Originally, the kernel strictly checked the size of the optval in
getsockopt(TCP_ZEROCOPY_RECEIVE) to be equal to sizeof(struct
tcp_zerocopy_receive). With c8856c05, this was changed to allow
optvals of different sizes.

The bpf code in the sockopt_sk test was still performing the strict size
check. This fix adapts the kernel behavior from c8856c05 in the
selftest, i.e., just check if the required fields are there.

Fixes: 9cacf81f ("bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE")
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/6f569cca2e45473f9a724d54d03fdfb45f29e35f.1643129402.git.fmaurer@redhat.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Andrii Nakryiko says:

====================

Another batch of simple deprecations. One of the last few, hopefully, as we
are getting close to deprecating all the planned APIs/features. See
individual patches for details.

v1->v2:
  - rebased on latest bpf-next, fixed Closes: reference.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf_program__set_<type>() APIs are deprecated, use generic
bpf_program__set_type() APIs instead.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-8-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Use preferred setter and getter APIs instead of deprecated ones.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-7-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Switch to using preferred setters and getters instead of deprecated ones.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-6-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Use bpf_program__type() instead of discouraged bpf_program__get_type().
Also switch to bpf_map__set_max_entries() instead of bpf_map__resize().
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-5-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Not sure why these APIs were added in the first place instead of
a completely generic (and not requiring constantly adding new APIs with
each new BPF program type) bpf_program__type() and
bpf_program__set_type() APIs. But as it is right now, there are 13 such
specialized is_type/set_type APIs, while latest kernel is already at 30+
BPF program types.

Instead of completing the set of APIs and keep chasing kernel's
bpf_prog_type enum, deprecate existing subset and recommend generic
bpf_program__type() and bpf_program__set_type() APIs.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-4-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Deprecated bpf_map__resize() in favor of bpf_map__set_max_entries()
setter. In addition to having a surprising name (users often don't
realize that they need to use bpf_map__resize()), the name also implies
some magic way of resizing BPF map after it is created, which is clearly
not the case.

Another minor annoyance is that bpf_map__resize() disallows 0 value for
max_entries, which in some cases is totally acceptable (e.g., like for
BPF perf buf case to let libbpf auto-create one buffer per each
available CPU core).

  [0] Closes: https://github.com/libbpf/libbpf/issues/304Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-3-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Move a bunch of "getters" into libbpf_legacy.h to keep them there in
libbpf 1.0. See [0] for discussion of "Discouraged APIs". These getters
don't add any maintenance burden and are simple alias, but they are
inconsistent in naming. So keep them in libbpf_legacy.h instead of
libbpf.h to "hide" them in favor of preferred getters ([1]). Also add two
missing getters: bpf_program__type() and bpf_program__expected_attach_type().

  [0] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#handling-deprecation-of-apis-and-functionality
  [1] Closes: https://github.com/libbpf/libbpf/issues/307Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-2-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Kenta Tada says:

====================
Currently, rcx is read as the fourth parameter of syscall on x86_64.
But x86_64 Linux System Call convention uses r10 actually.
This commit adds the wrapper for users who want to access to
syscall params to analyze the user space.

Changelog:
----------
v1 -> v2:
- Rebase to current bpf-next
https://lore.kernel.org/bpf/20211222213924.1869758-1-andrii@kernel.org/

v2 -> v3:
- Modify the definition of SYSCALL macros for only targeted archs.
- Define __BPF_TARGET_MISSING variants for completeness.
- Remove CORE variants. These macros will not be used.
- Add a selftest.

v3 -> v4:
- Modify a selftest not to use serial tests.
- Modify a selftest to use ASSERT_EQ().
- Extract syscall wrapper for all the other tests.
- Add CORE variants.

v4 -> v5:
- Modify the CORE variant macro not to read memory directly.
- Remove the unnecessary comment.
- Add a selftest for the CORE variant.
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

Add a selftest to verify the behavior of PT_REGS_xxx
and the CORE variant.
Signed-off-by: Kenta Tada <Kenta.Tada@sony.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220124141622.4378-4-Kenta.Tada@sony.com

Currently, rcx is read as the fourth parameter of syscall on x86_64.
But x86_64 Linux System Call convention uses r10 actually.
This commit adds the wrapper for users who want to access to
syscall params to analyze the user space.
Signed-off-by: Kenta Tada <Kenta.Tada@sony.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220124141622.4378-3-Kenta.Tada@sony.com

Extract the helper to set up SYS_PREFIX for fentry and kprobe selftests
that use __x86_sys_* attach functions.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kenta Tada <Kenta.Tada@sony.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220124141622.4378-2-Kenta.Tada@sony.com

Mark bpf_object__open_xattr() as deprecated, use
bpf_object__open_file() instead.

  [0] Closes: https://github.com/libbpf/libbpf/issues/287Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220125010917.679975-1-christylee@fb.com

Christy Lee says:

====================

Deprecate bpf_object__open_buffer() API, replace all usage
with bpf_object__open_mem().

====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

bpf_object__open_buffer() API is deprecated, use the unified opts
bpf_object__open_mem() API in perf instead. This requires at least
libbpf 0.0.6.
Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220125005923.418339-3-christylee@fb.com

Deprecate bpf_object__open_buffer() API in favor of the unified
opts-based bpf_object__open_mem() API.
Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220125005923.418339-2-christylee@fb.com

Kenny Yu says:

====================

This patch series makes the following changes:
* Adds a new bpf helper `bpf_copy_from_user_task` to read user space
  memory from a different task.
* Adds the ability to create sleepable bpf iterator programs.

As an example of how this will be used, at Meta we are using bpf task
iterator programs and this new bpf helper to read C++ async stack traces of
a running process for debugging C++ binaries in production.

Changes since v6:
* Split first patch into two patches: first patch to add support
  for bpf iterators to use sleepable helpers, and the second to add
  the new bpf helper.
* Simplify implementation of `bpf_copy_from_user_task` based on feedback.
* Add to docs that the destination buffer will be zero-ed on error.

Changes since v5:
* Rename `bpf_access_process_vm` to `bpf_copy_from_user_task`.
* Change return value to be all-or-nothing. If we get a partial read,
  memset all bytes to 0 and return -EFAULT.
* Add to docs that the helper can only be used by sleepable BPF programs.
* Fix nits in selftests.

Changes since v4:
* Make `flags` into u64.
* Use `user_ptr` arg name to be consistent with `bpf_copy_from_user`.
* Add an extra check in selftests to verify access_process_vm calls
  succeeded.

Changes since v3:
* Check if `flags` is 0 and return -EINVAL if not.
* Rebase on latest bpf-next branch and fix merge conflicts.

Changes since v2:
* Reorder arguments in `bpf_access_process_vm` to match existing related
  bpf helpers (e.g. `bpf_probe_read_kernel`, `bpf_probe_read_user`,
  `bpf_copy_from_user`).
* `flags` argument is provided for future extensibility and is not
  currently used, and we always invoke `access_process_vm` with no flags.
* Merge bpf helper patch and `bpf_iter_run_prog` patch together for better
  bisectability in case of failures.
* Clean up formatting and comments in selftests.

Changes since v1:
* Fixed "Invalid wait context" issue in `bpf_iter_run_prog` by using
  `rcu_read_lock_trace()` for sleepable bpf iterator programs.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

This adds a test for bpf iterator programs to make use of sleepable
bpf helpers.
Signed-off-by: Kenny Yu <kennyyu@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124185403.468466-5-kennyyu@fb.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

This adds a new bpf section "iter.s" to allow bpf iterator programs to
be sleepable.
Signed-off-by: Kenny Yu <kennyyu@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124185403.468466-4-kennyyu@fb.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

This adds a helper for bpf programs to read the memory of other
tasks.

As an example use case at Meta, we are using a bpf task iterator program
and this new helper to print C++ async stack traces for all threads of
a given process.
Signed-off-by: Kenny Yu <kennyyu@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124185403.468466-3-kennyyu@fb.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

This patch allows bpf iterator programs to use sleepable helpers by
changing `bpf_iter_run_prog` to use the appropriate synchronization.
With sleepable bpf iterator programs, we can no longer use
`rcu_read_lock()` and must use `rcu_read_lock_trace()` instead
to protect the bpf program.
Signed-off-by: Kenny Yu <kennyyu@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124185403.468466-2-kennyyu@fb.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Daniel Borkmann says:

====================
pull-request: bpf-next 2022-01-24

We've added 80 non-merge commits during the last 14 day(s) which contain
a total of 128 files changed, 4990 insertions(+), 895 deletions(-).

The main changes are:

1) Add XDP multi-buffer support and implement it for the mvneta driver,
   from Lorenzo Bianconi, Eelco Chaudron and Toke Høiland-Jørgensen.

2) Add unstable conntrack lookup helpers for BPF by using the BPF kfunc
   infra, from Kumar Kartikeya Dwivedi.

3) Extend BPF cgroup programs to export custom ret value to userspace via
   two helpers bpf_get_retval() and bpf_set_retval(), from YiFei Zhu.

4) Add support for AF_UNIX iterator batching, from Kuniyuki Iwashima.

5) Complete missing UAPI BPF helper description and change bpf_doc.py script
   to enforce consistent & complete helper documentation, from Usama Arif.

6) Deprecate libbpf's legacy BPF map definitions and streamline XDP APIs to
   follow tc-based APIs, from Andrii Nakryiko.

7) Support BPF_PROG_QUERY for BPF programs attached to sockmap, from Di Zhu.

8) Deprecate libbpf's bpf_map__def() API and replace users with proper getters
   and setters, from Christy Lee.

9) Extend libbpf's btf__add_btf() with an additional hashmap for strings to
   reduce overhead, from Kui-Feng Lee.

10) Fix bpftool and libbpf error handling related to libbpf's hashmap__new()
    utility function, from Mauricio Vásquez.

11) Add support to BTF program names in bpftool's program dump, from Raman Shukhau.

12) Fix resolve_btfids build to pick up host flags, from Connor O'Brien.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (80 commits)
  selftests, bpf: Do not yet switch to new libbpf XDP APIs
  selftests, xsk: Fix rx_full stats test
  bpf: Fix flexible_array.cocci warnings
  xdp: disable XDP_REDIRECT for xdp frags
  bpf: selftests: add CPUMAP/DEVMAP selftests for xdp frags
  bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest
  net: xdp: introduce bpf_xdp_pointer utility routine
  bpf: generalise tail call map compatibility check
  libbpf: Add SEC name for xdp frags programs
  bpf: selftests: update xdp_adjust_tail selftest to include xdp frags
  bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature
  bpf: introduce frags support to bpf_prog_test_run_xdp()
  bpf: move user_size out of bpf_test_init
  bpf: add frags support to xdp copy helpers
  bpf: add frags support to the bpf_xdp_adjust_tail() API
  bpf: introduce bpf_xdp_get_buff_len helper
  net: mvneta: enable jumbo frames if the loaded XDP program support frags
  bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf program
  net: mvneta: add frags support to XDP_TX
  xdp: add frags support to xdp_return_{buff/frame}
  ...
====================

Link: https://lore.kernel.org/r/20220124221235.18993-1-daniel@iogearbox.netSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Revert commit 54435652 ("selftests/bpf: switch to new libbpf XDP APIs")
for now given this will heavily conflict with 4b27480d ("bpf/selftests:
convert xdp_link test to ASSERT_* macros") upon merge. Andrii agreed to redo
the conversion cleanly after trees merged.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>

Merge tag 'linux-can-fixes-for-5.17-20220124' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2022-01-24

The first patch updates the email address of Brian Silverman from his
former employer to his private address.

The next patch fixes DT bindings information for the tcan4x5x SPI CAN
driver.

The following patch targets the m_can driver and fixes the
introduction of FIFO bulk read support.

Another patch for the tcan4x5x driver, which fixes the max register
value for the regmap config.

The last patch for the flexcan driver marks the RX mailbox support for
the MCF5441X as support.

* tag 'linux-can-fixes-for-5.17-20220124' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
  can: flexcan: mark RX via mailboxes as supported on MCF5441X
  can: tcan4x5x: regmap: fix max register value
  can: m_can: m_can_fifo_{read,write}: don't read or write from/to FIFO if length is 0
  dt-bindings: can: tcan4x5x: fix mram-cfg RX FIFO config
  mailmap: update email address of Brian Silverman
====================

Link: https://lore.kernel.org/r/20220124175955.3464134-1-mkl@pengutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Most flexcan IP cores support 2 RX modes:
- FIFO
- mailbox

The flexcan IP core on the MCF5441X cannot receive CAN RTR messages
via mailboxes. However the mailbox mode is more performant. The commit

| 1c45f577 ("can: flexcan: add ethtool support to change rx-rtr setting during runtime")

added support to switch from FIFO to mailbox mode on these cores.

After testing the mailbox mode on the MCF5441X by Angelo Dureghello,
this patch marks it (without RTR capability) as supported. Further the
IP core overview table is updated, that RTR reception via mailboxes is
not supported.

Link: https://lore.kernel.org/all/20220121084425.3141218-1-mkl@pengutronix.deTested-by: Angelo Dureghello <angelo@kernel-space.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The MRAM of the tcan4x5x has a size of 2K and starts at 0x8000. There
are no further registers in the tcan4x5x making 0x87fc the biggest
addressable register.

This patch fixes the max register value of the regmap config from
0x8ffc to 0x87fc.

Fixes: 6e1caaf8 ("can: tcan4x5x: fix max register value")
Link: https://lore.kernel.org/all/20220119064011.2943292-1-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

In order to optimize FIFO access, especially on m_can cores attached
to slow busses like SPI, in patch

| e3938177 ("can: m_can: Disable IRQs on FIFO bus errors")

bulk read/write support has been added to the m_can_fifo_{read,write}
functions.

That change leads to the tcan driver to call
regmap_bulk_{read,write}() with a length of 0 (for CAN frames with 0
data length). regmap treats this as an error:

| tcan4x5x spi1.0 tcan4x5x0: FIFO write returned -22

This patch fixes the problem by not calling the
cdev->ops->{read,write)_fifo() in case of a 0 length read/write.

Fixes: e3938177 ("can: m_can: Disable IRQs on FIFO bus errors")
Link: https://lore.kernel.org/all/20220114155751.2651888-1-mkl@pengutronix.de
Cc: stable@vger.kernel.org
Cc: Matt Kline <matt@bitbashing.io>
Cc: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Reported-by: Michael Anochin <anochin@photo-meter.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This tcan4x5x only comes with 2K of MRAM, a RX FIFO with a dept of 32
doesn't fit into the MRAM. Use a depth of 16 instead.

Fixes: 4edd396a ("dt-bindings: can: tcan4x5x: Add DT bindings for TCAN4x5X driver")
Link: https://lore.kernel.org/all/20220119062951.2939851-1-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Brian Silverman's address at bluerivertech.com is not valid anymore,
use Brian's private email address instead.

Link: https://lore.kernel.org/all/20220110082359.2019735-1-mkl@pengutronix.de
Cc: Brian Silverman <bsilver16384@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Fix the rx_full stats test so that it correctly reports pass even when
the fill ring is not full of buffers.

Fixes: 872a1184 ("selftests: xsk: Put the same buffer only once in the fill ring")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20220121123508.12759-1-magnus.karlsson@gmail.com

Zero-length and one-element arrays are deprecated, see:
Documentation/process/deprecated.rst

Flexible-array members should be used instead.

Generated by: scripts/coccinelle/misc/flexible_array.cocci

Fixes: c1ff181f ("selftests/bpf: Extend kfunc selftests")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/alpine.DEB.2.22.394.2201221206320.12220@hadrien

The tx_coalesce and mii_irq are not used at all now, so remove them.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Simplify code by using bitmap_weight() and bitmap_zero() instead of
hand-writing these functions.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When 'ping' changes to use PING socket instead of RAW socket by:

   # sysctl -w net.ipv4.ping_group_range="0 100"

the selftests 'router_broadcast.sh' will fail, as such command

  # ip vrf exec vrf-h1 ping -I veth0 198.51.100.255 -b

can't receive the response skb by the PING socket. It's caused by mismatch
of sk_bound_dev_if and dif in ping_rcv() when looking up the PING socket,
as dif is vrf-h1 if dif's master was set to vrf-h1.

This patch is to fix this regression by also checking the sk_bound_dev_if
against sdif so that the packets can stil be received even if the socket
is not bound to the vrf device but to the real iif.

Fixes: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind")
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We encountered a crash in smc_setsockopt() and it is caused by
accessing smc->clcsock after clcsock was released.

 BUG: kernel NULL pointer dereference, address: 0000000000000020
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 1 PID: 50309 Comm: nginx Kdump: loaded Tainted: G E     5.16.0-rc4+ #53
 RIP: 0010:smc_setsockopt+0x59/0x280 [smc]
 Call Trace:
  <TASK>
  __sys_setsockopt+0xfc/0x190
  __x64_sys_setsockopt+0x20/0x30
  do_syscall_64+0x34/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7f16ba83918e
  </TASK>

This patch tries to fix it by holding clcsock_release_lock and
checking whether clcsock has already been released before access.

In case that a crash of the same reason happens in smc_getsockopt()
or smc_switch_to_fallback(), this patch also checkes smc->clcsock
in them too. And the caller of smc_switch_to_fallback() will identify
whether fallback succeeds according to the return value.

Fixes: fd57770d ("net/smc: wait for pending work before clcsock release_sock")
Link: https://lore.kernel.org/lkml/5dd7ffd1-28e2-24cc-9442-1defec27375e@linux.ibm.com/T/Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

With previous bug fix, ->wait_capability flag is no longer needed and can
be removed.

Fixes: 249168ad ("ibmvnic: Make CRQ interrupt tasklet wait for all capabilities crqs")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ibmvnic_tasklet() continuously spins waiting for responses to all
capability requests. It does this to avoid encountering an error
during initialization of the vnic. However if there is a bug in the
VIOS and we do not receive a response to one or more queries the
tasklet ends up spinning continuously leading to hard lock ups.

If we fail to receive a message from the VIOS it is reasonable to
timeout the login attempt rather than spin indefinitely in the tasklet.

Fixes: 249168ad ("ibmvnic: Make CRQ interrupt tasklet wait for all capabilities crqs")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We use ->running_cap_crqs to determine when the ibmvnic_tasklet() should
send out the next protocol message type. i.e when we get back responses
to all our QUERY_CAPABILITY CRQs we send out REQUEST_CAPABILITY crqs.
Similiary, when we get responses to all the REQUEST_CAPABILITY crqs, we
send out the QUERY_IP_OFFLOAD CRQ.

We currently increment ->running_cap_crqs as we send out each CRQ and
have the ibmvnic_tasklet() send out the next message type, when this
running_cap_crqs count drops to 0.

This assumes that all the CRQs of the current type were sent out before
the count drops to 0. However it is possible that we send out say 6 CRQs,
get preempted and receive all the 6 responses before we send out the
remaining CRQs. This can result in ->running_cap_crqs count dropping to
zero before all messages of the current type were sent and we end up
sending the next protocol message too early.

Instead initialize the ->running_cap_crqs upfront so the tasklet will
only send the next protocol message after all responses are received.

Use the cap_reqs local variable to also detect any discrepancy (either
now or in future) in the number of capability requests we actually send.

Currently only send_query_cap() is affected by this behavior (of sending
next message early) since it is called from the worker thread (during
reset) and from application thread (during ->ndo_open()) and they can be
preempted. send_request_cap() is only called from the tasklet  which
processes CRQ responses sequentially, is not be affected.  But to
maintain the existing symmtery with send_query_capability() we update
send_request_capability() also.

Fixes: 249168ad ("ibmvnic: Make CRQ interrupt tasklet wait for all capabilities crqs")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If auto-priority-failover (APF) is enabled and there are at least two
backing devices of different priorities, some resets like fail-over,
change-param etc can cause at least two back to back failovers. (Failover
from high priority backing device to lower priority one and then back
to the higher priority one if that is still functional).

Depending on the timimg of the two failovers it is possible to trigger
a "hard" reset and for the hard reset to fail due to failovers. When this
occurs, the driver assumes that the network is unstable and disables the
VNIC for a 60-second "settling time". This in turn can cause the ethtool
command to fail with "No such device" while the vnic automatically recovers
a little while later.

Given that it's possible to have two back to back failures, allow for extra
failures before disabling the vnic for the settling time.

Fixes: f15fde9d ("ibmvnic: delay next reset if hard reset fails")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>