Two helpers (trace_printk and seq_printf) have very similar
implementations of format string parsing and a third one is coming
(snprintf). To avoid code duplication and make the code easier to
maintain, this moves the operations associated with format string
parsing (validation and argument sanitization) into one generic
function.

The implementation of the two existing helpers already drifted quite a
bit so unifying them entailed a lot of changes:

- bpf_trace_printk always expected fmt[fmt_size] to be the terminating
  NULL character, this is no longer true, the first 0 is terminating.
- bpf_trace_printk now supports %% (which produces the percentage char).
- bpf_trace_printk now skips width formating fields.
- bpf_trace_printk now supports the X modifier (capital hexadecimal).
- bpf_trace_printk now supports %pK, %px, %pB, %pi4, %pI4, %pi6 and %pI6
- argument casting on 32 bit has been simplified into one macro and
  using an enum instead of obscure int increments.

- bpf_seq_printf now uses bpf_trace_copy_string instead of
  strncpy_from_kernel_nofault and handles the %pks %pus specifiers.
- bpf_seq_printf now prints longs correctly on 32 bit architectures.

- both were changed to use a global per-cpu tmp buffer instead of one
  stack buffer for trace_printk and 6 small buffers for seq_printf.
- to avoid per-cpu buffer usage conflict, these helpers disable
  preemption while the per-cpu buffer is in use.
- both helpers now support the %ps and %pS specifiers to print symbols.

The implementation is also moved from bpf_trace.c to helpers.c because
the upcoming bpf_snprintf helper will be made available to all BPF
programs and will need it.
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210419155243.1632274-2-revest@chromium.org

Yonghong Song says:

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

To build kernel with clang, people typically use
  make -j60 LLVM=1 LLVM_IAS=1
LLVM_IAS=1 is not required for non-LTO build but
is required for LTO build. In my environment,
I am always having LLVM_IAS=1 regardless of
whether LTO is enabled or not.

After kernel is build with clang, the following command
can be used to build selftests with clang:
  make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1

I am using latest bpf-next kernel code base and
latest clang built from source from
  https://github.com/llvm/llvm-project.git
Using earlier version of llvm may have compilation errors, see
  tools/testing/selftests/bpf
due to continuous development in llvm bpf features and selftests
to use these features.

To run bpf selftest properly, you need have certain necessary
kernel configs like at:
  bpf-next:tools/testing/selftests/bpf/config
(not that this is not a complete .config file and some other configs
 might still be needed.)

Currently, using the above command, some compilations
still use gcc and there are also compilation errors and warnings.
This patch set intends to fix these issues.
Patch #1 and #2 fixed the issue so clang/clang++ is
used instead of gcc/g++. Patch #3 fixed a compilation
failure. Patch #4 and #5 fixed various compiler warnings.

Changelog:
  v2 -> v3:
    . more test environment description in cover letter. (Sedat)
    . use a different fix, but similar to other use in selftests/bpf
      Makefile, to exclude header files from CXX compilation command
      line. (Andrii)
    . fix codes instead of adding -Wno-format-security. (Andrii)
  v1 -> v2:
    . add -Wno-unused-command-line-argument and -Wno-format-security
      for clang only as (1). gcc does not exhibit those
      warnings, and (2). -Wno-unused-command-line-argument is
      only supported by clang. (Sedat)
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

With clang compiler:
  make -j60 LLVM=1 LLVM_IAS=1  <=== compile kernel
  # build selftests/bpf or bpftool
  make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
  make -j60 -C tools/bpf/bpftool LLVM=1 LLVM_IAS=1
the following compilation warning showed up,
  net.c:160:37: warning: comparison of integers of different signs: '__u32' (aka 'unsigned int') and 'int' [-Wsign-compare]
                for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
                                                  ^~~~~~~~~~~~~~~~~
  .../tools/include/uapi/linux/netlink.h:99:24: note: expanded from macro 'NLMSG_OK'
                           (nlh)->nlmsg_len <= (len))
                           ~~~~~~~~~~~~~~~~ ^   ~~~

In this particular case, "len" is defined as "int" and (nlh)->nlmsg_len is "unsigned int".
The macro NLMSG_OK is defined as below in uapi/linux/netlink.h.
  #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
                             (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
                             (nlh)->nlmsg_len <= (len))

The clang compiler complains the comparision "(nlh)->nlmsg_len <= (len))",
but in bpftool/net.c, it is already ensured that "len > 0" must be true.
So theoretically the compiler could deduce that comparison of
"(nlh)->nlmsg_len" and "len" is okay, but this really depends on compiler
internals. Let us add an explicit type conversion (from "int" to "unsigned int")
for "len" in NLMSG_OK to silence this warning right now.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153435.3029635-1-yhs@fb.com

With clang compiler:
  make -j60 LLVM=1 LLVM_IAS=1  <=== compile kernel
  make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
Some linker flags are not used/effective for some binaries and
we have warnings like:
  warning: -lelf: 'linker' input unused [-Wunused-command-line-argument]

We also have warnings like:
  .../selftests/bpf/prog_tests/ns_current_pid_tgid.c:74:57: note: treat the string as an argument to avoid this
        if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", strerror(errno)))
                                                               ^
                                                               "%s",
  .../selftests/bpf/test_progs.h:129:35: note: expanded from macro 'CHECK'
        _CHECK(condition, tag, duration, format)
                                         ^
  .../selftests/bpf/test_progs.h:108:21: note: expanded from macro '_CHECK'
                fprintf(stdout, ##format);                              \
                                  ^
The first warning can be silenced with clang option -Wno-unused-command-line-argument.
For the second warning, source codes are modified as suggested by the compiler
to silence the warning. Since gcc does not support the option
-Wno-unused-command-line-argument and the warning only happens with clang
compiler, the option -Wno-unused-command-line-argument is enabled only when
clang compiler is used.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153429.3029377-1-yhs@fb.com

With clang compiler:
  make -j60 LLVM=1 LLVM_IAS=1  <=== compile kernel
  make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
the test_cpp build failed due to the failure:
  warning: treating 'c-header' input as 'c++-header' when in C++ mode, this behavior is deprecated [-Wdeprecated]
  clang-13: error: cannot specify -o when generating multiple output files

test_cpp compilation flag looks like:
  clang++ -g -Og -rdynamic -Wall -I<...> ... \
  -Dbpf_prog_load=bpf_prog_test_load -Dbpf_load_program=bpf_test_load_program \
  test_cpp.cpp <...>/test_core_extern.skel.h <...>/libbpf.a <...>/test_stub.o \
  -lcap -lelf -lz -lrt -lpthread -o <...>/test_cpp

The clang++ compiler complains the header file in the command line and
also failed the compilation due to this.
Let us remove the header file from the command line which is not intended
any way, and this fixed the compilation problem.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153424.3028986-1-yhs@fb.com

selftests/bpf/Makefile includes tools/scripts/Makefile.include.
With the following command
  make -j60 LLVM=1 LLVM_IAS=1  <=== compile kernel
  make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1 V=1
some files are still compiled with gcc. This patch
fixed the case if CC/AR/LD/CXX/STRIP is allowed to be
overridden, it will be written to clang/llvm-ar/..., instead of
gcc binaries. The definition of CC_NO_CLANG is also relocated
to the place after the above CC is defined.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153419.3028165-1-yhs@fb.com

selftests/bpf/Makefile includes lib.mk. With the following command
  make -j60 LLVM=1 LLVM_IAS=1  <=== compile kernel
  make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1 V=1
some files are still compiled with gcc. This patch
fixed lib.mk issue which sets CC to gcc in all cases.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153413.3027426-1-yhs@fb.com

relo->processed is set, but not used. Remove it.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210415141817.53136-1-alexei.starovoitov@gmail.com

Remove unused variable "ret2".
Signed-off-by: zuoqilin <zuoqilin@yulong.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210414141639.1446-1-zuoqilin1@163.com

It is just missing a ';'. This macro is not used by any test yet.

Fixes: 22ba3635 ("selftests/bpf: Move and extend ASSERT_xxx() testing macros")
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210414155632.737866-1-revest@chromium.org

Extend the fexit_bpf2bpf test to check that the info for the bpf_link
returned by the kernel matches the expected values.

While we're updating the test, change existing uses of CHEC() to use the
much easier to read ASSERT_*() macros.

v2:
- Convert last CHECK() call and get rid of 'duration' var
- Split ASSERT_OK_PTR() checks to two separate if statements
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413091607.58945-2-toke@redhat.com

There is currently no way to discover the target of a tracing program
attachment after the fact. Add this information to bpf_link_info and return
it when querying the bpf_link fd.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413091607.58945-1-toke@redhat.com

pahole v1.21 supports the --btf_gen_floats flag, which makes it
generate the information about the floating-point types [1].

Adjust link-vmlinux.sh to pass this flag to pahole in case it's
supported, which is determined using a simple version check.

[1] https://lore.kernel.org/dwarves/YHRiXNX1JUF2Az0A@kernel.org/Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413190043.21918-1-iii@linux.ibm.com

In 'bpf_ringbuf_reserve()' we require the flag to '0' at the moment.

For 'bpf_ringbuf_{discard,submit,output}' a flag of '0' might send a
notification to the process if needed.
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210412192434.944343-1-pctammela@mojatatu.com

The last refcnt of the psock can be gone right after
sock_map_remove_links(), so sk_psock_stop() could trigger a UAF.
The reason why I placed sk_psock_stop() there is to avoid RCU read
critical section, and more importantly, some callee of
sock_map_remove_links() is supposed to be called with RCU read lock,
we can not simply get rid of RCU read lock here. Therefore, the only
choice we have is to grab an additional refcnt with sk_psock_get()
and put it back after sk_psock_stop().

Fixes: 799aa7f9 ("skmsg: Avoid lock_sock() in sk_psock_backlog()")
Reported-by: syzbot+7b6548ae483d6f4c64ae@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210408030556.45134-1-xiyou.wangcong@gmail.com

Using sk_psock() to retrieve psock pointer from sock requires
RCU read lock, but we already get psock pointer before calling
->psock_update_sk_prot() in both cases, so we can just pass it
without bothering sk_psock().

Fixes: 8a59f9d1 ("sock: Introduce sk->sk_prot->psock_update_sk_prot()")
Reported-by: syzbot+320a3bc8d80f478c37e4@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+320a3bc8d80f478c37e4@syzkaller.appspotmail.com
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210407032111.33398-1-xiyou.wangcong@gmail.com

Synchronize tools/include/uapi/linux/bpf.h which was missing changes
from various commits:

  - f3c45326 ("bpf: Document PROG_TEST_RUN limitations")
  - e5e35e75 ("bpf: BPF-helper for MTU checking add length input")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Per net/bpf/test_run.c, particular prog types have additional
restrictions around the parameters that can be provided, so document
these in the header.

I didn't bother documenting the limitation on duration for raw
tracepoints since that's an output parameter anyway.

Tested with ./tools/testing/selftests/bpf/test_doc_build.sh.
Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Lorenz Bauer <lmb@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210410174549.816482-1-joe@cilium.io

Yauheni Kaliuta says:

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

A set of fixes for selftests to make them working on systems with PAGE_SIZE > 4K
+ cleanup (version) and ringbuf_multi extention.
---
v3->v4:
- zero initialize BPF programs' static variables;
- add bpf_map__inner_map to libbpf.map in alphabetical order;
- add bpf_map__set_inner_map_fd test to ringbuf_multi;

v2->v3:
 - reorder: move version removing patch first to keep main patches in
   one group;
 - rename "selftests/bpf: pass page size from userspace in sockopt_sk"
   as suggested;
 - convert sockopt_sk test to use ASSERT macros;
 - set page size from userspace
 - split patches to pairs userspace/bpf. It's easier to check that
   every conversion works as expected;

v1->v2:

- add missed 'selftests/bpf: test_progs/sockopt_sk: Convert to use BPF skeleton'
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

Test map__set_inner_map_fd() interaction with map-in-map
initialization. Use hashmap of maps just to make it different to
existing array of maps.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-9-yauheni.kaliuta@redhat.com

Set bpf table sizes dynamically according to the runtime page size
value.

Do not switch to ASSERT macros, keep CHECK, for consistency with the
rest of the test. Can be a separate cleanup patch.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-8-yauheni.kaliuta@redhat.com

The API gives access to inner map for map in map types (array or
hash of map). It will be used to dynamically set max_entries in it.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-7-yauheni.kaliuta@redhat.com

Replace hardcoded 4096 with runtime value in the userspace part of
the test and set bpf table sizes dynamically according to the value.

Do not switch to ASSERT macros, keep CHECK, for consistency with the
rest of the test. Can be a separate cleanup patch.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-6-yauheni.kaliuta@redhat.com

Replace hardcoded 4096 with runtime value in the userspace part of
the test and set bpf table sizes dynamically according to the value.

Do not switch to ASSERT macros, keep CHECK, for consistency with the
rest of the test. Can be a separate cleanup patch.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-5-yauheni.kaliuta@redhat.com

Use ASSERT to check result but keep CHECK where format was used to
report error.

Use bpf_map__set_max_entries() to set map size dynamically from
userspace according to page size.

Zero-initialize the variable in bpf prog, otherwise it will cause
problems on some versions of Clang.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-4-yauheni.kaliuta@redhat.com

Since there is no convenient way for bpf program to get PAGE_SIZE
from inside of the kernel, pass the value from userspace.

Zero-initialize the variable in bpf prog, otherwise it will cause
problems on some versions of Clang.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-3-yauheni.kaliuta@redhat.com

Switch the test to use BPF skeleton to save some boilerplate and
make it easy to access bpf program bss segment.

The latter will be used to pass PAGE_SIZE from userspace since there
is no convenient way for bpf program to get it from inside of the
kernel.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-2-yauheni.kaliuta@redhat.com

As pointed by Andrii Nakryiko, _version is useless now, remove it.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-1-yauheni.kaliuta@redhat.com

bpf_preload_lock is already defined with DEFINE_MUTEX(). There is no
need to initialize it again. Remove the extraneous initialization.
Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210405194904.GA148013@LEGION

These comments in udp_bpf_update_proto() are copied from the
original TCP code and apparently do not apply to UDP. Just
remove them.
Reported-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210403052715.13854-1-xiyou.wangcong@gmail.com

Add missing ')' for KERNEL_VERSION macro.
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210405040119.802188-1-hengqi.chen@gmail.com

The tracing test and the recent kfunc call test require
CONFIG_DYNAMIC_FTRACE.  This patch adds it to the config file.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210403002921.3419721-1-kafai@fb.com

Remove redundant semi-colon in finalize_btf_ext().
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210402012634.1965453-1-yangyingliang@huawei.com

struct btf_type is declared twice. One is declared at 35th line. The below
one is not needed, hence remove the duplicate.
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210401072037.995849-1-wanjiabing@vivo.com

struct bpf_prog is declared twice. There is one declaration which is
independent on the macro at 18th line. So the below one is not needed
though. Remove the duplicate.
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210401064637.993327-1-wanjiabing@vivo.com

'stack' parameter is not used in ___bpf_prog_run() after f696b8f4
("bpf: split bpf core interpreter"), the base address have been set to
FP reg. So consequently remove it.
Signed-off-by: He Fengqing <hefengqing@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210331075135.3850782-1-hefengqing@huawei.com

With a relatively recent clang master branch test_map skips a section,

 libbpf: elf: skipping unrecognized data section(5) .rodata.str1.1

the cause is some pointless strings from bpf_printks in the BPF program
loaded during testing. After just removing the prints to fix above error
Daniel points out the program is a bit pointless and could be simply the
empty program returning SK_PASS.

Here we do just that and return simply SK_PASS. This program is used with
test_maps selftests to test insert/remove of a program into the sockmap
and sockhash maps. Its not testing actual functionality of the TCP
sockmap programs, these are tested from test_sockmap. So we shouldn't
lose in test coverage and fix above warnings. This original test was
added before test_sockmap existed and has been copied around ever since,
clean it up now.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/161731595664.74613.1603087410166945302.stgit@john-XPS-13-9370

Group all the often used fields in the first cache line,
to reduce cache line misses.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Order fields to increase locality for most used protocols.

udplite and icmp are moved at the end.

Same for proc_net_devsnmp6 which is not used in fast path.

This potentially saves one cache line miss for typical TCP/UDP over IPv4/IPv6.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the "type_a->nfcid_len" is too large then it would lead to memory
corruption in pn533_target_found_type_a() when we do:

	memcpy(nfc_tgt->nfcid1, tgt_type_a->nfcid_data, nfc_tgt->nfcid1_len);

Fixes: c3b1e1e8 ("NFC: Export NFCID1 from pn533")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>