The existing code did not expect users would initialize the TLS ULP
without subsequently calling the TLS TX enabling socket option.
If the application tries to send data after the TLS ULP enable op
but before the TLS TX enable op the BPF sk_msg verdict program is
skipped. This patch resolves this by converting the ipv4 sock ops
to be calculated at init time the same way ipv6 ops are done. This
pulls in any changes to the sock ops structure that have been made
after the socket was created including the changes from adding the
socket to a sock{map|hash}.

This was discovered by running OpenSSL master branch which calls
the TLS ULP setsockopt early in TLS handshake but only enables
the TLS TX path once the handshake has completed. As a result the
datapath missed the initial handshake messages.

Fixes: 02c558b2 ("bpf: sockmap, support for msg_peek in sk_msg with redirect ingress")
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

A sockmap program that redirects through a kTLS ULP enabled socket
will not work correctly because the ULP layer is skipped. This
fixes the behavior to call through the ULP layer on redirect to
ensure any operations required on the data stream at the ULP layer
continue to be applied.

To do this we add an internal flag MSG_SENDPAGE_NOPOLICY to avoid
calling the BPF layer on a redirected message. This is
required to avoid calling the BPF layer multiple times (possibly
recursively) which is not the current/expected behavior without
ULPs. In the future we may add a redirect flag if users _do_
want the policy applied again but this would need to work for both
ULP and non-ULP sockets and be opt-in to avoid breaking existing
programs.

Also to avoid polluting the flag space with an internal flag we
reuse the flag space overlapping MSG_SENDPAGE_NOPOLICY with
MSG_WAITFORONE. Here WAITFORONE is specific to recv path and
SENDPAGE_NOPOLICY is only used for sendpage hooks. The last thing
to verify is user space API is masked correctly to ensure the flag
can not be set by user. (Note this needs to be true regardless
because we have internal flags already in-use that user space
should not be able to set). But for completeness we have two UAPI
paths into sendpage, sendfile and splice.

In the sendfile case the function do_sendfile() zero's flags,

./fs/read_write.c:
 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
		   	    size_t count, loff_t max)
 {
   ...
   fl = 0;
#if 0
   /*
    * We need to debate whether we can enable this or not. The
    * man page documents EAGAIN return for the output at least,
    * and the application is arguably buggy if it doesn't expect
    * EAGAIN on a non-blocking file descriptor.
    */
    if (in.file->f_flags & O_NONBLOCK)
	fl = SPLICE_F_NONBLOCK;
#endif
    file_start_write(out.file);
    retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
 }

In the splice case the pipe_to_sendpage "actor" is used which
masks flags with SPLICE_F_MORE.

./fs/splice.c:
 static int pipe_to_sendpage(struct pipe_inode_info *pipe,
			    struct pipe_buffer *buf, struct splice_desc *sd)
 {
   ...
   more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0;
   ...
 }

Confirming what we expect that internal flags  are in fact internal
to socket side.

Fixes: d3b18ad3 ("tls: add bpf support to sk_msg handling")
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

In addition to releasing any cork'ed data on a psock when the psock
is removed we should also release any skb's in the ingress work queue.
Otherwise the skb's eventually get free'd but late in the tear
down process so we see the WARNING due to non-zero sk_forward_alloc.

  void sk_stream_kill_queues(struct sock *sk)
  {
	...
	WARN_ON(sk->sk_forward_alloc);
	...
  }

Fixes: 604326b4 ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

When a skb verdict program is in-use and either another BPF program
redirects to that socket or the new SK_PASS support is used the
data_ready callback does not wake up application. Instead because
the stream parser/verdict is using the sk data_ready callback we wake
up the stream parser/verdict block.

Fix this by adding a helper to check if the stream parser block is
enabled on the sk and if so call the saved pointer which is the
upper layers wake up function.

This fixes application stalls observed when an application is waiting
for data in a blocking read().

Fixes: d829e9c4 ("tls: convert to generic sk_msg interface")
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Add SK_PASS verdict support to SK_SKB_VERDICT programs. Now that
support for redirects exists we can implement SK_PASS as a redirect
to the same socket. This simplifies the BPF programs and avoids an
extra map lookup on RX path for simple visibility cases.

Further, reduces user (BPF programmer in this context) confusion
when their program drops skb due to lack of support.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Enforce comment on structure layout dependency with a BUILD_BUG_ON
to ensure the condition is maintained.
Suggested-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The check for max offset in sk_msg_is_valid_access uses sizeof()
which is incorrect because it would allow accessing possibly
past the end of the struct in the padded case. Further, it doesn't
preclude accessing any padding that may be added in the middle of
a struct. All told this makes it fragile to rely on.

To fix this explicitly check offsets with fields using the
bpf_ctx_range() and bpf_ctx_range_till() macros.

For reference the current structure layout looks as follows (reported
by pahole)

struct sk_msg_md {
	union {
		void *             data;                 /*           8 */
	};                                               /*     0     8 */
	union {
		void *             data_end;             /*           8 */
	};                                               /*     8     8 */
	__u32                      family;               /*    16     4 */
	__u32                      remote_ip4;           /*    20     4 */
	__u32                      local_ip4;            /*    24     4 */
	__u32                      remote_ip6[4];        /*    28    16 */
	__u32                      local_ip6[4];         /*    44    16 */
	__u32                      remote_port;          /*    60     4 */
	/* --- cacheline 1 boundary (64 bytes) --- */
	__u32                      local_port;           /*    64     4 */
	__u32                      size;                 /*    68     4 */

	/* size: 72, cachelines: 2, members: 10 */
	/* last cacheline: 8 bytes */
};

So there should be no padding at the moment but fixing this now
prevents future errors.
Reported-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Currently, the test to ensure reads past the end of the sk_msg_md
data structure fail is incorrectly expecting success. Fix this
typo and use correct expected error.

Fixes: 945a47d8 ("bpf: sk_msg, add tests for size field")
Reported-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The frame_size passed to build_skb must be aligned, else it is
possible that the embedded struct skb_shared_info gets unaligned.

For correctness make sure that xdpf->headroom in included in the
alignment. No upstream drivers can hit this, as all XDP drivers provide
an aligned headroom.  This was discovered when playing with implementing
XDP support for mvneta, which have a 2 bytes DSA header, and this
Marvell ARM64 platform didn't like doing atomic operations on an
unaligned skb_shinfo(skb)->dataref addresses.

Fixes: 1c601d82 ("bpf: cpumap xdp_buff to skb conversion and allocation")
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Jakub Kicinski says:

====================
This is a v2 of the patch set to teach the verifier about BPF_JSET
instruction.  There is also a number of tests include for both
basic functioning of the instruction and the verifier logic.
The NFP JIT handling of JSET is tweaked.  Last patch adds missing
file to gitignore.

Reposting part of previous series without the dead code elimination.
====================
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

commit 435f90a3 ("selftests/bpf: add a test case for sock_ops
perf-event notification") missed adding new test to gitignore.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The top word of the constant can only have bits set if sign
extension set it to all-1, therefore we don't really have to
mask the top half of the register.  We can just OR it into
the result as is.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The verifier will now understand the JSET instruction, so don't
mark the dead branch in the JIT as noop.  We won't generate any
code, anyway.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Reorder the calls to check_max_stack_depth() and sanitize_dead_code()
to separate functions which can rewrite instructions from pure checks.

No functional changes.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NJiong Wang <jiong.wang@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Validate that the verifier reasons correctly about the bounds
and removes dead code based on results of JSET instruction.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Some JITs (nfp) try to optimize code on their own.  It could make
sense in case of BPF_JSET instruction which is currently not interpreted
by the verifier, meaning for instance that dead could would not be
detected if it was under BPF_JSET branch.

Teach the verifier basics of BPF_JSET, JIT optimizations will be
removed shortly.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NJiong Wang <jiong.wang@netronome.com>
Acked-by: NEdward Cree <ecree@solarflare.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

We seem to have no JSET instruction test, and LLVM does not
generate it at all, so let's add a simple hand-coded test
to make sure JIT implementations are correct.

v2:
 - extend test_verifier to handle multiple inputs and
   add the sample there (Daniel)
 - add a sign extension case
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This patch enables sparc64's bpf_int_jit_compile() to provide
bpf_line_info by calling bpf_prog_fill_jited_linfo().
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Martin KaFai Lau says:

====================
This series ensures the line_info (passed by the userspace during
bpf_prog_load) cannot have its line_info.insn_off pointing to a
zero bpf insn code.  F.e. a broken userspace tool might
generate a line_info.insn_off that points to the second
8 bytes of a BPF_LD_IMM64.

The first patch is the kernel change.
The second patch is a new test case.
====================
Acked-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

This patch adds a BPF_LD_IMM64 case to the line_info test
to ensure the kernel rejects linfo_info.insn_off pointing
to the 2nd 8 bytes of the BPF_LD_IMM64.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

This patch rejects a line_info if the bpf insn code referred by
line_info.insn_off is 0. F.e. a broken userspace tool might generate
a line_info.insn_off that points to the second 8 bytes of a BPF_LD_IMM64.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

This allows transparent cross-compilation with CROSS_COMPILE by
relying on 7ed1c190 ("tools: fix cross-compile var clobbering").
Signed-off-by: NIvan Babrou <ivan@cloudflare.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Prior this commit, when the struct socket object was being released,
the UMEM did not have its reference count decreased. Instead, this was
done in the struct sock sk_destruct function.

There is no reason to keep the UMEM reference around when the socket
is being orphaned, so in this patch the xdp_put_mem is called in the
xsk_release function. This results in that the xsk_destruct function
can be removed!

Note that, it still holds that a struct xsk_sock reference might still
linger in the XSKMAP after the UMEM is released, e.g. if a user does
not clear the XSKMAP prior to closing the process. This sock will be
in a "released" zombie like state, until the XSKMAP is removed.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Current btf internal verbose logger logs fwd type as
  [2] FWD A type_id=0
where A is the type name.

Commit 9d5f9f70 ("bpf: btf: fix struct/union/fwd types
with kind_flag") introduced kind_flag which can be used
to distinguish whether a forward type is a struct or
union.

Also, "type_id=0" does not carry any meaningful
information for fwd type as btf_type.type = 0 is simply
enforced during btf verification and is not used
anywhere else.

This commit changed the log to
  [2] FWD A struct
if kind_flag = 0, or
  [2] FWD A union
if kind_flag = 1.
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

John Fastabend says:

====================
This adds a size field to the sk_msg_md data structure used by SK_MSG
programs. Without this in the zerocopy case and in the copy case
where multiple iovs are in use its difficult to know how much data
can be pulled in. The normal method of reading data and data_end
only give the current contiguous buffer. BPF programs can attempt to
pull in extra data but have to guess if it exists. This can result
in multiple "guesses" its much better if we know upfront the size
of the sk_msg.
====================
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This adds tests to read the size field to test_verifier.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Add the size field to sk_msg_md for tools.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This adds metadata to sk_msg_md for BPF programs to read the sk_msg
size.

When the SK_MSG program is running under an application that is using
sendfile the data is not copied into sk_msg buffers by default. Rather
the BPF program uses sk_msg_pull_data to read the bytes in. This
avoids doing the costly memcopy instructions when they are not in
fact needed. However, if we don't know the size of the sk_msg we
have to guess if needed bytes are available by doing a pull request
which may fail. By including the size of the sk_msg BPF programs can
check the size before issuing sk_msg_pull_data requests.

Additionally, the same applies for sendmsg calls when the application
provides multiple iovs. Here the BPF program needs to pull in data
to update data pointers but its not clear where the data ends without
a size parameter. In many cases "guessing" is not easy to do
and results in multiple calls to pull and without bounded loops
everything gets fairly tricky.

Clean this up by including a u32 size field. Note, all writes into
sk_msg_md are rejected already from sk_msg_is_valid_access so nothing
additional is needed there.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Verifier is supposed to support sharing stack slot allocated to ptr with
SCALAR_VALUE for privileged program. However this doesn't happen for some
cases.

The reason is verifier is not clearing slot_type STACK_SPILL for all bytes,
it only clears part of them, while verifier is using:

  slot_type[0] == STACK_SPILL

as a convention to check one slot is ptr type.

So, the consequence of partial clearing slot_type is verifier could treat a
partially overridden ptr slot, which should now be a SCALAR_VALUE slot,
still as ptr slot, and rejects some valid programs.

Before this patch, test_xdp_noinline.o under bpf selftests, bpf_lxc.o and
bpf_netdev.o under Cilium bpf repo, when built with -mattr=+alu32 are
rejected due to this issue. After this patch, they all accepted.

There is no processed insn number change before and after this patch on
Cilium bpf programs.
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NJiong Wang <jiong.wang@netronome.com>
Reviewed-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Distributions build drivers as modules, including network and filesystem
drivers which export numerous tracepoints.  This enables
bpf(BPF_RAW_TRACEPOINT_OPEN) to attach to those tracepoints.
Signed-off-by: NMatt Mullins <mmullins@fb.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Quentin Monnet says:

====================
This series focus on mounting (or not mounting) tracefs with bpftool.

First patch makes bpftool attempt to mount tracefs if tracefs is not
found when running "bpftool prog tracelog".

Second patch adds an option to bpftool to prevent it from attempting
to mount any file system (tracefs or bpffs), in case this behaviour
is undesirable for some users.
====================
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

In order to make life easier for users, bpftool automatically attempts
to mount the BPF virtual file system, if it is not mounted already,
before trying to pin objects in it. Similarly, it attempts to mount
tracefs if necessary before trying to dump the trace pipe to the
console.

While mounting file systems on-the-fly can improve user experience, some
administrators might prefer to avoid that. Let's add an option to block
these mount attempts. Note that it does not prevent automatic mounting
of tracefs by debugfs for the "bpftool prog tracelog" command.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

As a follow-up to commit 30da46b5 ("tools: bpftool: add a command to
dump the trace pipe"), attempt to mount the tracefs virtual file system
if it is not detected on the system before trying to dump content of the
tracing pipe on an invocation of "bpftool prog tracelog".

Usually, tracefs in automatically mounted by debugfs when the user tries
to access it (e.g. "ls /sys/kernel/debug/tracing" mounts the tracefs).
So if we failed to find it, it is probably that debugfs is not here
either. Therefore, we just attempt a single mount, at a location that
does not involve debugfs: /sys/kernel/tracing.
Suggested-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Current btf func_info, line_info and jited_line are designed to be
extensible. The record sizes for {func,line}_info are passed to kernel,
and the record sizes for {func,line,jited_line}_info are returned to
userspace during bpf_prog_info query.

In bpf selftests test_btf.c, when testing whether kernel returns
a legitimate {func,line, jited_line)_info rec_size, the test only
compares to the minimum allowed size. If the returned rec_size is smaller
than the minimum allowed size, it is considered incorrect.
The minimum allowed size for these three info sizes are equal to
current value of sizeof(struct bpf_func_info), sizeof(struct bpf_line_info)
and sizeof(__u64).

The original thinking was that in the future when rec_size is increased
in kernel, the same test should run correctly. But this sacrificed
the precision of testing under the very kernel the test is shipped with,
and bpf selftest is typically run with the same repo kernel.

So this patch changed the testing of rec_size such that the
kernel returned value should be equal to the size defined by
tools uapi header bpf.h which syncs with kernel uapi header.

Martin discovered a bug in one of rec_size comparisons.
Instead of comparing to minimum func_info rec_size 8, it compares to 4.
This patch fixed that issue as well.

Fixes: 999d82cb ("tools/bpf: enhance test_btf file testing to test func info")
Fixes: 05687352 ("bpf: Refactor and bug fix in test_func_type in test_btf.c")
Fixes: 4d6304c7 ("bpf: Add unit tests for bpf_line_info")
Suggested-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This patch fixes a memory leak in libbpf by freeing up line_info
member of struct bpf_program while unloading a program.

Fixes: 3d650141 ("bpf: libbpf: Add btf_line_info support to libbpf")
Signed-off-by: NPrashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Yonghong Song says:

====================
Commit 69b693f0 ("bpf: btf: Introduce BPF Type Format (BTF)")
introduced BTF, a debug info format for BTF.

The original design has a couple of issues though.
First, the bitfield size is only encoded in int type.
If the struct member bitfield type is enum, pahole ([1])
or llvm is forced to replace enum with int type. As a result, the original
type information gets lost.

Second, the original BTF design does not envision the possibility of
BTF=>header_file conversion ([2]), hence does not encode "struct" or
"union" info for a forward type. Such information is necessary to
convert BTF to a header file.

This patch set fixed the issue by introducing kind_flag, using one bit
in type->info. When kind_flag, the struct/union btf_member->offset
will encode both bitfield_size and bit_offset, covering both
int and enum base types. The kind_flag is also used to indicate whether
the forward type is a union (when set) or a struct.

Patch #1 refactors function btf_int_bits_seq_show() so Patch #2
can reuse part of the function.
Patch #2 implemented kind_flag support for struct/union/fwd types.
Patch #3 added kind_flag support for cgroup local storage map pretty print.
Patch #4 syncs kernel uapi btf.h to tools directory.
Patch #5 added unit tests for kind_flag.
Patch #6 added tests for kernel bpffs based pretty print with kind_flag.
Patch #7 refactors function btf_dumper_int_bits() so Patch #8
can reuse part of the function.
Patch #8 added bpftool support of pretty print with kind_flag set.

  [1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=b18354f64cc215368c3bc0df4a7e5341c55c378c
  [2] https://lwn.net/SubscriberLink/773198/fe3074838f5c3f26/

Change logs:
  v2 -> v3:
    . Relocated comments about bitfield_size/bit_offset interpretation
      of the "offset" field right before the "offset" struct member.
    . Added missing byte alignment checking for non-bitfield enum
      member of a struct with kind_flag set.
    . Added two test cases in unit tests for struct type, kind_flag set,
      non-bitfield int/enum member, not-byte aligned bit offsets.
    . Added comments to help understand there is no overflow for
      total_bits_offset in bpftool function btf_dumper_int_bits().
    . Added explanation of typedef type dumping fix in Patch #8 commit
      message.

  v1 -> v2:
    . If kind_flag is set for a structure, ensure an int member,
      whether it is a bitfield or not, is a regular int type.
    . Added support so cgroup local storage map pretty print
      works with kind_flag.
====================
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The following example shows map pretty print with structures
which include bitfield members.

  enum A { A1, A2, A3, A4, A5 };
  typedef enum A ___A;
  struct tmp_t {
       char a1:4;
       int  a2:4;
       int  :4;
       __u32 a3:4;
       int b;
       ___A b1:4;
       enum A b2:4;
  };
  struct bpf_map_def SEC("maps") tmpmap = {
       .type = BPF_MAP_TYPE_ARRAY,
       .key_size = sizeof(__u32),
       .value_size = sizeof(struct tmp_t),
       .max_entries = 1,
  };
  BPF_ANNOTATE_KV_PAIR(tmpmap, int, struct tmp_t);

and the following map update in the bpf program:

  key = 0;
  struct tmp_t t = {};
  t.a1 = 2;
  t.a2 = 4;
  t.a3 = 6;
  t.b = 7;
  t.b1 = 8;
  t.b2 = 10;
  bpf_map_update_elem(&tmpmap, &key, &t, 0);

With this patch, I am able to print out the map values
correctly with this patch:
bpftool map dump id 187
  [{
        "key": 0,
        "value": {
            "a1": 0x2,
            "a2": 0x4,
            "a3": 0x6,
            "b": 7,
            "b1": 0x8,
            "b2": 0xa
        }
    }
  ]

Previously, if a function prototype argument has a typedef
type, the prototype is not printed since
function __btf_dumper_type_only() bailed out with error
if the type is a typedef. This commit corrected this
behavior by printing out typedef properly.

The following example shows forward type and
typedef type can be properly printed in function prototype
with modified test_btf_haskv.c.

  struct t;
  union  u;

  __attribute__((noinline))
  static int test_long_fname_1(struct dummy_tracepoint_args *arg,
                               struct t *p1, union u *p2,
                               __u32 unused)
  ...
  int _dummy_tracepoint(struct dummy_tracepoint_args *arg) {
    return test_long_fname_1(arg, 0, 0, 0);
  }

  $ bpftool p d xlated id 24
  ...
  int test_long_fname_1(struct dummy_tracepoint_args * arg,
                        struct t * p1, union u * p2,
                        __u32 unused)
  ...
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The core dump funcitonality in btf_dumper_int_bits() is
refactored into a separate function btf_dumper_bitfield()
which will be used by the next patch.
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The new tests are added to test bpffs map pretty print in kernel with kind_flag
for structure type.

  $ test_btf -p
  ......
  BTF pretty print array(#1)......OK
  BTF pretty print array(#2)......OK
  PASS:8 SKIP:0 FAIL:0
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This patch added unit tests for different types handling
type->info.kind_flag. The following new tests are added:
  $ test_btf
  ...
  BTF raw test[82] (invalid int kind_flag): OK
  BTF raw test[83] (invalid ptr kind_flag): OK
  BTF raw test[84] (invalid array kind_flag): OK
  BTF raw test[85] (invalid enum kind_flag): OK
  BTF raw test[86] (valid fwd kind_flag): OK
  BTF raw test[87] (invalid typedef kind_flag): OK
  BTF raw test[88] (invalid volatile kind_flag): OK
  BTF raw test[89] (invalid const kind_flag): OK
  BTF raw test[90] (invalid restrict kind_flag): OK
  BTF raw test[91] (invalid func kind_flag): OK
  BTF raw test[92] (invalid func_proto kind_flag): OK
  BTF raw test[93] (valid struct kind_flag, bitfield_size = 0): OK
  BTF raw test[94] (valid struct kind_flag, int member, bitfield_size != 0): OK
  BTF raw test[95] (valid union kind_flag, int member, bitfield_size != 0): OK
  BTF raw test[96] (valid struct kind_flag, enum member, bitfield_size != 0): OK
  BTF raw test[97] (valid union kind_flag, enum member, bitfield_size != 0): OK
  BTF raw test[98] (valid struct kind_flag, typedef member, bitfield_size != 0): OK
  BTF raw test[99] (valid union kind_flag, typedef member, bitfield_size != 0): OK
  BTF raw test[100] (invalid struct type, bitfield_size greater than struct size): OK
  BTF raw test[101] (invalid struct type, kind_flag bitfield base_type int not regular): OK
  BTF raw test[102] (invalid struct type, kind_flag base_type int not regular): OK
  BTF raw test[103] (invalid union type, bitfield_size greater than struct size): OK
  ...
  PASS:122 SKIP:0 FAIL:0

The second parameter name of macro
  BTF_INFO_ENC(kind, root, vlen)
in selftests test_btf.c is also renamed from "root" to "kind_flag".
Note that before this patch "root" is not used and always 0.
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>