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[pull] master from torvalds:master #80

Merged
merged 69 commits into from
Jun 27, 2020
Merged

[pull] master from torvalds:master #80

merged 69 commits into from
Jun 27, 2020

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damien-lemoal and others added 30 commits June 17, 2020 12:13
Make sure that the local variable rzone in dmz_do_reclaim() is always
initialized before being used for printing debug messages.

Fixes: f97809a ("dm zoned: per-device reclaim")
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The unit of max_io_len is sector instead of byte (spotted through
code review), so fix it.

Fixes: 3b1a94c ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
…entry

When uncommitted entry has been discarded, correct wc->uncommitted_block
for getting the exact number.

Fixes: 48debaf ("dm: add writecache target")
Cc: stable@vger.kernel.org
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The array bio_in_progress is only used with ssd mode. So skip
writecache_wait_for_ios in writecache_discard when pmem mode.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct dm_target_deps {
      ...
        __u64 dev[0];   /* out */
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Solves this Sphinx warning:
	Documentation/admin-guide/device-mapper/dm-ebs.rst: WARNING: document isn't included in any toctree

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When dm zoned has multiple devices, metadata is on the cache device, not
in random zones of the zoned devices. Then the number of metadata zones
shall be checked with the number of cache zones, not random zones.

Fixes: 34f5aff ("dm zoned: separate random and cache zones")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Naohiro reported that issuing zone-append bios to a zoned block device
underneath a dm-linear device does not work as expected.

This because we forgot to reverse-map the sector the device wrote to the
original bio.

For zone-append bios, get the offset in the zone of the written sector
from the clone bio and add that to the original bio's sector position.

Fixes: 0512a75 ("block: Introduce REQ_OP_ZONE_APPEND")
Cc: stable@vger.kernel.org
Reported-by: Naohiro Aota <Naohiro.Aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit 2094045 ("dm zoned: prefer full zones for reclaim")
modified dmz_get_rnd_zone_for_reclaim() to add a search for the buffer
zone with the heaviest weight as an optimal candidate for reclaim. This
modification uses the zone pointer variabl "last" which is set only once
and never modified as zones are scanned, resulting in the search being
inefective. Furthermore, if the selected buffer zone at the end of the
search loop is active or already locked for reclaim,
dmz_get_rnd_zone_for_reclaim() returns NULL even if other random zones
with a lesser weight can be reclaimed.

To fix the search and to guarantee that reclaim can make forward
progress, fix dmz_get_rnd_zone_for_reclaim() loop to correctly find
the buffer zone with the heaviest weight using the variable maxw_z.
Also make sure to fallback to finding the first random zone that can
be reclaimed if this best candidate zone cannot be reclaimed.

While at it, also fix the device index check to consider only random
zones, ignoring cache zones belonging to the cache device if one is
used as that device does not have a reclaim process.

Fixes: 2094045 ("dm zoned: prefer full zones for reclaim")
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When dm zoned has multiple devices, random zones are never selected for
reclaim if all reserved sequential write zones are in use and no
sequential write required zones can be selected for reclaim. This can
lead to deadlocks as selecting a cache zone allows reclaiming a
sequential zone, ensuring forward progress.

Fix this by always defaulting to selecting a random zone when no
sequential write required zone can be selected.

[Damien: fix commit message]

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add cond_resched() to a loop that fills in the mapper memory area
because the loop can be executed many times.

Fixes: 48debaf ("dm: add writecache target")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Building the current 5.8 kernel for an e500 machine with
CONFIG_RANDOMIZE_BASE=y and CONFIG_BLOCK=n yields the following
failure:

  arch/powerpc/mm/nohash/kaslr_booke.c: In function 'kaslr_early_init':
  arch/powerpc/mm/nohash/kaslr_booke.c:387:2: error: implicit
  declaration of function 'flush_icache_range'; did you mean 'flush_tlb_range'?

Indeed, including asm/cacheflush.h into kaslr_booke.c fixes the build.

Fixes: 2b0e86c ("powerpc/fsl_booke/32: implement KASLR infrastructure")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Acked-by: Scott Wood <oss@buserror.net>
[mpe: Tweak change log to mention CONFIG_BLOCK=n]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200613162801.1946619-1-asolokha@kb.kras.ru
With CONFIG_DEBUG_VIRTUAL=y, __pa() checks for addr value and if it's
less than PAGE_OFFSET it leads to a BUG().

  #define __pa(x)
  ({
  	VIRTUAL_BUG_ON((unsigned long)(x) < PAGE_OFFSET);
  	(unsigned long)(x) & 0x0fffffffffffffffUL;
  })

  kernel BUG at arch/powerpc/kvm/book3s_64_mmu_radix.c:43!
  cpu 0x70: Vector: 700 (Program Check) at [c0000018a2187360]
      pc: c000000000161b30: __kvmhv_copy_tofrom_guest_radix+0x130/0x1f0
      lr: c000000000161d5c: kvmhv_copy_from_guest_radix+0x3c/0x80
  ...
  kvmhv_copy_from_guest_radix+0x3c/0x80
  kvmhv_load_from_eaddr+0x48/0xc0
  kvmppc_ld+0x98/0x1e0
  kvmppc_load_last_inst+0x50/0x90
  kvmppc_hv_emulate_mmio+0x288/0x2b0
  kvmppc_book3s_radix_page_fault+0xd8/0x2b0
  kvmppc_book3s_hv_page_fault+0x37c/0x1050
  kvmppc_vcpu_run_hv+0xbb8/0x1080
  kvmppc_vcpu_run+0x34/0x50
  kvm_arch_vcpu_ioctl_run+0x2fc/0x410
  kvm_vcpu_ioctl+0x2b4/0x8f0
  ksys_ioctl+0xf4/0x150
  sys_ioctl+0x28/0x80
  system_call_exception+0x104/0x1d0
  system_call_common+0xe8/0x214

kvmhv_copy_tofrom_guest_radix() uses a NULL value for to/from to
indicate direction of copy.

Avoid calling __pa() if the value is NULL to avoid the BUG().

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Massage change log a bit to mention CONFIG_DEBUG_VIRTUAL]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200611120159.680284-1-aneesh.kumar@linux.ibm.com
r_xprt->rx_ep is known to be good while the transport's send lock is
held.  Otherwise additional references on rx_ep must be held when it
is used outside of that lock's critical sections.

For now, bump the rx_ep reference count once whenever there is at
least one outstanding Receive WR. This avoids the memory bandwidth
overhead of taking and releasing the reference count for every
ib_post_recv() and Receive completion.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: Sometimes creating a fresh rpcrdma_ep can fail. That's why
xprt_rdma_connect() always checks if the r_xprt->rx_ep pointer is
valid before dereferencing it. Instead, xprt_rdma_connect() can
simply check rpcrdma_xprt_connect()'s return value.

Also, there's no need to set re_connect_status to zero just after
the rpcrdma_ep is created, since it is allocated with kzalloc.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Refactor: Pass struct rpcrdma_xprt instead of an IB layer object.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
1. Ensure that only rpcrdma_cm_event_handler() modifies
   ep->re_connect_status to avoid racy changes to that field.

2. Ensure that xprt_force_disconnect() is invoked only once as a
   transport is closed or destroyed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The RPC client currently doesn't handle ERR_CHUNK replies correctly.
rpcrdma_complete_rqst() incorrectly passes a negative number to
xprt_complete_rqst() as the number of bytes copied. Instead, set
task->tk_status to the error value, and return zero bytes copied.

In these cases, return -EIO rather than -EREMOTEIO. The RPC client's
finite state machine doesn't know what to do with -EREMOTEIO.

Additional clean ups:
- Don't double-count RDMA_ERROR replies
- Remove a stale comment

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@kernel.vger.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Commit 7e9f5e6 ("arm64: vdso: Add --eh-frame-hdr to ldflags") results
in a .eh_frame_hdr section for the vDSO, which in turn causes the libgcc
unwinder to unwind out of signal handlers using the .eh_frame information
populated by our .cfi directives. In conjunction with a4eb355
("arm64: vdso: Fix CFI directives in sigreturn trampoline"), this has
been shown to cause segmentation faults originating from within the
unwinder during thread cancellation:

 | Thread 14 "virtio-net-rx" received signal SIGSEGV, Segmentation fault.
 | 0x0000000000435e24 in uw_frame_state_for ()
 | (gdb) bt
 | #0  0x0000000000435e24 in uw_frame_state_for ()
 | #1  0x0000000000436e88 in _Unwind_ForcedUnwind_Phase2 ()
 | #2  0x00000000004374d8 in _Unwind_ForcedUnwind ()
 | #3  0x0000000000428400 in __pthread_unwind (buf=<optimized out>) at unwind.c:121
 | #4  0x0000000000429808 in __do_cancel () at ./pthreadP.h:304
 | #5  sigcancel_handler (sig=32, si=0xffff33c743f0, ctx=<optimized out>) at nptl-init.c:200
 | #6  sigcancel_handler (sig=<optimized out>, si=0xffff33c743f0, ctx=<optimized out>) at nptl-init.c:165
 | #7  <signal handler called>
 | #8  futex_wait_cancelable (private=0, expected=0, futex_word=0x3890b708) at ../sysdeps/unix/sysv/linux/futex-internal.h:88

After considerable bashing of heads, it appears that our CFI directives
for unwinding out of the sigreturn trampoline are only processed by libgcc
when both a .eh_frame_hdr section is present *and* the mysterious NOP is
covered by an entry in .eh_frame. With both of these now in place, it has
highlighted that our CFI directives are not comprehensive enough to
restore the stack pointer of the interrupted context. This results in libgcc
falling back to an arm64-specific unwinder after computing a bogus PC value
from the unwind tables. The unwinder promptly dereferences this bogus address
in an attempt to see if the pointed-to instruction sequence looks like
the sigreturn trampoline.

Restore the old unwind behaviour, which relied solely on heuristics in
the unwinder, by removing the .eh_frame_hdr section from the vDSO and
commenting out the insufficient CFI directives for now. Add comments to
explain the current, miserable state of affairs.

Cc: Tamas Zsoldos <tamas.zsoldos@arm.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Kiss <daniel.kiss@arm.com>
Acked-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reported-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
In preparation for removing the signal trampoline from the compat vDSO,
allow the sigpage and the compat vDSO to co-exist.

For the moment the vDSO signal trampoline will still be used when built.
Subsequent patches will move to the sigpage consistently.

Acked-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
The 32-bit sigreturn trampoline in the compat sigpage matches the binary
representation of the arch/arm/ sigpage exactly. This is important for
debuggers (e.g. GDB) and unwinders (e.g. libunwind) since they rely
on matching the instruction sequence in order to identify that they are
unwinding through a signal. The same cannot be said for the sigreturn
trampoline in the compat vDSO, which defeats the unwinder heuristics and
instead attempts to use unwind directives for the unwinding. This is in
contrast to arch/arm/, which never uses the vDSO for sigreturn.

Ensure compatibility with arch/arm/ and existing unwinders by always
using the sigpage for the sigreturn trampoline, regardless of the
presence of the compat vDSO.

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
The sigreturn code in the compat vDSO is unused. Remove it.

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Versions of binutils prior to 2.33.1 don't understand the ELF notes that
are added by modern compilers to indicate the PAC and BTI options used
to build the code. This causes them to emit large numbers of warnings in
the form:

aarch64-linux-gnu-nm: warning: .tmp_vmlinux.kallsyms2: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000

during the kernel build which is currently causing quite a bit of
disruption for automated build testing using clang.

In commit 15cd0e6 (arm64: Kconfig: ptrauth: Add binutils version
check to fix mismatch) we added a dependency on binutils to avoid this
issue when building with versions of GCC that emit the notes but did not
do so for clang as it was believed that the existing check for
.cfi_negate_ra_state was already requiring a new enough binutils. This
does not appear to be the case for some versions of binutils (eg, the
binutils in Debian 10) so instead refactor so we require a new enough
GNU binutils in all cases other than when we are using an old GCC
version that does not emit notes.

Other, more exotic, combinations of tools are possible such as using
clang, lld and gas together are possible and may have further problems
but rather than adding further version checks it looks like the most
robust thing will be to just test that we can build cleanly with the
configured tools but that will require more review and discussion so do
this for now to address the immediate problem disrupting build testing.

Reported-by: KernelCI <bot@kernelci.org>
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: ClangBuiltLinux#1054
Link: https://lore.kernel.org/r/20200619123550.48098-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
When the user consumes and generates sqe at a fast rate,
io_sqring_entries can always get sqe, and ret will not be equal to -EBUSY,
so that io_sq_thread will never call cond_resched or schedule, and then
we will get the following system error prompt:

rcu: INFO: rcu_sched self-detected stall on CPU
or
watchdog: BUG: soft lockup-CPU#23 stuck for 112s! [io_uring-sq:1863]

This patch checks whether need to call cond_resched() by checking
the need_resched() function every cycle.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 87676cf ("arm64: vdso: Disable dwarf unwinding through the
sigreturn trampoline") unconditionally passes the '--no-eh-frame-hdr'
option to the linker when building the native vDSO in an attempt to
prevent generation of the .eh_frame_hdr section, the presence of which
has been implicated in segfaults originating from the libgcc unwinder.

Unfortunately, not all versions of binutils support this option, which
has been shown to cause build failures in linux-next:

  |   CALL    scripts/atomic/check-atomics.sh
  |   CALL    scripts/checksyscalls.sh
  |   LD      arch/arm64/kernel/vdso/vdso.so.dbg
  | ld: unrecognized option '--no-eh-frame-hdr'
  | ld: use the --help option for usage information
  | arch/arm64/kernel/vdso/Makefile:64: recipe for target
  | 'arch/arm64/kernel/vdso/vdso.so.dbg' failed
  | make[1]: *** [arch/arm64/kernel/vdso/vdso.so.dbg] Error 1
  | arch/arm64/Makefile:175: recipe for target 'vdso_prepare' failed
  | make: *** [vdso_prepare] Error 2

Only link the vDSO with '--no-eh-frame-hdr' when the linker supports it.
If we end up with the section due to linker defaults, the absence of CFI
information in the sigreturn trampoline will prevent the unwinder from
breaking.

Link: https://lore.kernel.org/r/7a7e31a8-9a7b-2428-ad83-2264f20bdc2d@hisilicon.com
Fixes: 87676cf ("arm64: vdso: Disable dwarf unwinding through the sigreturn trampoline")
Reported-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
Don't use gcc plugins for building arch/arm64/kernel/vdso/vgettimeofday.c
to avoid unneeded instrumentation.

Signed-off-by: Alexander Popov <alex.popov@linux.com>
Link: https://lore.kernel.org/r/20200624123330.83226-4-alex.popov@linux.com
Signed-off-by: Will Deacon <will@kernel.org>
Some ftrace features are broken since commit 714a8d0 ("arm64: asm:
Override SYM_FUNC_START when building the kernel with BTI"). For example
the function_graph tracer:

$ echo function_graph > /sys/kernel/debug/tracing/current_tracer
[   36.107016] WARNING: CPU: 0 PID: 115 at kernel/trace/ftrace.c:2691 ftrace_modify_all_code+0xc8/0x14c

When ftrace_modify_graph_caller() attempts to write a branch at
ftrace_graph_call, it finds the "BTI J" instruction inserted by
SYM_INNER_LABEL() instead of a NOP, and aborts.

It turns out we don't currently need the BTI landing pads inserted by
SYM_INNER_LABEL:

* ftrace_call and ftrace_graph_call are only used for runtime patching
  of the active tracer. The patched code is not reached from a branch.
* install_el2_stub is reached from a CBZ instruction, which doesn't
  change PSTATE.BTYPE.
* __guest_exit is reached from B instructions in the hyp-entry vectors,
  which aren't subject to BTI checks either.

Remove the BTI annotation from SYM_INNER_LABEL.

Fixes: 714a8d0 ("arm64: asm: Override SYM_FUNC_START when building the kernel with BTI")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200624112253.1602786-1-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
QCOM KRYO{3,4}XX silver/LITTLE CPU cores are based on Cortex-A55
and are meltdown safe, hence add them to kpti_safe_list[].

Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Link: https://lore.kernel.org/r/20200624123406.3472-1-saiprakash.ranjan@codeaurora.org
Signed-off-by: Will Deacon <will@kernel.org>
The arm64 signal tests generate warnings during build since both they and
the toplevel lib.mk define a clean target:

Makefile:25: warning: overriding recipe for target 'clean'
../../lib.mk:126: warning: ignoring old recipe for target 'clean'

Since the inclusion of lib.mk is in the signal Makefile there is no
situation where this warning could be avoided so just remove the redundant
clean target.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200624104933.21125-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Release bip using kfree() in error path when that was allocated
by kmalloc().

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
VincentZWC and others added 18 commits June 25, 2020 15:15
Add extern declarations for vDSO time-related functions to notify the
compiler these functions will be used in somewhere to avoid
"no previous prototype" compile warning.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
For linux-5.8-rc1, enable ftrace of riscv will cause boot panic:

[    2.388980] Run /sbin/init as init process
[    2.529938] init[39]: unhandled signal 4 code 0x1 at 0x0000003ff449e000
[    2.531078] CPU: 0 PID: 39 Comm: init Not tainted 5.8.0-rc1-dirty #13
[    2.532719] epc: 0000003ff449e000 ra : 0000003ff449e954 sp : 0000003fffedb900
[    2.534005]  gp : 00000000000e8528 tp : 0000003ff449d800 t0 : 000000000000001e
[    2.534965]  t1 : 000000000000000a t2 : 0000003fffedb89e s0 : 0000003fffedb920
[    2.536279]  s1 : 0000003fffedb940 a0 : 0000003ff43d4b2c a1 : 0000000000000000
[    2.537334]  a2 : 0000000000000001 a3 : 0000000000000000 a4 : fffffffffbad8000
[    2.538466]  a5 : 0000003ff449e93a a6 : 0000000000000000 a7 : 0000000000000000
[    2.539511]  s2 : 0000000000000000 s3 : 0000003ff448412c s4 : 0000000000000010
[    2.541260]  s5 : 0000000000000016 s6 : 00000000000d0a30 s7 : 0000003fffedba70
[    2.542152]  s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000003fffedb960
[    2.543335]  s11: 0000000000000000 t3 : 0000000000000000 t4 : 0000003fffedb8a0
[    2.544471]  t5 : 0000000000000000 t6 : 0000000000000000
[    2.545730] status: 0000000000004020 badaddr: 00000000464c457f cause: 0000000000000002
[    2.549867] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
[    2.551267] CPU: 0 PID: 1 Comm: init Not tainted 5.8.0-rc1-dirty #13
[    2.552061] Call Trace:
[    2.552626] [<ffffffe00020374a>] walk_stackframe+0x0/0xc4
[    2.553486] [<ffffffe0002039f4>] show_stack+0x40/0x4c
[    2.553995] [<ffffffe00054a6ae>] dump_stack+0x7a/0x98
[    2.554615] [<ffffffe00020b9b8>] panic+0x114/0x2f4
[    2.555395] [<ffffffe00020ebd6>] do_exit+0x89c/0x8c2
[    2.555949] [<ffffffe00020f930>] do_group_exit+0x3a/0x90
[    2.556715] [<ffffffe000219e08>] get_signal+0xe2/0x6e6
[    2.557388] [<ffffffe000202d72>] do_notify_resume+0x6a/0x37a
[    2.558089] [<ffffffe000201c16>] ret_from_exception+0x0/0xc

"ra:0x3ff449e954" is the return address of "call _mcount" in the
prologue of __vdso_gettimeofday(). Without proper relocate, pc jmp
to 0x0000003ff449e000 (vdso map base) with a illegal instruction
trap.

The solution comes from arch/arm64/kernel/vdso/Makefile:

CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS)

 - CC_FLAGS_SCS is ShadowCallStack feature in Clang and only
   implemented for arm64, no use for riscv.

Fixes: ad5d112 ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Cc: stable@vger.kernel.org
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
We use OUTPUT directory as TMPOUT for checking no-pie option.

Since commit f2f02eb ("kbuild: improve cc-option to clean up all
temporary files") when building powerpc/ from selftests directory, the
OUTPUT directory points to powerpc/pmu/ebb/ and gets removed when
checking for -no-pie option in try-run routine, subsequently build
fails with the following:

  $ make -C powerpc
  ...
  TARGET=ebb; BUILD_TARGET=$OUTPUT/$TARGET; mkdir -p $BUILD_TARGET; make OUTPUT=$BUILD_TARGET -k -C $TARGET all
  make[2]: Entering directory '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb'
  make[2]: *** No rule to make target 'Makefile'.
  make[2]: Failed to remake makefile 'Makefile'.
  make[2]: *** No rule to make target 'ebb.c', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
  make[2]: *** No rule to make target 'ebb_handler.S', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
  make[2]: *** No rule to make target 'trace.c', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
  make[2]: *** No rule to make target 'busy_loop.S', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
  make[2]: Target 'all' not remade because of errors.

Fix this by adding a suffix to the OUTPUT directory so that the
failure is avoided.

Fixes: 9686813 ("selftests/powerpc: Fix try-run when source tree is not writable")
Signed-off-by: Harish <harish@linux.ibm.com>
[mpe: Mention that commit that triggered the breakage]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200625165721.264904-1-harish@linux.ibm.com
__rpc_depopulate(gssd_dentry) was lost on error path

cc: stable@vger.kernel.org
Fixes: commit 4b9a445 ("sunrpc: create a new dummy pipe for gssd to hold open")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The try_location function is called within a loop by nfs_follow_referral.
try_location calls nfs4_pathname_string to created the export_path.
nfs4_pathname_string allocates the memory. export_path is stored in the
nfs_fs_context/fs_context structure similarly as hostname and source.
But whereas the ctx hostname and source are freed before assignment,
export_path is not.  So if there are multiple loops, the new export_path
will overwrite the old without the old being freed.

So call kfree for export_path.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If the mirror count changes in the new layout we pick up inside
ff_layout_pg_init_write(), then we can end up adding the
request to the wrong mirror and corrupting the mirror->pg_list.

Fixes: d600ad1 ("NFS41: pop some layoutget errors to application")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Figuring out the root case for the REMOVE/CLOSE race and
suggesting the solution was done by Neil Brown.

Currently what happens is that direct IO calls hold a reference
on the open context which is decremented as an asynchronous task
in the nfs_direct_complete(). Before reference is decremented,
control is returned to the application which is free to close the
file. When close is being processed, it decrements its reference
on the open_context but since directIO still holds one, it doesn't
sent a close on the wire. It returns control to the application
which is free to do other operations. For instance, it can delete a
file. Direct IO is finally releasing its reference and triggering
an asynchronous close. Which races with the REMOVE. On the server,
REMOVE can be processed before the CLOSE, failing the REMOVE with
EACCES as the file is still opened.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Suggested-by: Neil Brown <neilb@suse.com>
CC: stable@vger.kernel.org
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
@Subbuf is an output parameter of xdr_buf_subsegment(). A survey of
call sites shows that @Subbuf is always uninitialized before
xdr_buf_segment() is invoked by callers.

There are some execution paths through xdr_buf_subsegment() that do
not set all of the fields in @Subbuf, leaving some pointer fields
containing garbage addresses. Subsequent processing of that buffer
then results in a page fault.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
In kgdb context, calling console handlers aren't safe due to locks used
in those handlers which could in turn lead to a deadlock. Although, using
oops_in_progress increases the chance to bypass locks in most console
handlers but it might not be sufficient enough in case a console uses
more locks (VT/TTY is good example).

Currently when a driver provides both polling I/O and a console then kdb
will output using the console. We can increase robustness by using the
currently active polling I/O driver (which should be lockless) instead
of the corresponding console. For several common cases (e.g. an
embedded system with a single serial port that is used both for console
output and debugger I/O) this will result in no console handler being
used.

In order to achieve this we need to reverse the order of preference to
use dbg_io_ops (uses polling I/O mode) over console APIs. So we just
store "struct console" that represents debugger I/O in dbg_io_ops and
while emitting kdb messages, skip console that matches dbg_io_ops
console in order to avoid duplicate messages. After this change,
"is_console" param becomes redundant and hence removed.

Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/1591264879-25920-5-git-send-email-sumit.garg@linaro.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
At times when I'm using kgdb I see a splat on my console about
suspicious RCU usage.  I managed to come up with a case that could
reproduce this that looked like this:

  WARNING: suspicious RCU usage
  5.7.0-rc4+ #609 Not tainted
  -----------------------------
  kernel/pid.c:395 find_task_by_pid_ns() needs rcu_read_lock() protection!

  other info that might help us debug this:

    rcu_scheduler_active = 2, debug_locks = 1
  3 locks held by swapper/0/1:
   #0: ffffff81b6b8e988 (&dev->mutex){....}-{3:3}, at: __device_attach+0x40/0x13c
   #1: ffffffd01109e9e8 (dbg_master_lock){....}-{2:2}, at: kgdb_cpu_enter+0x20c/0x7ac
   #2: ffffffd01109ea90 (dbg_slave_lock){....}-{2:2}, at: kgdb_cpu_enter+0x3ec/0x7ac

  stack backtrace:
  CPU: 7 PID: 1 Comm: swapper/0 Not tainted 5.7.0-rc4+ #609
  Hardware name: Google Cheza (rev3+) (DT)
  Call trace:
   dump_backtrace+0x0/0x1b8
   show_stack+0x1c/0x24
   dump_stack+0xd4/0x134
   lockdep_rcu_suspicious+0xf0/0x100
   find_task_by_pid_ns+0x5c/0x80
   getthread+0x8c/0xb0
   gdb_serial_stub+0x9d4/0xd04
   kgdb_cpu_enter+0x284/0x7ac
   kgdb_handle_exception+0x174/0x20c
   kgdb_brk_fn+0x24/0x30
   call_break_hook+0x6c/0x7c
   brk_handler+0x20/0x5c
   do_debug_exception+0x1c8/0x22c
   el1_sync_handler+0x3c/0xe4
   el1_sync+0x7c/0x100
   rpmh_rsc_probe+0x38/0x420
   platform_drv_probe+0x94/0xb4
   really_probe+0x134/0x300
   driver_probe_device+0x68/0x100
   __device_attach_driver+0x90/0xa8
   bus_for_each_drv+0x84/0xcc
   __device_attach+0xb4/0x13c
   device_initial_probe+0x18/0x20
   bus_probe_device+0x38/0x98
   device_add+0x38c/0x420

If I understand properly we should just be able to blanket kgdb under
one big RCU read lock and the problem should go away.  We'll add it to
the beast-of-a-function known as kgdb_cpu_enter().

With this I no longer get any splats and things seem to work fine.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200602154729.v2.1.I70e0d4fd46d5ed2aaf0c98a355e8e1b7a5bb7e4e@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
…git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "The big fix here is to our vDSO sigreturn trampoline as, after a
  painfully long stint of debugging, it turned out that fixing some of
  our CFI directives in the merge window lit up a bunch of logic in
  libgcc which has been shown to SEGV in some cases during asynchronous
  pthread cancellation.

  It looks like we can fix this by extending the directives to restore
  most of the interrupted register state from the sigcontext, but it's
  risky and hard to test so we opted to remove the CFI directives for
  now and rely on the unwinder fallback path like we used to.

   - Fix unwinding through vDSO sigreturn trampoline

   - Fix build warnings by raising minimum LD version for PAC

   - Whitelist some Kryo Cortex-A55 derivatives for Meltdown and SSB

   - Fix perf register PC reporting for compat tasks

   - Fix 'make clean' warning for arm64 signal selftests

   - Fix ftrace when BTI is compiled in

   - Avoid building the compat vDSO using GCC plugins"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Add KRYO{3,4}XX silver CPU cores to SSB safelist
  arm64: perf: Report the PC value in REGS_ABI_32 mode
  kselftest: arm64: Remove redundant clean target
  arm64: kpti: Add KRYO{3, 4}XX silver CPU cores to kpti safelist
  arm64: Don't insert a BTI instruction at inner labels
  arm64: vdso: Don't use gcc plugins for building vgettimeofday.c
  arm64: vdso: Only pass --no-eh-frame-hdr when linker supports it
  arm64: Depend on newer binutils when building PAC
  arm64: compat: Remove 32-bit sigreturn code from the vDSO
  arm64: compat: Always use sigpage for sigreturn trampoline
  arm64: compat: Allow 32-bit vdso and sigpage to co-exist
  arm64: vdso: Disable dwarf unwinding through the sigreturn trampoline
…inux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:
 "This contains a handful of fixes I'd like to target for rc3.

  Most of them fix issues with the conversion of our vDSO to C. There is
  also one fix to the SiFive PRCI driver that I picked up as it's
  causing boot issues on the hardware.

   - A fix to allow kernels with dynamic ftrace to use the vDSO.

   - Some build fixes for the C vDSO functions.

   - A fix to the PRCI driver's memory allocation, which was the cause
     of some boot panics with FREELIST_RANDOM"

* tag 'riscv-for-linus-5.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Fixup __vdso_gettimeofday broke dynamic ftrace
  riscv: Add extern declarations for vDSO time-related functions
  clk: sifive: allocate sufficient memory for struct __prci_data
  riscv: Add -fPIC option to CFLAGS_vgettimeofday.o
…l/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - A fix for a crash in nested KVM when CONFIG_DEBUG_VIRTUAL=y.

 - Two minor build fixes.

Thanks to: Aneesh Kumar K.V, Arseny Solokha, Harish.

* tag 'powerpc-5.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  selftests/powerpc: Fix build failure in ebb tests
  powerpc/kvm/book3s64: Fix kernel crash with nested kvm & DEBUG_VIRTUAL
  powerpc/fsl_booke/32: Fix build with CONFIG_RANDOMIZE_BASE
…/git/danielt/linux

Pull kgdb fixes from Daniel Thompson:
 "The main change here is a fix for a number of unsafe interactions
  between kdb and the console system. The fixes are specific to kdb
  (pure kgdb debugging does not use the console system at all). On
  systems with an NMI then kdb, if it is enabled, must get messages to
  the user despite potentially running from some "difficult" calling
  contexts. These fixes avoid using the console system where we have
  been provided an alternative (safer) way to interact with the user
  and, if using the console system in unavoidable, use oops_in_progress
  for deadlock avoidance. These fixes also ensure kdb honours the
  console enable flag.

  Also included is a fix that wraps kgdb trap handling in an RCU read
  lock to avoids triggering diagnostic warnings. This is a wide lock
  scope but this is OK because kgdb is a stop-the-world debugger. When
  we stop the world we put all the CPUs into holding pens and this
  inhibits RCU update anyway"

* tag 'kgdb-5.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
  kgdb: Avoid suspicious RCU usage warning
  kdb: Switch to use safer dbg_io_ops over console APIs
  kdb: Make kdb_printf() console handling more robust
  kdb: Check status of console prior to invoking handlers
  kdb: Re-factor kdb_printf() message write code
…rnel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Quite a few DM zoned target fixes and a Zone append fix in DM core.

   Considering the amount of dm-zoned changes that went in during the
   5.8 merge window these fixes are not that surprising.

 - A few DM writecache target fixes.

 - A fix to Documentation index to include DM ebs target docs.

 - Small cleanup to use struct_size() in DM core's retrieve_deps().

* tag 'for-5.8/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm writecache: add cond_resched to loop in persistent_memory_claim()
  dm zoned: Fix reclaim zone selection
  dm zoned: Fix random zone reclaim selection
  dm: update original bio sector on Zone Append
  dm zoned: Fix metadata zone size check
  docs: device-mapper: add dm-ebs.rst to an index file
  dm ioctl: use struct_size() helper in retrieve_deps()
  dm writecache: skip writecache_wait when using pmem mode
  dm writecache: correct uncommitted_block when discarding uncommitted entry
  dm zoned: assign max_io_len correctly
  dm zoned: fix uninitialized pointer dereference
Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph:
    - multipath deadlock fixes (Anton)
    - NUMA fixes (Max)
    - RDMA completion vector fix (Max)
    - IO deadlock fix (Sagi)
    - multipath reference fix (Sagi)
    - NS mutation fix (Sagi)

 - Use right allocator when freeing bip in error path (Chengguang)

* tag 'block-5.8-2020-06-26' of git://git.kernel.dk/linux-block:
  nvme-multipath: fix bogus request queue reference put
  nvme-multipath: fix deadlock due to head->lock
  nvme: don't protect ns mutation with ns->head->lock
  nvme-multipath: fix deadlock between ana_work and scan_work
  nvme: fix possible deadlock when I/O is blocked
  nvme-rdma: assign completion vector correctly
  nvme-loop: initialize tagset numa value to the value of the ctrl
  nvme-tcp: initialize tagset numa value to the value of the ctrl
  nvme-pci: initialize tagset numa value to the value of the ctrl
  nvme-pci: override the value of the controller's numa node
  nvme: set initial value for controller's numa node
  block: release bip in a right way in error path
Pull io_uring fixes from Jens Axboe:
 "Three small fixes:

   - Close a corner case for polled IO resubmission (Pavel)

   - Toss commands when exiting (Pavel)

   - Fix SQPOLL conditional reschedule on perpetually busy submit
     (Xuan)"

* tag 'io_uring-5.8-2020-06-26' of git://git.kernel.dk/linux-block:
  io_uring: fix current->mm NULL dereference on exit
  io_uring: fix hanging iopoll in case of -EAGAIN
  io_uring: fix io_sq_thread no schedule when busy
…nux-nfs

Pull NFS client bugfixes from Anna Schumaker:
 "Stable Fixes:
   - xprtrdma: Fix handling of RDMA_ERROR replies
   - sunrpc: Fix rollback in rpc_gssd_dummy_populate()
   - pNFS/flexfiles: Fix list corruption if the mirror count changes
   - NFSv4: Fix CLOSE not waiting for direct IO completion
   - SUNRPC: Properly set the @Subbuf parameter of xdr_buf_subsegment()

  Other Fixes:
   - xprtrdma: Fix a use-after-free with r_xprt->rx_ep
   - Fix other xprtrdma races during disconnect
   - NFS: Fix memory leak of export_path"

* tag 'nfs-for-5.8-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  SUNRPC: Properly set the @Subbuf parameter of xdr_buf_subsegment()
  NFSv4 fix CLOSE not waiting for direct IO compeletion
  pNFS/flexfiles: Fix list corruption if the mirror count changes
  nfs: Fix memory leak of export_path
  sunrpc: fixed rollback in rpc_gssd_dummy_populate()
  xprtrdma: Fix handling of RDMA_ERROR replies
  xprtrdma: Clean up disconnect
  xprtrdma: Clean up synopsis of rpcrdma_flush_disconnect()
  xprtrdma: Use re_connect_status safely in rpcrdma_xprt_connect()
  xprtrdma: Prevent dereferencing r_xprt->rx_ep after it is freed
@pull pull bot added the ⤵️ pull label Jun 27, 2020
@pull pull bot merged commit 4e99b32 into bergwolf:master Jun 27, 2020
pull bot pushed a commit that referenced this pull request Jul 11, 2020
syzkaller found its way into setsockopt with TCP_CONGESTION "cdg".
tcp_cdg_init() does a kcalloc to store the gradients. As sk_clone_lock
just copies all the memory, the allocated pointer will be copied as
well, if the app called setsockopt(..., TCP_CONGESTION) on the listener.
If now the socket will be destroyed before the congestion-control
has properly been initialized (through a call to tcp_init_transfer), we
will end up freeing memory that does not belong to that particular
socket, opening the door to a double-free:

[   11.413102] ==================================================================
[   11.414181] BUG: KASAN: double-free or invalid-free in tcp_cleanup_congestion_control+0x58/0xd0
[   11.415329]
[   11.415560] CPU: 3 PID: 4884 Comm: syz-executor.5 Not tainted 5.8.0-rc2 #80
[   11.416544] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[   11.418148] Call Trace:
[   11.418534]  <IRQ>
[   11.418834]  dump_stack+0x7d/0xb0
[   11.419297]  print_address_description.constprop.0+0x1a/0x210
[   11.422079]  kasan_report_invalid_free+0x51/0x80
[   11.423433]  __kasan_slab_free+0x15e/0x170
[   11.424761]  kfree+0x8c/0x230
[   11.425157]  tcp_cleanup_congestion_control+0x58/0xd0
[   11.425872]  tcp_v4_destroy_sock+0x57/0x5a0
[   11.426493]  inet_csk_destroy_sock+0x153/0x2c0
[   11.427093]  tcp_v4_syn_recv_sock+0xb29/0x1100
[   11.427731]  tcp_get_cookie_sock+0xc3/0x4a0
[   11.429457]  cookie_v4_check+0x13d0/0x2500
[   11.433189]  tcp_v4_do_rcv+0x60e/0x780
[   11.433727]  tcp_v4_rcv+0x2869/0x2e10
[   11.437143]  ip_protocol_deliver_rcu+0x23/0x190
[   11.437810]  ip_local_deliver+0x294/0x350
[   11.439566]  __netif_receive_skb_one_core+0x15d/0x1a0
[   11.441995]  process_backlog+0x1b1/0x6b0
[   11.443148]  net_rx_action+0x37e/0xc40
[   11.445361]  __do_softirq+0x18c/0x61a
[   11.445881]  asm_call_on_stack+0x12/0x20
[   11.446409]  </IRQ>
[   11.446716]  do_softirq_own_stack+0x34/0x40
[   11.447259]  do_softirq.part.0+0x26/0x30
[   11.447827]  __local_bh_enable_ip+0x46/0x50
[   11.448406]  ip_finish_output2+0x60f/0x1bc0
[   11.450109]  __ip_queue_xmit+0x71c/0x1b60
[   11.451861]  __tcp_transmit_skb+0x1727/0x3bb0
[   11.453789]  tcp_rcv_state_process+0x3070/0x4d3a
[   11.456810]  tcp_v4_do_rcv+0x2ad/0x780
[   11.457995]  __release_sock+0x14b/0x2c0
[   11.458529]  release_sock+0x4a/0x170
[   11.459005]  __inet_stream_connect+0x467/0xc80
[   11.461435]  inet_stream_connect+0x4e/0xa0
[   11.462043]  __sys_connect+0x204/0x270
[   11.465515]  __x64_sys_connect+0x6a/0xb0
[   11.466088]  do_syscall_64+0x3e/0x70
[   11.466617]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   11.467341] RIP: 0033:0x7f56046dc469
[   11.467844] Code: Bad RIP value.
[   11.468282] RSP: 002b:00007f5604dccdd8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
[   11.469326] RAX: ffffffffffffffda RBX: 000000000068bf00 RCX: 00007f56046dc469
[   11.470379] RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000004
[   11.471311] RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000
[   11.472286] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[   11.473341] R13: 000000000041427c R14: 00007f5604dcd5c0 R15: 0000000000000003
[   11.474321]
[   11.474527] Allocated by task 4884:
[   11.475031]  save_stack+0x1b/0x40
[   11.475548]  __kasan_kmalloc.constprop.0+0xc2/0xd0
[   11.476182]  tcp_cdg_init+0xf0/0x150
[   11.476744]  tcp_init_congestion_control+0x9b/0x3a0
[   11.477435]  tcp_set_congestion_control+0x270/0x32f
[   11.478088]  do_tcp_setsockopt.isra.0+0x521/0x1a00
[   11.478744]  __sys_setsockopt+0xff/0x1e0
[   11.479259]  __x64_sys_setsockopt+0xb5/0x150
[   11.479895]  do_syscall_64+0x3e/0x70
[   11.480395]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   11.481097]
[   11.481321] Freed by task 4872:
[   11.481783]  save_stack+0x1b/0x40
[   11.482230]  __kasan_slab_free+0x12c/0x170
[   11.482839]  kfree+0x8c/0x230
[   11.483240]  tcp_cleanup_congestion_control+0x58/0xd0
[   11.483948]  tcp_v4_destroy_sock+0x57/0x5a0
[   11.484502]  inet_csk_destroy_sock+0x153/0x2c0
[   11.485144]  tcp_close+0x932/0xfe0
[   11.485642]  inet_release+0xc1/0x1c0
[   11.486131]  __sock_release+0xc0/0x270
[   11.486697]  sock_close+0xc/0x10
[   11.487145]  __fput+0x277/0x780
[   11.487632]  task_work_run+0xeb/0x180
[   11.488118]  __prepare_exit_to_usermode+0x15a/0x160
[   11.488834]  do_syscall_64+0x4a/0x70
[   11.489326]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Wei Wang fixed a part of these CDG-malloc issues with commit c120144
("tcp: memset ca_priv data to 0 properly").

This patch here fixes the listener-scenario: We make sure that listeners
setting the congestion-control through setsockopt won't initialize it
(thus CDG never allocates on listeners). For those who use AF_UNSPEC to
reuse a socket, tcp_disconnect() is changed to cleanup afterwards.

(The issue can be reproduced at least down to v4.4.x.)

Cc: Wei Wang <weiwan@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Fixes: 2b0a8c9 ("tcp: add CDG congestion control")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
pull bot pushed a commit that referenced this pull request Nov 2, 2021
Now that the user space TLS register is assigned on every return to user
space, we can use it to keep the 'current' pointer while running in the
kernel. This removes the need to access it via thread_info, which is
located at the base of the stack, but will be moved out of there in a
subsequent patch.

Use the __builtin_thread_pointer() helper when available - this will
help GCC understand that reloading the value within the same function is
not necessary, even when using the per-task stack protector (which also
generates accesses via the TLS register). For example, the generated
code below loads TPIDRURO only once, and uses it to access both the
stack canary and the preempt_count fields.

<do_one_initcall>:
       e92d 41f0       stmdb   sp!, {r4, r5, r6, r7, r8, lr}
       ee1d 4f70       mrc     15, 0, r4, cr13, cr0, {3}
       4606            mov     r6, r0
       b094            sub     sp, #80 ; 0x50
       f8d4 34e8       ldr.w   r3, [r4, #1256] ; 0x4e8  <- stack canary
       9313            str     r3, [sp, #76]   ; 0x4c
       f8d4 8004       ldr.w   r8, [r4, #4]             <- preempt count

Co-developed-by: Keith Packard <keithpac@amazon.com>
Signed-off-by: Keith Packard <keithpac@amazon.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
pull bot pushed a commit that referenced this pull request May 24, 2022
If a compat process tries to execute an unknown system call above the
__ARM_NR_COMPAT_END number, the kernel sends a SIGILL signal to the
offending process. Information about the error is printed to dmesg in
compat_arm_syscall() -> arm64_notify_die() -> arm64_force_sig_fault() ->
arm64_show_signal().

arm64_show_signal() interprets a non-zero value for
current->thread.fault_code as an exception syndrome and displays the
message associated with the ESR_ELx.EC field (bits 31:26).
current->thread.fault_code is set in compat_arm_syscall() ->
arm64_notify_die() with the bad syscall number instead of a valid ESR_ELx
value. This means that the ESR_ELx.EC field has the value that the user set
for the syscall number and the kernel can end up printing bogus exception
messages*. For example, for the syscall number 0x68000000, which evaluates
to ESR_ELx.EC value of 0x1A (ESR_ELx_EC_FPAC) the kernel prints this error:

[   18.349161] syscall[300]: unhandled exception: ERET/ERETAA/ERETAB, ESR 0x68000000, Oops - bad compat syscall(2) in syscall[10000+50000]
[   18.350639] CPU: 2 PID: 300 Comm: syscall Not tainted 5.18.0-rc1 #79
[   18.351249] Hardware name: Pine64 RockPro64 v2.0 (DT)
[..]

which is misleading, as the bad compat syscall has nothing to do with
pointer authentication.

Stop arm64_show_signal() from printing exception syndrome information by
having compat_arm_syscall() set the ESR_ELx value to 0, as it has no
meaning for an invalid system call number. The example above now becomes:

[   19.935275] syscall[301]: unhandled exception: Oops - bad compat syscall(2) in syscall[10000+50000]
[   19.936124] CPU: 1 PID: 301 Comm: syscall Not tainted 5.18.0-rc1-00005-g7e08006d4102 #80
[   19.936894] Hardware name: Pine64 RockPro64 v2.0 (DT)
[..]

which although shows less information because the syscall number,
wrongfully advertised as the ESR value, is missing, it is better than
showing plainly wrong information. The syscall number can be easily
obtained with strace.

*A 32-bit value above or equal to 0x8000_0000 is interpreted as a negative
integer in compat_arm_syscal() and the condition scno < __ARM_NR_COMPAT_END
evaluates to true; the syscall will exit to userspace in this case with the
ENOSYS error code instead of arm64_notify_die() being called.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220425114444.368693-3-alexandru.elisei@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
pull bot pushed a commit that referenced this pull request May 30, 2022
This commit adds python script to parse CoreSight tracing event and
print out source line and disassembly, it generates readable program
execution flow for easier humans inspecting.

The script receives CoreSight tracing packet with below format:

                +------------+------------+------------+
  packet(n):    |    addr    |    ip      |    cpu     |
                +------------+------------+------------+
  packet(n+1):  |    addr    |    ip      |    cpu     |
                +------------+------------+------------+

packet::addr presents the start address of the coming branch sample, and
packet::ip is the last address of the branch smple.  Therefore, a code
section between branches starts from packet(n)::addr and it stops at
packet(n+1)::ip.  As results we combines the two continuous packets to
generate the address range for instructions:

  [ sample(n)::addr .. sample(n+1)::ip ]

The script supports both objdump or llvm-objdump for disassembly with
specifying option '-d'.  If doesn't specify option '-d', the script
simply outputs source lines and symbols.

Below shows usages with llvm-objdump or objdump to output disassembly.

  # perf script -s scripts/python/arm-cs-trace-disasm.py -- -d llvm-objdump-11 -k ./vmlinux
  ARM CoreSight Trace Data Assembler Dump
  	ffff800008eb3198 <etm4_enable_hw>:
  	ffff800008eb3310: c0 38 00 35  	cbnz	w0, 0xffff800008eb3a28 <etm4_enable_hw+0x890>
  	ffff800008eb3314: 9f 3f 03 d5  	dsb	sy
  	ffff800008eb3318: df 3f 03 d5  	isb
  	ffff800008eb331c: f5 5b 42 a9  	ldp	x21, x22, [sp, #32]
  	ffff800008eb3320: fb 73 45 a9  	ldp	x27, x28, [sp, #80]
  	ffff800008eb3324: e0 82 40 39  	ldrb	w0, [x23, #32]
  	ffff800008eb3328: 60 00 00 34  	cbz	w0, 0xffff800008eb3334 <etm4_enable_hw+0x19c>
  	ffff800008eb332c: e0 03 19 aa  	mov	x0, x25
  	ffff800008eb3330: 8c fe ff 97  	bl	0xffff800008eb2d60 <etm4_cs_lock.isra.0.part.0>
              main  6728/6728  [0004]         0.000000000  etm4_enable_hw+0x198                    [kernel.kallsyms]
  	ffff800008eb2d60 <etm4_cs_lock.isra.0.part.0>:
  	ffff800008eb2d60: 1f 20 03 d5  	nop
  	ffff800008eb2d64: 1f 20 03 d5  	nop
  	ffff800008eb2d68: 3f 23 03 d5  	hint	#25
  	ffff800008eb2d6c: 00 00 40 f9  	ldr	x0, [x0]
  	ffff800008eb2d70: 9f 3f 03 d5  	dsb	sy
  	ffff800008eb2d74: 00 c0 3e 91  	add	x0, x0, #4016
  	ffff800008eb2d78: 1f 00 00 b9  	str	wzr, [x0]
  	ffff800008eb2d7c: bf 23 03 d5  	hint	#29
  	ffff800008eb2d80: c0 03 5f d6  	ret
              main  6728/6728  [0004]         0.000000000  etm4_cs_lock.isra.0.part.0+0x20

  # perf script -s scripts/python/arm-cs-trace-disasm.py -- -d objdump -k ./vmlinux
  ARM CoreSight Trace Data Assembler Dump
  	ffff800008eb3310 <etm4_enable_hw+0x178>:
  	ffff800008eb3310:	350038c0 	cbnz	w0, ffff800008eb3a28 <etm4_enable_hw+0x890>
  	ffff800008eb3314:	d5033f9f 	dsb	sy
  	ffff800008eb3318:	d5033fdf 	isb
  	ffff800008eb331c:	a9425bf5 	ldp	x21, x22, [sp, #32]
  	ffff800008eb3320:	a94573fb 	ldp	x27, x28, [sp, #80]
  	ffff800008eb3324:	394082e0 	ldrb	w0, [x23, #32]
  	ffff800008eb3328:	34000060 	cbz	w0, ffff800008eb3334 <etm4_enable_hw+0x19c>
  	ffff800008eb332c:	aa1903e0 	mov	x0, x25
  	ffff800008eb3330:	97fffe8c 	bl	ffff800008eb2d60 <etm4_cs_lock.isra.0.part.0>
              main  6728/6728  [0004]         0.000000000  etm4_enable_hw+0x198                    [kernel.kallsyms]
  	ffff800008eb2d60 <etm4_cs_lock.isra.0.part.0>:
  	ffff800008eb2d60:	d503201f 	nop
  	ffff800008eb2d64:	d503201f 	nop
  	ffff800008eb2d68:	d503233f 	paciasp
  	ffff800008eb2d6c:	f9400000 	ldr	x0, [x0]
  	ffff800008eb2d70:	d5033f9f 	dsb	sy
  	ffff800008eb2d74:	913ec000 	add	x0, x0, #0xfb0
  	ffff800008eb2d78:	b900001f 	str	wzr, [x0]
  	ffff800008eb2d7c:	d50323bf 	autiasp
  	ffff800008eb2d80:	d65f03c0 	ret
              main  6728/6728  [0004]         0.000000000  etm4_cs_lock.isra.0.part.0+0x20

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Co-authored-by: Al Grant <al.grant@arm.com>
Co-authored-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Co-authored-by: Tor Jeremiassen <tor@ti.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Eelco Chaudron <echaudro@redhat.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Tanmay Jagdale <tanmay@marvell.com>
Cc: coresight@lists.linaro.org
Cc: zengshun . wu <zengshun.wu@outlook.com>
Link: https://lore.kernel.org/r/20220521130446.4163597-3-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
pull bot pushed a commit that referenced this pull request Feb 11, 2023
As interrupts are Level-triggered,unless and until we deassert the register
the interrupts are generated which causes spurious interrupts unhandled.

Now we deasserted the interrupt at top half which solved the below
"nobody cared" warning.

warning reported in dmesg:
	irq 80: nobody cared (try booting with the "irqpoll" option)
	CPU: 5 PID: 2735 Comm: irq/80-AudioDSP
		Not tainted 5.15.86-15817-g4c19f3e06d49 #1 1bd3fd932cf58caacc95b0504d6ea1e3eab22289
	Hardware name: Google Skyrim/Skyrim, BIOS Google_Skyrim.15303.0.0 01/03/2023
	Call Trace:
	<IRQ>
	dump_stack_lvl+0x69/0x97
	 __report_bad_irq+0x3a/0xae
	note_interrupt+0x1a9/0x1e3
	handle_irq_event_percpu+0x4b/0x6e
	handle_irq_event+0x36/0x5b
	handle_fasteoi_irq+0xae/0x171
	 __common_interrupt+0x48/0xc4
	</IRQ>

	handlers:
	acp_irq_handler [snd_sof_amd_acp] threaded [<000000007e089f34>] acp_irq_thread [snd_sof_amd_acp]
	Disabling IRQ #80

Signed-off-by: V sujith kumar Reddy <Vsujithkumar.Reddy@amd.com>
Link: https://lore.kernel.org/r/20230203123254.1898794-1-Vsujithkumar.Reddy@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>
pull bot pushed a commit that referenced this pull request Sep 3, 2023
In commit 0345691 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle") the
new function report_idle_softirq() was created by breaking code out of the
existing can_stop_idle_tick() for kernels v5.18 and newer.

In doing so, the code essentially went from a one conditional:

	if (a && b && c)
		warn();

to a three conditional:

	if (!a)
		return;
	if (!b)
		return;
	if (!c)
		return;
	warn();

But that conversion got the condition for the RT specific
local_bh_blocked() wrong. The original condition was:

   	!local_bh_blocked()

but the conversion failed to negate it so it ended up as:

        if (!local_bh_blocked())
		return false;

This issue lay dormant until another fixup for the same commit was added
in commit a7e282c ("tick/rcu: Fix bogus ratelimit condition").
This commit realized the ratelimit was essentially set to zero instead
of ten, and hence *no* softirq pending messages would ever be issued.

Once this commit was backported via linux-stable, both the v6.1 and v6.4
preempt-rt kernels started printing out 10 instances of this at boot:

  NOHZ tick-stop error: local softirq work is pending, handler #80!!!

Remove the negation and return when local_bh_blocked() evaluates to true to
bring the correct behaviour back.

Fixes: 0345691 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle")
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Reviewed-by: Wen Yang <wenyang.linux@foxmail.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230818200757.1808398-1-paul.gortmaker@windriver.com
pull bot pushed a commit that referenced this pull request Sep 9, 2023
With latest clang18, I hit test_progs failures for the following test:

  #13/2    bpf_cookie/multi_kprobe_link_api:FAIL
  #13/3    bpf_cookie/multi_kprobe_attach_api:FAIL
  #13      bpf_cookie:FAIL
  #75      fentry_fexit:FAIL
  #76/1    fentry_test/fentry:FAIL
  #76      fentry_test:FAIL
  #80/1    fexit_test/fexit:FAIL
  #80      fexit_test:FAIL
  #110/1   kprobe_multi_test/skel_api:FAIL
  #110/2   kprobe_multi_test/link_api_addrs:FAIL
  #110/3   kprobe_multi_test/link_api_syms:FAIL
  #110/4   kprobe_multi_test/attach_api_pattern:FAIL
  #110/5   kprobe_multi_test/attach_api_addrs:FAIL
  #110/6   kprobe_multi_test/attach_api_syms:FAIL
  #110     kprobe_multi_test:FAIL

For example, for #13/2, the error messages are:

  [...]
  kprobe_multi_test_run:FAIL:kprobe_test7_result unexpected kprobe_test7_result: actual 0 != expected 1
  [...]
  kprobe_multi_test_run:FAIL:kretprobe_test7_result unexpected kretprobe_test7_result: actual 0 != expected 1

clang17 does not have this issue.

Further investigation shows that kernel func bpf_fentry_test7(), used in
the above tests, is inlined by the compiler although it is marked as
noinline.

  int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
  {
        return (long)arg;
  }

It is known that for simple functions like the above (e.g. just returning
a constant or an input argument), the clang compiler may still do inlining
for a noinline function. Adding 'asm volatile ("")' in the beginning of the
bpf_fentry_test7() can prevent inlining.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20230826200843.2210074-1-yonghong.song@linux.dev
pull bot pushed a commit that referenced this pull request Nov 9, 2023
Right now it is possible to do a vfe_get() with the internal reference
count at 1. If vfe_check_clock_rates() returns non-zero then we will
leave the reference count as-is and

run:
- pm_runtime_put_sync()
- vfe->ops->pm_domain_off()

skip:
- camss_disable_clocks()

Subsequent vfe_put() calls will when the ref-count is non-zero
unconditionally run:

- pm_runtime_put_sync()
- vfe->ops->pm_domain_off()
- camss_disable_clocks()

vfe_get() should not attempt to roll-back on error when the ref-count is
non-zero as the upper layers will still do their own vfe_put() operations.

vfe_put() will drop the reference count and do the necessary power
domain release, the cleanup jumps in vfe_get() should only be run when
the ref-count is zero.

[   50.095796] CPU: 7 PID: 3075 Comm: cam Not tainted 6.3.2+ #80
[   50.095798] Hardware name: LENOVO 21BXCTO1WW/21BXCTO1WW, BIOS N3HET82W (1.54 ) 05/26/2023
[   50.095799] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   50.095802] pc : refcount_warn_saturate+0xf4/0x148
[   50.095804] lr : refcount_warn_saturate+0xf4/0x148
[   50.095805] sp : ffff80000c7cb8b0
[   50.095806] x29: ffff80000c7cb8b0 x28: ffff16ecc0e3fc10 x27: 0000000000000000
[   50.095810] x26: 0000000000000000 x25: 0000000000020802 x24: 0000000000000000
[   50.095813] x23: ffff16ecc7360640 x22: 00000000ffffffff x21: 0000000000000005
[   50.095815] x20: ffff16ed175f4400 x19: ffffb4d9852942a8 x18: ffffffffffffffff
[   50.095818] x17: ffffb4d9852d4a48 x16: ffffb4d983da5db8 x15: ffff80000c7cb320
[   50.095821] x14: 0000000000000001 x13: 2e656572662d7265 x12: 7466612d65737520
[   50.095823] x11: 00000000ffffefff x10: ffffb4d9850cebf0 x9 : ffffb4d9835cf954
[   50.095826] x8 : 0000000000017fe8 x7 : c0000000ffffefff x6 : 0000000000057fa8
[   50.095829] x5 : ffff16f813fe3d08 x4 : 0000000000000000 x3 : ffff621e8f4d2000
[   50.095832] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff16ed32119040
[   50.095835] Call trace:
[   50.095836]  refcount_warn_saturate+0xf4/0x148
[   50.095838]  device_link_put_kref+0x84/0xc8
[   50.095843]  device_link_del+0x38/0x58
[   50.095846]  vfe_pm_domain_off+0x3c/0x50 [qcom_camss]
[   50.095860]  vfe_put+0x114/0x140 [qcom_camss]
[   50.095869]  csid_set_power+0x2c8/0x408 [qcom_camss]
[   50.095878]  pipeline_pm_power_one+0x164/0x170 [videodev]
[   50.095896]  pipeline_pm_power+0xc4/0x110 [videodev]
[   50.095909]  v4l2_pipeline_pm_use+0x5c/0xa0 [videodev]
[   50.095923]  v4l2_pipeline_pm_get+0x1c/0x30 [videodev]
[   50.095937]  video_open+0x7c/0x100 [qcom_camss]
[   50.095945]  v4l2_open+0x84/0x130 [videodev]
[   50.095960]  chrdev_open+0xc8/0x250
[   50.095964]  do_dentry_open+0x1bc/0x498
[   50.095966]  vfs_open+0x34/0x40
[   50.095968]  path_openat+0xb44/0xf20
[   50.095971]  do_filp_open+0xa4/0x160
[   50.095974]  do_sys_openat2+0xc8/0x188
[   50.095975]  __arm64_sys_openat+0x6c/0xb8
[   50.095977]  invoke_syscall+0x50/0x128
[   50.095982]  el0_svc_common.constprop.0+0x4c/0x100
[   50.095985]  do_el0_svc+0x40/0xa8
[   50.095988]  el0_svc+0x2c/0x88
[   50.095991]  el0t_64_sync_handler+0xf4/0x120
[   50.095994]  el0t_64_sync+0x190/0x198
[   50.095996] ---[ end trace 0000000000000000 ]---

Fixes: 7790969 ("media: camss: vfe: Fix runtime PM imbalance on error")
Cc: stable@vger.kernel.org
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
pull bot pushed a commit that referenced this pull request Dec 1, 2023
When I perform the following test operations:
1.ip link add br0 type bridge
2.brctl addif br0 eth0
3.ip addr add 239.0.0.1/32 dev eth0
4.ip addr add 239.0.0.1/32 dev br0
5.ip addr add 224.0.0.1/32 dev br0
6.while ((1))
    do
        ifconfig br0 up
        ifconfig br0 down
    done
7.send IGMPv2 query packets to port eth0 continuously. For example,
./mausezahn ethX -c 0 "01 00 5e 00 00 01 00 72 19 88 aa 02 08 00 45 00 00
1c 00 01 00 00 01 02 0e 7f c0 a8 0a b7 e0 00 00 01 11 64 ee 9b 00 00 00 00"

The preceding tests may trigger the refcnt uaf issue of the mc list. The
stack is as follows:
	refcount_t: addition on 0; use-after-free.
	WARNING: CPU: 21 PID: 144 at lib/refcount.c:25 refcount_warn_saturate (lib/refcount.c:25)
	CPU: 21 PID: 144 Comm: ksoftirqd/21 Kdump: loaded Not tainted 6.7.0-rc1-next-20231117-dirty #80
	Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
	RIP: 0010:refcount_warn_saturate (lib/refcount.c:25)
	RSP: 0018:ffffb68f00657910 EFLAGS: 00010286
	RAX: 0000000000000000 RBX: ffff8a00c3bf96c0 RCX: ffff8a07b6160908
	RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff8a07b6160900
	RBP: ffff8a00cba36862 R08: 0000000000000000 R09: 00000000ffff7fff
	R10: ffffb68f006577c0 R11: ffffffffb0fdcdc8 R12: ffff8a00c3bf9680
	R13: ffff8a00c3bf96f0 R14: 0000000000000000 R15: ffff8a00d8766e00
	FS:  0000000000000000(0000) GS:ffff8a07b6140000(0000) knlGS:0000000000000000
	CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
	CR2: 000055f10b520b28 CR3: 000000039741a000 CR4: 00000000000006f0
	Call Trace:
	<TASK>
	igmp_heard_query (net/ipv4/igmp.c:1068)
	igmp_rcv (net/ipv4/igmp.c:1132)
	ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205)
	ip_local_deliver_finish (net/ipv4/ip_input.c:234)
	__netif_receive_skb_one_core (net/core/dev.c:5529)
	netif_receive_skb_internal (net/core/dev.c:5729)
	netif_receive_skb (net/core/dev.c:5788)
	br_handle_frame_finish (net/bridge/br_input.c:216)
	nf_hook_bridge_pre (net/bridge/br_input.c:294)
	__netif_receive_skb_core (net/core/dev.c:5423)
	__netif_receive_skb_list_core (net/core/dev.c:5606)
	__netif_receive_skb_list (net/core/dev.c:5674)
	netif_receive_skb_list_internal (net/core/dev.c:5764)
	napi_gro_receive (net/core/gro.c:609)
	e1000_clean_rx_irq (drivers/net/ethernet/intel/e1000/e1000_main.c:4467)
	e1000_clean (drivers/net/ethernet/intel/e1000/e1000_main.c:3805)
	__napi_poll (net/core/dev.c:6533)
	net_rx_action (net/core/dev.c:6735)
	__do_softirq (kernel/softirq.c:554)
	run_ksoftirqd (kernel/softirq.c:913)
	smpboot_thread_fn (kernel/smpboot.c:164)
	kthread (kernel/kthread.c:388)
	ret_from_fork (arch/x86/kernel/process.c:153)
	ret_from_fork_asm (arch/x86/entry/entry_64.S:250)
	</TASK>

The root causes are as follows:
Thread A					Thread B
...						netif_receive_skb
br_dev_stop					...
    br_multicast_leave_snoopers			...
        __ip_mc_dec_group			...
            __igmp_group_dropped		igmp_rcv
                igmp_stop_timer			    igmp_heard_query         //ref = 1
                ip_ma_put			        igmp_mod_timer
                    refcount_dec_and_test	            igmp_start_timer //ref = 0
			...                                     refcount_inc //ref increases from 0
When the device receives an IGMPv2 Query message, it starts the timer
immediately, regardless of whether the device is running. If the device is
down and has left the multicast group, it will cause the mc list refcount
uaf issue.

Fixes: 1da177e ("Linux-2.6.12-rc2")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
pull bot pushed a commit that referenced this pull request Sep 22, 2024
While the BPF scheduler is being unloaded, the following warning messages
trigger sometimes:

 NOHZ tick-stop error: local softirq work is pending, handler #80!!!

This is caused by the CPU entering idle while there are pending softirqs.
The main culprit is the bypassing state assertion not being synchronized
with rq operations. As the BPF scheduler cannot be trusted in the disable
path, the first step is entering the bypass mode where the BPF scheduler is
ignored and scheduling becomes global FIFO.

This is implemented by turning scx_ops_bypassing() true. However, the
transition isn't synchronized against anything and it's possible for enqueue
and dispatch paths to have different ideas on whether bypass mode is on.

Make each rq track its own bypass state with SCX_RQ_BYPASSING which is
modified while rq is locked.

This removes most of the NOHZ tick-stop messages but not completely. I
believe the stragglers are from the sched core bug where pick_task_scx() can
be called without preceding balance_scx(). Once that bug is fixed, we should
verify that all occurrences of this error message are gone too.

v2: scx_enabled() test moved inside the for_each_possible_cpu() loop so that
    the per-cpu states are always synchronized with the global state.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: David Vernet <void@manifault.com>
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