This patch adds libbpf support for kernel module function call support.
The fd_array parameter is used during BPF program load to pass module
BTFs referenced by the program. insn->off is set to index into this
array, but starts from 1, because insn->off as 0 is reserved for
btf_vmlinux.

We try to use existing insn->off for a module, since the kernel limits
the maximum distinct module BTFs for kfuncs to 256, and also because
index must never exceed the maximum allowed value that can fit in
insn->off (INT16_MAX). In the future, if kernel interprets signed offset
as unsigned for kfunc calls, this limit can be increased to UINT16_MAX.

Also introduce a btf__find_by_name_kind_own helper to start searching
from module BTF's start id when we know that the BTF ID is not present
in vmlinux BTF (in find_ksym_btf_id).
Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-7-memxor@gmail.com

This commit allows specifying the base BTF for resolving btf id
lists/sets during link time in the resolve_btfids tool. The base BTF is
set to NULL if no path is passed. This allows resolving BTF ids for
module kernel objects.

Also, drop the --no-fail option, as it is only used in case .BTF_ids
section is not present, instead make no-fail the default mode. The long
option name is same as that of pahole.
Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-5-memxor@gmail.com

This patch adds support for testing the encap (ip6ip6) mode of IOAM.
Signed-off-by: NJustin Iurman <justin.iurman@uliege.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For this test we are exercising the VCAP ES0 block's ability to match on
a packet with a given VLAN ID, and push an ES0 TAG A with a VID derived
from VID_A_VAL plus the classified VLAN.

$eth3.200 is the generator port
$eth0 is the bridged DUT port that receives
$eth1 is the bridged DUT port that forwards and rewrites VID 200 to 300
      on egress via VCAP ES0
$eth2 is the port that receives from the DUT port $eth1

Since the egress rewriting happens outside the bridging service, VID 300
does not need to be in the bridge VLAN table of $eth1.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There will be one more VLAN modification selftest added, this time for
egress. Rename the one that exists right now to be more specific.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Looks like when I wrote the selftests I was using a network manager that
brought up the ports automatically. In order to not rely on that, let
the script open them up.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change map definitions in BPF selftests to use BTF-defined
key/value types. This unifies the map definitions and ensures
libbpf won't emit warning about retrying map creation.
Signed-off-by: NHengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210930161456.3444544-3-hengqi.chen@gmail.com

A bunch of BPF maps do not support specifying BTF types for key and value.
This is non-uniform and inconvenient[0]. Currently, libbpf uses a retry
logic which removes BTF type IDs when BPF map creation failed. Instead
of retrying, this commit recognizes those specialized maps and removes
BTF type IDs when creating BPF map.

  [0] Closes: https://github.com/libbpf/libbpf/issues/355Signed-off-by: NHengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210930161456.3444544-2-hengqi.chen@gmail.com

There are several test cases in the bpf directory are still using
exit 0 when they need to be skipped. Use kselftest framework skip
code instead so it can help us to distinguish the return status.

Criterion to filter out what should be fixed in bpf directory:
  grep -r "exit 0" -B1 | grep -i skip

This change might cause some false-positives if people are running
these test scripts directly and only checking their return codes,
which will change from 0 to 4. However I think the impact should be
small as most of our scripts here are already using this skip code.
And there will be no such issue if running them with the kselftest
framework.
Signed-off-by: NPo-Hsu Lin <po-hsu.lin@canonical.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210929051250.13831-1-po-hsu.lin@canonical.com

When the loader indicates an internal error (result of a checked bpf
system call), it returns the result in attr.test.retval. However, tests
that rely on ASSERT_OK_PTR on NULL (returned from light skeleton) may
miss that NULL denotes an error if errno is set to 0. This would result
in skel pointer being NULL, while ASSERT_OK_PTR returning 1, leading to
a SEGV on dereference of skel, because libbpf_get_error relies on the
assumption that errno is always set in case of error for ptr == NULL.

In particular, this was observed for the ksyms_module test. When
executed using `./test_progs -t ksyms`, prior tests manipulated errno
and the test didn't crash when it failed at ksyms_module load, while
using `./test_progs -t ksyms_module` crashed due to errno being
untouched.

Fixes: 67234743 (libbpf: Generate loader program out of BPF ELF file.)
Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210927145941.1383001-11-memxor@gmail.com

The previous patch to ignore STT_SECTION symbols only added the ignore
condition in one of them. This fails if there's more than one map
definition in the 'maps' section, because the subsequent modulus check will
fail, resulting in error messages like:

libbpf: elf: unable to determine legacy map definition size in ./xdpdump_xdp.o

Fix this by also ignoring STT_SECTION in the first loop.

Fixes: c3e8c44a ("libbpf: Ignore STT_SECTION symbols in 'maps' section")
Signed-off-by: NToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210929213837.832449-1-toke@redhat.com

Align gen_loader data to 8 byte boundary to make sure union bpf_attr,
bpf_insns and other structs are aligned.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210927145941.1383001-9-memxor@gmail.com

Cleanup code uses while (cpu++ < cpu_cnt) for closing fds, which means
it starts iterating from 1 for closing fds. If the first fd is -1, it
skips over it and closes garbage fds (typically zero) in the remaining
array. This leads to test failures for future tests when they end up
storing fd 0 (as the slot becomes free due to close(0)) in ldimm64's BTF
fd, ending up trying to match module BTF id with vmlinux.

This was observed as spurious CI failure for the ksym_module_libbpf and
module_attach tests. The test ends up closing fd 0 and breaking libbpf's
assumption that module BTF fd will always be > 0, which leads to the
kernel thinking that we are pointing to a BTF ID in vmlinux BTF.

Fixes: 025bd7c7 (selftests/bpf: Add test for bpf_get_branch_snapshot)
Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210927145941.1383001-12-memxor@gmail.com

clang build kernel failed the selftest probe_user.
  $ ./test_progs -t probe_user
  $ ...
  $ test_probe_user:PASS:get_kprobe_res 0 nsec
  $ test_probe_user:FAIL:check_kprobe_res wrong kprobe res from probe read: 0.0.0.0:0
  $ #94 probe_user:FAIL

The test attached to kernel function __sys_connect(). In net/socket.c, we have
  int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
  {
        ......
  }
  ...
  SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
                  int, addrlen)
  {
        return __sys_connect(fd, uservaddr, addrlen);
  }

The gcc compiler (8.5.0) does not inline __sys_connect() in syscall entry
function. But latest clang trunk did the inlining. So the bpf program
is not triggered.

To make the test more reliable, let us kprobe the syscall entry function
instead. Note that x86_64, arm64 and s390 have syscall wrappers and they have
to be handled specially.
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210929033000.3711921-1-yhs@fb.com

"?:" is a GNU C extension, some environment has warning flags for its
use, or even prohibit it directly.  This patch avoid triggering these
problems by simply expand it to its full form, no functionality change.
Signed-off-by: NYucong Sun <fallentree@fb.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210928184221.1545079-1-fallentree@fb.com

Update "sk_lookup/" definition to be a stand-alone type specifier,
with backwards-compatible prefix match logic in non-libbpf-1.0 mode.

Currently in selftests all the "sk_lookup/<whatever>" uses just use
<whatever> for duplicated unique name encoding, which is redundant as
BPF program's name (C function name) uniquely and descriptively
identifies the intended use for such BPF programs.

With libbpf's SEC_DEF("sk_lookup") definition updated, switch existing
sk_lookup programs to use "unqualified" SEC("sk_lookup") section names,
with no random text after it.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-11-andrii@kernel.org

Implement strict ELF section name handling for BPF programs. It utilizes
`libbpf_set_strict_mode()` framework and adds new flag: LIBBPF_STRICT_SEC_NAME.

If this flag is set, libbpf will enforce exact section name matching for
a lot of program types that previously allowed just partial prefix
match. E.g., if previously SEC("xdp_whatever_i_want") was allowed, now
in strict mode only SEC("xdp") will be accepted, which makes SEC("")
definitions cleaner and more structured. SEC() now won't be used as yet
another way to uniquely encode BPF program identifier (for that
C function name is better and is guaranteed to be unique within
bpf_object). Now SEC() is strictly BPF program type and, depending on
program type, extra load/attach parameter specification.

Libbpf completely supports multiple BPF programs in the same ELF
section, so multiple BPF programs of the same type/specification easily
co-exist together within the same bpf_object scope.

Additionally, a new (for now internal) convention is introduced: section
name that can be a stand-alone exact BPF program type specificator, but
also could have extra parameters after '/' delimiter. An example of such
section is "struct_ops", which can be specified by itself, but also
allows to specify the intended operation to be attached to, e.g.,
"struct_ops/dctcp_init". Note, that "struct_ops_some_op" is not allowed.
Such section definition is specified as "struct_ops+".

This change is part of libbpf 1.0 effort ([0], [1]).

  [0] Closes: https://github.com/libbpf/libbpf/issues/271
  [1] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#stricter-and-more-uniform-bpf-program-section-name-sec-handlingSigned-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-10-andrii@kernel.org

Complete SEC() table refactoring towards unified form by rewriting
BPF_APROG_SEC and BPF_EAPROG_SEC definitions with
SEC_DEF(SEC_ATTACHABLE_OPT) (for optional expected_attach_type) and
SEC_DEF(SEC_ATTACHABLE) (mandatory expected_attach_type), respectively.
Drop BPF_APROG_SEC, BPF_EAPROG_SEC, and BPF_PROG_SEC_IMPL macros after
that, leaving SEC_DEF() macro as the only one used.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-9-andrii@kernel.org

Refactor ELF section handler definitions table to use a set of flags and
unified SEC_DEF() macro. This allows for more succinct and table-like
set of definitions, and allows to more easily extend the logic without
adding more verbosity (this is utilized in later patches in the series).

This approach is also making libbpf-internal program pre-load callback
not rely on bpf_sec_def definition, which demonstrates that future
pluggable ELF section handlers will be able to achieve similar level of
integration without libbpf having to expose extra types and APIs.

For starters, update SEC_DEF() definitions and make them more succinct.
Also convert BPF_PROG_SEC() and BPF_APROG_COMPAT() definitions to
a common SEC_DEF() use.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-8-andrii@kernel.org

Move closer to not relying on bpf_sec_def internals that won't be part
of public API, when pluggable SEC() handlers will be allowed. Drop
pre-calculated prefix length, and in various helpers don't rely on this
prefix length availability. Also minimize reliance on knowing
bpf_sec_def's prefix for few places where section prefix shortcuts are
supported (e.g., tp vs tracepoint, raw_tp vs raw_tracepoint).

Given checking some string for having a given string-constant prefix is
such a common operation and so annoying to be done with pure C code, add
a small macro helper, str_has_pfx(), and reuse it throughout libbpf.c
where prefix comparison is performed. With __builtin_constant_p() it's
possible to have a convenient helper that checks some string for having
a given prefix, where prefix is either string literal (or compile-time
known string due to compiler optimization) or just a runtime string
pointer, which is quite convenient and saves a lot of typing and string
literal duplication.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-7-andrii@kernel.org

Refactor internals of libbpf to allow adding custom SEC() handling logic
easily from outside of libbpf. To that effect, each SEC()-handling
registration sets mandatory program type/expected attach type for
a given prefix and can provide three callbacks called at different
points of BPF program lifetime:

  - init callback for right after bpf_program is initialized and
  prog_type/expected_attach_type is set. This happens during
  bpf_object__open() step, close to the very end of constructing
  bpf_object, so all the libbpf APIs for querying and updating
  bpf_program properties should be available;

  - pre-load callback is called right before BPF_PROG_LOAD command is
  called in the kernel. This callbacks has ability to set both
  bpf_program properties, as well as program load attributes, overriding
  and augmenting the standard libbpf handling of them;

  - optional auto-attach callback, which makes a given SEC() handler
  support auto-attachment of a BPF program through bpf_program__attach()
  API and/or BPF skeletons <skel>__attach() method.

Each callbacks gets a `long cookie` parameter passed in, which is
specified during SEC() handling. This can be used by callbacks to lookup
whatever additional information is necessary.

This is not yet completely ready to be exposed to the outside world,
mainly due to non-public nature of struct bpf_prog_load_params. Instead
of making it part of public API, we'll wait until the planned low-level
libbpf API improvements for BPF_PROG_LOAD and other typical bpf()
syscall APIs, at which point we'll have a public, probably OPTS-based,
way to fully specify BPF program load parameters, which will be used as
an interface for custom pre-load callbacks.

But this change itself is already a good first step to unify the BPF
program hanling logic even within the libbpf itself. As one example, all
the extra per-program type handling (sleepable bit, attach_btf_id
resolution, unsetting optional expected attach type) is now more obvious
and is gathered in one place.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-6-andrii@kernel.org

Normalize all the other non-conforming SEC() usages across all
selftests. This is in preparation for libbpf to start to enforce
stricter SEC() rules in libbpf 1.0 mode.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-5-andrii@kernel.org

Convert all SEC("classifier*") uses to a new and strict SEC("tc")
section name. In reference_tracking selftests switch from ambiguous
searching by program title (section name) to non-ambiguous searching by
name in some selftests, getting closer to completely removing
bpf_object__find_program_by_title().
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-4-andrii@kernel.org

Convert almost all SEC("xdp_blah") uses to strict SEC("xdp") to comply
with strict libbpf 1.0 logic of exact section name match for XDP program
types. There is only one exception, which is only tested through
iproute2 and defines multiple XDP programs within the same BPF object.
Given iproute2 still works in non-strict libbpf mode and it doesn't have
means to specify XDP programs by its name (not section name/title),
leave that single file alone for now until iproute2 gains lookup by
function/program name.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-3-andrii@kernel.org

As argued in [0], add "tc" ELF section definition for SCHED_CLS BPF
program type. "classifier" is a misleading terminology and should be
migrated away from.

  [0] https://lore.kernel.org/bpf/270e27b1-e5be-5b1c-b343-51bd644d0747@iogearbox.net/Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-2-andrii@kernel.org

It's not enough to set net.ipv4.conf.all.rp_filter=0, that does not override
a greater rp_filter value on the individual interfaces. We also need to set
net.ipv4.conf.default.rp_filter=0 before creating the interfaces. That way,
they'll also get their own rp_filter value of zero.

Fixes: 0fde56e4 ("selftests: bpf: add test_lwt_ip_encap selftest")
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/b1cdd9d469f09ea6e01e9c89a6071c79b7380f89.1632386362.git.jbenc@redhat.com

When building bpf selftest with make -j, I'm randomly getting build failures
such as this one:

  In file included from progs/bpf_flow.c:19:
  [...]/tools/testing/selftests/bpf/tools/include/bpf/bpf_helpers.h:11:10: fatal error: 'bpf_helper_defs.h' file not found
  #include "bpf_helper_defs.h"
           ^~~~~~~~~~~~~~~~~~~

The file that fails the build varies between runs but it's always in the
progs/ subdir.

The reason is a missing make dependency on libbpf for the .o files in
progs/. There was a dependency before commit 3ac2e20f but that commit
removed it to prevent unneeded rebuilds. However, that only works if libbpf
has been built already; the 'wildcard' prerequisite does not trigger when
there's no bpf_helper_defs.h generated yet.

Keep the libbpf as an order-only prerequisite to satisfy both goals. It is
always built before the progs/ objects but it does not trigger unnecessary
rebuilds by itself.

Fixes: 3ac2e20f ("selftests/bpf: BPF object files should depend only on libbpf headers")
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/ee84ab66436fba05a197f952af23c98d90eb6243.1632758415.git.jbenc@redhat.com

When a BPF object is compiled without BTF info (without -g),
trying to link such objects using bpftool causes a SIGSEGV due to
btf__get_nr_types accessing obj->btf which is NULL. Fix this by
checking for the NULL pointer, and return error.

Reproducer:
$ cat a.bpf.c
extern int foo(void);
int bar(void) { return foo(); }
$ cat b.bpf.c
int foo(void) { return 0; }
$ clang -O2 -target bpf -c a.bpf.c
$ clang -O2 -target bpf -c b.bpf.c
$ bpftool gen obj out a.bpf.o b.bpf.o
Segmentation fault (core dumped)

After fix:
$ bpftool gen obj out a.bpf.o b.bpf.o
libbpf: failed to find BTF info for object 'a.bpf.o'
Error: failed to link 'a.bpf.o': Unknown error -22 (-22)

Fixes: a4634922 (libbpf: Add linker extern resolution support for functions and global variables)
Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210924023725.70228-1-memxor@gmail.com

When parsing legacy map definitions, libbpf would error out when
encountering an STT_SECTION symbol. This becomes a problem because some
versions of binutils will produce SECTION symbols for every section when
processing an ELF file, so BPF files run through 'strip' will end up with
such symbols, making libbpf refuse to load them.

There's not really any reason why erroring out is strictly necessary, so
change libbpf to just ignore SECTION symbols when parsing the ELF.
Signed-off-by: NToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210927205810.715656-1-toke@redhat.com

Add a test for the frame_headroom feature that can be set on the
umem. The logic added validates that all offsets in all tests and
packets are valid, not just the ones that have a specifically
configured frame_headroom.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922075613.12186-14-magnus.karlsson@gmail.com

Change the interleaving of packets in unaligned mode. With the current
buffer addresses in the packet stream, the last buffer in the umem
could not be used as a large packet could potentially write over the
end of the umem. The kernel correctly threw this buffer address away
and refused to use it. This is perfectly fine for all regular packet
streams, but the ones used for unaligned mode have every other packet
being at some different offset. As we will add checks for correct
offsets in the next patch, this needs to be fixed. Just start these
page-boundary straddling buffers one page earlier so that the last
one is not on the last page of the umem, making all buffers valid.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922075613.12186-13-magnus.karlsson@gmail.com

Add a test where a single packet is sent and received. This might
sound like a silly test, but since many of the interfaces in xsk are
batched, it is important to be able to validate that we did not break
something as fundamental as just receiving single packets, instead of
batches of packets at high speed.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922075613.12186-12-magnus.karlsson@gmail.com

Introduce pacing of traffic so that the Tx thread can never send more
packets than the receiver has processed plus the number of packets it
can have in its umem. So at any point in time, the number of in flight
packets (not processed by the Rx thread) are less than or equal to the
number of packets that can be held in the Rx thread's umem.

The batch size is also increased to improve running time.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922075613.12186-11-magnus.karlsson@gmail.com

The socket creation retry unnecessarily registered the umem once for
every retry. No reason to do this. It wastes memory and it might lead
to too many pages being locked at some point and the failure of a
test.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922075613.12186-10-magnus.karlsson@gmail.com

Fix a problem where the fill ring was populated with too many
entries. If number of buffers in the umem was smaller than the fill
ring size, the code used to loop over from the beginning of the umem
and start putting the same buffers in again. This is racy indeed as a
later packet can be received overwriting an earlier one before the Rx
thread manages to validate it.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922075613.12186-9-magnus.karlsson@gmail.com

Fix missing initialization of the member rx_pkt_nb in the packet
stream. This leads to some tests declaring success too early as the
test thought all packets had already been received.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922075613.12186-8-magnus.karlsson@gmail.com

If the 'perf iostat' user specifies two or more iio_root_ports and also
specifies the cpu(s) by -C which is not *connected to all* the above iio
ports, the iostat_print_metric() will run into trouble:

For example:

  $ perf iostat list
  S0-uncore_iio_0<0000:16>
  S1-uncore_iio_0<0000:97> # <--- CPU 1 is located in the socket S0

  $ perf iostat 0000:16,0000:97 -C 1 -- ls
  port 	Inbound Read(MB)	Inbound Write(MB)	Outbound Read(MB)	Outbound
  Write(MB) ../perf-iostat: line 12: 104418 Segmentation fault
  (core dumped) perf stat --iostat$DELIMITER$*

The core-dump stack says, in the above corner case, the returned
(struct perf_counts_values *) count will be NULL, and the caller
iostat_print_metric() apparently doesn't not handle this case.

  433	struct perf_counts_values *count = perf_counts(evsel->counts, die, 0);
  434
  435	if (count->run && count->ena) {
  (gdb) p count
  $1 = (struct perf_counts_values *) 0x0

The deeper reason is that there are actually no statistics from the user
specified pair "iostat 0000:X, -C (disconnected) Y ", but let's fix it with
minimum cost by adding a NULL check in the user space.

Fixes: f9ed693e ("perf stat: Enable iostat mode for x86 platforms")
Signed-off-by: NLike Xu <likexu@tencent.com>
Cc: Alexander Antonov <alexander.antonov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210927081115.39568-2-likexu@tencent.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

An iostate use case like "perf iostat 0000:16,0000:97 -- ls" should be
implemented to work in system-wide mode to ensure that the output from
print_header() is consistent with the user documentation perf-iostat.txt,
rather than incorrectly assuming that the kernel does not support it:

 Error:
 The sys_perf_event_open() syscall returned with 22 (Invalid argument) \
 for event (uncore_iio_0/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/).
 /bin/dmesg | grep -i perf may provide additional information.

This error is easily fixed by assigning system-wide mode by default
for IOSTAT_RUN only when the target cpu_list is unspecified.

Fixes: f07952b1 ("perf stat: Basic support for iostat in perf")
Signed-off-by: NLike Xu <likexu@tencent.com>
Cc: Alexander Antonov <alexander.antonov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210927081115.39568-1-likexu@tencent.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If there is no configuration file at first, the user can write any pair
of "key.subkey=value" to the newly created configuration file, while
value validation against a valid configurable key is *deferred* until
the next execution or the implied execution of "perf config ... ".

For example:

  $ rm ~/.perfconfig
  $ perf config call-graph.dump-size=65529
  $ cat ~/.perfconfig
  # this file is auto-generated.
  [call-graph]
 	dump-size = 65529
  $ perf config call-graph.dump-size=2048
  callchain: Incorrect stack dump size (max 65528): 65529
  Error: wrong config key-value pair call-graph.dump-size=65529

The user might expect that the second value 2048 is valid and can be
updated to the configuration file, but the error message is very
confusing because the first value 65529 is not reported as an error
during the last configuration.

It is recommended not to change the current behavior of delayed
validation (as more effort is needed), but to refine the original error
message to *clearly indicate* that the cause of the error is the
configuration file.
Signed-off-by: NLike Xu <likexu@tencent.com>
Acked-by: NIan Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210924115817.58689-1-likexu@tencent.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Considering that perf and its subcommands have so many parameters, the
documentation is always the first stop for perf beginners. Fixing some
spelling errors will relax the eyes of some readers a little bit.

 s/specicfication/specification/
 s/caheline/cacheline/
 s/tranasaction/transaction/
 s/complan/complain/
 s/sched_wakep/sched_wakeup/
 s/possble/possible/
 s/methology/methodology/
Signed-off-by: NLike Xu <likexu@tencent.com>
Acked-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210924081942.38368-1-likexu@tencent.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>