) from [<c0324294>]
 #15 [<c0324294>] (do_fsync) from [<c0324014>]
 #16 [<c0324014>] (sys_fsync) from [<c0108bc0>]

This can be caused by flush_dirty_inode() in f2fs_sync_node_pages() where
iput() requires f2fs_lock_op() again resulting in livelock.

Reported-by: Zhiguo Niu <Zhiguo.Niu@unisoc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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