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Add support for f2fs and crc32 #6

Merged
merged 1 commit into from
Aug 7, 2018
Merged

Add support for f2fs and crc32 #6

merged 1 commit into from
Aug 7, 2018

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ShapeShifter499
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Add support for f2fs and it's dependency crc32 to rock64.

This patch may or may not need to be included as well due to this bug https://bugs.debian.org/819725 A official patch was added by Debian https://salsa.debian.org/kernel-team/linux/blob/master/debian/patches/bugfix/all/fs-add-module_softdep-declarations-for-hard-coded-cr.patch

Add support for f2fs and it's dependency crc32 to rock64.

This patch may or may not need to be included as well due to this bug https://bugs.debian.org/819725    A official patch was added by Debian https://salsa.debian.org/kernel-team/linux/blob/master/debian/patches/bugfix/all/fs-add-module_softdep-declarations-for-hard-coded-cr.patch
@ayufan ayufan merged commit ad33935 into ayufan-rock64:master Aug 7, 2018
ddimension pushed a commit to ddimension/linux-mainline-kernel that referenced this pull request Sep 13, 2018
commit a5ba1d9 upstream.

We have reports of the following crash:

    PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0"
    #0 [ffff88085c6db710] machine_kexec at ffffffff81046239
    ayufan-rock64#1 [ffff88085c6db760] crash_kexec at ffffffff810fc248
    ayufan-rock64#2 [ffff88085c6db830] oops_end at ffffffff81008ae7
    ayufan-rock64#3 [ffff88085c6db860] no_context at ffffffff81050b8f
    ayufan-rock64#4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75
    ayufan-rock64#5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83
    ayufan-rock64#6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e
    ayufan-rock64#7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c
    ayufan-rock64#8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122
    [exception RIP: uart_put_char+149]
    RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006
    RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081
    RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120
    RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320
    R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000
    R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
    ayufan-rock64#9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544
    ayufan-rock64#10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c
    ayufan-rock64#11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b
    ayufan-rock64#12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2
    ayufan-rock64#13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b
    ayufan-rock64#14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a
    ayufan-rock64#15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016
    ayufan-rock64#16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194
    ayufan-rock64#17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a
    ayufan-rock64#18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2
    ayufan-rock64#19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d
    ayufan-rock64#20 [ffff88085c6dbeb0] kthread at ffffffff81096384
    ayufan-rock64#21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f​

after slogging through some dissasembly:

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

for our build, this is crashing at:

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

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

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

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

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

Signed-off-by: Tycho Andersen <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ddimension pushed a commit to ddimension/linux-mainline-kernel that referenced this pull request Sep 13, 2018
commit 286e877 upstream.

Commit efda1b5 ("acpi, nfit, libnvdimm: fix / harden ars_status output length handling")
Introduced additional hardening for ambiguity in the ACPI spec for
ars_status output sizing. However, it had a couple of cases mixed up.
Where it should have been checking for (and returning) "out_field[1] -
4" it was using "out_field[1] - 8" and vice versa.

This caused a four byte discrepancy in the buffer size passed on to
the command handler, and in some cases, this caused memory corruption
like:

  ./daxdev-errors.sh: line 76: 24104 Aborted   (core dumped) ./daxdev-errors $busdev $region
  malloc(): memory corruption
  Program received signal SIGABRT, Aborted.
  [...]
  ayufan-rock64#5  0x00007ffff7865a2e in calloc () from /lib64/libc.so.6
  ayufan-rock64#6  0x00007ffff7bc2970 in ndctl_bus_cmd_new_ars_status (ars_cap=ars_cap@entry=0x6153b0) at ars.c:136
  ayufan-rock64#7  0x0000000000401644 in check_ars_status (check=0x7fffffffdeb0, bus=0x604c20) at daxdev-errors.c:144
  ayufan-rock64#8  test_daxdev_clear_error (region_name=<optimized out>, bus_name=<optimized out>)
      at daxdev-errors.c:332

Cc: <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Keith Busch <[email protected]>
Cc: Lukasz Dorau <[email protected]>
Cc: Dan Williams <[email protected]>
Fixes: efda1b5 ("acpi, nfit, libnvdimm: fix / harden ars_status output length handling")
Signed-off-by: Vishal Verma <[email protected]>
Reviewed-by: Keith Busch <[email protected]>
Signed-of-by: Dave Jiang <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ddimension pushed a commit to ddimension/linux-mainline-kernel that referenced this pull request Sep 28, 2018
[ Upstream commit 46b3722 ]

We occasionaly hit following assert failure in 'perf top', when processing the
/proc info in multiple threads.

  perf: ...include/linux/refcount.h:109: refcount_inc:
        Assertion `!(!refcount_inc_not_zero(r))' failed.

The gdb backtrace looks like this:

  [Switching to Thread 0x7ffff11ba700 (LWP 13749)]
  0x00007ffff50839fb in raise () from /lib64/libc.so.6
  (gdb)
  #0  0x00007ffff50839fb in raise () from /lib64/libc.so.6
  ayufan-rock64#1  0x00007ffff5085800 in abort () from /lib64/libc.so.6
  ayufan-rock64#2  0x00007ffff507c0da in __assert_fail_base () from /lib64/libc.so.6
  ayufan-rock64#3  0x00007ffff507c152 in __assert_fail () from /lib64/libc.so.6
  ayufan-rock64#4  0x0000000000535373 in refcount_inc (r=0x7fffdc009be0)
      at ...include/linux/refcount.h:109
  ayufan-rock64#5  0x00000000005354f1 in comm_str__get (cs=0x7fffdc009bc0)
      at util/comm.c:24
  ayufan-rock64#6  0x00000000005356bd in __comm_str__findnew (str=0x7fffd000b260 ":2",
      root=0xbed5c0 <comm_str_root>) at util/comm.c:72
  ayufan-rock64#7  0x000000000053579e in comm_str__findnew (str=0x7fffd000b260 ":2",
      root=0xbed5c0 <comm_str_root>) at util/comm.c:95
  ayufan-rock64#8  0x000000000053582e in comm__new (str=0x7fffd000b260 ":2",
      timestamp=0, exec=false) at util/comm.c:111
  ayufan-rock64#9  0x00000000005363bc in thread__new (pid=2, tid=2) at util/thread.c:57
  ayufan-rock64#10 0x0000000000523da0 in ____machine__findnew_thread (machine=0xbfde38,
      threads=0xbfdf28, pid=2, tid=2, create=true) at util/machine.c:457
  ayufan-rock64#11 0x0000000000523eb4 in __machine__findnew_thread (machine=0xbfde38,
  ...

The failing assertion is this one:

  REFCOUNT_WARN(!refcount_inc_not_zero(r), ...

The problem is that we keep global comm_str_root list, which
is accessed by multiple threads during the 'perf top' startup
and following 2 paths can race:

  thread 1:
    ...
    thread__new
      comm__new
        comm_str__findnew
          down_write(&comm_str_lock);
          __comm_str__findnew
            comm_str__get

  thread 2:
    ...
    comm__override or comm__free
      comm_str__put
        refcount_dec_and_test
          down_write(&comm_str_lock);
          rb_erase(&cs->rb_node, &comm_str_root);

Because thread 2 first decrements the refcnt and only after then it removes the
struct comm_str from the list, the thread 1 can find this object on the list
with refcnt equls to 0 and hit the assert.

This patch fixes the thread 1 __comm_str__findnew path, by ignoring objects
that already dropped the refcnt to 0. For the rest of the objects we take the
refcnt before comparing its name and release it afterwards with comm_str__put,
which can also release the object completely.

Signed-off-by: Jiri Olsa <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Lukasz Odzioba <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/20180720101740.GA27176@krava
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ayufan pushed a commit that referenced this pull request Oct 23, 2018
Fixes a crash when the report encounters an address that could not be
associated with an mmaped region:

  #0  0x00005555557bdc4a in callchain_srcline (ip=<error reading variable: Cannot access memory at address 0x38>, sym=0x0, map=0x0) at util/machine.c:2329
  #1  unwind_entry (entry=entry@entry=0x7fffffff9180, arg=arg@entry=0x7ffff5642498) at util/machine.c:2329
  #2  0x00005555558370af in entry (arg=0x7ffff5642498, cb=0x5555557bdb50 <unwind_entry>, thread=<optimized out>, ip=18446744073709551615) at util/unwind-libunwind-local.c:586
  #3  get_entries (ui=ui@entry=0x7fffffff9620, cb=0x5555557bdb50 <unwind_entry>, arg=0x7ffff5642498, max_stack=<optimized out>) at util/unwind-libunwind-local.c:703
  #4  0x0000555555837192 in _unwind__get_entries (cb=<optimized out>, arg=<optimized out>, thread=<optimized out>, data=<optimized out>, max_stack=<optimized out>) at util/unwind-libunwind-local.c:725
  #5  0x00005555557c310f in thread__resolve_callchain_unwind (max_stack=127, sample=0x7fffffff9830, evsel=0x555555c7b3b0, cursor=0x7ffff5642498, thread=0x555555c7f6f0) at util/machine.c:2351
  #6  thread__resolve_callchain (thread=0x555555c7f6f0, cursor=0x7ffff5642498, evsel=0x555555c7b3b0, sample=0x7fffffff9830, parent=0x7fffffff97b8, root_al=0x7fffffff9750, max_stack=127) at util/machine.c:2378
  #7  0x00005555557ba4ee in sample__resolve_callchain (sample=<optimized out>, cursor=<optimized out>, parent=parent@entry=0x7fffffff97b8, evsel=<optimized out>, al=al@entry=0x7fffffff9750,
      max_stack=<optimized out>) at util/callchain.c:1085

Signed-off-by: Milian Wolff <[email protected]>
Tested-by: Sandipan Das <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Namhyung Kim <[email protected]>
Fixes: 2a9d505 ("perf script: Show correct offsets for DWARF-based unwinding")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
ayufan pushed a commit that referenced this pull request Oct 23, 2018
This reverts commit d76c743.

While commit d76c743 ("serial: 8250_dw: Fix runtime PM handling")
fixes runtime PM handling when using kgdb, it introduces a traceback for
everyone else.

BUG: sleeping function called from invalid context at
	/mnt/host/source/src/third_party/kernel/next/drivers/base/power/runtime.c:1034
in_atomic(): 1, irqs_disabled(): 1, pid: 1, name: swapper/0
7 locks held by swapper/0/1:
 #0: 000000005ec5bc72 (&dev->mutex){....}, at: __driver_attach+0xb5/0x12b
 #1: 000000005d5fa9e5 (&dev->mutex){....}, at: __device_attach+0x3e/0x15b
 #2: 0000000047e93286 (serial_mutex){+.+.}, at: serial8250_register_8250_port+0x51/0x8bb
 #3: 000000003b328f07 (port_mutex){+.+.}, at: uart_add_one_port+0xab/0x8b0
 #4: 00000000fa313d4d (&port->mutex){+.+.}, at: uart_add_one_port+0xcc/0x8b0
 #5: 00000000090983ca (console_lock){+.+.}, at: vprintk_emit+0xdb/0x217
 #6: 00000000c743e583 (console_owner){-...}, at: console_unlock+0x211/0x60f
irq event stamp: 735222
__down_trylock_console_sem+0x4a/0x84
console_unlock+0x338/0x60f
__do_softirq+0x4a4/0x50d
irq_exit+0x64/0xe2
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc5 #6
Hardware name: Google Caroline/Caroline, BIOS Google_Caroline.7820.286.0 03/15/2017
Call Trace:
 dump_stack+0x7d/0xbd
 ___might_sleep+0x238/0x259
 __pm_runtime_resume+0x4e/0xa4
 ? serial8250_rpm_get+0x2e/0x44
 serial8250_console_write+0x44/0x301
 ? lock_acquire+0x1b8/0x1fa
 console_unlock+0x577/0x60f
 vprintk_emit+0x1f0/0x217
 printk+0x52/0x6e
 register_console+0x43b/0x524
 uart_add_one_port+0x672/0x8b0
 ? set_io_from_upio+0x150/0x162
 serial8250_register_8250_port+0x825/0x8bb
 dw8250_probe+0x80c/0x8b0
 ? dw8250_serial_inq+0x8e/0x8e
 ? dw8250_check_lcr+0x108/0x108
 ? dw8250_runtime_resume+0x5b/0x5b
 ? dw8250_serial_outq+0xa1/0xa1
 ? dw8250_remove+0x115/0x115
 platform_drv_probe+0x76/0xc5
 really_probe+0x1f1/0x3ee
 ? driver_allows_async_probing+0x5d/0x5d
 driver_probe_device+0xd6/0x112
 ? driver_allows_async_probing+0x5d/0x5d
 bus_for_each_drv+0xbe/0xe5
 __device_attach+0xdd/0x15b
 bus_probe_device+0x5a/0x10b
 device_add+0x501/0x894
 ? _raw_write_unlock+0x27/0x3a
 platform_device_add+0x224/0x2b7
 mfd_add_device+0x718/0x75b
 ? __kmalloc+0x144/0x16a
 ? mfd_add_devices+0x38/0xdb
 mfd_add_devices+0x9b/0xdb
 intel_lpss_probe+0x7d4/0x8ee
 intel_lpss_pci_probe+0xac/0xd4
 pci_device_probe+0x101/0x18e
...

Revert the offending patch until a more comprehensive solution
is available.

Cc: Tony Lindgren <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Phil Edworthy <[email protected]>
Fixes: d76c743 ("serial: 8250_dw: Fix runtime PM handling")
Signed-off-by: Guenter Roeck <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ayufan pushed a commit that referenced this pull request Oct 23, 2018
When the function name for an inline frame is invalid, we must not try
to demangle this symbol, otherwise we crash with:

  #0  0x0000555555895c01 in bfd_demangle ()
  #1  0x0000555555823262 in demangle_sym (dso=0x555555d92b90, elf_name=0x0, kmodule=0) at util/symbol-elf.c:215
  #2  dso__demangle_sym (dso=dso@entry=0x555555d92b90, kmodule=<optimized out>, kmodule@entry=0, elf_name=elf_name@entry=0x0) at util/symbol-elf.c:400
  #3  0x00005555557fef4b in new_inline_sym (funcname=0x0, base_sym=0x555555d92b90, dso=0x555555d92b90) at util/srcline.c:89
  #4  inline_list__append_dso_a2l (dso=dso@entry=0x555555c7bb00, node=node@entry=0x555555e31810, sym=sym@entry=0x555555d92b90) at util/srcline.c:264
  #5  0x00005555557ff27f in addr2line (dso_name=dso_name@entry=0x555555d92430 "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf", addr=addr@entry=2888, file=file@entry=0x0,
      line=line@entry=0x0, dso=dso@entry=0x555555c7bb00, unwind_inlines=unwind_inlines@entry=true, node=0x555555e31810, sym=0x555555d92b90) at util/srcline.c:313
  #6  0x00005555557ffe7c in addr2inlines (sym=0x555555d92b90, dso=0x555555c7bb00, addr=2888, dso_name=0x555555d92430 "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf")
      at util/srcline.c:358

So instead handle the case where we get invalid function names for
inlined frames and use a fallback '??' function name instead.

While this crash was originally reported by Hadrien for rust code, I can
now also reproduce it with trivial C++ code. Indeed, it seems like
libbfd fails to interpret the debug information for the inline frame
symbol name:

  $ addr2line -e /home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf -if b48
  main
  /usr/include/c++/8.2.1/complex:610
  ??
  /usr/include/c++/8.2.1/complex:618
  ??
  /usr/include/c++/8.2.1/complex:675
  ??
  /usr/include/c++/8.2.1/complex:685
  main
  /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39

I've reported this bug upstream and also attached a patch there which
should fix this issue:

https://sourceware.org/bugzilla/show_bug.cgi?id=23715

Reported-by: Hadrien Grasland <[email protected]>
Signed-off-by: Milian Wolff <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Fixes: a64489c ("perf report: Find the inline stack for a given address")
[ The above 'Fixes:' cset is where originally the problem was
  introduced, i.e.  using a2l->funcname without checking if it is NULL,
  but this current patch fixes the current codebase, i.e. multiple csets
  were applied after a64489c before the problem was reported by Hadrien ]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
ayufan pushed a commit that referenced this pull request Oct 23, 2018
Add support for f2fs and it's dependency crc32 to rock64.

This patch may or may not need to be included as well due to this bug https://bugs.debian.org/819725    A official patch was added by Debian https://salsa.debian.org/kernel-team/linux/blob/master/debian/patches/bugfix/all/fs-add-module_softdep-declarations-for-hard-coded-cr.patch
ayufan pushed a commit that referenced this pull request Dec 30, 2018
ibmvnic_reset can create and schedule a reset work item from
an IRQ context, so do not use a mutex, which can sleep. Convert
the reset work item mutex to a spin lock. Locking debugger generated
the trace output below.

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908
in_atomic(): 1, irqs_disabled(): 1, pid: 120, name: kworker/8:1
4 locks held by kworker/8:1/120:
 #0: 0000000017c05720 ((wq_completion)"events"){+.+.}, at: process_one_work+0x188/0x710
 #1: 00000000ace90706 ((linkwatch_work).work){+.+.}, at: process_one_work+0x188/0x710
 #2: 000000007632871f (rtnl_mutex){+.+.}, at: rtnl_lock+0x30/0x50
 #3: 00000000fc36813a (&(&crq->lock)->rlock){..-.}, at: ibmvnic_tasklet+0x88/0x2010 [ibmvnic]
irq event stamp: 26293
hardirqs last  enabled at (26292): [<c000000000122468>] tasklet_action_common.isra.12+0x78/0x1c0
hardirqs last disabled at (26293): [<c000000000befce8>] _raw_spin_lock_irqsave+0x48/0xf0
softirqs last  enabled at (26288): [<c000000000a8ac78>] dev_deactivate_queue.constprop.28+0xc8/0x160
softirqs last disabled at (26289): [<c0000000000306e0>] call_do_softirq+0x14/0x24
CPU: 8 PID: 120 Comm: kworker/8:1 Kdump: loaded Not tainted 4.20.0-rc6 #6
Workqueue: events linkwatch_event
Call Trace:
[c0000003fffa7a50] [c000000000bc83e4] dump_stack+0xe8/0x164 (unreliable)
[c0000003fffa7aa0] [c00000000015ba0c] ___might_sleep+0x2dc/0x320
[c0000003fffa7b20] [c000000000be960c] __mutex_lock+0x8c/0xb40
[c0000003fffa7c30] [d000000006202ac8] ibmvnic_reset+0x78/0x330 [ibmvnic]
[c0000003fffa7cc0] [d0000000062097f4] ibmvnic_tasklet+0x1054/0x2010 [ibmvnic]
[c0000003fffa7e00] [c0000000001224c8] tasklet_action_common.isra.12+0xd8/0x1c0
[c0000003fffa7e60] [c000000000bf1238] __do_softirq+0x1a8/0x64c
[c0000003fffa7f90] [c0000000000306e0] call_do_softirq+0x14/0x24
[c0000003f3f87980] [c00000000001ba50] do_softirq_own_stack+0x60/0xb0
[c0000003f3f879c0] [c0000000001218a8] do_softirq+0xa8/0x100
[c0000003f3f879f0] [c000000000121a74] __local_bh_enable_ip+0x174/0x180
[c0000003f3f87a60] [c000000000bf003c] _raw_spin_unlock_bh+0x5c/0x80
[c0000003f3f87a90] [c000000000a8ac78] dev_deactivate_queue.constprop.28+0xc8/0x160
[c0000003f3f87ad0] [c000000000a8c8b0] dev_deactivate_many+0xd0/0x520
[c0000003f3f87b70] [c000000000a8cd40] dev_deactivate+0x40/0x60
[c0000003f3f87ba0] [c000000000a5e0c4] linkwatch_do_dev+0x74/0xd0
[c0000003f3f87bd0] [c000000000a5e694] __linkwatch_run_queue+0x1a4/0x1f0
[c0000003f3f87c30] [c000000000a5e728] linkwatch_event+0x48/0x60
[c0000003f3f87c50] [c0000000001444e8] process_one_work+0x238/0x710
[c0000003f3f87d20] [c000000000144a48] worker_thread+0x88/0x4e0
[c0000003f3f87db0] [c00000000014e3a8] kthread+0x178/0x1c0
[c0000003f3f87e20] [c00000000000bfd0] ret_from_kernel_thread+0x5c/0x6c

Signed-off-by: Thomas Falcon <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
ayufan pushed a commit that referenced this pull request Dec 30, 2018
Commit 9b6f7e1 ("mm: rework memcg kernel stack accounting") will
result in fork failing if allocating a kernel stack for a task in
dup_task_struct exceeds the kernel memory allowance for that cgroup.

Unfortunately, it also results in a crash.

This is due to the code jumping to free_stack and calling
free_thread_stack when the memcg kernel stack charge fails, but without
tsk->stack pointing at the freshly allocated stack.

This in turn results in the vfree_atomic in free_thread_stack oopsing
with a backtrace like this:

#5 [ffffc900244efc88] die at ffffffff8101f0ab
 #6 [ffffc900244efcb8] do_general_protection at ffffffff8101cb86
 #7 [ffffc900244efce0] general_protection at ffffffff818ff082
    [exception RIP: llist_add_batch+7]
    RIP: ffffffff8150d487  RSP: ffffc900244efd98  RFLAGS: 00010282
    RAX: 0000000000000000  RBX: ffff88085ef55980  RCX: 0000000000000000
    RDX: ffff88085ef55980  RSI: 343834343531203a  RDI: 343834343531203a
    RBP: ffffc900244efd98   R8: 0000000000000001   R9: ffff8808578c3600
    R10: 0000000000000000  R11: 0000000000000001  R12: ffff88029f6c21c0
    R13: 0000000000000286  R14: ffff880147759b00  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #8 [ffffc900244efda0] vfree_atomic at ffffffff811df2c7
 #9 [ffffc900244efdb8] copy_process at ffffffff81086e37
#10 [ffffc900244efe98] _do_fork at ffffffff810884e0
#11 [ffffc900244eff10] sys_vfork at ffffffff810887ff
#12 [ffffc900244eff20] do_syscall_64 at ffffffff81002a43
    RIP: 000000000049b948  RSP: 00007ffcdb307830  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 0000000000896030  RCX: 000000000049b948
    RDX: 0000000000000000  RSI: 00007ffcdb307790  RDI: 00000000005d7421
    RBP: 000000000067370f   R8: 00007ffcdb3077b0   R9: 000000000001ed00
    R10: 0000000000000008  R11: 0000000000000246  R12: 0000000000000040
    R13: 000000000000000f  R14: 0000000000000000  R15: 000000000088d018
    ORIG_RAX: 000000000000003a  CS: 0033  SS: 002b

The simplest fix is to assign tsk->stack right where it is allocated.

Link: http://lkml.kernel.org/r/[email protected]
Fixes: 9b6f7e1 ("mm: rework memcg kernel stack accounting")
Signed-off-by: Rik van Riel <[email protected]>
Acked-by: Roman Gushchin <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
ayufan pushed a commit that referenced this pull request Dec 30, 2018
Add support for f2fs and it's dependency crc32 to rock64.

This patch may or may not need to be included as well due to this bug https://bugs.debian.org/819725    A official patch was added by Debian https://salsa.debian.org/kernel-team/linux/blob/master/debian/patches/bugfix/all/fs-add-module_softdep-declarations-for-hard-coded-cr.patch
ayufan pushed a commit that referenced this pull request Dec 30, 2018
Add support for f2fs and it's dependency crc32 to rock64.

This patch may or may not need to be included as well due to this bug https://bugs.debian.org/819725    A official patch was added by Debian https://salsa.debian.org/kernel-team/linux/blob/master/debian/patches/bugfix/all/fs-add-module_softdep-declarations-for-hard-coded-cr.patch
ayufan pushed a commit that referenced this pull request Dec 30, 2018
Add support for f2fs and it's dependency crc32 to rock64.

This patch may or may not need to be included as well due to this bug https://bugs.debian.org/819725    A official patch was added by Debian https://salsa.debian.org/kernel-team/linux/blob/master/debian/patches/bugfix/all/fs-add-module_softdep-declarations-for-hard-coded-cr.patch
nuumio pushed a commit to nuumio/rp64-linux-mainline-kernel that referenced this pull request Dec 31, 2018
Function graph tracing recurses into itself when stackleak is enabled,
causing the ftrace graph selftest to run for up to 90 seconds and
trigger the softlockup watchdog.

Breakpoint 2, ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:200
200             mcount_get_lr_addr        x0    //     pointer to function's saved lr
(gdb) bt
\#0  ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:200
\ayufan-rock64#1  0xffffff80081d5280 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:153
\ayufan-rock64#2  0xffffff8008555484 in stackleak_track_stack () at ../kernel/stackleak.c:106
\ayufan-rock64#3  0xffffff8008421ff8 in ftrace_ops_test (ops=0xffffff8009eaa840 <graph_ops>, ip=18446743524091297036, regs=<optimized out>) at ../kernel/trace/ftrace.c:1507
\ayufan-rock64#4  0xffffff8008428770 in __ftrace_ops_list_func (regs=<optimized out>, ignored=<optimized out>, parent_ip=<optimized out>, ip=<optimized out>) at ../kernel/trace/ftrace.c:6286
\ayufan-rock64#5  ftrace_ops_no_ops (ip=18446743524091297036, parent_ip=18446743524091242824) at ../kernel/trace/ftrace.c:6321
\ayufan-rock64#6  0xffffff80081d5280 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:153
\ayufan-rock64#7  0xffffff800832fd10 in irq_find_mapping (domain=0xffffffc03fc4bc80, hwirq=27) at ../kernel/irq/irqdomain.c:876
\ayufan-rock64#8  0xffffff800832294c in __handle_domain_irq (domain=0xffffffc03fc4bc80, hwirq=27, lookup=true, regs=0xffffff800814b840) at ../kernel/irq/irqdesc.c:650
\ayufan-rock64#9  0xffffff80081d52b4 in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:205

Rework so we mark stackleak_track_stack as notrace

Co-developed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Anders Roxell <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
nuumio pushed a commit to nuumio/rp64-linux-mainline-kernel that referenced this pull request Dec 31, 2018
The *_frag_reasm() functions are susceptible to miscalculating the byte
count of packet fragments in case the truesize of a head buffer changes.
The truesize member may be changed by the call to skb_unclone(), leaving
the fragment memory limit counter unbalanced even if all fragments are
processed. This miscalculation goes unnoticed as long as the network
namespace which holds the counter is not destroyed.

Should an attempt be made to destroy a network namespace that holds an
unbalanced fragment memory limit counter the cleanup of the namespace
never finishes. The thread handling the cleanup gets stuck in
inet_frags_exit_net() waiting for the percpu counter to reach zero. The
thread is usually in running state with a stacktrace similar to:

 PID: 1073   TASK: ffff880626711440  CPU: 1   COMMAND: "kworker/u48:4"
  ayufan-rock64#5 [ffff880621563d48] _raw_spin_lock at ffffffff815f5480
  ayufan-rock64#6 [ffff880621563d48] inet_evict_bucket at ffffffff8158020b
  ayufan-rock64#7 [ffff880621563d80] inet_frags_exit_net at ffffffff8158051c
  ayufan-rock64#8 [ffff880621563db0] ops_exit_list at ffffffff814f5856
  ayufan-rock64#9 [ffff880621563dd8] cleanup_net at ffffffff814f67c0
 ayufan-rock64#10 [ffff880621563e38] process_one_work at ffffffff81096f14

It is not possible to create new network namespaces, and processes
that call unshare() end up being stuck in uninterruptible sleep state
waiting to acquire the net_mutex.

The bug was observed in the IPv6 netfilter code by Per Sundstrom.
I thank him for his analysis of the problem. The parts of this patch
that apply to IPv4 and IPv6 fragment reassembly are preemptive measures.

Signed-off-by: Jiri Wiesner <[email protected]>
Reported-by: Per Sundstrom <[email protected]>
Acked-by: Peter Oskolkov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
ayufan pushed a commit that referenced this pull request Oct 2, 2019
Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

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

Signed-off-by: Mikulas Patocka <[email protected]>
Cc: [email protected]
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <[email protected]>
ayufan pushed a commit that referenced this pull request Apr 6, 2020
nuumio pushed a commit to nuumio/rp64-linux-mainline-kernel that referenced this pull request Jul 25, 2020
This BUG halt was reported a while back, but the patch somehow got
missed:

PID: 2879   TASK: c16adaa0  CPU: 1   COMMAND: "sctpn"
 #0 [f418dd28] crash_kexec at c04a7d8c
 ayufan-rock64#1 [f418dd7c] oops_end at c0863e02
 ayufan-rock64#2 [f418dd90] do_invalid_op at c040aaca
 ayufan-rock64#3 [f418de28] error_code (via invalid_op) at c08631a5
    EAX: f34baac0  EBX: 00000090  ECX: f418deb0  EDX: f5542950  EBP: 00000000
    DS:  007b      ESI: f34ba800  ES:  007b      EDI: f418dea0  GS:  00e0
    CS:  0060      EIP: c046fa5e  ERR: ffffffff  EFLAGS: 00010286
 ayufan-rock64#4 [f418de5c] add_timer at c046fa5e
 ayufan-rock64#5 [f418de68] sctp_do_sm at f8db8c77 [sctp]
 ayufan-rock64#6 [f418df30] sctp_primitive_SHUTDOWN at f8dcc1b5 [sctp]
 ayufan-rock64#7 [f418df48] inet_shutdown at c080baf9
 ayufan-rock64#8 [f418df5c] sys_shutdown at c079eedf
 ayufan-rock64#9 [f418df7] sys_socketcall at c079fe88
    EAX: ffffffda  EBX: 0000000d  ECX: bfceea90  EDX: 0937af98
    DS:  007b      ESI: 0000000c  ES:  007b      EDI: b7150ae4
    SS:  007b      ESP: bfceea7c  EBP: bfceeaa8  GS:  0033
    CS:  0073      EIP: b775c424  ERR: 00000066  EFLAGS: 00000282

It appears that the side effect that starts the shutdown timer was processed
multiple times, which can happen as multiple paths can trigger it.  This of
course leads to the BUG halt in add_timer getting called.

Fix seems pretty straightforward, just check before the timer is added if its
already been started.  If it has mod the timer instead to min(current
expiration, new expiration)

Its been tested but not confirmed to fix the problem, as the issue has only
occured in production environments where test kernels are enjoined from being
installed.  It appears to be a sane fix to me though.  Also, recentely,
Jere found a reproducer posted on list to confirm that this resolves the
issues

Signed-off-by: Neil Horman <[email protected]>
CC: Vlad Yasevich <[email protected]>
CC: "David S. Miller" <[email protected]>
CC: [email protected]
CC: [email protected]
CC: [email protected]
Acked-by: Marcelo Ricardo Leitner <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
drewlsvern pushed a commit to drewlsvern/linux-mainline-kernel that referenced this pull request Mar 9, 2022
Add support for f2fs and it's dependency crc32 to rock64.

This patch may or may not need to be included as well due to this bug https://bugs.debian.org/819725    A official patch was added by Debian https://salsa.debian.org/kernel-team/linux/blob/master/debian/patches/bugfix/all/fs-add-module_softdep-declarations-for-hard-coded-cr.patch
ayufan pushed a commit that referenced this pull request Dec 27, 2023
…f-times'

Eduard Zingerman says:

====================
verify callbacks as if they are called unknown number of times

This series updates verifier logic for callback functions handling.
Current master simulates callback body execution exactly once,
which leads to verifier not detecting unsafe programs like below:

    static int unsafe_on_zero_iter_cb(__u32 idx, struct num_context *ctx)
    {
        ctx->i = 0;
        return 0;
    }

    SEC("?raw_tp")
    int unsafe_on_zero_iter(void *unused)
    {
        struct num_context loop_ctx = { .i = 32 };
        __u8 choice_arr[2] = { 0, 1 };

        bpf_loop(100, unsafe_on_zero_iter_cb, &loop_ctx, 0);
        return choice_arr[loop_ctx.i];
    }

This was reported previously in [0].
The basic idea of the fix is to schedule callback entry state for
verification in env->head until some identical, previously visited
state in current DFS state traversal is found. Same logic as with open
coded iterators, and builds on top recent fixes [1] for those.

The series is structured as follows:
- patches #1,2,3 update strobemeta, xdp_synproxy selftests and
  bpf_loop_bench benchmark to allow convergence of the bpf_loop
  callback states;
- patches #4,5 just shuffle the code a bit;
- patch #6 is the main part of the series;
- patch #7 adds test cases for #6;
- patch #8 extend patch #6 with same speculative scalar widening
  logic, as used for open coded iterators;
- patch #9 adds test cases for #8;
- patch #10 extends patch #6 to track maximal number of callback
  executions specifically for bpf_loop();
- patch #11 adds test cases for #10.

Veristat results comparing this series to master+patches #1,2,3 using selftests
show the following difference:

File                       Program        States (A)  States (B)  States (DIFF)
-------------------------  -------------  ----------  ----------  -------------
bpf_loop_bench.bpf.o       benchmark               1           2  +1 (+100.00%)
pyperf600_bpf_loop.bpf.o   on_event              322         407  +85 (+26.40%)
strobemeta_bpf_loop.bpf.o  on_event              113         151  +38 (+33.63%)
xdp_synproxy_kern.bpf.o    syncookie_tc          341         291  -50 (-14.66%)
xdp_synproxy_kern.bpf.o    syncookie_xdp         344         301  -43 (-12.50%)

Veristat results comparing this series to master using Tetragon BPF
files [2] also show some differences.
States diff varies from +2% to +15% on 23 programs out of 186,
no new failures.

Changelog:
- V3 [5] -> V4, changes suggested by Andrii:
  - validate mark_chain_precision() result in patch #10;
  - renaming s/cumulative_callback_depth/callback_unroll_depth/.
- V2 [4] -> V3:
  - fixes in expected log messages for test cases:
    - callback_result_precise;
    - parent_callee_saved_reg_precise_with_callback;
    - parent_stack_slot_precise_with_callback;
  - renamings (suggested by Alexei):
    - s/callback_iter_depth/cumulative_callback_depth/
    - s/is_callback_iter_next/calls_callback/
    - s/mark_callback_iter_next/mark_calls_callback/
  - prepare_func_exit() updated to exit with -EFAULT when
    callee->in_callback_fn is true but calls_callback() is not true
    for callsite;
  - test case 'bpf_loop_iter_limit_nested' rewritten to use return
    value check instead of verifier log message checks
    (suggested by Alexei).
- V1 [3] -> V2, changes suggested by Andrii:
  - small changes for error handling code in __check_func_call();
  - callback body processing log is now matched in relevant
    verifier_subprog_precision.c tests;
  - R1 passed to bpf_loop() is now always marked as precise;
  - log level 2 message for bpf_loop() iteration termination instead of
    iteration depth messages;
  - __no_msg macro removed;
  - bpf_loop_iter_limit_nested updated to avoid using __no_msg;
  - commit message for patch #3 updated according to Alexei's request.

[0] https://lore.kernel.org/bpf/CA+vRuzPChFNXmouzGG+wsy=6eMcfr1mFG0F3g7rbg-sedGKW3w@mail.gmail.com/
[1] https://lore.kernel.org/bpf/[email protected]/
[2] [email protected]:cilium/tetragon.git
[3] https://lore.kernel.org/bpf/[email protected]/T/#t
[4] https://lore.kernel.org/bpf/[email protected]/T/#t
[5] https://lore.kernel.org/bpf/[email protected]/T/#t
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
ayufan pushed a commit that referenced this pull request Dec 27, 2023
When scanning namespaces, it is possible to get valid data from the first
call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second
call in nvme_update_ns_info_block().  In particular, if the NSID becomes
inactive between the two commands, a storage device may return a buffer
filled with zero as per 4.1.5.1.  In this case, we can get a kernel crash
due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will
be set to zero.

PID: 326      TASK: ffff95fec3cd8000  CPU: 29   COMMAND: "kworker/u98:10"
 #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7
 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa
 #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788
 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb
 #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce
 #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595
 #6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6
 #7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926
    [exception RIP: blk_stack_limits+434]
    RIP: ffffffff92191872  RSP: ffffad8f8702fc80  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff95efa0c91800  RCX: 0000000000000001
    RDX: 0000000000000000  RSI: 0000000000000001  RDI: 0000000000000001
    RBP: 00000000ffffffff   R8: ffff95fec7df35a8   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000001  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: ffff95fed33c09a8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core]
 #9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core]

This happened when the check for valid data was moved out of nvme_identify_ns()
into one of the callers.  Fix this by checking in both callers.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186
Fixes: 0dd6fff ("nvme: bring back auto-removal of deleted namespaces during sequential scan")
Cc: [email protected]
Signed-off-by: Ewan D. Milne <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
ayufan pushed a commit that referenced this pull request Dec 27, 2023
When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a
cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when
removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be
dereferenced as wrong struct in irdma_free_pending_cqp_request().

  PID: 3669   TASK: ffff88aef892c000  CPU: 28  COMMAND: "kworker/28:0"
   #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34
   #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2
   #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f
   #3 [fffffe0000549eb8] do_nmi at ffffffff81079582
   #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4
      [exception RIP: native_queued_spin_lock_slowpath+1291]
      RIP: ffffffff8127e72b  RSP: ffff88aa841ef778  RFLAGS: 00000046
      RAX: 0000000000000000  RBX: ffff88b01f849700  RCX: ffffffff8127e47e
      RDX: 0000000000000000  RSI: 0000000000000004  RDI: ffffffff83857ec0
      RBP: ffff88afe3e4efc8   R8: ffffed15fc7c9dfa   R9: ffffed15fc7c9dfa
      R10: 0000000000000001  R11: ffffed15fc7c9df9  R12: 0000000000740000
      R13: ffff88b01f849708  R14: 0000000000000003  R15: ffffed1603f092e1
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
  -- <NMI exception stack> --
   #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b
   #6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4
   #7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363
   #8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma]
   #9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma]
   #10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma]
   #11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma]
   #12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb
   #13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6
   #14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278
   #15 [ffff88aa841efb88] device_del at ffffffff82179d23
   #16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice]
   #17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice]
   #18 [ffff88aa841efde8] process_one_work at ffffffff811c589a
   #19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff
   #20 [ffff88aa841eff10] kthread at ffffffff811d87a0
   #21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f

Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions")
Link: https://lore.kernel.org/r/[email protected]
Suggested-by: "Ismail, Mustafa" <[email protected]>
Signed-off-by: Shifeng Li <[email protected]>
Reviewed-by: Shiraz Saleem <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
ayufan pushed a commit that referenced this pull request Dec 27, 2023
When working on LED support for r8169 I got the following lockdep
warning. Easiest way to prevent this scenario seems to be to take
the RTNL lock before the trigger_data lock in set_device_name().

======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc2-next-20231124+ #2 Not tainted
------------------------------------------------------
bash/383 is trying to acquire lock:
ffff888103aa1c68 (&trigger_data->lock){+.+.}-{3:3}, at: netdev_trig_notify+0xec/0x190 [ledtrig_netdev]

but task is already holding lock:
ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (rtnl_mutex){+.+.}-{3:3}:
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       rtnl_lock+0x12/0x20
       set_device_name+0xa9/0x120 [ledtrig_netdev]
       netdev_trig_activate+0x1a1/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

-> #0 (&trigger_data->lock){+.+.}-{3:3}:
       __lock_acquire+0x1459/0x25a0
       lock_acquire+0xc8/0x2d0
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
       call_netdevice_register_net_notifiers+0x5a/0x100
       register_netdevice_notifier+0x85/0x120
       netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(rtnl_mutex);
                               lock(&trigger_data->lock);
                               lock(rtnl_mutex);
  lock(&trigger_data->lock);

 *** DEADLOCK ***

8 locks held by bash/383:
 #0: ffff888103ff33f0 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x6c/0xf0
 #1: ffff888103aa1e88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x114/0x210
 #2: ffff8881036f1890 (kn->active#82){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x11d/0x210
 #3: ffff888108e2c358 (&led_cdev->led_access){+.+.}-{3:3}, at: led_trigger_write+0x30/0x140
 #4: ffffffff8cdd9e10 (triggers_list_lock){++++}-{3:3}, at: led_trigger_write+0x75/0x140
 #5: ffff888108e2c270 (&led_cdev->trigger_lock){++++}-{3:3}, at: led_trigger_write+0xe3/0x140
 #6: ffffffff8cdde3d0 (pernet_ops_rwsem){++++}-{3:3}, at: register_netdevice_notifier+0x1c/0x120
 #7: ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

stack backtrace:
CPU: 0 PID: 383 Comm: bash Not tainted 6.7.0-rc2-next-20231124+ #2
Hardware name: Default string Default string/Default string, BIOS ADLN.M6.SODIMM.ZB.CY.015 08/08/2023
Call Trace:
 <TASK>
 dump_stack_lvl+0x5c/0xd0
 dump_stack+0x10/0x20
 print_circular_bug+0x2dd/0x410
 check_noncircular+0x131/0x150
 __lock_acquire+0x1459/0x25a0
 lock_acquire+0xc8/0x2d0
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 __mutex_lock+0x9b/0xb50
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __this_cpu_preempt_check+0x13/0x20
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __cancel_work_timer+0x11c/0x1b0
 ? __mutex_lock+0x123/0xb50
 mutex_lock_nested+0x16/0x20
 ? mutex_lock_nested+0x16/0x20
 netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 call_netdevice_register_net_notifiers+0x5a/0x100
 register_netdevice_notifier+0x85/0x120
 netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
 led_trigger_set+0x172/0x2c0
 ? preempt_count_add+0x49/0xc0
 led_trigger_write+0xf1/0x140
 sysfs_kf_bin_write+0x5d/0x80
 kernfs_fop_write_iter+0x15d/0x210
 vfs_write+0x1f0/0x510
 ksys_write+0x6c/0xf0
 __x64_sys_write+0x14/0x20
 do_syscall_64+0x3f/0xf0
 entry_SYSCALL_64_after_hwframe+0x6c/0x74
RIP: 0033:0x7f269055d034
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d 35 c3 0d 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 48 89 54 24 18 48
RSP: 002b:00007ffddb7ef748 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007f269055d034
RDX: 0000000000000007 RSI: 000055bf5f4af3c0 RDI: 0000000000000001
RBP: 000055bf5f4af3c0 R08: 0000000000000073 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000007
R13: 00007f26906325c0 R14: 00007f269062ff20 R15: 0000000000000000
 </TASK>

Fixes: d5e0126 ("leds: trigger: netdev: add additional specific link speed mode")
Cc: [email protected]
Signed-off-by: Heiner Kallweit <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Acked-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
ayufan pushed a commit that referenced this pull request Dec 27, 2023
I conducted real-time testing and observed that
madvise_cold_or_pageout_pte_range() causes significant latency under
memory pressure, which can be effectively reduced by adding cond_resched()
within the loop.

I tested on the LicheePi 4A board using Cylictest for latency testing and
Ftrace for latency tracing.  The board uses TH1520 processor and has a
memory size of 8GB.  The kernel version is 6.5.0 with the PREEMPT_RT patch
applied.

The script I tested is as follows:

echo wakeup_rt > /sys/kernel/tracing/current_tracer
echo 1 > /sys/kernel/tracing/tracing_on
echo 0 > /sys/kernel/tracing/tracing_max_latency
stress-ng --vm 8 --vm-bytes 2G &
cyclictest --mlockall --smp --priority=99 --distance=0 --duration=30m
echo 0 > /sys/kernel/tracing/tracing_on
cat /sys/kernel/tracing/trace 

The tracing results before modification are as follows:

# tracer: wakeup_rt
#
# wakeup_rt latency trace v1.1.5 on 6.5.0-rt6-r1208-00003-g999d221864bf
# --------------------------------------------------------------------
# latency: 2552 us, #6/6, CPU#3 | (M:preempt_rt VP:0, KP:0, SP:0 HP:0 #P:4)
#    -----------------
#    | task: cyclictest-196 (uid:0 nice:0 policy:1 rt_prio:99)
#    -----------------
#
#                    _--------=> CPU#
#                   / _-------=> irqs-off/BH-disabled
#                  | / _------=> need-resched
#                  || / _-----=> need-resched-lazy
#                  ||| / _----=> hardirq/softirq
#                  |||| / _---=> preempt-depth
#                  ||||| / _--=> preempt-lazy-depth
#                  |||||| / _-=> migrate-disable
#                  ||||||| /     delay
#  cmd     pid     |||||||| time  |   caller
#     \   /        ||||||||  \    |    /
stress-n-206       3dn.h512    2us :      206:120:R   + [003]     196:  0:R cyclictest
stress-n-206       3dn.h512    7us : <stack trace>
 => __ftrace_trace_stack
 => __trace_stack
 => probe_wakeup
 => ttwu_do_activate
 => try_to_wake_up
 => wake_up_process
 => hrtimer_wakeup
 => __hrtimer_run_queues
 => hrtimer_interrupt
 => riscv_timer_interrupt
 => handle_percpu_devid_irq
 => generic_handle_domain_irq
 => riscv_intc_irq
 => handle_riscv_irq
 => do_irq
stress-n-206       3dn.h512    9us#: 0
stress-n-206       3d...3.. 2544us : __schedule
stress-n-206       3d...3.. 2545us :      206:120:R ==> [003]     196:  0:R cyclictest
stress-n-206       3d...3.. 2551us : <stack trace>
 => __ftrace_trace_stack
 => __trace_stack
 => probe_wakeup_sched_switch
 => __schedule
 => preempt_schedule
 => migrate_enable
 => rt_spin_unlock
 => madvise_cold_or_pageout_pte_range
 => walk_pgd_range
 => __walk_page_range
 => walk_page_range
 => madvise_pageout
 => madvise_vma_behavior
 => do_madvise
 => sys_madvise
 => do_trap_ecall_u
 => ret_from_exception

The tracing results after modification are as follows:

# tracer: wakeup_rt
#
# wakeup_rt latency trace v1.1.5 on 6.5.0-rt6-r1208-00004-gca3876fc69a6-dirty
# --------------------------------------------------------------------
# latency: 1689 us, #6/6, CPU#0 | (M:preempt_rt VP:0, KP:0, SP:0 HP:0 #P:4)
#    -----------------
#    | task: cyclictest-217 (uid:0 nice:0 policy:1 rt_prio:99)
#    -----------------
#
#                    _--------=> CPU#
#                   / _-------=> irqs-off/BH-disabled
#                  | / _------=> need-resched
#                  || / _-----=> need-resched-lazy
#                  ||| / _----=> hardirq/softirq
#                  |||| / _---=> preempt-depth
#                  ||||| / _--=> preempt-lazy-depth
#                  |||||| / _-=> migrate-disable
#                  ||||||| /     delay
#  cmd     pid     |||||||| time  |   caller
#     \   /        ||||||||  \    |    /
stress-n-232       0dn.h413    1us+:      232:120:R   + [000]     217:  0:R cyclictest
stress-n-232       0dn.h413   12us : <stack trace>
 => __ftrace_trace_stack
 => __trace_stack
 => probe_wakeup
 => ttwu_do_activate
 => try_to_wake_up
 => wake_up_process
 => hrtimer_wakeup
 => __hrtimer_run_queues
 => hrtimer_interrupt
 => riscv_timer_interrupt
 => handle_percpu_devid_irq
 => generic_handle_domain_irq
 => riscv_intc_irq
 => handle_riscv_irq
 => do_irq
stress-n-232       0dn.h413   19us#: 0
stress-n-232       0d...3.. 1671us : __schedule
stress-n-232       0d...3.. 1676us+:      232:120:R ==> [000]     217:  0:R cyclictest
stress-n-232       0d...3.. 1687us : <stack trace>
 => __ftrace_trace_stack
 => __trace_stack
 => probe_wakeup_sched_switch
 => __schedule
 => preempt_schedule
 => migrate_enable
 => free_unref_page_list
 => release_pages
 => free_pages_and_swap_cache
 => tlb_batch_pages_flush
 => tlb_flush_mmu
 => unmap_page_range
 => unmap_vmas
 => unmap_region
 => do_vmi_align_munmap.constprop.0
 => do_vmi_munmap
 => __vm_munmap
 => sys_munmap
 => do_trap_ecall_u
 => ret_from_exception

After the modification, the cause of maximum latency is no longer
madvise_cold_or_pageout_pte_range(), so this modification can reduce the
latency caused by madvise_cold_or_pageout_pte_range().


Currently the madvise_cold_or_pageout_pte_range() function exhibits
significant latency under memory pressure, which can be effectively
reduced by adding cond_resched() within the loop.

When the batch_count reaches SWAP_CLUSTER_MAX, we reschedule
the task to ensure fairness and avoid long lock holding times.

Link: https://lkml.kernel.org/r/85363861af65fac66c7a98c251906afc0d9c8098.1695291046.git.wangjiexun@tinylab.org
Signed-off-by: Jiexun Wang <[email protected]>
Cc: Zhangjin Wu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
ayufan pushed a commit that referenced this pull request Feb 6, 2024
…te_call_indirect

kprobe_emulate_call_indirect currently uses int3_emulate_call to emulate
indirect calls. However, int3_emulate_call always assumes the size of
the call to be 5 bytes when calculating the return address. This is
incorrect for register-based indirect calls in x86, which can be either
2 or 3 bytes depending on whether REX prefix is used. At kprobe runtime,
the incorrect return address causes control flow to land onto the wrong
place after return -- possibly not a valid instruction boundary. This
can lead to a panic like the following:

[    7.308204][    C1] BUG: unable to handle page fault for address: 000000000002b4d8
[    7.308883][    C1] #PF: supervisor read access in kernel mode
[    7.309168][    C1] #PF: error_code(0x0000) - not-present page
[    7.309461][    C1] PGD 0 P4D 0
[    7.309652][    C1] Oops: 0000 [#1] SMP
[    7.309929][    C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.7.0-rc5-trace-for-next #6
[    7.310397][    C1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-20220807_005459-localhost 04/01/2014
[    7.311068][    C1] RIP: 0010:__common_interrupt+0x52/0xc0
[    7.311349][    C1] Code: 01 00 4d 85 f6 74 39 49 81 fe 00 f0 ff ff 77 30 4c 89 f7 4d 8b 5e 68 41 ba 91 76 d8 42 45 03 53 fc 74 02 0f 0b cc ff d3 65 48 <8b> 05 30 c7 ff 7e 65 4c 89 3d 28 c7 ff 7e 5b 41 5c 41 5e 41 5f c3
[    7.312512][    C1] RSP: 0018:ffffc900000e0fd0 EFLAGS: 00010046
[    7.312899][    C1] RAX: 0000000000000001 RBX: 0000000000000023 RCX: 0000000000000001
[    7.313334][    C1] RDX: 00000000000003cd RSI: 0000000000000001 RDI: ffff888100d302a4
[    7.313702][    C1] RBP: 0000000000000001 R08: 0ef439818636191f R09: b1621ff338a3b482
[    7.314146][    C1] R10: ffffffff81e5127b R11: ffffffff81059810 R12: 0000000000000023
[    7.314509][    C1] R13: 0000000000000000 R14: ffff888100d30200 R15: 0000000000000000
[    7.314951][    C1] FS:  0000000000000000(0000) GS:ffff88813bc80000(0000) knlGS:0000000000000000
[    7.315396][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.315691][    C1] CR2: 000000000002b4d8 CR3: 0000000003028003 CR4: 0000000000370ef0
[    7.316153][    C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    7.316508][    C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    7.316948][    C1] Call Trace:
[    7.317123][    C1]  <IRQ>
[    7.317279][    C1]  ? __die_body+0x64/0xb0
[    7.317482][    C1]  ? page_fault_oops+0x248/0x370
[    7.317712][    C1]  ? __wake_up+0x96/0xb0
[    7.317964][    C1]  ? exc_page_fault+0x62/0x130
[    7.318211][    C1]  ? asm_exc_page_fault+0x22/0x30
[    7.318444][    C1]  ? __cfi_native_send_call_func_single_ipi+0x10/0x10
[    7.318860][    C1]  ? default_idle+0xb/0x10
[    7.319063][    C1]  ? __common_interrupt+0x52/0xc0
[    7.319330][    C1]  common_interrupt+0x78/0x90
[    7.319546][    C1]  </IRQ>
[    7.319679][    C1]  <TASK>
[    7.319854][    C1]  asm_common_interrupt+0x22/0x40
[    7.320082][    C1] RIP: 0010:default_idle+0xb/0x10
[    7.320309][    C1] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 66 90 0f 00 2d 09 b9 3b 00 fb f4 <fa> c3 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 e9
[    7.321449][    C1] RSP: 0018:ffffc9000009bee8 EFLAGS: 00000256
[    7.321808][    C1] RAX: ffff88813bca8b68 RBX: 0000000000000001 RCX: 000000000001ef0c
[    7.322227][    C1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000001ef0c
[    7.322656][    C1] RBP: ffffc9000009bef8 R08: 8000000000000000 R09: 00000000000008c2
[    7.323083][    C1] R10: 0000000000000000 R11: ffffffff81058e70 R12: 0000000000000000
[    7.323530][    C1] R13: ffff8881002b30c0 R14: 0000000000000000 R15: 0000000000000000
[    7.323948][    C1]  ? __cfi_lapic_next_deadline+0x10/0x10
[    7.324239][    C1]  default_idle_call+0x31/0x50
[    7.324464][    C1]  do_idle+0xd3/0x240
[    7.324690][    C1]  cpu_startup_entry+0x25/0x30
[    7.324983][    C1]  start_secondary+0xb4/0xc0
[    7.325217][    C1]  secondary_startup_64_no_verify+0x179/0x17b
[    7.325498][    C1]  </TASK>
[    7.325641][    C1] Modules linked in:
[    7.325906][    C1] CR2: 000000000002b4d8
[    7.326104][    C1] ---[ end trace 0000000000000000 ]---
[    7.326354][    C1] RIP: 0010:__common_interrupt+0x52/0xc0
[    7.326614][    C1] Code: 01 00 4d 85 f6 74 39 49 81 fe 00 f0 ff ff 77 30 4c 89 f7 4d 8b 5e 68 41 ba 91 76 d8 42 45 03 53 fc 74 02 0f 0b cc ff d3 65 48 <8b> 05 30 c7 ff 7e 65 4c 89 3d 28 c7 ff 7e 5b 41 5c 41 5e 41 5f c3
[    7.327570][    C1] RSP: 0018:ffffc900000e0fd0 EFLAGS: 00010046
[    7.327910][    C1] RAX: 0000000000000001 RBX: 0000000000000023 RCX: 0000000000000001
[    7.328273][    C1] RDX: 00000000000003cd RSI: 0000000000000001 RDI: ffff888100d302a4
[    7.328632][    C1] RBP: 0000000000000001 R08: 0ef439818636191f R09: b1621ff338a3b482
[    7.329223][    C1] R10: ffffffff81e5127b R11: ffffffff81059810 R12: 0000000000000023
[    7.329780][    C1] R13: 0000000000000000 R14: ffff888100d30200 R15: 0000000000000000
[    7.330193][    C1] FS:  0000000000000000(0000) GS:ffff88813bc80000(0000) knlGS:0000000000000000
[    7.330632][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.331050][    C1] CR2: 000000000002b4d8 CR3: 0000000003028003 CR4: 0000000000370ef0
[    7.331454][    C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    7.331854][    C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    7.332236][    C1] Kernel panic - not syncing: Fatal exception in interrupt
[    7.332730][    C1] Kernel Offset: disabled
[    7.333044][    C1] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

The relevant assembly code is (from objdump, faulting address
highlighted):

ffffffff8102ed9d:       41 ff d3                  call   *%r11
ffffffff8102eda0:       65 48 <8b> 05 30 c7 ff    mov    %gs:0x7effc730(%rip),%rax

The emulation incorrectly sets the return address to be ffffffff8102ed9d
+ 0x5 = ffffffff8102eda2, which is the 8b byte in the middle of the next
mov. This in turn causes incorrect subsequent instruction decoding and
eventually triggers the page fault above.

Instead of invoking int3_emulate_call, perform push and jmp emulation
directly in kprobe_emulate_call_indirect. At this point we can obtain
the instruction size from p->ainsn.size so that we can calculate the
correct return address.

Link: https://lore.kernel.org/all/[email protected]/

Fixes: 6256e66 ("x86/kprobes: Use int3 instead of debug trap for single-step")
Cc: [email protected]
Signed-off-by: Jinghao Jia <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
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2 participants