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kcov: collect coverage from remote threads #2

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@xairy xairy commented Jan 9, 2019

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xairy added a commit to xairy/syzkaller that referenced this pull request Jan 16, 2019
Right now syzkaller only supports coverage collected from the threads that
execute syscalls. However some useful things happen in background threads,
and it would be nice to collect coverage from those threads as well.

This change adds extra coverage support to syzkaller. This coverage is not
associated with a particular syscall, but rather with the whole program.
Executor passes extra coverage over the same ipc mechanism to syz-fuzzer
with syscall number set to -1. syz-fuzzer then passes this coverage to
syz-manager with the call name "extra".

This change requires the following kcov patch:
xairy/linux#2
xairy added a commit to google/syzkaller that referenced this pull request Jan 16, 2019
Right now syzkaller only supports coverage collected from the threads that
execute syscalls. However some useful things happen in background threads,
and it would be nice to collect coverage from those threads as well.

This change adds extra coverage support to syzkaller. This coverage is not
associated with a particular syscall, but rather with the whole program.
Executor passes extra coverage over the same ipc mechanism to syz-fuzzer
with syscall number set to -1. syz-fuzzer then passes this coverage to
syz-manager with the call name "extra".

This change requires the following kcov patch:
xairy/linux#2
xairy pushed a commit that referenced this pull request Mar 8, 2019
When option CONFIG_KASAN is enabled toghether with ftrace, function
ftrace_graph_caller() gets in to a recursion, via functions
kasan_check_read() and kasan_check_write().

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

Rework so that the kasan implementation isn't traced.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anders Roxell <[email protected]>
Acked-by: Dmitry Vyukov <[email protected]>
Tested-by: Dmitry Vyukov <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
xairy pushed a commit that referenced this pull request Mar 21, 2019
[ Upstream commit 5845f70 ]

It can be reproduced by following steps:
1. virtio_net NIC is configured with gso/tso on
2. configure nginx as http server with an index file bigger than 1M bytes
3. use tc netem to produce duplicate packets and delay:
   tc qdisc add dev eth0 root netem delay 100ms 10ms 30% duplicate 90%
4. continually curl the nginx http server to get index file on client
5. BUG_ON is seen quickly

[10258690.371129] kernel BUG at net/core/skbuff.c:4028!
[10258690.371748] invalid opcode: 0000 [#1] SMP PTI
[10258690.372094] CPU: 5 PID: 0 Comm: swapper/5 Tainted: G        W         5.0.0-rc6 #2
[10258690.372094] RSP: 0018:ffffa05797b43da0 EFLAGS: 00010202
[10258690.372094] RBP: 00000000000005ea R08: 0000000000000000 R09: 00000000000005ea
[10258690.372094] R10: ffffa0579334d800 R11: 00000000000002c0 R12: 0000000000000002
[10258690.372094] R13: 0000000000000000 R14: ffffa05793122900 R15: ffffa0578f7cb028
[10258690.372094] FS:  0000000000000000(0000) GS:ffffa05797b40000(0000) knlGS:0000000000000000
[10258690.372094] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[10258690.372094] CR2: 00007f1a6dc00868 CR3: 000000001000e000 CR4: 00000000000006e0
[10258690.372094] Call Trace:
[10258690.372094]  <IRQ>
[10258690.372094]  skb_to_sgvec+0x11/0x40
[10258690.372094]  start_xmit+0x38c/0x520 [virtio_net]
[10258690.372094]  dev_hard_start_xmit+0x9b/0x200
[10258690.372094]  sch_direct_xmit+0xff/0x260
[10258690.372094]  __qdisc_run+0x15e/0x4e0
[10258690.372094]  net_tx_action+0x137/0x210
[10258690.372094]  __do_softirq+0xd6/0x2a9
[10258690.372094]  irq_exit+0xde/0xf0
[10258690.372094]  smp_apic_timer_interrupt+0x74/0x140
[10258690.372094]  apic_timer_interrupt+0xf/0x20
[10258690.372094]  </IRQ>

In __skb_to_sgvec(), the skb->len is not equal to the sum of the skb's
linear data size and nonlinear data size, thus BUG_ON triggered.
Because the skb is cloned and a part of nonlinear data is split off.

Duplicate packet is cloned in netem_enqueue() and may be delayed
some time in qdisc. When qdisc len reached the limit and returns
NET_XMIT_DROP, the skb will be retransmit later in write queue.
the skb will be fragmented by tso_fragment(), the limit size
that depends on cwnd and mss decrease, the skb's nonlinear
data will be split off. The length of the skb cloned by netem
will not be updated. When we use virtio_net NIC and invoke skb_to_sgvec(),
the BUG_ON trigger.

To fix it, netem returns NET_XMIT_SUCCESS to upper stack
when it clones a duplicate packet.

Fixes: 35d889d ("sch_netem: fix skb leak in netem_enqueue()")
Signed-off-by: Sheng Lan <[email protected]>
Reported-by: Qin Ji <[email protected]>
Suggested-by: Eric Dumazet <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
xairy pushed a commit that referenced this pull request Mar 21, 2019
[ Upstream commit afc9f65 ]

When building the kernel as Thumb-2 with binutils 2.29 or newer, if the
assembler has seen the .type directive (via ENDPROC()) for a symbol, it
automatically handles the setting of the lowest bit when the symbol is
used with ADR.  The badr macro on the other hand handles this lowest bit
manually.  This leads to a jump to a wrong address in the wrong state
in the syscall return path:

 Internal error: Oops - undefined instruction: 0 [#2] SMP THUMB2
 Modules linked in:
 CPU: 0 PID: 652 Comm: modprobe Tainted: G      D           4.18.0-rc3+ torvalds#8
 PC is at ret_fast_syscall+0x4/0x62
 LR is at sys_brk+0x109/0x128
 pc : [<80101004>]    lr : [<801c8a35>]    psr: 60000013
 Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
 Control: 50c5387d  Table: 9e82006a  DAC: 00000051
 Process modprobe (pid: 652, stack limit = 0x(ptrval))

 80101000 <ret_fast_syscall>:
 80101000:       b672            cpsid   i
 80101002:       f8d9 2008       ldr.w   r2, [r9, torvalds#8]
 80101006:       f1b2 4ffe       cmp.w   r2, #2130706432 ; 0x7f000000

 80101184 <local_restart>:
 80101184:       f8d9 a000       ldr.w   sl, [r9]
 80101188:       e92d 0030       stmdb   sp!, {r4, r5}
 8010118c:       f01a 0ff0       tst.w   sl, torvalds#240        ; 0xf0
 80101190:       d117            bne.n   801011c2 <__sys_trace>
 80101192:       46ba            mov     sl, r7
 80101194:       f5ba 7fc8       cmp.w   sl, torvalds#400        ; 0x190
 80101198:       bf28            it      cs
 8010119a:       f04f 0a00       movcs.w sl, #0
 8010119e:       f3af 8014       nop.w   {20}
 801011a2:       f2af 1ea2       subw    lr, pc, torvalds#418    ; 0x1a2

To fix this, add a new symbol name which doesn't have ENDPROC used on it
and use that with badr.  We can't remove the badr usage since that would
would cause breakage with older binutils.

Signed-off-by: Vincent Whitchurch <[email protected]>
Signed-off-by: Russell King <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Mar 21, 2019
[ Upstream commit a843dc4 ]

In func check_6rd,tunnel->ip6rd.relay_prefixlen may equal to
32,so UBSAN complain about it.

UBSAN: Undefined behaviour in net/ipv6/sit.c:781:47
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 6 PID: 20036 Comm: syz-executor.0 Not tainted 4.19.27 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1
04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
ubsan_epilogue+0xe/0x81 lib/ubsan.c:159
__ubsan_handle_shift_out_of_bounds+0x293/0x2e8 lib/ubsan.c:425
check_6rd.constprop.9+0x433/0x4e0 net/ipv6/sit.c:781
try_6rd net/ipv6/sit.c:806 [inline]
ipip6_tunnel_xmit net/ipv6/sit.c:866 [inline]
sit_tunnel_xmit+0x141c/0x2720 net/ipv6/sit.c:1033
__netdev_start_xmit include/linux/netdevice.h:4300 [inline]
netdev_start_xmit include/linux/netdevice.h:4309 [inline]
xmit_one net/core/dev.c:3243 [inline]
dev_hard_start_xmit+0x17c/0x780 net/core/dev.c:3259
__dev_queue_xmit+0x1656/0x2500 net/core/dev.c:3829
neigh_output include/net/neighbour.h:501 [inline]
ip6_finish_output2+0xa36/0x2290 net/ipv6/ip6_output.c:120
ip6_finish_output+0x3e7/0xa20 net/ipv6/ip6_output.c:154
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip6_output+0x1e2/0x720 net/ipv6/ip6_output.c:171
dst_output include/net/dst.h:444 [inline]
ip6_local_out+0x99/0x170 net/ipv6/output_core.c:176
ip6_send_skb+0x9d/0x2f0 net/ipv6/ip6_output.c:1697
ip6_push_pending_frames+0xc0/0x100 net/ipv6/ip6_output.c:1717
rawv6_push_pending_frames net/ipv6/raw.c:616 [inline]
rawv6_sendmsg+0x2435/0x3530 net/ipv6/raw.c:946
inet_sendmsg+0xf8/0x5c0 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg+0xc8/0x110 net/socket.c:631
___sys_sendmsg+0x6cf/0x890 net/socket.c:2114
__sys_sendmsg+0xf0/0x1b0 net/socket.c:2152
do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: linmiaohe <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
xairy pushed a commit that referenced this pull request Mar 28, 2019
(Commit 0d0c8de upstream).

When option CONFIG_KASAN is enabled toghether with ftrace, function
ftrace_graph_caller() gets in to a recursion, via functions
kasan_check_read() and kasan_check_write().

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

Rework so that the kasan implementation isn't traced.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anders Roxell <[email protected]>
Acked-by: Dmitry Vyukov <[email protected]>
Tested-by: Dmitry Vyukov <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Bug: 128674696
Test: build, boot and insmod test_kasan.ko with various configs
Signed-off-by: Andrey Konovalov <[email protected]>
Change-Id: Ic2db4990fafababc7d1bb344e4f2feff13d0cbe7
xairy pushed a commit that referenced this pull request Jun 17, 2019
commit fe67888 upstream.

An already deleted SCSI device can exist on the Scsi_Host and remain there
because something still holds a reference.  A new SCSI device with the same
H:C:T:L and FCP device, target port WWPN, and FCP LUN can be created.  When
we try to unblock an rport, we still find the deleted SCSI device and
return early because the zfcp_scsi_dev of that SCSI device is not
ZFCP_STATUS_COMMON_UNBLOCKED. Hence we miss to unblock the rport, even if
the new proper SCSI device would be in good state.

Therefore, skip deleted SCSI devices when iterating the sdevs of the shost.
[cf. __scsi_device_lookup{_by_target}() or scsi_device_get()]

The following abbreviated trace sequence can indicate such problem:

Area           : REC
Tag            : ersfs_3
LUN            : 0x4045400300000000
WWPN           : 0x50050763031bd327
LUN status     : 0x40000000     not ZFCP_STATUS_COMMON_UNBLOCKED
Ready count    : n		not incremented yet
Running count  : 0x00000000
ERP want       : 0x01
ERP need       : 0xc1		ZFCP_ERP_ACTION_NONE

Area           : REC
Tag            : ersfs_3
LUN            : 0x4045400300000000
WWPN           : 0x50050763031bd327
LUN status     : 0x41000000
Ready count    : n+1
Running count  : 0x00000000
ERP want       : 0x01
ERP need       : 0x01

...

Area           : REC
Level          : 4		only with increased trace level
Tag            : ertru_l
LUN            : 0x4045400300000000
WWPN           : 0x50050763031bd327
LUN status     : 0x40000000
Request ID     : 0x0000000000000000
ERP status     : 0x01800000
ERP step       : 0x1000
ERP action     : 0x01
ERP count      : 0x00

NOT followed by a trace record with tag "scpaddy"
for WWPN 0x50050763031bd327.

Signed-off-by: Steffen Maier <[email protected]>
Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery")
Cc: <[email protected]> #2.6.32+
Reviewed-by: Jens Remus <[email protected]>
Reviewed-by: Benjamin Block <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
xairy pushed a commit that referenced this pull request Jun 17, 2019
[ Upstream commit 92d1d07 ]

Kmemleak throws endless warnings during boot due to in
__alloc_alien_cache(),

    alc = kmalloc_node(memsize, gfp, node);
    init_arraycache(&alc->ac, entries, batch);
    kmemleak_no_scan(ac);

Kmemleak does not track the array cache (alc->ac) but the alien cache
(alc) instead, so let it track the latter by lifting kmemleak_no_scan()
out of init_arraycache().

There is another place that calls init_arraycache(), but
alloc_kmem_cache_cpus() uses the percpu allocation where will never be
considered as a leak.

  kmemleak: Found object by alias at 0xffff8007b9aa7e38
  CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2
  Call trace:
   dump_backtrace+0x0/0x168
   show_stack+0x24/0x30
   dump_stack+0x88/0xb0
   lookup_object+0x84/0xac
   find_and_get_object+0x84/0xe4
   kmemleak_no_scan+0x74/0xf4
   setup_kmem_cache_node+0x2b4/0x35c
   __do_tune_cpucache+0x250/0x2d4
   do_tune_cpucache+0x4c/0xe4
   enable_cpucache+0xc8/0x110
   setup_cpu_cache+0x40/0x1b8
   __kmem_cache_create+0x240/0x358
   create_cache+0xc0/0x198
   kmem_cache_create_usercopy+0x158/0x20c
   kmem_cache_create+0x50/0x64
   fsnotify_init+0x58/0x6c
   do_one_initcall+0x194/0x388
   kernel_init_freeable+0x668/0x688
   kernel_init+0x18/0x124
   ret_from_fork+0x10/0x18
  kmemleak: Object 0xffff8007b9aa7e00 (size 256):
  kmemleak:   comm "swapper/0", pid 1, jiffies 4294697137
  kmemleak:   min_count = 1
  kmemleak:   count = 0
  kmemleak:   flags = 0x1
  kmemleak:   checksum = 0
  kmemleak:   backtrace:
       kmemleak_alloc+0x84/0xb8
       kmem_cache_alloc_node_trace+0x31c/0x3a0
       __kmalloc_node+0x58/0x78
       setup_kmem_cache_node+0x26c/0x35c
       __do_tune_cpucache+0x250/0x2d4
       do_tune_cpucache+0x4c/0xe4
       enable_cpucache+0xc8/0x110
       setup_cpu_cache+0x40/0x1b8
       __kmem_cache_create+0x240/0x358
       create_cache+0xc0/0x198
       kmem_cache_create_usercopy+0x158/0x20c
       kmem_cache_create+0x50/0x64
       fsnotify_init+0x58/0x6c
       do_one_initcall+0x194/0x388
       kernel_init_freeable+0x668/0x688
       kernel_init+0x18/0x124
  kmemleak: Not scanning unknown object at 0xffff8007b9aa7e38
  CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2
  Call trace:
   dump_backtrace+0x0/0x168
   show_stack+0x24/0x30
   dump_stack+0x88/0xb0
   kmemleak_no_scan+0x90/0xf4
   setup_kmem_cache_node+0x2b4/0x35c
   __do_tune_cpucache+0x250/0x2d4
   do_tune_cpucache+0x4c/0xe4
   enable_cpucache+0xc8/0x110
   setup_cpu_cache+0x40/0x1b8
   __kmem_cache_create+0x240/0x358
   create_cache+0xc0/0x198
   kmem_cache_create_usercopy+0x158/0x20c
   kmem_cache_create+0x50/0x64
   fsnotify_init+0x58/0x6c
   do_one_initcall+0x194/0x388
   kernel_init_freeable+0x668/0x688
   kernel_init+0x18/0x124
   ret_from_fork+0x10/0x18

Link: http://lkml.kernel.org/r/[email protected]
Fixes: 1fe00d5 ("slab: factor out initialization of array cache")
Signed-off-by: Qian Cai <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Catalin Marinas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Jun 17, 2019
[ Upstream commit 54569ba ]

Detected with gcc's ASan:

  Direct leak of 66 byte(s) in 5 object(s) allocated from:
      #0 0x7ff3b1f32070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
      #1 0x560c8761034d in collect_config util/config.c:597
      #2 0x560c8760d9cb in get_value util/config.c:169
      #3 0x560c8760dfd7 in perf_parse_file util/config.c:285
      #4 0x560c8760e0d2 in perf_config_from_file util/config.c:476
      #5 0x560c876108fd in perf_config_set__init util/config.c:661
      torvalds#6 0x560c87610c72 in perf_config_set__new util/config.c:709
      torvalds#7 0x560c87610d2f in perf_config__init util/config.c:718
      torvalds#8 0x560c87610e5d in perf_config util/config.c:730
      torvalds#9 0x560c875ddea0 in main /home/changbin/work/linux/tools/perf/perf.c:442
      torvalds#10 0x7ff3afb8609a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Cc: Taeung Song <[email protected]>
Fixes: 20105ca ("perf config: Introduce perf_config_set class")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Jun 17, 2019
[ Upstream commit 8bde851 ]

Detected with gcc's ASan:

  Direct leak of 4356 byte(s) in 120 object(s) allocated from:
      #0 0x7ff1a2b5a070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
      #1 0x55719aef4814 in build_id_cache__origname util/build-id.c:215
      #2 0x55719af649b6 in print_sdt_events util/parse-events.c:2339
      #3 0x55719af66272 in print_events util/parse-events.c:2542
      #4 0x55719ad1ecaa in cmd_list /home/changbin/work/linux/tools/perf/builtin-list.c:58
      #5 0x55719aec745d in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      torvalds#6 0x55719aec7d1a in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      torvalds#7 0x55719aec8184 in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      torvalds#8 0x55719aeca41a in main /home/changbin/work/linux/tools/perf/perf.c:520
      torvalds#9 0x7ff1a07ae09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Fixes: 40218da ("perf list: Show SDT and pre-cached events")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Jun 17, 2019
[ Upstream commit 42dfa45 ]

Using gcc's ASan, Changbin reports:

  =================================================================
  ==7494==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 48 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5625e5330a5e in zalloc util/util.h:23
      #2 0x5625e5330a9b in perf_counts__new util/counts.c:10
      #3 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      #4 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      #5 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      torvalds#6 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      torvalds#7 0x5625e51528e6 in run_test tests/builtin-test.c:358
      torvalds#8 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      torvalds#9 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      torvalds#10 0x5625e515572f in cmd_test tests/builtin-test.c:722
      torvalds#11 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      torvalds#12 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      torvalds#13 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      torvalds#14 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      torvalds#15 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 72 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5625e532560d in zalloc util/util.h:23
      #2 0x5625e532566b in xyarray__new util/xyarray.c:10
      #3 0x5625e5330aba in perf_counts__new util/counts.c:15
      #4 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      #5 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      torvalds#6 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      torvalds#7 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      torvalds#8 0x5625e51528e6 in run_test tests/builtin-test.c:358
      torvalds#9 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      torvalds#10 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      torvalds#11 0x5625e515572f in cmd_test tests/builtin-test.c:722
      torvalds#12 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      torvalds#13 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      torvalds#14 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      torvalds#15 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      torvalds#16 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

His patch took care of evsel->prev_raw_counts, but the above backtraces
are about evsel->counts, so fix that instead.

Reported-by: Changbin Du <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Jun 17, 2019
…_event_on_all_cpus test

[ Upstream commit 93faa52 ]

  =================================================================
  ==7497==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a88f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      #1 0x5625e5326213 in cpu_map__trim_new util/cpumap.c:45
      #2 0x5625e5326703 in cpu_map__read util/cpumap.c:103
      #3 0x5625e53267ef in cpu_map__read_all_cpu_map util/cpumap.c:120
      #4 0x5625e5326915 in cpu_map__new util/cpumap.c:135
      #5 0x5625e517b355 in test__openat_syscall_event_on_all_cpus tests/openat-syscall-all-cpus.c:36
      torvalds#6 0x5625e51528e6 in run_test tests/builtin-test.c:358
      torvalds#7 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      torvalds#8 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      torvalds#9 0x5625e515572f in cmd_test tests/builtin-test.c:722
      torvalds#10 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      torvalds#11 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      torvalds#12 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      torvalds#13 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      torvalds#14 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Fixes: f30a79b ("perf tools: Add reference counting for cpu_map object")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Jun 17, 2019
[ Upstream commit d982b33 ]

  =================================================================
  ==20875==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 1160 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc84138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x55bd50005599 in zalloc util/util.h:23
      #2 0x55bd500068f5 in perf_evsel__newtp_idx util/evsel.c:327
      #3 0x55bd4ff810fc in perf_evsel__newtp /home/work/linux/tools/perf/util/evsel.h:216
      #4 0x55bd4ff81608 in test__perf_evsel__tp_sched_test tests/evsel-tp-sched.c:69
      #5 0x55bd4ff528e6 in run_test tests/builtin-test.c:358
      torvalds#6 0x55bd4ff52baf in test_and_print tests/builtin-test.c:388
      torvalds#7 0x55bd4ff543fe in __cmd_test tests/builtin-test.c:583
      torvalds#8 0x55bd4ff5572f in cmd_test tests/builtin-test.c:722
      torvalds#9 0x55bd4ffc4087 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      torvalds#10 0x55bd4ffc45c6 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      torvalds#11 0x55bd4ffc49ca in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      torvalds#12 0x55bd4ffc5138 in main /home/changbin/work/linux/tools/perf/perf.c:520
      torvalds#13 0x7f1b6e34809a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 19 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc83f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      #1 0x7f1b6e3ac30f in vasprintf (/lib/x86_64-linux-gnu/libc.so.6+0x8830f)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Fixes: 6a6cd11 ("perf test: Add test for the sched tracepoint format fields")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Jan 24, 2023
commit cf12983 upstream.

When a match has been made to the nth duplicate symbol, return
success not error.

Example:

  Before:

    $ cat file.c
    cat: file.c: No such file or directory
    $ cat file1.c
    #include <stdio.h>

    static void func(void)
    {
            printf("First func\n");
    }

    void other(void);

    int main()
    {
            func();
            other();
            return 0;
    }
    $ cat file2.c
    #include <stdio.h>

    static void func(void)
    {
            printf("Second func\n");
    }

    void other(void)
    {
            func();
    }

    $ gcc -Wall -Wextra -o test file1.c file2.c
    $ perf record -e intel_pt//u --filter 'filter func @ ./test' -- ./test
    Multiple symbols with name 'func'
    #1      0x1149  l       func
                    which is near           main
    #2      0x1179  l       func
                    which is near           other
    Disambiguate symbol name by inserting #n after the name e.g. func #2
    Or select a global symbol by inserting #0 or #g or #G
    Failed to parse address filter: 'filter func @ ./test'
    Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
    Where multiple filters are separated by space or comma.
    $ perf record -e intel_pt//u --filter 'filter func #2 @ ./test' -- ./test
    Failed to parse address filter: 'filter func #2 @ ./test'
    Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
    Where multiple filters are separated by space or comma.

  After:

    $ perf record -e intel_pt//u --filter 'filter func #2 @ ./test' -- ./test
    First func
    Second func
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.016 MB perf.data ]
    $ perf script --itrace=b -Ftime,flags,ip,sym,addr --ns
    1231062.526977619:   tr strt                               0 [unknown] =>     558495708179 func
    1231062.526977619:   tr end  call               558495708188 func =>     558495708050 _init
    1231062.526979286:   tr strt                               0 [unknown] =>     55849570818d func
    1231062.526979286:   tr end  return             55849570818f func =>     55849570819d other

Fixes: 1b36c03 ("perf record: Add support for using symbols in address filters")
Reported-by: Dmitrii Dolgov <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Dmitry Dolgov <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
xairy pushed a commit that referenced this pull request Jan 24, 2023
commit 76d588d upstream.

Current imc-pmu code triggers a WARNING with CONFIG_DEBUG_ATOMIC_SLEEP
and CONFIG_PROVE_LOCKING enabled, while running a thread_imc event.

Command to trigger the warning:
  # perf stat -e thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/ sleep 5

   Performance counter stats for 'sleep 5':

                   0      thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/

         5.002117947 seconds time elapsed

         0.000131000 seconds user
         0.001063000 seconds sys

Below is snippet of the warning in dmesg:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 2869, name: perf-exec
  preempt_count: 2, expected: 0
  4 locks held by perf-exec/2869:
   #0: c00000004325c540 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: bprm_execve+0x64/0xa90
   #1: c00000004325c5d8 (&sig->exec_update_lock){++++}-{3:3}, at: begin_new_exec+0x460/0xef0
   #2: c0000003fa99d4e0 (&cpuctx_lock){-...}-{2:2}, at: perf_event_exec+0x290/0x510
   #3: c000000017ab8418 (&ctx->lock){....}-{2:2}, at: perf_event_exec+0x29c/0x510
  irq event stamp: 4806
  hardirqs last  enabled at (4805): [<c000000000f65b94>] _raw_spin_unlock_irqrestore+0x94/0xd0
  hardirqs last disabled at (4806): [<c0000000003fae44>] perf_event_exec+0x394/0x510
  softirqs last  enabled at (0): [<c00000000013c404>] copy_process+0xc34/0x1ff0
  softirqs last disabled at (0): [<0000000000000000>] 0x0
  CPU: 36 PID: 2869 Comm: perf-exec Not tainted 6.2.0-rc2-00011-g1247637727f2 torvalds#61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  Call Trace:
    dump_stack_lvl+0x98/0xe0 (unreliable)
    __might_resched+0x2f8/0x310
    __mutex_lock+0x6c/0x13f0
    thread_imc_event_add+0xf4/0x1b0
    event_sched_in+0xe0/0x210
    merge_sched_in+0x1f0/0x600
    visit_groups_merge.isra.92.constprop.166+0x2bc/0x6c0
    ctx_flexible_sched_in+0xcc/0x140
    ctx_sched_in+0x20c/0x2a0
    ctx_resched+0x104/0x1c0
    perf_event_exec+0x340/0x510
    begin_new_exec+0x730/0xef0
    load_elf_binary+0x3f8/0x1e10
  ...
  do not call blocking ops when !TASK_RUNNING; state=2001 set at [<00000000fd63e7cf>] do_nanosleep+0x60/0x1a0
  WARNING: CPU: 36 PID: 2869 at kernel/sched/core.c:9912 __might_sleep+0x9c/0xb0
  CPU: 36 PID: 2869 Comm: sleep Tainted: G        W          6.2.0-rc2-00011-g1247637727f2 torvalds#61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  NIP:  c000000000194a1c LR: c000000000194a18 CTR: c000000000a78670
  REGS: c00000004d2134e0 TRAP: 0700   Tainted: G        W           (6.2.0-rc2-00011-g1247637727f2)
  MSR:  9000000000021033 <SF,HV,ME,IR,DR,RI,LE>  CR: 48002824  XER: 00000000
  CFAR: c00000000013fb64 IRQMASK: 1

The above warning triggered because the current imc-pmu code uses mutex
lock in interrupt disabled sections. The function mutex_lock()
internally calls __might_resched(), which will check if IRQs are
disabled and in case IRQs are disabled, it will trigger the warning.

Fix the issue by changing the mutex lock to spinlock.

Fixes: 8f95faa ("powerpc/powernv: Detect and create IMC device")
Reported-by: Michael Petlan <[email protected]>
Reported-by: Peter Zijlstra <[email protected]>
Signed-off-by: Kajol Jain <[email protected]>
[mpe: Fix comments, trim oops in change log, add reported-by tags]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
xairy pushed a commit that referenced this pull request Jan 24, 2023
[ Upstream commit b18cba0 ]

Commit 9130b8d ("SUNRPC: allow for upcalls for the same uid
but different gss service") introduced `auth` argument to
__gss_find_upcall(), but in gss_pipe_downcall() it was left as NULL
since it (and auth->service) was not (yet) determined.

When multiple upcalls with the same uid and different service are
ongoing, it could happen that __gss_find_upcall(), which returns the
first match found in the pipe->in_downcall list, could not find the
correct gss_msg corresponding to the downcall we are looking for.
Moreover, it might return a msg which is not sent to rpc.gssd yet.

We could see mount.nfs process hung in D state with multiple mount.nfs
are executed in parallel.  The call trace below is of CentOS 7.9
kernel-3.10.0-1160.24.1.el7.x86_64 but we observed the same hang w/
elrepo kernel-ml-6.0.7-1.el7.

PID: 71258  TASK: ffff91ebd4be0000  CPU: 36  COMMAND: "mount.nfs"
 #0 [ffff9203ca3234f8] __schedule at ffffffffa3b8899f
 #1 [ffff9203ca323580] schedule at ffffffffa3b88eb9
 #2 [ffff9203ca323590] gss_cred_init at ffffffffc0355818 [auth_rpcgss]
 #3 [ffff9203ca323658] rpcauth_lookup_credcache at ffffffffc0421ebc
[sunrpc]
 #4 [ffff9203ca3236d8] gss_lookup_cred at ffffffffc0353633 [auth_rpcgss]
 #5 [ffff9203ca3236e8] rpcauth_lookupcred at ffffffffc0421581 [sunrpc]
 torvalds#6 [ffff9203ca323740] rpcauth_refreshcred at ffffffffc04223d3 [sunrpc]
 torvalds#7 [ffff9203ca3237a0] call_refresh at ffffffffc04103dc [sunrpc]
 torvalds#8 [ffff9203ca3237b8] __rpc_execute at ffffffffc041e1c9 [sunrpc]
 torvalds#9 [ffff9203ca323820] rpc_execute at ffffffffc0420a48 [sunrpc]

The scenario is like this. Let's say there are two upcalls for
services A and B, A -> B in pipe->in_downcall, B -> A in pipe->pipe.

When rpc.gssd reads pipe to get the upcall msg corresponding to
service B from pipe->pipe and then writes the response, in
gss_pipe_downcall the msg corresponding to service A will be picked
because only uid is used to find the msg and it is before the one for
B in pipe->in_downcall.  And the process waiting for the msg
corresponding to service A will be woken up.

Actual scheduing of that process might be after rpc.gssd processes the
next msg.  In rpc_pipe_generic_upcall it clears msg->errno (for A).
The process is scheduled to see gss_msg->ctx == NULL and
gss_msg->msg.errno == 0, therefore it cannot break the loop in
gss_create_upcall and is never woken up after that.

This patch adds a simple check to ensure that a msg which is not
sent to rpc.gssd yet is not chosen as the matching upcall upon
receiving a downcall.

Signed-off-by: minoura makoto <[email protected]>
Signed-off-by: Hiroshi Shimamoto <[email protected]>
Tested-by: Hiroshi Shimamoto <[email protected]>
Cc: Trond Myklebust <[email protected]>
Fixes: 9130b8d ("SUNRPC: allow for upcalls for same uid but different gss service")
Signed-off-by: Trond Myklebust <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Jan 24, 2023
…ed_text_end" symbol on s/390

[ Upstream commit d8d85ce ]

The test case perf lock contention dumps core on s390. Run the following
commands:

  # ./perf lock record -- ./perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

      Total time: 2.799 [sec]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.073 MB perf.data (100 samples) ]
  #
  # ./perf lock contention
  Segmentation fault (core dumped)
  #

The function call stack is lengthy, here are the top 5 functions:

  # gdb ./perf core.24048
  GNU gdb (GDB) Fedora Linux 12.1-6.fc37
  Core was generated by `./perf lock contention'.
  Program terminated with signal SIGSEGV, Segmentation fault.
  #0  0x00000000011dd25c in machine__is_lock_function (machine=0x3029e28, addr=1789230) at util/machine.c:3356
         3356 machine->sched.text_end = kmap->unmap_ip(kmap, sym->start);

 (gdb) where
  #0  0x00000000011dd25c in machine__is_lock_function (machine=0x3029e28, addr=1789230) at util/machine.c:3356
  #1  0x000000000109f244 in callchain_id (evsel=0x30313e0, sample=0x3ffea4f77d0) at builtin-lock.c:957
  #2  0x000000000109e094 in get_key_by_aggr_mode (key=0x3ffea4f7290, addr=27758136, evsel=0x30313e0, sample=0x3ffea4f77d0) at builtin-lock.c:586
  #3  0x000000000109f4d0 in report_lock_contention_begin_event (evsel=0x30313e0, sample=0x3ffea4f77d0) at builtin-lock.c:1004
  #4  0x00000000010a00ae in evsel__process_contention_begin (evsel=0x30313e0, sample=0x3ffea4f77d0) at builtin-lock.c:1254
  #5  0x00000000010a0e14 in process_sample_event (tool=0x3ffea4f8480, event=0x3ff85601ef8, sample=0x3ffea4f77d0, evsel=0x30313e0, machine=0x3029e28) at builtin-lock.c:1464
  .....

The issue is in function machine__is_lock_function() in file
./util/machine.c lines 3355:

   /* should not fail from here */
   sym = machine__find_kernel_symbol_by_name(machine, "__sched_text_end", &kmap);
   machine->sched.text_end = kmap->unmap_ip(kmap, sym->start)

On s390 the symbol __sched_text_end is *NOT* in the symbol list and the
resulting pointer sym is set to NULL. The sym->start is then a NULL pointer
access and generates the core dump.

The reason why __sched_text_end is not in the symbol list on s390 is
simple:

When the symbol list is created at perf start up with function calls

  dso__load
  +--> dso__load_vmlinux_path
       +--> dso__load_vmlinux
            +--> dso__load_sym
	         +--> dso__load_sym_internal (reads kernel symbols)
		 +--> symbols__fixup_end
		 +--> symbols__fixup_duplicate

The issue is in function symbols__fixup_duplicate(). It deletes all
symbols with have the same address. On s390:

  # nm -g  ~/linux/vmlinux| fgrep c68390
  0000000000c68390 T __cpuidle_text_start
  0000000000c68390 T __sched_text_end
  #

two symbols have identical addresses and __sched_text_end is considered
duplicate (in ascending sort order) and removed from the symbol list.
Therefore it is missing and an invalid pointer reference occurs.  The
code checks for symbol __sched_text_start and when it exists assumes
symbol __sched_text_end is also in the symbol table. However this is not
the case on s390.

Same situation exists for symbol __lock_text_start:

0000000000c68770 T __cpuidle_text_end
0000000000c68770 T __lock_text_start

This symbol is also removed from the symbol table but used in function
machine__is_lock_function().

To fix this and keep duplicate symbols in the symbol table, set
symbol_conf.allow_aliases to true. This prevents the removal of
duplicate symbols in function symbols__fixup_duplicate().

Output After:

 # ./perf lock contention
 contended total wait  max wait  avg wait    type   caller

        48   124.39 ms 123.99 ms   2.59 ms rwsem:W unlink_anon_vmas+0x24a
        47    83.68 ms  83.26 ms   1.78 ms rwsem:W free_pgtables+0x132
         5    41.22 us  10.55 us   8.24 us rwsem:W free_pgtables+0x140
         4    40.12 us  20.55 us  10.03 us rwsem:W copy_process+0x1ac8
 #

Fixes: 0d2997f ("perf lock: Look up callchain for the contended locks")
Signed-off-by: Thomas Richter <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Sumanth Korikkar <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Jan 24, 2023
commit cf12983 upstream.

When a match has been made to the nth duplicate symbol, return
success not error.

Example:

  Before:

    $ cat file.c
    cat: file.c: No such file or directory
    $ cat file1.c
    #include <stdio.h>

    static void func(void)
    {
            printf("First func\n");
    }

    void other(void);

    int main()
    {
            func();
            other();
            return 0;
    }
    $ cat file2.c
    #include <stdio.h>

    static void func(void)
    {
            printf("Second func\n");
    }

    void other(void)
    {
            func();
    }

    $ gcc -Wall -Wextra -o test file1.c file2.c
    $ perf record -e intel_pt//u --filter 'filter func @ ./test' -- ./test
    Multiple symbols with name 'func'
    #1      0x1149  l       func
                    which is near           main
    #2      0x1179  l       func
                    which is near           other
    Disambiguate symbol name by inserting #n after the name e.g. func #2
    Or select a global symbol by inserting #0 or #g or #G
    Failed to parse address filter: 'filter func @ ./test'
    Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
    Where multiple filters are separated by space or comma.
    $ perf record -e intel_pt//u --filter 'filter func #2 @ ./test' -- ./test
    Failed to parse address filter: 'filter func #2 @ ./test'
    Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
    Where multiple filters are separated by space or comma.

  After:

    $ perf record -e intel_pt//u --filter 'filter func #2 @ ./test' -- ./test
    First func
    Second func
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.016 MB perf.data ]
    $ perf script --itrace=b -Ftime,flags,ip,sym,addr --ns
    1231062.526977619:   tr strt                               0 [unknown] =>     558495708179 func
    1231062.526977619:   tr end  call               558495708188 func =>     558495708050 _init
    1231062.526979286:   tr strt                               0 [unknown] =>     55849570818d func
    1231062.526979286:   tr end  return             55849570818f func =>     55849570819d other

Fixes: 1b36c03 ("perf record: Add support for using symbols in address filters")
Reported-by: Dmitrii Dolgov <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Dmitry Dolgov <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
xairy pushed a commit that referenced this pull request Jan 24, 2023
commit 76d588d upstream.

Current imc-pmu code triggers a WARNING with CONFIG_DEBUG_ATOMIC_SLEEP
and CONFIG_PROVE_LOCKING enabled, while running a thread_imc event.

Command to trigger the warning:
  # perf stat -e thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/ sleep 5

   Performance counter stats for 'sleep 5':

                   0      thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/

         5.002117947 seconds time elapsed

         0.000131000 seconds user
         0.001063000 seconds sys

Below is snippet of the warning in dmesg:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 2869, name: perf-exec
  preempt_count: 2, expected: 0
  4 locks held by perf-exec/2869:
   #0: c00000004325c540 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: bprm_execve+0x64/0xa90
   #1: c00000004325c5d8 (&sig->exec_update_lock){++++}-{3:3}, at: begin_new_exec+0x460/0xef0
   #2: c0000003fa99d4e0 (&cpuctx_lock){-...}-{2:2}, at: perf_event_exec+0x290/0x510
   #3: c000000017ab8418 (&ctx->lock){....}-{2:2}, at: perf_event_exec+0x29c/0x510
  irq event stamp: 4806
  hardirqs last  enabled at (4805): [<c000000000f65b94>] _raw_spin_unlock_irqrestore+0x94/0xd0
  hardirqs last disabled at (4806): [<c0000000003fae44>] perf_event_exec+0x394/0x510
  softirqs last  enabled at (0): [<c00000000013c404>] copy_process+0xc34/0x1ff0
  softirqs last disabled at (0): [<0000000000000000>] 0x0
  CPU: 36 PID: 2869 Comm: perf-exec Not tainted 6.2.0-rc2-00011-g1247637727f2 torvalds#61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  Call Trace:
    dump_stack_lvl+0x98/0xe0 (unreliable)
    __might_resched+0x2f8/0x310
    __mutex_lock+0x6c/0x13f0
    thread_imc_event_add+0xf4/0x1b0
    event_sched_in+0xe0/0x210
    merge_sched_in+0x1f0/0x600
    visit_groups_merge.isra.92.constprop.166+0x2bc/0x6c0
    ctx_flexible_sched_in+0xcc/0x140
    ctx_sched_in+0x20c/0x2a0
    ctx_resched+0x104/0x1c0
    perf_event_exec+0x340/0x510
    begin_new_exec+0x730/0xef0
    load_elf_binary+0x3f8/0x1e10
  ...
  do not call blocking ops when !TASK_RUNNING; state=2001 set at [<00000000fd63e7cf>] do_nanosleep+0x60/0x1a0
  WARNING: CPU: 36 PID: 2869 at kernel/sched/core.c:9912 __might_sleep+0x9c/0xb0
  CPU: 36 PID: 2869 Comm: sleep Tainted: G        W          6.2.0-rc2-00011-g1247637727f2 torvalds#61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  NIP:  c000000000194a1c LR: c000000000194a18 CTR: c000000000a78670
  REGS: c00000004d2134e0 TRAP: 0700   Tainted: G        W           (6.2.0-rc2-00011-g1247637727f2)
  MSR:  9000000000021033 <SF,HV,ME,IR,DR,RI,LE>  CR: 48002824  XER: 00000000
  CFAR: c00000000013fb64 IRQMASK: 1

The above warning triggered because the current imc-pmu code uses mutex
lock in interrupt disabled sections. The function mutex_lock()
internally calls __might_resched(), which will check if IRQs are
disabled and in case IRQs are disabled, it will trigger the warning.

Fix the issue by changing the mutex lock to spinlock.

Fixes: 8f95faa ("powerpc/powernv: Detect and create IMC device")
Reported-by: Michael Petlan <[email protected]>
Reported-by: Peter Zijlstra <[email protected]>
Signed-off-by: Kajol Jain <[email protected]>
[mpe: Fix comments, trim oops in change log, add reported-by tags]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
xairy added a commit that referenced this pull request Jan 31, 2023
Give more meaningful names to hash table-related constants and variables:

1. Rename STACK_HASH_SCALE to STACK_TABLE_SCALE to point out that it is
   related to scaling the hash table.

2. Rename STACK_HASH_ORDER_MIN/MAX to STACK_BUCKET_NUMBER_ORDER_MIN/MAX
   to point out that it is related to the number of hash table buckets.

3. Rename stack_hash_order to stack_bucket_number_order for the same
   reason as #2.

No functional changes.

Signed-off-by: Andrey Konovalov <[email protected]>
xairy pushed a commit that referenced this pull request Jan 31, 2023
Current imc-pmu code triggers a WARNING with CONFIG_DEBUG_ATOMIC_SLEEP
and CONFIG_PROVE_LOCKING enabled, while running a thread_imc event.

Command to trigger the warning:
  # perf stat -e thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/ sleep 5

   Performance counter stats for 'sleep 5':

                   0      thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/

         5.002117947 seconds time elapsed

         0.000131000 seconds user
         0.001063000 seconds sys

Below is snippet of the warning in dmesg:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 2869, name: perf-exec
  preempt_count: 2, expected: 0
  4 locks held by perf-exec/2869:
   #0: c00000004325c540 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: bprm_execve+0x64/0xa90
   #1: c00000004325c5d8 (&sig->exec_update_lock){++++}-{3:3}, at: begin_new_exec+0x460/0xef0
   #2: c0000003fa99d4e0 (&cpuctx_lock){-...}-{2:2}, at: perf_event_exec+0x290/0x510
   #3: c000000017ab8418 (&ctx->lock){....}-{2:2}, at: perf_event_exec+0x29c/0x510
  irq event stamp: 4806
  hardirqs last  enabled at (4805): [<c000000000f65b94>] _raw_spin_unlock_irqrestore+0x94/0xd0
  hardirqs last disabled at (4806): [<c0000000003fae44>] perf_event_exec+0x394/0x510
  softirqs last  enabled at (0): [<c00000000013c404>] copy_process+0xc34/0x1ff0
  softirqs last disabled at (0): [<0000000000000000>] 0x0
  CPU: 36 PID: 2869 Comm: perf-exec Not tainted 6.2.0-rc2-00011-g1247637727f2 torvalds#61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  Call Trace:
    dump_stack_lvl+0x98/0xe0 (unreliable)
    __might_resched+0x2f8/0x310
    __mutex_lock+0x6c/0x13f0
    thread_imc_event_add+0xf4/0x1b0
    event_sched_in+0xe0/0x210
    merge_sched_in+0x1f0/0x600
    visit_groups_merge.isra.92.constprop.166+0x2bc/0x6c0
    ctx_flexible_sched_in+0xcc/0x140
    ctx_sched_in+0x20c/0x2a0
    ctx_resched+0x104/0x1c0
    perf_event_exec+0x340/0x510
    begin_new_exec+0x730/0xef0
    load_elf_binary+0x3f8/0x1e10
  ...
  do not call blocking ops when !TASK_RUNNING; state=2001 set at [<00000000fd63e7cf>] do_nanosleep+0x60/0x1a0
  WARNING: CPU: 36 PID: 2869 at kernel/sched/core.c:9912 __might_sleep+0x9c/0xb0
  CPU: 36 PID: 2869 Comm: sleep Tainted: G        W          6.2.0-rc2-00011-g1247637727f2 torvalds#61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  NIP:  c000000000194a1c LR: c000000000194a18 CTR: c000000000a78670
  REGS: c00000004d2134e0 TRAP: 0700   Tainted: G        W           (6.2.0-rc2-00011-g1247637727f2)
  MSR:  9000000000021033 <SF,HV,ME,IR,DR,RI,LE>  CR: 48002824  XER: 00000000
  CFAR: c00000000013fb64 IRQMASK: 1

The above warning triggered because the current imc-pmu code uses mutex
lock in interrupt disabled sections. The function mutex_lock()
internally calls __might_resched(), which will check if IRQs are
disabled and in case IRQs are disabled, it will trigger the warning.

Fix the issue by changing the mutex lock to spinlock.

Fixes: 8f95faa ("powerpc/powernv: Detect and create IMC device")
Reported-by: Michael Petlan <[email protected]>
Reported-by: Peter Zijlstra <[email protected]>
Signed-off-by: Kajol Jain <[email protected]>
[mpe: Fix comments, trim oops in change log, add reported-by tags]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
xairy pushed a commit that referenced this pull request Jan 31, 2023
When a match has been made to the nth duplicate symbol, return
success not error.

Example:

  Before:

    $ cat file.c
    cat: file.c: No such file or directory
    $ cat file1.c
    #include <stdio.h>

    static void func(void)
    {
            printf("First func\n");
    }

    void other(void);

    int main()
    {
            func();
            other();
            return 0;
    }
    $ cat file2.c
    #include <stdio.h>

    static void func(void)
    {
            printf("Second func\n");
    }

    void other(void)
    {
            func();
    }

    $ gcc -Wall -Wextra -o test file1.c file2.c
    $ perf record -e intel_pt//u --filter 'filter func @ ./test' -- ./test
    Multiple symbols with name 'func'
    #1      0x1149  l       func
                    which is near           main
    #2      0x1179  l       func
                    which is near           other
    Disambiguate symbol name by inserting #n after the name e.g. func #2
    Or select a global symbol by inserting #0 or #g or #G
    Failed to parse address filter: 'filter func @ ./test'
    Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
    Where multiple filters are separated by space or comma.
    $ perf record -e intel_pt//u --filter 'filter func #2 @ ./test' -- ./test
    Failed to parse address filter: 'filter func #2 @ ./test'
    Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
    Where multiple filters are separated by space or comma.

  After:

    $ perf record -e intel_pt//u --filter 'filter func #2 @ ./test' -- ./test
    First func
    Second func
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.016 MB perf.data ]
    $ perf script --itrace=b -Ftime,flags,ip,sym,addr --ns
    1231062.526977619:   tr strt                               0 [unknown] =>     558495708179 func
    1231062.526977619:   tr end  call               558495708188 func =>     558495708050 _init
    1231062.526979286:   tr strt                               0 [unknown] =>     55849570818d func
    1231062.526979286:   tr end  return             55849570818f func =>     55849570819d other

Fixes: 1b36c03 ("perf record: Add support for using symbols in address filters")
Reported-by: Dmitrii Dolgov <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Dmitry Dolgov <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
xairy pushed a commit that referenced this pull request Jan 31, 2023
Patch series "mm/hugetlb: uffd-wp fixes for hugetlb_change_protection()".

Playing with virtio-mem and background snapshots (using uffd-wp) on
hugetlb in QEMU, I managed to trigger a VM_BUG_ON().  Looking into the
details, hugetlb_change_protection() seems to not handle uffd-wp correctly
in all cases.

Patch #1 fixes my test case.  I don't have reproducers for patch #2, as it
requires running into migration entries.

I did not yet check in detail yet if !hugetlb code requires similar care.


This patch (of 2):

There are two problematic cases when stumbling over a PTE marker in
hugetlb_change_protection():

(1) We protect an uffd-wp PTE marker a second time using uffd-wp: we will
    end up in the "!huge_pte_none(pte)" case and mess up the PTE marker.

(2) We unprotect a uffd-wp PTE marker: we will similarly end up in the
    "!huge_pte_none(pte)" case even though we cleared the PTE, because
    the "pte" variable is stale. We'll mess up the PTE marker.

For example, if we later stumble over such a "wrongly modified" PTE marker,
we'll treat it like a present PTE that maps some garbage page.

This can, for example, be triggered by mapping a memfd backed by huge
pages, registering uffd-wp, uffd-wp'ing an unmapped page and (a)
uffd-wp'ing it a second time; or (b) uffd-unprotecting it; or (c)
unregistering uffd-wp. Then, ff we trigger fallocate(FALLOC_FL_PUNCH_HOLE)
on that file range, we will run into a VM_BUG_ON:

[  195.039560] page:00000000ba1f2987 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0
[  195.039565] flags: 0x7ffffc0001000(reserved|node=0|zone=0|lastcpupid=0x1fffff)
[  195.039568] raw: 0007ffffc0001000 ffffe742c0000008 ffffe742c0000008 0000000000000000
[  195.039569] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
[  195.039569] page dumped because: VM_BUG_ON_PAGE(compound && !PageHead(page))
[  195.039573] ------------[ cut here ]------------
[  195.039574] kernel BUG at mm/rmap.c:1346!
[  195.039579] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[  195.039581] CPU: 7 PID: 4777 Comm: qemu-system-x86 Not tainted 6.0.12-200.fc36.x86_64 #1
[  195.039583] Hardware name: LENOVO 20WNS1F81N/20WNS1F81N, BIOS N35ET50W (1.50 ) 09/15/2022
[  195.039584] RIP: 0010:page_remove_rmap+0x45b/0x550
[  195.039588] Code: [...]
[  195.039589] RSP: 0018:ffffbc03c3633ba8 EFLAGS: 00010292
[  195.039591] RAX: 0000000000000040 RBX: ffffe742c0000000 RCX: 0000000000000000
[  195.039592] RDX: 0000000000000002 RSI: ffffffff8e7aac1a RDI: 00000000ffffffff
[  195.039592] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffbc03c3633a08
[  195.039593] R10: 0000000000000003 R11: ffffffff8f146328 R12: ffff9b04c42754b0
[  195.039594] R13: ffffffff8fcc6328 R14: ffffbc03c3633c80 R15: ffff9b0484ab9100
[  195.039595] FS:  00007fc7aaf68640(0000) GS:ffff9b0bbf7c0000(0000) knlGS:0000000000000000
[  195.039596] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  195.039597] CR2: 000055d402c49110 CR3: 0000000159392003 CR4: 0000000000772ee0
[  195.039598] PKRU: 55555554
[  195.039599] Call Trace:
[  195.039600]  <TASK>
[  195.039602]  __unmap_hugepage_range+0x33b/0x7d0
[  195.039605]  unmap_hugepage_range+0x55/0x70
[  195.039608]  hugetlb_vmdelete_list+0x77/0xa0
[  195.039611]  hugetlbfs_fallocate+0x410/0x550
[  195.039612]  ? _raw_spin_unlock_irqrestore+0x23/0x40
[  195.039616]  vfs_fallocate+0x12e/0x360
[  195.039618]  __x64_sys_fallocate+0x40/0x70
[  195.039620]  do_syscall_64+0x58/0x80
[  195.039623]  ? syscall_exit_to_user_mode+0x17/0x40
[  195.039624]  ? do_syscall_64+0x67/0x80
[  195.039626]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[  195.039628] RIP: 0033:0x7fc7b590651f
[  195.039653] Code: [...]
[  195.039654] RSP: 002b:00007fc7aaf66e70 EFLAGS: 00000293 ORIG_RAX: 000000000000011d
[  195.039655] RAX: ffffffffffffffda RBX: 0000558ef4b7f370 RCX: 00007fc7b590651f
[  195.039656] RDX: 0000000018000000 RSI: 0000000000000003 RDI: 000000000000000c
[  195.039657] RBP: 0000000008000000 R08: 0000000000000000 R09: 0000000000000073
[  195.039658] R10: 0000000008000000 R11: 0000000000000293 R12: 0000000018000000
[  195.039658] R13: 00007fb8bbe00000 R14: 000000000000000c R15: 0000000000001000
[  195.039661]  </TASK>

Fix it by not going into the "!huge_pte_none(pte)" case if we stumble over
an exclusive marker.  spin_unlock() + continue would get the job done.

However, instead, make it clearer that there are no fall-through
statements: we process each case (hwpoison, migration, marker, !none,
none) and then unlock the page table to continue with the next PTE.  Let's
avoid "continue" statements and use a single spin_unlock() at the end.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 60dfaad ("mm/hugetlb: allow uffd wr-protect none ptes")
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Reviewed-by: Mike Kravetz <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
xairy pushed a commit that referenced this pull request Jan 31, 2023
This lockdep splat says it better than I could:

================================
WARNING: inconsistent lock state
6.2.0-rc2-07010-ga9b9500ffaac-dirty torvalds#967 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
kworker/1:3/179 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff3ec4036ce098 (_xmit_ETHER#2){+.?.}-{3:3}, at: netif_freeze_queues+0x5c/0xc0
{IN-SOFTIRQ-W} state was registered at:
  _raw_spin_lock+0x5c/0xc0
  sch_direct_xmit+0x148/0x37c
  __dev_queue_xmit+0x528/0x111c
  ip6_finish_output2+0x5ec/0xb7c
  ip6_finish_output+0x240/0x3f0
  ip6_output+0x78/0x360
  ndisc_send_skb+0x33c/0x85c
  ndisc_send_rs+0x54/0x12c
  addrconf_rs_timer+0x154/0x260
  call_timer_fn+0xb8/0x3a0
  __run_timers.part.0+0x214/0x26c
  run_timer_softirq+0x3c/0x74
  __do_softirq+0x14c/0x5d8
  ____do_softirq+0x10/0x20
  call_on_irq_stack+0x2c/0x5c
  do_softirq_own_stack+0x1c/0x30
  __irq_exit_rcu+0x168/0x1a0
  irq_exit_rcu+0x10/0x40
  el1_interrupt+0x38/0x64
irq event stamp: 7825
hardirqs last  enabled at (7825): [<ffffdf1f7200cae4>] exit_to_kernel_mode+0x34/0x130
hardirqs last disabled at (7823): [<ffffdf1f708105f0>] __do_softirq+0x550/0x5d8
softirqs last  enabled at (7824): [<ffffdf1f7081050c>] __do_softirq+0x46c/0x5d8
softirqs last disabled at (7811): [<ffffdf1f708166e0>] ____do_softirq+0x10/0x20

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(_xmit_ETHER#2);
  <Interrupt>
    lock(_xmit_ETHER#2);

 *** DEADLOCK ***

3 locks held by kworker/1:3/179:
 #0: ffff3ec400004748 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1f4/0x6c0
 #1: ffff80000a0bbdc8 ((work_completion)(&priv->tx_onestep_tstamp)){+.+.}-{0:0}, at: process_one_work+0x1f4/0x6c0
 #2: ffff3ec4036cd438 (&dev->tx_global_lock){+.+.}-{3:3}, at: netif_tx_lock+0x1c/0x34

Workqueue: events enetc_tx_onestep_tstamp
Call trace:
 print_usage_bug.part.0+0x208/0x22c
 mark_lock+0x7f0/0x8b0
 __lock_acquire+0x7c4/0x1ce0
 lock_acquire.part.0+0xe0/0x220
 lock_acquire+0x68/0x84
 _raw_spin_lock+0x5c/0xc0
 netif_freeze_queues+0x5c/0xc0
 netif_tx_lock+0x24/0x34
 enetc_tx_onestep_tstamp+0x20/0x100
 process_one_work+0x28c/0x6c0
 worker_thread+0x74/0x450
 kthread+0x118/0x11c

but I'll say it anyway: the enetc_tx_onestep_tstamp() work item runs in
process context, therefore with softirqs enabled (i.o.w., it can be
interrupted by a softirq). If we hold the netif_tx_lock() when there is
an interrupt, and the NET_TX softirq then gets scheduled, this will take
the netif_tx_lock() a second time and deadlock the kernel.

To solve this, use netif_tx_lock_bh(), which blocks softirqs from
running.

Fixes: 7294380 ("enetc: support PTP Sync packet one-step timestamping")
Signed-off-by: Vladimir Oltean <[email protected]>
Reviewed-by: Alexander Duyck <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
xairy pushed a commit that referenced this pull request Jan 31, 2023
This fixes the following trace caused by attempting to lock
cmd_sync_work_lock while holding the rcu_read_lock:

kworker/u3:2/212 is trying to lock:
ffff888002600910 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}, at:
hci_cmd_sync_queue+0xad/0x140
other info that might help us debug this:
context-{4:4}
4 locks held by kworker/u3:2/212:
 #0: ffff8880028c6530 ((wq_completion)hci0#2){+.+.}-{0:0}, at:
 process_one_work+0x4dc/0x9a0
 #1: ffff888001aafde0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0},
 at: process_one_work+0x4dc/0x9a0
 #2: ffff888002600070 (&hdev->lock){+.+.}-{3:3}, at:
 hci_cc_le_set_cig_params+0x64/0x4f0
 #3: ffffffffa5994b00 (rcu_read_lock){....}-{1:2}, at:
 hci_cc_le_set_cig_params+0x2f9/0x4f0

Fixes: 26afbd8 ("Bluetooth: Add initial implementation of CIS connections")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
xairy pushed a commit that referenced this pull request Jan 31, 2023
This attempts to fix the following trace:

iso-tester/52 is trying to acquire lock:
ffff8880024e0070 (&hdev->lock){+.+.}-{3:3}, at:
iso_sock_listen+0x29e/0x440

but task is already holding lock:
ffff888001978130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at:
iso_sock_listen+0x8b/0x440

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
       lock_acquire+0x176/0x3d0
       lock_sock_nested+0x32/0x80
       iso_connect_cfm+0x1a3/0x630
       hci_cc_le_setup_iso_path+0x195/0x340
       hci_cmd_complete_evt+0x1ae/0x500
       hci_event_packet+0x38e/0x7c0
       hci_rx_work+0x34c/0x980
       process_one_work+0x5a5/0x9a0
       worker_thread+0x89/0x6f0
       kthread+0x14e/0x180
       ret_from_fork+0x22/0x30

-> #1 (hci_cb_list_lock){+.+.}-{3:3}:
       lock_acquire+0x176/0x3d0
       __mutex_lock+0x13b/0xf50
       hci_le_remote_feat_complete_evt+0x17e/0x320
       hci_event_packet+0x38e/0x7c0
       hci_rx_work+0x34c/0x980
       process_one_work+0x5a5/0x9a0
       worker_thread+0x89/0x6f0
       kthread+0x14e/0x180
       ret_from_fork+0x22/0x30

-> #0 (&hdev->lock){+.+.}-{3:3}:
       check_prev_add+0xfc/0x1190
       __lock_acquire+0x1e27/0x2750
       lock_acquire+0x176/0x3d0
       __mutex_lock+0x13b/0xf50
       iso_sock_listen+0x29e/0x440
       __sys_listen+0xe6/0x160
       __x64_sys_listen+0x25/0x30
       do_syscall_64+0x42/0x90
       entry_SYSCALL_64_after_hwframe+0x62/0xcc

other info that might help us debug this:

Chain exists of:
  &hdev->lock --> hci_cb_list_lock --> sk_lock-AF_BLUETOOTH-BTPROTO_ISO

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
                               lock(hci_cb_list_lock);
                               lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
  lock(&hdev->lock);

 *** DEADLOCK ***

1 lock held by iso-tester/52:
 #0: ffff888001978130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at:
 iso_sock_listen+0x8b/0x440

Fixes: f764a6c ("Bluetooth: ISO: Add broadcast support")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
xairy pushed a commit that referenced this pull request Jan 31, 2023
The cited commit changed class of tc_ht internal mutex in order to avoid
false lock dependency with fs_core node and flow_table hash table
structures. However, hash table implementation internally also includes a
workqueue task with its own lockdep map which causes similar bogus lockdep
splat[0]. Fix it by also adding dedicated class for hash table workqueue
work structure of tc_ht.

[0]:

[ 1139.672465] ======================================================
[ 1139.673552] WARNING: possible circular locking dependency detected
[ 1139.674635] 6.1.0_for_upstream_debug_2022_12_12_17_02 #1 Not tainted
[ 1139.675734] ------------------------------------------------------
[ 1139.676801] modprobe/5998 is trying to acquire lock:
[ 1139.677726] ffff88811e7b93b8 (&node->lock){++++}-{3:3}, at: down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.679662]
               but task is already holding lock:
[ 1139.680703] ffff88813c1f96a0 (&tc_ht_lock_key){+.+.}-{3:3}, at: rhashtable_free_and_destroy+0x38/0x6f0
[ 1139.682223]
               which lock already depends on the new lock.

[ 1139.683640]
               the existing dependency chain (in reverse order) is:
[ 1139.684887]
               -> #2 (&tc_ht_lock_key){+.+.}-{3:3}:
[ 1139.685975]        __mutex_lock+0x12c/0x14b0
[ 1139.686659]        rht_deferred_worker+0x35/0x1540
[ 1139.687405]        process_one_work+0x7c2/0x1310
[ 1139.688134]        worker_thread+0x59d/0xec0
[ 1139.688820]        kthread+0x28f/0x330
[ 1139.689444]        ret_from_fork+0x1f/0x30
[ 1139.690106]
               -> #1 ((work_completion)(&ht->run_work)){+.+.}-{0:0}:
[ 1139.691250]        __flush_work+0xe8/0x900
[ 1139.691915]        __cancel_work_timer+0x2ca/0x3f0
[ 1139.692655]        rhashtable_free_and_destroy+0x22/0x6f0
[ 1139.693472]        del_sw_flow_table+0x22/0xb0 [mlx5_core]
[ 1139.694592]        tree_put_node+0x24c/0x450 [mlx5_core]
[ 1139.695686]        tree_remove_node+0x6e/0x100 [mlx5_core]
[ 1139.696803]        mlx5_destroy_flow_table+0x187/0x690 [mlx5_core]
[ 1139.698017]        mlx5e_tc_nic_cleanup+0x2f8/0x400 [mlx5_core]
[ 1139.699217]        mlx5e_cleanup_nic_rx+0x2b/0x210 [mlx5_core]
[ 1139.700397]        mlx5e_detach_netdev+0x19d/0x2b0 [mlx5_core]
[ 1139.701571]        mlx5e_suspend+0xdb/0x140 [mlx5_core]
[ 1139.702665]        mlx5e_remove+0x89/0x190 [mlx5_core]
[ 1139.703756]        auxiliary_bus_remove+0x52/0x70
[ 1139.704492]        device_release_driver_internal+0x3c1/0x600
[ 1139.705360]        bus_remove_device+0x2a5/0x560
[ 1139.706080]        device_del+0x492/0xb80
[ 1139.706724]        mlx5_rescan_drivers_locked+0x194/0x6a0 [mlx5_core]
[ 1139.707961]        mlx5_unregister_device+0x7a/0xa0 [mlx5_core]
[ 1139.709138]        mlx5_uninit_one+0x5f/0x160 [mlx5_core]
[ 1139.710252]        remove_one+0xd1/0x160 [mlx5_core]
[ 1139.711297]        pci_device_remove+0x96/0x1c0
[ 1139.722721]        device_release_driver_internal+0x3c1/0x600
[ 1139.723590]        unbind_store+0x1b1/0x200
[ 1139.724259]        kernfs_fop_write_iter+0x348/0x520
[ 1139.725019]        vfs_write+0x7b2/0xbf0
[ 1139.725658]        ksys_write+0xf3/0x1d0
[ 1139.726292]        do_syscall_64+0x3d/0x90
[ 1139.726942]        entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 1139.727769]
               -> #0 (&node->lock){++++}-{3:3}:
[ 1139.728698]        __lock_acquire+0x2cf5/0x62f0
[ 1139.729415]        lock_acquire+0x1c1/0x540
[ 1139.730076]        down_write+0x8e/0x1f0
[ 1139.730709]        down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.731841]        mlx5_del_flow_rules+0x6f/0x610 [mlx5_core]
[ 1139.732982]        __mlx5_eswitch_del_rule+0xdd/0x560 [mlx5_core]
[ 1139.734207]        mlx5_eswitch_del_offloaded_rule+0x14/0x20 [mlx5_core]
[ 1139.735491]        mlx5e_tc_rule_unoffload+0x104/0x2b0 [mlx5_core]
[ 1139.736716]        mlx5e_tc_unoffload_fdb_rules+0x10c/0x1f0 [mlx5_core]
[ 1139.738007]        mlx5e_tc_del_fdb_flow+0xc3c/0xfa0 [mlx5_core]
[ 1139.739213]        mlx5e_tc_del_flow+0x146/0xa20 [mlx5_core]
[ 1139.740377]        _mlx5e_tc_del_flow+0x38/0x60 [mlx5_core]
[ 1139.741534]        rhashtable_free_and_destroy+0x3be/0x6f0
[ 1139.742351]        mlx5e_tc_ht_cleanup+0x1b/0x30 [mlx5_core]
[ 1139.743512]        mlx5e_cleanup_rep_tx+0x4a/0xe0 [mlx5_core]
[ 1139.744683]        mlx5e_detach_netdev+0x1ca/0x2b0 [mlx5_core]
[ 1139.745860]        mlx5e_netdev_change_profile+0xd9/0x1c0 [mlx5_core]
[ 1139.747098]        mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core]
[ 1139.748372]        mlx5e_vport_rep_unload+0x16a/0x1b0 [mlx5_core]
[ 1139.749590]        __esw_offloads_unload_rep+0xb1/0xd0 [mlx5_core]
[ 1139.750813]        mlx5_eswitch_unregister_vport_reps+0x409/0x5f0 [mlx5_core]
[ 1139.752147]        mlx5e_rep_remove+0x62/0x80 [mlx5_core]
[ 1139.753293]        auxiliary_bus_remove+0x52/0x70
[ 1139.754028]        device_release_driver_internal+0x3c1/0x600
[ 1139.754885]        driver_detach+0xc1/0x180
[ 1139.755553]        bus_remove_driver+0xef/0x2e0
[ 1139.756260]        auxiliary_driver_unregister+0x16/0x50
[ 1139.757059]        mlx5e_rep_cleanup+0x19/0x30 [mlx5_core]
[ 1139.758207]        mlx5e_cleanup+0x12/0x30 [mlx5_core]
[ 1139.759295]        mlx5_cleanup+0xc/0x49 [mlx5_core]
[ 1139.760384]        __x64_sys_delete_module+0x2b5/0x450
[ 1139.761166]        do_syscall_64+0x3d/0x90
[ 1139.761827]        entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 1139.762663]
               other info that might help us debug this:

[ 1139.763925] Chain exists of:
                 &node->lock --> (work_completion)(&ht->run_work) --> &tc_ht_lock_key

[ 1139.765743]  Possible unsafe locking scenario:

[ 1139.766688]        CPU0                    CPU1
[ 1139.767399]        ----                    ----
[ 1139.768111]   lock(&tc_ht_lock_key);
[ 1139.768704]                                lock((work_completion)(&ht->run_work));
[ 1139.769869]                                lock(&tc_ht_lock_key);
[ 1139.770770]   lock(&node->lock);
[ 1139.771326]
                *** DEADLOCK ***

[ 1139.772345] 2 locks held by modprobe/5998:
[ 1139.772994]  #0: ffff88813c1ff0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x8d/0x600
[ 1139.774399]  #1: ffff88813c1f96a0 (&tc_ht_lock_key){+.+.}-{3:3}, at: rhashtable_free_and_destroy+0x38/0x6f0
[ 1139.775822]
               stack backtrace:
[ 1139.776579] CPU: 3 PID: 5998 Comm: modprobe Not tainted 6.1.0_for_upstream_debug_2022_12_12_17_02 #1
[ 1139.777935] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 1139.779529] Call Trace:
[ 1139.779992]  <TASK>
[ 1139.780409]  dump_stack_lvl+0x57/0x7d
[ 1139.781015]  check_noncircular+0x278/0x300
[ 1139.781687]  ? print_circular_bug+0x460/0x460
[ 1139.782381]  ? rcu_read_lock_sched_held+0x3f/0x70
[ 1139.783121]  ? lock_release+0x487/0x7c0
[ 1139.783759]  ? orc_find.part.0+0x1f1/0x330
[ 1139.784423]  ? mark_lock.part.0+0xef/0x2fc0
[ 1139.785091]  __lock_acquire+0x2cf5/0x62f0
[ 1139.785754]  ? register_lock_class+0x18e0/0x18e0
[ 1139.786483]  lock_acquire+0x1c1/0x540
[ 1139.787093]  ? down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.788195]  ? lockdep_hardirqs_on_prepare+0x3f0/0x3f0
[ 1139.788978]  ? register_lock_class+0x18e0/0x18e0
[ 1139.789715]  down_write+0x8e/0x1f0
[ 1139.790292]  ? down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.791380]  ? down_write_killable+0x220/0x220
[ 1139.792080]  ? find_held_lock+0x2d/0x110
[ 1139.792713]  down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.793795]  mlx5_del_flow_rules+0x6f/0x610 [mlx5_core]
[ 1139.794879]  __mlx5_eswitch_del_rule+0xdd/0x560 [mlx5_core]
[ 1139.796032]  ? __esw_offloads_unload_rep+0xd0/0xd0 [mlx5_core]
[ 1139.797227]  ? xa_load+0x11a/0x200
[ 1139.797800]  ? __xa_clear_mark+0xf0/0xf0
[ 1139.798438]  mlx5_eswitch_del_offloaded_rule+0x14/0x20 [mlx5_core]
[ 1139.799660]  mlx5e_tc_rule_unoffload+0x104/0x2b0 [mlx5_core]
[ 1139.800821]  mlx5e_tc_unoffload_fdb_rules+0x10c/0x1f0 [mlx5_core]
[ 1139.802049]  ? mlx5_eswitch_get_uplink_priv+0x25/0x80 [mlx5_core]
[ 1139.803260]  mlx5e_tc_del_fdb_flow+0xc3c/0xfa0 [mlx5_core]
[ 1139.804398]  ? __cancel_work_timer+0x1c2/0x3f0
[ 1139.805099]  ? mlx5e_tc_unoffload_from_slow_path+0x460/0x460 [mlx5_core]
[ 1139.806387]  mlx5e_tc_del_flow+0x146/0xa20 [mlx5_core]
[ 1139.807481]  _mlx5e_tc_del_flow+0x38/0x60 [mlx5_core]
[ 1139.808564]  rhashtable_free_and_destroy+0x3be/0x6f0
[ 1139.809336]  ? mlx5e_tc_del_flow+0xa20/0xa20 [mlx5_core]
[ 1139.809336]  ? mlx5e_tc_del_flow+0xa20/0xa20 [mlx5_core]
[ 1139.810455]  mlx5e_tc_ht_cleanup+0x1b/0x30 [mlx5_core]
[ 1139.811552]  mlx5e_cleanup_rep_tx+0x4a/0xe0 [mlx5_core]
[ 1139.812655]  mlx5e_detach_netdev+0x1ca/0x2b0 [mlx5_core]
[ 1139.813768]  mlx5e_netdev_change_profile+0xd9/0x1c0 [mlx5_core]
[ 1139.814952]  mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core]
[ 1139.816166]  mlx5e_vport_rep_unload+0x16a/0x1b0 [mlx5_core]
[ 1139.817336]  __esw_offloads_unload_rep+0xb1/0xd0 [mlx5_core]
[ 1139.818507]  mlx5_eswitch_unregister_vport_reps+0x409/0x5f0 [mlx5_core]
[ 1139.819788]  ? mlx5_eswitch_uplink_get_proto_dev+0x30/0x30 [mlx5_core]
[ 1139.821051]  ? kernfs_find_ns+0x137/0x310
[ 1139.821705]  mlx5e_rep_remove+0x62/0x80 [mlx5_core]
[ 1139.822778]  auxiliary_bus_remove+0x52/0x70
[ 1139.823449]  device_release_driver_internal+0x3c1/0x600
[ 1139.824240]  driver_detach+0xc1/0x180
[ 1139.824842]  bus_remove_driver+0xef/0x2e0
[ 1139.825504]  auxiliary_driver_unregister+0x16/0x50
[ 1139.826245]  mlx5e_rep_cleanup+0x19/0x30 [mlx5_core]
[ 1139.827322]  mlx5e_cleanup+0x12/0x30 [mlx5_core]
[ 1139.828345]  mlx5_cleanup+0xc/0x49 [mlx5_core]
[ 1139.829382]  __x64_sys_delete_module+0x2b5/0x450
[ 1139.830119]  ? module_flags+0x300/0x300
[ 1139.830750]  ? task_work_func_match+0x50/0x50
[ 1139.831440]  ? task_work_cancel+0x20/0x20
[ 1139.832088]  ? lockdep_hardirqs_on_prepare+0x273/0x3f0
[ 1139.832873]  ? syscall_enter_from_user_mode+0x1d/0x50
[ 1139.833661]  ? trace_hardirqs_on+0x2d/0x100
[ 1139.834328]  do_syscall_64+0x3d/0x90
[ 1139.834922]  entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 1139.835700] RIP: 0033:0x7f153e71288b
[ 1139.836302] Code: 73 01 c3 48 8b 0d 9d 75 0e 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 6d 75 0e 00 f7 d8 64 89 01 48
[ 1139.838866] RSP: 002b:00007ffe0a3ed938 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[ 1139.840020] RAX: ffffffffffffffda RBX: 0000564c2cbf8220 RCX: 00007f153e71288b
[ 1139.841043] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 0000564c2cbf8288
[ 1139.842072] RBP: 0000564c2cbf8220 R08: 0000000000000000 R09: 0000000000000000
[ 1139.843094] R10: 00007f153e7a3ac0 R11: 0000000000000206 R12: 0000564c2cbf8288
[ 1139.844118] R13: 0000000000000000 R14: 0000564c2cbf7ae8 R15: 00007ffe0a3efcb8

Fixes: 9ba3333 ("net/mlx5e: Avoid false lock depenency warning on tc_ht")
Signed-off-by: Vlad Buslov <[email protected]>
Reviewed-by: Eli Cohen <[email protected]>
Reviewed-by: Roi Dayan <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
xairy pushed a commit that referenced this pull request Jan 31, 2023
The commit 4af1b64 ("octeontx2-pf: Fix lmtst ID used in aura
free") uses the get/put_cpu() to protect the usage of percpu pointer
in ->aura_freeptr() callback, but it also unnecessarily disable the
preemption for the blockable memory allocation. The commit 87b93b6
("octeontx2-pf: Avoid use of GFP_KERNEL in atomic context") tried to
fix these sleep inside atomic warnings. But it only fix the one for
the non-rt kernel. For the rt kernel, we still get the similar warnings
like below.
  BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
  preempt_count: 1, expected: 0
  RCU nest depth: 0, expected: 0
  3 locks held by swapper/0/1:
   #0: ffff800009fc5fe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x24/0x30
   #1: ffff000100c276c0 (&mbox->lock){+.+.}-{3:3}, at: otx2_init_hw_resources+0x8c/0x3a4
   #2: ffffffbfef6537e0 (&cpu_rcache->lock){+.+.}-{2:2}, at: alloc_iova_fast+0x1ac/0x2ac
  Preemption disabled at:
  [<ffff800008b1908c>] otx2_rq_aura_pool_init+0x14c/0x284
  CPU: 20 PID: 1 Comm: swapper/0 Tainted: G        W          6.2.0-rc3-rt1-yocto-preempt-rt #1
  Hardware name: Marvell OcteonTX CN96XX board (DT)
  Call trace:
   dump_backtrace.part.0+0xe8/0xf4
   show_stack+0x20/0x30
   dump_stack_lvl+0x9c/0xd8
   dump_stack+0x18/0x34
   __might_resched+0x188/0x224
   rt_spin_lock+0x64/0x110
   alloc_iova_fast+0x1ac/0x2ac
   iommu_dma_alloc_iova+0xd4/0x110
   __iommu_dma_map+0x80/0x144
   iommu_dma_map_page+0xe8/0x260
   dma_map_page_attrs+0xb4/0xc0
   __otx2_alloc_rbuf+0x90/0x150
   otx2_rq_aura_pool_init+0x1c8/0x284
   otx2_init_hw_resources+0xe4/0x3a4
   otx2_open+0xf0/0x610
   __dev_open+0x104/0x224
   __dev_change_flags+0x1e4/0x274
   dev_change_flags+0x2c/0x7c
   ic_open_devs+0x124/0x2f8
   ip_auto_config+0x180/0x42c
   do_one_initcall+0x90/0x4dc
   do_basic_setup+0x10c/0x14c
   kernel_init_freeable+0x10c/0x13c
   kernel_init+0x2c/0x140
   ret_from_fork+0x10/0x20

Of course, we can shuffle the get/put_cpu() to only wrap the invocation
of ->aura_freeptr() as what commit 87b93b6 does. But there are only
two ->aura_freeptr() callbacks, otx2_aura_freeptr() and
cn10k_aura_freeptr(). There is no usage of perpcu variable in the
otx2_aura_freeptr() at all, so the get/put_cpu() seems redundant to it.
We can move the get/put_cpu() into the corresponding callback which
really has the percpu variable usage and avoid the sprinkling of
get/put_cpu() in several places.

Fixes: 4af1b64 ("octeontx2-pf: Fix lmtst ID used in aura free")
Signed-off-by: Kevin Hao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
xairy pushed a commit that referenced this pull request Jan 31, 2023
…kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.2, take #2

- Pass the correct address to mte_clear_page_tags() on initialising
  a tagged page

- Plug a race against a GICv4.1 doorbell interrupt while saving
  the vgic-v3 pending state.
xairy pushed a commit that referenced this pull request Feb 9, 2023
[ Upstream commit 3c46372 ]

This lockdep splat says it better than I could:

================================
WARNING: inconsistent lock state
6.2.0-rc2-07010-ga9b9500ffaac-dirty torvalds#967 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
kworker/1:3/179 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff3ec4036ce098 (_xmit_ETHER#2){+.?.}-{3:3}, at: netif_freeze_queues+0x5c/0xc0
{IN-SOFTIRQ-W} state was registered at:
  _raw_spin_lock+0x5c/0xc0
  sch_direct_xmit+0x148/0x37c
  __dev_queue_xmit+0x528/0x111c
  ip6_finish_output2+0x5ec/0xb7c
  ip6_finish_output+0x240/0x3f0
  ip6_output+0x78/0x360
  ndisc_send_skb+0x33c/0x85c
  ndisc_send_rs+0x54/0x12c
  addrconf_rs_timer+0x154/0x260
  call_timer_fn+0xb8/0x3a0
  __run_timers.part.0+0x214/0x26c
  run_timer_softirq+0x3c/0x74
  __do_softirq+0x14c/0x5d8
  ____do_softirq+0x10/0x20
  call_on_irq_stack+0x2c/0x5c
  do_softirq_own_stack+0x1c/0x30
  __irq_exit_rcu+0x168/0x1a0
  irq_exit_rcu+0x10/0x40
  el1_interrupt+0x38/0x64
irq event stamp: 7825
hardirqs last  enabled at (7825): [<ffffdf1f7200cae4>] exit_to_kernel_mode+0x34/0x130
hardirqs last disabled at (7823): [<ffffdf1f708105f0>] __do_softirq+0x550/0x5d8
softirqs last  enabled at (7824): [<ffffdf1f7081050c>] __do_softirq+0x46c/0x5d8
softirqs last disabled at (7811): [<ffffdf1f708166e0>] ____do_softirq+0x10/0x20

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(_xmit_ETHER#2);
  <Interrupt>
    lock(_xmit_ETHER#2);

 *** DEADLOCK ***

3 locks held by kworker/1:3/179:
 #0: ffff3ec400004748 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1f4/0x6c0
 #1: ffff80000a0bbdc8 ((work_completion)(&priv->tx_onestep_tstamp)){+.+.}-{0:0}, at: process_one_work+0x1f4/0x6c0
 #2: ffff3ec4036cd438 (&dev->tx_global_lock){+.+.}-{3:3}, at: netif_tx_lock+0x1c/0x34

Workqueue: events enetc_tx_onestep_tstamp
Call trace:
 print_usage_bug.part.0+0x208/0x22c
 mark_lock+0x7f0/0x8b0
 __lock_acquire+0x7c4/0x1ce0
 lock_acquire.part.0+0xe0/0x220
 lock_acquire+0x68/0x84
 _raw_spin_lock+0x5c/0xc0
 netif_freeze_queues+0x5c/0xc0
 netif_tx_lock+0x24/0x34
 enetc_tx_onestep_tstamp+0x20/0x100
 process_one_work+0x28c/0x6c0
 worker_thread+0x74/0x450
 kthread+0x118/0x11c

but I'll say it anyway: the enetc_tx_onestep_tstamp() work item runs in
process context, therefore with softirqs enabled (i.o.w., it can be
interrupted by a softirq). If we hold the netif_tx_lock() when there is
an interrupt, and the NET_TX softirq then gets scheduled, this will take
the netif_tx_lock() a second time and deadlock the kernel.

To solve this, use netif_tx_lock_bh(), which blocks softirqs from
running.

Fixes: 7294380 ("enetc: support PTP Sync packet one-step timestamping")
Signed-off-by: Vladimir Oltean <[email protected]>
Reviewed-by: Alexander Duyck <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Feb 9, 2023
[ Upstream commit 3c938cc ]

In case of PREEMPT_RT, there is a raw_spinlock -> spinlock dependency
as the lockdep report shows.

__irq_set_handler
  irq_get_desc_buslock
    __irq_get_desc_lock
      raw_spin_lock_irqsave(&desc->lock, *flags);  // raw spinlock get here
  __irq_do_set_handler
    mask_ack_irq
      dwapb_irq_ack
        spin_lock_irqsave(&gc->bgpio_lock, flags); // sleep able spinlock
  irq_put_desc_busunlock

Replace with a raw lock to avoid BUGs. This lock is only used to access
registers, and It's safe to replace with the raw lock without bad
influence.

[   15.090359][    T1] =============================
[   15.090365][    T1] [ BUG: Invalid wait context ]
[   15.090373][    T1] 5.10.59-rt52-00983-g186a6841c682-dirty #3 Not tainted
[   15.090386][    T1] -----------------------------
[   15.090392][    T1] swapper/0/1 is trying to lock:
[   15.090402][    T1] 70ff00018507c188 (&gc->bgpio_lock){....}-{3:3}, at: _raw_spin_lock_irqsave+0x1c/0x28
[   15.090470][    T1] other info that might help us debug this:
[   15.090477][    T1] context-{5:5}
[   15.090485][    T1] 3 locks held by swapper/0/1:
[   15.090497][    T1]  #0: c2ff0001816de1a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock+0x98/0x104
[   15.090553][    T1]  #1: ffff90001485b4b8 (irq_domain_mutex){+.+.}-{4:4}, at: irq_domain_associate+0xbc/0x6d4
[   15.090606][    T1]  #2: 4bff000185d7a8e0 (lock_class){....}-{2:2}, at: _raw_spin_lock_irqsave+0x1c/0x28
[   15.090654][    T1] stack backtrace:
[   15.090661][    T1] CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.10.59-rt52-00983-g186a6841c682-dirty #3
[   15.090682][    T1] Hardware name: Horizon Robotics Journey 5 DVB (DT)
[   15.090692][    T1] Call trace:
......
[   15.090811][    T1]  _raw_spin_lock_irqsave+0x1c/0x28
[   15.090828][    T1]  dwapb_irq_ack+0xb4/0x300
[   15.090846][    T1]  __irq_do_set_handler+0x494/0xb2c
[   15.090864][    T1]  __irq_set_handler+0x74/0x114
[   15.090881][    T1]  irq_set_chip_and_handler_name+0x44/0x58
[   15.090900][    T1]  gpiochip_irq_map+0x210/0x644

Signed-off-by: Schspa Shi <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Acked-by: Doug Berger <[email protected]>
Acked-by: Serge Semin <[email protected]>
Signed-off-by: Bartosz Golaszewski <[email protected]>
Stable-dep-of: e546427 ("gpio: mxc: Protect GPIO irqchip RMW with bgpio spinlock")
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Feb 9, 2023
[ Upstream commit 55ba18d ]

The commit 4af1b64 ("octeontx2-pf: Fix lmtst ID used in aura
free") uses the get/put_cpu() to protect the usage of percpu pointer
in ->aura_freeptr() callback, but it also unnecessarily disable the
preemption for the blockable memory allocation. The commit 87b93b6
("octeontx2-pf: Avoid use of GFP_KERNEL in atomic context") tried to
fix these sleep inside atomic warnings. But it only fix the one for
the non-rt kernel. For the rt kernel, we still get the similar warnings
like below.
  BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
  preempt_count: 1, expected: 0
  RCU nest depth: 0, expected: 0
  3 locks held by swapper/0/1:
   #0: ffff800009fc5fe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x24/0x30
   #1: ffff000100c276c0 (&mbox->lock){+.+.}-{3:3}, at: otx2_init_hw_resources+0x8c/0x3a4
   #2: ffffffbfef6537e0 (&cpu_rcache->lock){+.+.}-{2:2}, at: alloc_iova_fast+0x1ac/0x2ac
  Preemption disabled at:
  [<ffff800008b1908c>] otx2_rq_aura_pool_init+0x14c/0x284
  CPU: 20 PID: 1 Comm: swapper/0 Tainted: G        W          6.2.0-rc3-rt1-yocto-preempt-rt #1
  Hardware name: Marvell OcteonTX CN96XX board (DT)
  Call trace:
   dump_backtrace.part.0+0xe8/0xf4
   show_stack+0x20/0x30
   dump_stack_lvl+0x9c/0xd8
   dump_stack+0x18/0x34
   __might_resched+0x188/0x224
   rt_spin_lock+0x64/0x110
   alloc_iova_fast+0x1ac/0x2ac
   iommu_dma_alloc_iova+0xd4/0x110
   __iommu_dma_map+0x80/0x144
   iommu_dma_map_page+0xe8/0x260
   dma_map_page_attrs+0xb4/0xc0
   __otx2_alloc_rbuf+0x90/0x150
   otx2_rq_aura_pool_init+0x1c8/0x284
   otx2_init_hw_resources+0xe4/0x3a4
   otx2_open+0xf0/0x610
   __dev_open+0x104/0x224
   __dev_change_flags+0x1e4/0x274
   dev_change_flags+0x2c/0x7c
   ic_open_devs+0x124/0x2f8
   ip_auto_config+0x180/0x42c
   do_one_initcall+0x90/0x4dc
   do_basic_setup+0x10c/0x14c
   kernel_init_freeable+0x10c/0x13c
   kernel_init+0x2c/0x140
   ret_from_fork+0x10/0x20

Of course, we can shuffle the get/put_cpu() to only wrap the invocation
of ->aura_freeptr() as what commit 87b93b6 does. But there are only
two ->aura_freeptr() callbacks, otx2_aura_freeptr() and
cn10k_aura_freeptr(). There is no usage of perpcu variable in the
otx2_aura_freeptr() at all, so the get/put_cpu() seems redundant to it.
We can move the get/put_cpu() into the corresponding callback which
really has the percpu variable usage and avoid the sprinkling of
get/put_cpu() in several places.

Fixes: 4af1b64 ("octeontx2-pf: Fix lmtst ID used in aura free")
Signed-off-by: Kevin Hao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
xairy pushed a commit that referenced this pull request Jul 12, 2023
Thread #1:

[122554.641906][   T92]  f2fs_getxattr+0xd4/0x5fc
    -> waiting for f2fs_down_read(&F2FS_I(inode)->i_xattr_sem);

[122554.641927][   T92]  __f2fs_get_acl+0x50/0x284
[122554.641948][   T92]  f2fs_init_acl+0x84/0x54c
[122554.641969][   T92]  f2fs_init_inode_metadata+0x460/0x5f0
[122554.641990][   T92]  f2fs_add_inline_entry+0x11c/0x350
    -> Locked dir->inode_page by f2fs_get_node_page()

[122554.642009][   T92]  f2fs_do_add_link+0x100/0x1e4
[122554.642025][   T92]  f2fs_create+0xf4/0x22c
[122554.642047][   T92]  vfs_create+0x130/0x1f4

Thread #2:

[123996.386358][   T92]  __get_node_page+0x8c/0x504
    -> waiting for dir->inode_page lock

[123996.386383][   T92]  read_all_xattrs+0x11c/0x1f4
[123996.386405][   T92]  __f2fs_setxattr+0xcc/0x528
[123996.386424][   T92]  f2fs_setxattr+0x158/0x1f4
    -> f2fs_down_write(&F2FS_I(inode)->i_xattr_sem);

[123996.386443][   T92]  __f2fs_set_acl+0x328/0x430
[123996.386618][   T92]  f2fs_set_acl+0x38/0x50
[123996.386642][   T92]  posix_acl_chmod+0xc8/0x1c8
[123996.386669][   T92]  f2fs_setattr+0x5e0/0x6bc
[123996.386689][   T92]  notify_change+0x4d8/0x580
[123996.386717][   T92]  chmod_common+0xd8/0x184
[123996.386748][   T92]  do_fchmodat+0x60/0x124
[123996.386766][   T92]  __arm64_sys_fchmodat+0x28/0x3c

Bug: 280545073
Fixes: 27161f1 "f2fs: avoid race in between read xattr & write xattr"
Cc: <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
(cherry picked from commit 82d8a4f642421ece594542e1fabc689dcb094b1a)
Change-Id: Iec383216e1887e11c69374d28e4ecdedda133919
xairy pushed a commit that referenced this pull request Jun 27, 2024
As previously noted in commit 66e4f4a ("rtc: cmos: Use
spin_lock_irqsave() in cmos_interrupt()"):

<4>[  254.192378] WARNING: inconsistent lock state
<4>[  254.192384] 5.12.0-rc1-CI-CI_DRM_9834+ #1 Not tainted
<4>[  254.192396] --------------------------------
<4>[  254.192400] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
<4>[  254.192409] rtcwake/5309 [HC0[0]:SC0[0]:HE1:SE1] takes:
<4>[  254.192429] ffffffff8263c5f8 (rtc_lock){?...}-{2:2}, at: cmos_interrupt+0x18/0x100
<4>[  254.192481] {IN-HARDIRQ-W} state was registered at:
<4>[  254.192488]   lock_acquire+0xd1/0x3d0
<4>[  254.192504]   _raw_spin_lock+0x2a/0x40
<4>[  254.192519]   cmos_interrupt+0x18/0x100
<4>[  254.192536]   rtc_handler+0x1f/0xc0
<4>[  254.192553]   acpi_ev_fixed_event_detect+0x109/0x13c
<4>[  254.192574]   acpi_ev_sci_xrupt_handler+0xb/0x28
<4>[  254.192596]   acpi_irq+0x13/0x30
<4>[  254.192620]   __handle_irq_event_percpu+0x43/0x2c0
<4>[  254.192641]   handle_irq_event_percpu+0x2b/0x70
<4>[  254.192661]   handle_irq_event+0x2f/0x50
<4>[  254.192680]   handle_fasteoi_irq+0x9e/0x150
<4>[  254.192693]   __common_interrupt+0x76/0x140
<4>[  254.192715]   common_interrupt+0x96/0xc0
<4>[  254.192732]   asm_common_interrupt+0x1e/0x40
<4>[  254.192750]   _raw_spin_unlock_irqrestore+0x38/0x60
<4>[  254.192767]   resume_irqs+0xba/0xf0
<4>[  254.192786]   dpm_resume_noirq+0x245/0x3d0
<4>[  254.192811]   suspend_devices_and_enter+0x230/0xaa0
<4>[  254.192835]   pm_suspend.cold.8+0x301/0x34a
<4>[  254.192859]   state_store+0x7b/0xe0
<4>[  254.192879]   kernfs_fop_write_iter+0x11d/0x1c0
<4>[  254.192899]   new_sync_write+0x11d/0x1b0
<4>[  254.192916]   vfs_write+0x265/0x390
<4>[  254.192933]   ksys_write+0x5a/0xd0
<4>[  254.192949]   do_syscall_64+0x33/0x80
<4>[  254.192965]   entry_SYSCALL_64_after_hwframe+0x44/0xae
<4>[  254.192986] irq event stamp: 43775
<4>[  254.192994] hardirqs last  enabled at (43775): [<ffffffff81c00c42>] asm_sysvec_apic_timer_interrupt+0x12/0x20
<4>[  254.193023] hardirqs last disabled at (43774): [<ffffffff81aa691a>] sysvec_apic_timer_interrupt+0xa/0xb0
<4>[  254.193049] softirqs last  enabled at (42548): [<ffffffff81e00342>] __do_softirq+0x342/0x48e
<4>[  254.193074] softirqs last disabled at (42543): [<ffffffff810b45fd>] irq_exit_rcu+0xad/0xd0
<4>[  254.193101]
                  other info that might help us debug this:
<4>[  254.193107]  Possible unsafe locking scenario:

<4>[  254.193112]        CPU0
<4>[  254.193117]        ----
<4>[  254.193121]   lock(rtc_lock);
<4>[  254.193137]   <Interrupt>
<4>[  254.193142]     lock(rtc_lock);
<4>[  254.193156]
                   *** DEADLOCK ***

<4>[  254.193161] 6 locks held by rtcwake/5309:
<4>[  254.193174]  #0: ffff888104861430 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x5a/0xd0
<4>[  254.193232]  #1: ffff88810f823288 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xe7/0x1c0
<4>[  254.193282]  #2: ffff888100cef3c0 (kn->active#285
<7>[  254.192706] i915 0000:00:02.0: [drm:intel_modeset_setup_hw_state [i915]] [CRTC:51:pipe A] hw state readout: disabled
<4>[  254.193307] ){.+.+}-{0:0}, at: kernfs_fop_write_iter+0xf0/0x1c0
<4>[  254.193333]  #3: ffffffff82649fa8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend.cold.8+0xce/0x34a
<4>[  254.193387]  #4: ffffffff827a2108 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x47/0x70
<4>[  254.193433]  #5: ffff8881019ea178 (&dev->mutex){....}-{3:3}, at: device_resume+0x68/0x1e0
<4>[  254.193485]
                  stack backtrace:
<4>[  254.193492] CPU: 1 PID: 5309 Comm: rtcwake Not tainted 5.12.0-rc1-CI-CI_DRM_9834+ #1
<4>[  254.193514] Hardware name: Google Soraka/Soraka, BIOS MrChromebox-4.10 08/25/2019
<4>[  254.193524] Call Trace:
<4>[  254.193536]  dump_stack+0x7f/0xad
<4>[  254.193567]  mark_lock.part.47+0x8ca/0xce0
<4>[  254.193604]  __lock_acquire+0x39b/0x2590
<4>[  254.193626]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
<4>[  254.193660]  lock_acquire+0xd1/0x3d0
<4>[  254.193677]  ? cmos_interrupt+0x18/0x100
<4>[  254.193716]  _raw_spin_lock+0x2a/0x40
<4>[  254.193735]  ? cmos_interrupt+0x18/0x100
<4>[  254.193758]  cmos_interrupt+0x18/0x100
<4>[  254.193785]  cmos_resume+0x2ac/0x2d0
<4>[  254.193813]  ? acpi_pm_set_device_wakeup+0x1f/0x110
<4>[  254.193842]  ? pnp_bus_suspend+0x10/0x10
<4>[  254.193864]  pnp_bus_resume+0x5e/0x90
<4>[  254.193885]  dpm_run_callback+0x5f/0x240
<4>[  254.193914]  device_resume+0xb2/0x1e0
<4>[  254.193942]  ? pm_dev_err+0x25/0x25
<4>[  254.193974]  dpm_resume+0xea/0x3f0
<4>[  254.194005]  dpm_resume_end+0x8/0x10
<4>[  254.194030]  suspend_devices_and_enter+0x29b/0xaa0
<4>[  254.194066]  pm_suspend.cold.8+0x301/0x34a
<4>[  254.194094]  state_store+0x7b/0xe0
<4>[  254.194124]  kernfs_fop_write_iter+0x11d/0x1c0
<4>[  254.194151]  new_sync_write+0x11d/0x1b0
<4>[  254.194183]  vfs_write+0x265/0x390
<4>[  254.194207]  ksys_write+0x5a/0xd0
<4>[  254.194232]  do_syscall_64+0x33/0x80
<4>[  254.194251]  entry_SYSCALL_64_after_hwframe+0x44/0xae
<4>[  254.194274] RIP: 0033:0x7f07d79691e7
<4>[  254.194293] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
<4>[  254.194312] RSP: 002b:00007ffd9cc2c768 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
<4>[  254.194337] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f07d79691e7
<4>[  254.194352] RDX: 0000000000000004 RSI: 0000556ebfc63590 RDI: 000000000000000b
<4>[  254.194366] RBP: 0000556ebfc63590 R08: 0000000000000000 R09: 0000000000000004
<4>[  254.194379] R10: 0000556ebf0ec2a6 R11: 0000000000000246 R12: 0000000000000004

which breaks S3-resume on fi-kbl-soraka presumably as that's slow enough
to trigger the alarm during the suspend.

Fixes: 6950d04 ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
References: 66e4f4a ("rtc: cmos: Use spin_lock_irqsave() in cmos_interrupt()"):
Signed-off-by: Chris Wilson <[email protected]>
Cc: Xiaofei Tan <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Ville Syrjälä <[email protected]>
Reviewed-by: Ville Syrjälä <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
xairy pushed a commit that referenced this pull request Jun 27, 2024
btrfs_can_activate_zone() can be called with the device_list_mutex already
held, which will lead to a deadlock:

insert_dev_extents() // Takes device_list_mutex
`-> insert_dev_extent()
 `-> btrfs_insert_empty_item()
  `-> btrfs_insert_empty_items()
   `-> btrfs_search_slot()
    `-> btrfs_cow_block()
     `-> __btrfs_cow_block()
      `-> btrfs_alloc_tree_block()
       `-> btrfs_reserve_extent()
        `-> find_free_extent()
         `-> find_free_extent_update_loop()
          `-> can_allocate_chunk()
           `-> btrfs_can_activate_zone() // Takes device_list_mutex again

As we're only traversing the list for reads we can switch from the
device_list_mutex to an RCU traversal of the list.

  [15.166572] WARNING: possible recursive locking detected
  [15.167117] 5.17.0-rc6-dennis torvalds#79 Not tainted
  [15.167487] --------------------------------------------
  [15.167733] kworker/u8:3/146 is trying to acquire lock:
  [15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: find_free_extent+0x15a/0x14f0 [btrfs]
  [15.167733]
  [15.167733] but task is already holding lock:
  [15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs]
  [15.167733]
  [15.167733] other info that might help us debug this:
  [15.167733]  Possible unsafe locking scenario:
  [15.167733]
  [15.171834]        CPU0
  [15.171834]        ----
  [15.171834]   lock(&fs_devs->device_list_mutex);
  [15.171834]   lock(&fs_devs->device_list_mutex);
  [15.171834]
  [15.171834]  *** DEADLOCK ***
  [15.171834]
  [15.171834]  May be due to missing lock nesting notation
  [15.171834]
  [15.171834] 5 locks held by kworker/u8:3/146:
  [15.171834]  #0: ffff888100050938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0
  [15.171834]  #1: ffffc9000067be80 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0
  [15.176244]  #2: ffff88810521e620 (sb_internal){.+.+}-{0:0}, at: flush_space+0x335/0x600 [btrfs]
  [15.176244]  #3: ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs]
  [15.176244]  #4: ffff8881152e4b78 (btrfs-dev-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x130 [btrfs]
  [15.179641]
  [15.179641] stack backtrace:
  [15.179641] CPU: 1 PID: 146 Comm: kworker/u8:3 Not tainted 5.17.0-rc6-dennis torvalds#79
  [15.179641] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014
  [15.179641] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
  [15.179641] Call Trace:
  [15.179641]  <TASK>
  [15.179641]  dump_stack_lvl+0x45/0x59
  [15.179641]  __lock_acquire.cold+0x217/0x2b2
  [15.179641]  lock_acquire+0xbf/0x2b0
  [15.183838]  ? find_free_extent+0x15a/0x14f0 [btrfs]
  [15.183838]  __mutex_lock+0x8e/0x970
  [15.183838]  ? find_free_extent+0x15a/0x14f0 [btrfs]
  [15.183838]  ? find_free_extent+0x15a/0x14f0 [btrfs]
  [15.183838]  ? lock_is_held_type+0xd7/0x130
  [15.183838]  ? find_free_extent+0x15a/0x14f0 [btrfs]
  [15.183838]  find_free_extent+0x15a/0x14f0 [btrfs]
  [15.183838]  ? _raw_spin_unlock+0x24/0x40
  [15.183838]  ? btrfs_get_alloc_profile+0x106/0x230 [btrfs]
  [15.187601]  btrfs_reserve_extent+0x131/0x260 [btrfs]
  [15.187601]  btrfs_alloc_tree_block+0xb5/0x3b0 [btrfs]
  [15.187601]  __btrfs_cow_block+0x138/0x600 [btrfs]
  [15.187601]  btrfs_cow_block+0x10f/0x230 [btrfs]
  [15.187601]  btrfs_search_slot+0x55f/0xbc0 [btrfs]
  [15.187601]  ? lock_is_held_type+0xd7/0x130
  [15.187601]  btrfs_insert_empty_items+0x2d/0x60 [btrfs]
  [15.187601]  btrfs_create_pending_block_groups+0x2b3/0x560 [btrfs]
  [15.187601]  __btrfs_end_transaction+0x36/0x2a0 [btrfs]
  [15.192037]  flush_space+0x374/0x600 [btrfs]
  [15.192037]  ? find_held_lock+0x2b/0x80
  [15.192037]  ? btrfs_async_reclaim_data_space+0x49/0x180 [btrfs]
  [15.192037]  ? lock_release+0x131/0x2b0
  [15.192037]  btrfs_async_reclaim_data_space+0x70/0x180 [btrfs]
  [15.192037]  process_one_work+0x24c/0x5a0
  [15.192037]  worker_thread+0x4a/0x3d0

Fixes: a85f05e ("btrfs: zoned: avoid chunk allocation if active block group has enough space")
CC: [email protected] # 5.16+
Signed-off-by: Johannes Thumshirn <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
xairy pushed a commit that referenced this pull request Jun 27, 2024
Adjust helper function names and comments after mass rename of
struct netfs_read_*request to struct netfs_io_*request.

Changes
=======
ver #2)
 - Make the changes in the docs also.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
Link: https://lore.kernel.org/r/164622992433.3564931.6684311087845150271.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678196111.1200972.5001114956865989528.stgit@warthog.procyon.org.uk/ # v2
xairy pushed a commit that referenced this pull request Jun 27, 2024
Pass start and len to the rreq allocator. This should ensure that the
fields are set so that ->init_request() can use them.

Also add a parameter to indicates the origin of the request.  Ceph can use
this to tell whether to get caps.

Changes
=======
ver #3)
 - Change the author to me as Jeff feels that most of the patch is my
   changes now.

ver #2)
 - Show the request origin in the netfs_rreq tracepoint.

Signed-off-by: Jeff Layton <[email protected]>
Co-developed-by: David Howells <[email protected]>
Signed-off-by: David Howells <[email protected]>
cc: [email protected]
Link: https://lore.kernel.org/r/164622989020.3564931.17517006047854958747.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678208569.1200972.12153682697842916557.stgit@warthog.procyon.org.uk/ # v2
xairy pushed a commit that referenced this pull request Jun 27, 2024
Add a netfs_i_context struct that should be included in the network
filesystem's own inode struct wrapper, directly after the VFS's inode
struct, e.g.:

	struct my_inode {
		struct {
			struct inode		vfs_inode;
			struct netfs_i_context	netfs_ctx;
		};
	};

The netfs_i_context struct so far contains a single field for the network
filesystem to use - the cache cookie:

	struct netfs_i_context {
		...
		struct fscache_cookie	*cache;
	};

Three functions are provided to help with this:

 (1) void netfs_i_context_init(struct inode *inode,
			       const struct netfs_request_ops *ops);

     Initialise the netfs context and set the operations.

 (2) struct netfs_i_context *netfs_i_context(struct inode *inode);

     Find the netfs context from the VFS inode.

 (3) struct inode *netfs_inode(struct netfs_i_context *ctx);

     Find the VFS inode from the netfs context.

Changes
=======
ver #3)
 - Split out the bit to move ceph cap-getting on readahead into
   ceph_init_request()[1].

ver #2)
 - Adjust documentation to match.
 - Use "#if IS_ENABLED()" in netfs_i_cookie(), not "#ifdef".
 - Move the cap check from ceph_readahead() to ceph_init_request() to be
   called from netfslib.
 - Remove ceph_readahead() and use  netfs_readahead() directly instead.

Signed-off-by: David Howells <[email protected]>
cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]/ [1]
Link: https://lore.kernel.org/r/164622984545.3564931.15691742939278418580.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678213320.1200972.16807551936267647470.stgit@warthog.procyon.org.uk/ # v2
xairy pushed a commit that referenced this pull request Jun 27, 2024
Add a function to do the steps needed to begin a read request, allowing
this code to be removed from several other functions and consolidated.

Changes
=======
ver #2)
 - Move before the unstaticking patch so that some functions can be left
   static.
 - Set uninitialised return code in netfs_begin_read()[1][2].
 - Fixed a refleak caused by non-removal of a get from netfs_write_begin()
   when the request submission code got moved to netfs_begin_read().

Signed-off-by: David Howells <[email protected]>
cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]/ [1]
Link: https://lore.kernel.org/r/[email protected]/ [2]
Link: https://lore.kernel.org/r/164623004355.3564931.7275693529042495641.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678214287.1200972.16734134007649832160.stgit@warthog.procyon.org.uk/ # v2
xairy pushed a commit that referenced this pull request Jun 27, 2024
Rename netfs_rreq_unlock() to netfs_rreq_unlock_folios() to make it sound
less like it's dropping a lock on an netfs_io_request struct.

Remove the 'static' marker on netfs_rreq_unlock_folios() and declaring it
in internal.h preparatory to splitting the file.

Changes
=======
ver #2)
 - Slide this patch to after the one adding netfs_begin_read().
 - As a consequence, don't need to unstatic so many functions.

Signed-off-by: David Howells <[email protected]>
cc: [email protected]
Link: https://lore.kernel.org/r/164623002861.3564931.17340149482236413375.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678215208.1200972.9761906209395002182.stgit@warthog.procyon.org.uk/ # v2
xairy pushed a commit that referenced this pull request Jun 27, 2024
Rename the read_helper.c file to io.c before splitting out the buffered
read functions and some other bits.

Changes
=======
ver #2)
 - Rename read_helper.c before splitting.

Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/164678216109.1200972.16567696909952495832.stgit@warthog.procyon.org.uk/ # v2
xairy pushed a commit that referenced this pull request Jun 27, 2024
Split fs/netfs/read_helper.c into two pieces, one to deal with buffered
writes and one to deal with the I/O mechanism.

Changes
=======
ver #2)
 - Add kdoc reference to new file.

Signed-off-by: David Howells <[email protected]>
cc: [email protected]
Link: https://lore.kernel.org/r/164623005586.3564931.6149556072728481767.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678217075.1200972.5101072043126828757.stgit@warthog.procyon.org.uk/ # v2
xairy pushed a commit that referenced this pull request Jun 27, 2024
…k_under_node()

Patch series "drivers/base/memory: determine and store zone for single-zone memory blocks", v2.

I remember talking to Michal in the past about removing
test_pages_in_a_zone(), which we use for:
* verifying that a memory block we intend to offline is really only managed
  by a single zone. We don't support offlining of memory blocks that are
  managed by multiple zones (e.g., multiple nodes, DMA and DMA32)
* exposing that zone to user space via
  /sys/devices/system/memory/memory*/valid_zones

Now that I identified some more cases where test_pages_in_a_zone() might
go wrong, and we received an UBSAN report (see patch #3), let's get rid of
this PFN walker.

So instead of detecting the zone at runtime with test_pages_in_a_zone() by
scanning the memmap, let's determine and remember for each memory block if
it's managed by a single zone.  The stored zone can then be used for the
above two cases, avoiding a manual lookup using test_pages_in_a_zone().

This avoids eventually stumbling over uninitialized memmaps in corner
cases, especially when ZONE_DEVICE ranges partly fall into memory block
(that are responsible for managing System RAM).

Handling memory onlining is easy, because we online to exactly one zone.
Handling boot memory is more tricky, because we want to avoid scanning all
zones of all nodes to detect possible zones that overlap with the physical
memory region of interest.  Fortunately, we already have code that
determines the applicable nodes for a memory block, to create sysfs links
-- we'll hook into that.

Patch #1 is a simple cleanup I had laying around for a longer time.
Patch #2 contains the main logic to remove test_pages_in_a_zone() and
further details.

[1] https://lkml.kernel.org/r/[email protected]
[2] https://lkml.kernel.org/r/[email protected]

This patch (of 2):

Let's adjust the stale terminology, making it match
unregister_memory_block_under_nodes() and
do_register_memory_block_under_node().  We're dealing with memory block
devices, which span 1..X memory sections.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Oscar Salvador <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Rafael Parra <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
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