Add `bpftool gen object <output-file> <input_file>...` command to statically
link multiple BPF ELF object files into a single output BPF ELF object file.

This patch also updates bash completions and man page. Man page gets a short
section on `gen object` command, but also updates the skeleton example to show
off workflow for BPF application with two .bpf.c files, compiled individually
with Clang, then resulting object files are linked together with `gen object`,
and then final object file is used to generate usable BPF skeleton. This
should help new users understand realistic workflow w.r.t. compiling
mutli-file BPF application.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Reviewed-by: NQuentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-10-andrii@kernel.org

Add optional name OBJECT_NAME parameter to `gen skeleton` command to override
default object name, normally derived from input file name. This allows much
more flexibility during build time.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-9-andrii@kernel.org

Add .BTF and .BTF.ext static linking logic.

When multiple BPF object files are linked together, their respective .BTF and
.BTF.ext sections are merged together. BTF types are not just concatenated,
but also deduplicated. .BTF.ext data is grouped by type (func info, line info,
core_relos) and target section names, and then all the records are
concatenated together, preserving their relative order. All the BTF type ID
references and string offsets are updated as necessary, to take into account
possibly deduplicated strings and types.

BTF DATASEC types are handled specially. Their respective var_secinfos are
accumulated separately in special per-section data and then final DATASEC
types are emitted at the very end during bpf_linker__finalize() operation,
just before emitting final ELF output file.

BTF data can also provide "section annotations" for some extern variables.
Such concept is missing in ELF, but BTF will have DATASEC types for such
special extern datasections (e.g., .kconfig, .ksyms). Such sections are called
"ephemeral" internally. Internally linker will keep metadata for each such
section, collecting variables information, but those sections won't be emitted
into the final ELF file.

Also, given LLVM/Clang during compilation emits BTF DATASECS that are
incomplete, missing section size and variable offsets for static variables,
BPF static linker will initially fix up such DATASECs, using ELF symbols data.
The final DATASECs will preserve section sizes and all variable offsets. This
is handled correctly by libbpf already, so won't cause any new issues. On the
other hand, it's actually a nice property to have a complete BTF data without
runtime adjustments done during bpf_object__open() by libbpf. In that sense,
BPF static linker is also a BTF normalizer.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-8-andrii@kernel.org

Introduce BPF static linker APIs to libbpf. BPF static linker allows to
perform static linking of multiple BPF object files into a single combined
resulting object file, preserving all the BPF programs, maps, global
variables, etc.

Data sections (.bss, .data, .rodata, .maps, maps, etc) with the same name are
concatenated together. Similarly, code sections are also concatenated. All the
symbols and ELF relocations are also concatenated in their respective ELF
sections and are adjusted accordingly to the new object file layout.

Static variables and functions are handled correctly as well, adjusting BPF
instructions offsets to reflect new variable/function offset within the
combined ELF section. Such relocations are referencing STT_SECTION symbols and
that stays intact.

Data sections in different files can have different alignment requirements, so
that is taken care of as well, adjusting sizes and offsets as necessary to
satisfy both old and new alignment requirements.

DWARF data sections are stripped out, currently. As well as LLLVM_ADDRSIG
section, which is ignored by libbpf in bpf_object__open() anyways. So, in
a way, BPF static linker is an analogue to `llvm-strip -g`, which is a pretty
nice property, especially if resulting .o file is then used to generate BPF
skeleton.

Original string sections are ignored and instead we construct our own set of
unique strings using libbpf-internal `struct strset` API.

To reduce the size of the patch, all the .BTF and .BTF.ext processing was
moved into a separate patch.

The high-level API consists of just 4 functions:
  - bpf_linker__new() creates an instance of BPF static linker. It accepts
    output filename and (currently empty) options struct;
  - bpf_linker__add_file() takes input filename and appends it to the already
    processed ELF data; it can be called multiple times, one for each BPF
    ELF object file that needs to be linked in;
  - bpf_linker__finalize() needs to be called to dump final ELF contents into
    the output file, specified when bpf_linker was created; after
    bpf_linker__finalize() is called, no more bpf_linker__add_file() and
    bpf_linker__finalize() calls are allowed, they will return error;
  - regardless of whether bpf_linker__finalize() was called or not,
    bpf_linker__free() will free up all the used resources.

Currently, BPF static linker doesn't resolve cross-object file references
(extern variables and/or functions). This will be added in the follow up patch
set.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-7-andrii@kernel.org

Add btf__add_type() API that performs shallow copy of a given BTF type from
the source BTF into the destination BTF. All the information and type IDs are
preserved, but all the strings encountered are added into the destination BTF
and corresponding offsets are rewritten. BTF type IDs are assumed to be
correct or such that will be (somehow) modified afterwards.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-6-andrii@kernel.org

Extract BTF logic for maintaining a set of strings data structure, used for
BTF strings section construction in writable mode, into separate re-usable
API. This data structure is going to be used by bpf_linker to maintains ELF
STRTAB section, which has the same layout as BTF strings section.
Suggested-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-5-andrii@kernel.org

Rename btf_add_mem() and btf_ensure_mem() helpers that abstract away details
of dynamically resizable memory to use libbpf_ prefix, as they are not
BTF-specific. No functional changes.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-4-andrii@kernel.org

Extract and generalize the logic to iterate BTF type ID and string offset
fields within BTF types and .BTF.ext data. Expose this internally in libbpf
for re-use by bpf_linker.

Additionally, complete strings deduplication handling for BTF.ext (e.g., CO-RE
access strings), which was previously missing. There previously was no
case of deduplicating .BTF.ext data, but bpf_linker is going to use it.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-3-andrii@kernel.org

btf_type_by_id() is internal-only convenience API returning non-const pointer
to struct btf_type. Expose it outside of btf.c for re-use.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-2-andrii@kernel.org

We want to change the current ndo_xdp_xmit drop semantics because it will
allow us to implement better queue overflow handling. This is working
towards the larger goal of a XDP TX queue-hook. Move XDP_REDIRECT error
path handling from each XDP ethernet driver to devmap code. According to
the new APIs, the driver running the ndo_xdp_xmit pointer, will break tx
loop whenever the hw reports a tx error and it will just return to devmap
caller the number of successfully transmitted frames. It will be devmap
responsibility to free dropped frames.

Move each XDP ndo_xdp_xmit capable driver to the new APIs:

- veth
- virtio-net
- mvneta
- mvpp2
- socionext
- amazon ena
- bnxt
- freescale (dpaa2, dpaa)
- xen-frontend
- qede
- ice
- igb
- ixgbe
- i40e
- mlx5
- ti (cpsw, cpsw-new)
- tun
- sfc
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: NIlias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: NCamelia Groza <camelia.groza@nxp.com>
Acked-by: NEdward Cree <ecree.xilinx@gmail.com>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: NShay Agroskin <shayagr@amazon.com>
Link: https://lore.kernel.org/bpf/ed670de24f951cfd77590decf0229a0ad7fd12f6.1615201152.git.lorenzo@kernel.org

Andrii Nakryiko says:

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

Provide NULL and KERNEL_VERSION macros in bpf_helpers.h. Patch #2 removes such
custom NULL definition from one of the selftests.

v2->v3:
  - instead of vmlinux.h, do this in bpf_helpers.h;
  - added KERNEL_VERSION, which comes up periodically as well;
  - I dropped strict compilation patches for now, because we run into new
    warnings (e.g., not checking read() result) in kernel-patches CI, which
    I can't even reproduce locally. Also -Wdiscarded-qualifiers pragma for
    jit_disasm.c is not supported by Clang, it needs to be
    -Wincompatible-pointer-types-discards-qualifiers for Clang; we don't have
    to deal with that in this patch set;
v1->v2:
  - fix few typos and wrong copy/paste;
  - fix #pragma push -> pop.
====================
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Now that bpftool generates NULL definition as part of vmlinux.h, drop custom
NULL definition in skb_pkt_end.c.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20210317200510.1354627-3-andrii@kernel.orgSigned-off-by: NAlexei Starovoitov <ast@kernel.org>

Given that vmlinux.h is not compatible with headers like stddef.h, NULL poses
an annoying problem: it is defined as #define, so is not captured in BTF, so
is not emitted into vmlinux.h. This leads to users either sticking to explicit
0, or defining their own NULL (as progs/skb_pkt_end.c does).

But it's easy for bpf_helpers.h to provide (conditionally) NULL definition.
Similarly, KERNEL_VERSION is another commonly missed macro that came up
multiple times. So this patch adds both of them, along with offsetof(), that
also is typically defined in stddef.h, just like NULL.

This might cause compilation warning for existing BPF applications defining
their own NULL and/or KERNEL_VERSION already:

  progs/skb_pkt_end.c:7:9: warning: 'NULL' macro redefined [-Wmacro-redefined]
  #define NULL 0
          ^
  /tmp/linux/tools/testing/selftests/bpf/tools/include/vmlinux.h:4:9: note: previous definition is here
  #define NULL ((void *)0)
	  ^

It is trivial to fix, though, so long-term benefits outweight temporary
inconveniences.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20210317200510.1354627-2-andrii@kernel.orgSigned-off-by: NAlexei Starovoitov <ast@kernel.org>

The selftest failed to compile with clang-built bpf-next.
Adding LLVM=1 to your vmlinux and selftest build will use clang.
The error message is:
  progs/test_sk_storage_tracing.c:38:18: error: use of undeclared identifier 'BPF_TCP_CLOSE'
          if (newstate == BPF_TCP_CLOSE)
                          ^
  1 error generated.
  make: *** [Makefile:423: /bpf-next/tools/testing/selftests/bpf/test_sk_storage_tracing.o] Error 1

The reason for the failure is that BPF_TCP_CLOSE, a value of
an anonymous enum defined in uapi bpf.h, is not defined in
vmlinux.h. gcc does not have this problem. Since vmlinux.h
is derived from BTF which is derived from vmlinux DWARF,
that means gcc-produced vmlinux DWARF has BPF_TCP_CLOSE
while llvm-produced vmlinux DWARF does not have.

BPF_TCP_CLOSE is referenced in net/ipv4/tcp.c as
  BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE);
The following test mimics the above BUILD_BUG_ON, preprocessed
with clang compiler, and shows gcc DWARF contains BPF_TCP_CLOSE while
llvm DWARF does not.

  $ cat t.c
  enum {
    BPF_TCP_ESTABLISHED = 1,
    BPF_TCP_CLOSE = 7,
  };
  enum {
    TCP_ESTABLISHED = 1,
    TCP_CLOSE = 7,
  };

  int test() {
    do {
      extern void __compiletime_assert_767(void) ;
      if ((int)BPF_TCP_CLOSE != (int)TCP_CLOSE) __compiletime_assert_767();
    } while (0);
    return 0;
  }
  $ clang t.c -O2 -c -g && llvm-dwarfdump t.o | grep BPF_TCP_CLOSE
  $ gcc t.c -O2 -c -g && llvm-dwarfdump t.o | grep BPF_TCP_CLOSE
                    DW_AT_name    ("BPF_TCP_CLOSE")

Further checking clang code find clang actually tried to
evaluate condition at compile time. If it is definitely
true/false, it will perform optimization and the whole if condition
will be removed before generating IR/debuginfo.

This patch explicited add an expression after the
above mentioned BUILD_BUG_ON in net/ipv4/tcp.c like
  (void)BPF_TCP_ESTABLISHED
to enable generation of debuginfo for the anonymous
enum which also includes BPF_TCP_CLOSE.
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210317174132.589276-1-yhs@fb.com

Glibc's sleep() switched to clock_nanosleep() from nanosleep(), and thus
syscalls:sys_enter_nanosleep tracepoint is not hitting which is causing
testcase failure. Instead of depending on glibc sleep(), call nanosleep()
systemcall directly.

Before:

  # ./get_cgroup_id_user
  ...
  main:FAIL:compare_cgroup_id kern cgid 0 user cgid 483

After:

  # ./get_cgroup_id_user
  ...
  main:PASS:compare_cgroup_id
Signed-off-by: NRavi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210316153048.136447-1-ravi.bangoria@linux.ibm.com

Fix the following coccicheck warnings:

  ./tools/testing/selftests/bpf/progs/fexit_test.c:77:15-16: WARNING
  comparing pointer to 0.

  ./tools/testing/selftests/bpf/progs/fexit_test.c:68:12-13: WARNING
  comparing pointer to 0.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1615881577-3493-1-git-send-email-jiapeng.chong@linux.alibaba.com

Andrii Nakryiko says:

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

Build BPF selftests and libbpf and bpftool, that are used as part of
selftests, in debug mode (specifically, -Og). This makes it much simpler and
nicer to do development and/or bug fixing. See patch #4 for some unscientific
measurements.

This patch set fixes new maybe-unitialized warnings produced in -Og build
mode. Patch #1 fixes the blocker which was causing some XDP selftests failures
due to non-zero padding in bpf_xdp_set_link_opts, which only happened in debug
mode.
====================
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Build selftests, bpftool, and libbpf in debug mode with DWARF data to
facilitate easier debugging.

In terms of impact on building and running selftests. Build is actually faster
now:

BEFORE: make -j60  380.21s user 37.87s system 1466% cpu 28.503 total
AFTER:  make -j60  345.47s user 37.37s system 1599% cpu 23.939 total

test_progs runtime seems to be the same:

BEFORE:
real    1m5.139s
user    0m1.600s
sys     0m43.977s

AFTER:
real    1m3.799s
user    0m1.721s
sys     0m42.420s

Huge difference is being able to debug issues throughout test_progs, bpftool,
and libbpf without constantly updating 3 Makefiles by hand (including GDB
seeing the source code without any extra incantations).
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210313210920.1959628-5-andrii@kernel.org

xsk_ring_prod__reserve() doesn't necessarily set idx in some conditions, so
from static analysis point of view compiler is right about the problems like:

In file included from xdpxceiver.c:92:
xdpxceiver.c: In function ‘xsk_populate_fill_ring’:
/data/users/andriin/linux/tools/testing/selftests/bpf/tools/include/bpf/xsk.h:119:20: warning: ‘idx’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  return &addrs[idx & fill->mask];
                ~~~~^~~~~~~~~~~~
xdpxceiver.c:300:6: note: ‘idx’ was declared here
  u32 idx;
      ^~~
xdpxceiver.c: In function ‘tx_only’:
xdpxceiver.c:596:30: warning: ‘idx’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   struct xdp_desc *tx_desc = xsk_ring_prod__tx_desc(&xsk->tx, idx + i);
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix two warnings reported by compiler by pre-initializing variable.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210313210920.1959628-4-andrii@kernel.org

Somehow when bpftool is compiled in -Og mode, compiler produces new warnings
about possibly uninitialized variables. Fix all the reported problems.

Fixes: 2119f218 ("bpftool: add C output format option to btf dump subcommand")
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210313210920.1959628-3-andrii@kernel.org

Adding such anonymous padding fixes the issue with uninitialized portions of
bpf_xdp_set_link_opts when using LIBBPF_DECLARE_OPTS macro with inline field
initialization:

DECLARE_LIBBPF_OPTS(bpf_xdp_set_link_opts, opts, .old_fd = -1);

When such code is compiled in debug mode, compiler is generating code that
leaves padding bytes uninitialized, which triggers error inside libbpf APIs
that do strict zero initialization checks for OPTS structs.

Adding anonymous padding field fixes the issue.

Fixes: bd5ca3ef ("libbpf: Add function to set link XDP fd while specifying old program")
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210313210920.1959628-2-andrii@kernel.org

The sparse tool complains as follows:

kernel/bpf/bpf_task_storage.c:23:1: warning:
 symbol '__pcpu_scope_bpf_task_storage_busy' was not declared. Should it be static?

This symbol is not used outside of bpf_task_storage.c, so this
commit marks it static.

Fixes: bc235cdb ("bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]")
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210311131505.1901509-1-weiyongjun1@huawei.com

A typo is found out by codespell tool in 34th lines of hashtab.c:

$ codespell ./kernel/bpf/
./hashtab.c:34 : differrent ==> different

Fix a typo found by codespell.
Signed-off-by: NLiu xuzhi <liu.xuzhi@zte.com.cn>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210311123103.323589-1-liu.xuzhi@zte.com.cn

Implement BPF_AND, BPF_OR and BPF_XOR as the existing BPF_ADD. Since
the corresponding machine instructions return the old value, BPF_FETCH
happens by itself, the only additional thing that is required is
zero-extension.

There is no single instruction that implements BPF_XCHG on s390, so use
a COMPARE AND SWAP loop.

BPF_CMPXCHG, on the other hand, can be implemented by a single COMPARE
AND SWAP. Zero-extension is automatically inserted by the verifier.
Signed-off-by: NIlya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210304233002.149096-1-iii@linux.ibm.com

This seems to be a reminiscent from the hashmap tests.
Signed-off-by: NPedro Tammela <pctammela@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210315132954.603108-1-pctammela@gmail.com

This patch fixes a spelling typo in do_hbm_test.sh
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210315124454.1744594-1-standby24x7@gmail.com

Linux headers might pull 'linux/stddef.h' which defines
'__always_inline' as the following:

   #ifndef __always_inline
   #define __always_inline inline
   #endif

This becomes an issue if the program picks up the 'linux/stddef.h'
definition as the macro now just hints inline to clang.

This change now enforces the proper definition for BPF programs
regardless of the include order.
Signed-off-by: NPedro Tammela <pctammela@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210314173839.457768-1-pctammela@gmail.com

Augment the current set of options that are accessible via
bpf_{g,s}etsockopt to also support SO_REUSEPORT.
Signed-off-by: NManu Bretelle <chantra@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210310182305.1910312-1-chantra@fb.com

Björn Töpel says:

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

This series removes a header dependency from xsk.h, and moves
libbpf_util.h into xsk.h.

More details in each commit!

Thank you,
Björn
====================
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>

The only user of libbpf_util.h is xsk.h. Move the barriers to xsk.h,
and remove libbpf_util.h. The barriers are used as an implementation
detail, and should not be considered part of the stable API.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210310080929.641212-3-bjorn.topel@gmail.com

In commit 291471dd ("libbpf, xsk: Add libbpf_smp_store_release
libbpf_smp_load_acquire") linux/compiler.h was added as a dependency
to xsk.h, which is the user-facing API. This makes it harder for
userspace application to consume the library. Here the header
inclusion is removed, and instead {READ,WRITE}_ONCE() is added
explicitly.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210310080929.641212-2-bjorn.topel@gmail.com

Fix the following coccicheck warning:

./tools/testing/selftests/bpf/progs/fentry_test.c:67:12-13: WARNING
comparing pointer to 0.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1615360714-30381-1-git-send-email-jiapeng.chong@linux.alibaba.com

Fix the following coccicheck warning:

./tools/testing/selftests/bpf/progs/test_global_func10.c:17:12-13:
WARNING comparing pointer to 0.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1615357366-97612-1-git-send-email-jiapeng.chong@linux.alibaba.com

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-03-09

The following pull-request contains BPF updates for your *net-next* tree.

We've added 90 non-merge commits during the last 17 day(s) which contain
a total of 114 files changed, 5158 insertions(+), 1288 deletions(-).

The main changes are:

1) Faster bpf_redirect_map(), from Björn.

2) skmsg cleanup, from Cong.

3) Support for floating point types in BTF, from Ilya.

4) Documentation for sys_bpf commands, from Joe.

5) Support for sk_lookup in bpf_prog_test_run, form Lorenz.

6) Enable task local storage for tracing programs, from Song.

7) bpf_for_each_map_elem() helper, from Yonghong.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull networking fixes from David Miller:

 1) Fix transmissions in dynamic SMPS mode in ath9k, from Felix Fietkau.

 2) TX skb error handling fix in mt76 driver, also from Felix.

 3) Fix BPF_FETCH atomic in x86 JIT, from Brendan Jackman.

 4) Avoid double free of percpu pointers when freeing a cloned bpf prog.
    From Cong Wang.

 5) Use correct printf format for dma_addr_t in ath11k, from Geert
    Uytterhoeven.

 6) Fix resolve_btfids build with older toolchains, from Kun-Chuan
    Hsieh.

 7) Don't report truncated frames to mac80211 in mt76 driver, from
    Lorenzop Bianconi.

 8) Fix watcdog timeout on suspend/resume of stmmac, from Joakim Zhang.

 9) mscc ocelot needs NET_DEVLINK selct in Kconfig, from Arnd Bergmann.

10) Fix sign comparison bug in TCP_ZEROCOPY_RECEIVE getsockopt(), from
    Arjun Roy.

11) Ignore routes with deleted nexthop object in mlxsw, from Ido
    Schimmel.

12) Need to undo tcp early demux lookup sometimes in nf_nat, from
    Florian Westphal.

13) Fix gro aggregation for udp encaps with zero csum, from Daniel
    Borkmann.

14) Make sure to always use imp*_ndo_send when necessaey, from Jason A.
    Donenfeld.

15) Fix TRSCER masks in sh_eth driver from Sergey Shtylyov.

16) prevent overly huge skb allocationsd in qrtr, from Pavel Skripkin.

17) Prevent rx ring copnsumer index loss of sync in enetc, from Vladimir
    Oltean.

18) Make sure textsearch copntrol block is large enough, from Wilem de
    Bruijn.

19) Revert MAC changes to r8152 leading to instability, from Hates Wang.

20) Advance iov in 9p even for empty reads, from Jissheng Zhang.

21) Double hook unregister in nftables, from PabloNeira Ayuso.

22) Fix memleak in ixgbe, fropm Dinghao Liu.

23) Avoid dups in pkt scheduler class dumps, from Maximilian Heyne.

24) Various mptcp fixes from Florian Westphal, Paolo Abeni, and Geliang
    Tang.

25) Fix DOI refcount bugs in cipso, from Paul Moore.

26) One too many irqsave in ibmvnic, from Junlin Yang.

27) Fix infinite loop with MPLS gso segmenting via virtio_net, from
    Balazs Nemeth.

* git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net: (164 commits)
  s390/qeth: fix notification for pending buffers during teardown
  s390/qeth: schedule TX NAPI on QAOB completion
  s390/qeth: improve completion of pending TX buffers
  s390/qeth: fix memory leak after failed TX Buffer allocation
  net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0
  net: check if protocol extracted by virtio_net_hdr_set_proto is correct
  net: dsa: xrs700x: check if partner is same as port in hsr join
  net: lapbether: Remove netif_start_queue / netif_stop_queue
  atm: idt77252: fix null-ptr-dereference
  atm: uPD98402: fix incorrect allocation
  atm: fix a typo in the struct description
  net: qrtr: fix error return code of qrtr_sendmsg()
  mptcp: fix length of ADD_ADDR with port sub-option
  net: bonding: fix error return code of bond_neigh_init()
  net: enetc: allow hardware timestamping on TX queues with tc-etf enabled
  net: enetc: set MAC RX FIFO to recommended value
  net: davicom: Use platform_get_irq_optional()
  net: davicom: Fix regulator not turned off on driver removal
  net: davicom: Fix regulator not turned off on failed probe
  net: dsa: fix switchdev objects on bridge master mistakenly being applied on ports
  ...

Pull sparc fixes from David Miller:
 "Fix opcode filtering for exceptions, and clean up defconfig"

* git://git.kernel.org:/pub/scm/linux/kernel/git/davem/sparc:
  sparc: sparc64_defconfig: remove duplicate CONFIGs
  sparc64: Fix opcode filtering in handling of no fault loads

After my patch there is CONFIG_ATA defined twice.
Remove the duplicate one.
Same problem for CONFIG_HAPPYMEAL, except I added as builtin for boot
test with NFS.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Fixes: a57cdeb3 ("sparc: sparc64_defconfig: add necessary configs for qemu")
Signed-off-by: NCorentin Labbe <clabbe@baylibre.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

is_no_fault_exception() has two bugs which were discovered via random
opcode testing with stress-ng. Both are caused by improper filtering
of opcodes.

The first bug can be triggered by a floating point store with a no-fault
ASI, for instance "sta %f0, [%g0] #ASI_PNF", opcode C1A01040.

The code first tests op3[5] (0x1000000), which denotes a floating
point instruction, and then tests op3[2] (0x200000), which denotes a
store instruction. But these bits are not mutually exclusive, and the
above mentioned opcode has both bits set. The intent is to filter out
stores, so the test for stores must be done first in order to have
any effect.

The second bug can be triggered by a floating point load with one of
the invalid ASI values 0x8e or 0x8f, which pass this check in
is_no_fault_exception():
     if ((asi & 0xf2) == ASI_PNF)

An example instruction is "ldqa [%l7 + %o7] #ASI 0x8f, %f38",
opcode CF95D1EF. Asi values greater than 0x8b (ASI_SNFL) are fatal
in handle_ldf_stq(), and is_no_fault_exception() must not allow these
invalid asi values to make it that far.

In both of these cases, handle_ldf_stq() reacts by calling
sun4v_data_access_exception() or spitfire_data_access_exception(),
which call is_no_fault_exception() and results in an infinite
recursion.
Signed-off-by: NRob Gardner <rob.gardner@oracle.com>
Tested-by: NAnatoly Pugachev <matorola@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Julian Wiedmann says:

====================
s390/qeth: fixes 2021-03-09

please apply the following patch series to netdev's net tree.

This brings one fix for a memleak in an error path of the setup code.
Also several fixes for dealing with pending TX buffers - two for old
bugs in their completion handling, and one recent regression in a
teardown path.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The cited commit reworked the state machine for pending TX buffers.
In qeth_iqd_tx_complete() it turned PENDING into a transient state, and
uses NEED_QAOB for buffers that get parked while waiting for their QAOB
completion.

But it missed to adjust the check in qeth_tx_complete_buf(). So if
qeth_tx_complete_pending_bufs() is called during teardown to drain
the parked TX buffers, we no longer raise a notification for af_iucv.

Instead of updating the checked state, just move this code into
qeth_tx_complete_pending_bufs() itself. This also gets rid of the
special-case in the common TX completion path.

Fixes: 8908f36d ("s390/qeth: fix af_iucv notification race")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>