selftests/bpf: fix compiler warnings in RELEASE=1 mode

When compiling BPF selftests with RELEASE=1, we get two new
warnings, which are treated as errors. Fix them.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20231212225343.1723081-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf: rename BPF_F_TEST_SANITY_STRICT to BPF_F_TEST_REG_INVARIANTS

Rename verifier internal flag BPF_F_TEST_SANITY_STRICT to more neutral
BPF_F_TEST_REG_INVARIANTS. This is a follow up to [0].

A few selftests and veristat need to be adjusted in the same patch as
well.

[0] https://patchwork.kernel.org/project/netdevbpf/patch/20231112010609.848406-5-andrii@kernel.org/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231117171404.225508-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: add ability to set BPF_F_TEST_SANITY_STRICT flag with -r flag

Add a new flag -r (--test-sanity), similar to -t (--test-states), to add
extra BPF program flags when loading BPF programs.

This allows to use veristat to easily catch sanity violations in
production BPF programs.

reg_bounds tests are also enforcing BPF_F_TEST_SANITY_STRICT flag now.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231112010609.848406-13-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: add ability to filter top N results

Add ability to filter top B results, both in replay/verifier mode and
comparison mode. Just adding `-n10` will emit only first 10 rows, or
less, if there is not enough rows.

This is not just a shortcut instead of passing veristat output through
`head`, though. Filtering out all the other rows influences final table
formatting, as table column widths are calculated based on actual
emitted test.

To demonstrate the difference, compare two "equivalent" forms below, one
using head and another using -n argument.

TOP N FEATURE
=============
[vmuser@archvm bpf]$ sudo ./veristat -C ~/baseline-results-selftests.csv ~/sanity2-results-selftests.csv -e file,prog,insns,states -s '|insns_diff|' -n10
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
---------------------------------------- --------------------- --------- --------- ------------ ---------- ---------- -------------
test_seg6_loop.bpf.linked3.o __add_egr_x 12440 12360 -80 (-0.64%) 364 357 -7 (-1.92%)
async_stack_depth.bpf.linked3.o async_call_root_check 145 145 +0 (+0.00%) 3 3 +0 (+0.00%)
async_stack_depth.bpf.linked3.o pseudo_call_check 139 139 +0 (+0.00%) 3 3 +0 (+0.00%)
atomic_bounds.bpf.linked3.o sub 7 7 +0 (+0.00%) 0 0 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o kmalloc 5 5 +0 (+0.00%) 0 0 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o sched_process_fork 22 22 +0 (+0.00%) 2 2 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o socket_post_create 23 23 +0 (+0.00%) 2 2 +0 (+0.00%)
bind4_prog.bpf.linked3.o bind_v4_prog 358 358 +0 (+0.00%) 33 33 +0 (+0.00%)
bind6_prog.bpf.linked3.o bind_v6_prog 429 429 +0 (+0.00%) 37 37 +0 (+0.00%)
bind_perm.bpf.linked3.o bind_v4_prog 15 15 +0 (+0.00%) 1 1 +0 (+0.00%)

PIPING TO HEAD
==============
[vmuser@archvm bpf]$ sudo ./veristat -C ~/baseline-results-selftests.csv ~/sanity2-results-selftests.csv -e file,prog,insns,states -s '|insns_diff|' | head -n12
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
----------------------------------------------------- ---------------------------------------------------- --------- --------- ------------ ---------- ---------- -------------
test_seg6_loop.bpf.linked3.o __add_egr_x 12440 12360 -80 (-0.64%) 364 357 -7 (-1.92%)
async_stack_depth.bpf.linked3.o async_call_root_check 145 145 +0 (+0.00%) 3 3 +0 (+0.00%)
async_stack_depth.bpf.linked3.o pseudo_call_check 139 139 +0 (+0.00%) 3 3 +0 (+0.00%)
atomic_bounds.bpf.linked3.o sub 7 7 +0 (+0.00%) 0 0 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o kmalloc 5 5 +0 (+0.00%) 0 0 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o sched_process_fork 22 22 +0 (+0.00%) 2 2 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o socket_post_create 23 23 +0 (+0.00%) 2 2 +0 (+0.00%)
bind4_prog.bpf.linked3.o bind_v4_prog 358 358 +0 (+0.00%) 33 33 +0 (+0.00%)
bind6_prog.bpf.linked3.o bind_v6_prog 429 429 +0 (+0.00%) 37 37 +0 (+0.00%)
bind_perm.bpf.linked3.o bind_v4_prog 15 15 +0 (+0.00%) 1 1 +0 (+0.00%)

Note all the wasted whitespace in the "PIPING TO HEAD" variant.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231108051430.1830950-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: add ability to sort by stat's absolute value

Add ability to sort results by absolute values of specified stats. This
is especially useful to find biggest deviations in comparison mode. When
comparing verifier change effect against a large base of BPF object
files, it's necessary to see big changes both in positive and negative
directions, as both might be a signal for regressions or bugs.

The syntax is natural, e.g., adding `-s '|insns_diff|'^` will instruct
veristat to sort by absolute value of instructions difference in
ascending order.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231108051430.1830950-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: add -t flag for adding BPF_F_TEST_STATE_FREQ program flag

Sometimes during debugging it's important that BPF program is loaded
with BPF_F_TEST_STATE_FREQ flag set to force verifier to do frequent
state checkpointing. Teach veristat to do this when -t ("test state")
flag is specified.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: Add more veristat control over verifier log options

Add --log-size to be able to customize log buffer sent to bpf() syscall
for BPF program verification logging.

Add --log-fixed to enforce BPF_LOG_FIXED behavior for BPF verifier log.
This is useful in unlikely event that beginning of truncated verifier
log is more important than the end of it (which with rotating verifier
log behavior is the default now).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230406234205.323208-6-andrii@kernel.org

selftests/bpf: Prevent infinite loop in veristat when base file is too short

The following example forces veristat to loop indefinitely:

$ cat two-ok
file_name,prog_name,verdict,total_states
file-a,a,success,12
file-b,b,success,67

$ cat add-failure
file_name,prog_name,verdict,total_states
file-a,a,success,12
file-b,b,success,67
file-b,c,failure,32

$ veristat -C two-ok add-failure
<does not return>

The loop is caused by handle_comparison_mode() not checking if `base`
variable points to `fallback_stats` prior advancing joined results
using `base`.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230407154125.896927-1-eddyz87@gmail.com

veristat: small fixed found in -O2 mode

Fix few potentially unitialized variables uses, found while building
veristat.c in release (-O2) mode.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230331222405.3468634-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: avoid using kernel-internal headers

Drop linux/compiler.h include, which seems to be needed for ARRAY_SIZE
macro only. Redefine own version of ARRAY_SIZE instead.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230331222405.3468634-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: improve version reporting

For packaging version of the tool is important, so add a simple way to
specify veristat version for upstream mirror at Github.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230331222405.3468634-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: relicense veristat.c as dual GPL-2.0-only or BSD-2-Clause licensed

Dual-license veristat.c to dual GPL-2.0-only or BSD-2-Clause license.
This is needed to mirror it to Github to make it convenient for distro
packagers to package veristat as a separate package.

Veristat grew into a useful tool by itself, and there are already
a bunch of users relying on veristat as generic BPF loading and
verification helper tool. So making it easy to packagers by providing
Github mirror just like we do for bpftool and libbpf is the next step to
get veristat into the hands of users.

Apart from few typo fixes, I'm the sole contributor to veristat.c so
far, so no extra Acks should be needed for relicensing.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230331222405.3468634-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: change guess for __sk_buff from CGROUP_SKB to SCHED_CLS

SCHED_CLS seems to be a better option as a default guess for freplace
programs that have __sk_buff as a context type.

Reported-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230330190115.3942962-1-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

veristat: guess and substitue underlying program type for freplace (EXT) progs

SEC("freplace") (i.e., BPF_PROG_TYPE_EXT) programs are not loadable as
is through veristat, as kernel expects actual program's FD during
BPF_PROG_LOAD time, which veristat has no way of knowing.

Unfortunately, freplace programs are a pretty important class of
programs, especially when dealing with XDP chaining solutions, which
rely on EXT programs.

So let's do our best and teach veristat to try to guess the original
program type, based on program's context argument type. And if guessing
process succeeds, we manually override freplace/EXT with guessed program
type using bpf_program__set_type() setter to increase chances of proper
BPF verification.

We rely on BTF and maintain a simple lookup table. This process is
obviously not 100% bulletproof, as valid program might not use context
and thus wouldn't have to specify correct type. Also, __sk_buff is very
ambiguous and is the context type across many different program types.
We pick BPF_PROG_TYPE_CGROUP_SKB for now, which seems to work fine in
practice so far. Similarly, some program types require specifying attach
type, and so we pick one out of possible few variants.

Best effort at its best. But this makes veristat even more widely
applicable.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230327185202.1929145-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

veristat: add -d debug mode option to see debug libbpf log

Add -d option to allow requesting libbpf debug logs from veristat.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230327185202.1929145-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Fix typos in selftest/bpf files

Run spell checker on files in selftest/bpf and fixed typos.

Signed-off-by: Taichi Nishimura <awkrail01@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/bpf/20230216085537.519062-1-awkrail01@gmail.com

selftests/bpf: fix veristat's singular file-or-prog filter

Fix the bug of filtering out filename too early, before we know the
program name, if using unified file-or-prog filter (i.e., -f
<any-glob>). Because we try to filter BPF object file early without
opening and parsing it, if any_glob (file-or-prog) filter is used we
have to accept any filename just to get program name, which might match
any_glob.

Fixes: 10b1b3f3e56a ("selftests/bpf: consolidate and improve file/prog filtering in veristat")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20221111181242.2101192-1-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

selftests/bpf: support stat filtering in comparison mode in veristat

Finally add support for filtering stats values, similar to
non-comparison mode filtering. For comparison mode 4 variants of stats
are important for filtering, as they allow to filter either A or B side,
but even more importantly they allow to filter based on value
difference, and for verdict stat value difference is MATCH/MISMATCH
classification. So with these changes it's finally possible to easily
check if there were any mismatches between failure/success outcomes on
two separate data sets. Like in an example below:

$ ./veristat -e file,prog,verdict,insns -C ~/baseline-results.csv ~/shortest-results.csv -f verdict_diff=mismatch
File Program Verdict (A) Verdict (B) Verdict (DIFF) Insns (A) Insns (B) Insns (DIFF)
------------------------------------- --------------------- ----------- ----------- -------------- --------- --------- -------------------
dynptr_success.bpf.linked1.o test_data_slice success failure MISMATCH 85 0 -85 (-100.00%)
dynptr_success.bpf.linked1.o test_read_write success failure MISMATCH 1992 0 -1992 (-100.00%)
dynptr_success.bpf.linked1.o test_ringbuf success failure MISMATCH 74 0 -74 (-100.00%)
kprobe_multi.bpf.linked1.o test_kprobe failure success MISMATCH 0 246 +246 (+100.00%)
kprobe_multi.bpf.linked1.o test_kprobe_manual failure success MISMATCH 0 246 +246 (+100.00%)
kprobe_multi.bpf.linked1.o test_kretprobe failure success MISMATCH 0 248 +248 (+100.00%)
kprobe_multi.bpf.linked1.o test_kretprobe_manual failure success MISMATCH 0 248 +248 (+100.00%)
kprobe_multi.bpf.linked1.o trigger failure success MISMATCH 0 2 +2 (+100.00%)
netcnt_prog.bpf.linked1.o bpf_nextcnt failure success MISMATCH 0 56 +56 (+100.00%)
pyperf600_nounroll.bpf.linked1.o on_event success failure MISMATCH 568128 1000001 +431873 (+76.02%)
ringbuf_bench.bpf.linked1.o bench_ringbuf success failure MISMATCH 8 0 -8 (-100.00%)
strobemeta.bpf.linked1.o on_event success failure MISMATCH 557149 1000001 +442852 (+79.49%)
strobemeta_nounroll1.bpf.linked1.o on_event success failure MISMATCH 57240 1000001 +942761 (+1647.03%)
strobemeta_nounroll2.bpf.linked1.o on_event success failure MISMATCH 501725 1000001 +498276 (+99.31%)
strobemeta_subprogs.bpf.linked1.o on_event success failure MISMATCH 65420 1000001 +934581 (+1428.59%)
test_map_in_map_invalid.bpf.linked1.o xdp_noop0 success failure MISMATCH 2 0 -2 (-100.00%)
test_mmap.bpf.linked1.o test_mmap success failure MISMATCH 46 0 -46 (-100.00%)
test_verif_scale3.bpf.linked1.o balancer_ingress success failure MISMATCH 845499 1000001 +154502 (+18.27%)
------------------------------------- --------------------- ----------- ----------- -------------- --------- --------- -------------------

Note that by filtering on verdict_diff=mismatch, it's now extremely easy and
fast to see any changes in verdict. Example above showcases both failure ->
success transitions (which are generally surprising) and success -> failure
transitions (which are expected if bugs are present).

Given veristat allows to query relative percent difference values, internal
logic for comparison mode is based on floating point numbers, so requires a bit
of epsilon precision logic, deviating from typical integer simple handling
rules.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-11-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: support stats ordering in comparison mode in veristat

Introduce the concept of "stat variant", by which it's possible to
specify whether to use the value from A (baseline) side, B (comparison
or control) side, the absolute difference value or relative (percentage)
difference value.

To support specifying this, veristat recognizes `_a`, `_b`, `_diff`,
`_pct` suffixes, which can be appended to stat name(s). In
non-comparison mode variants are ignored (there is only `_a` variant
effectively), if no variant suffix is provided, `_b` is assumed, as
control group is of primary interest in comparison mode.

These stat variants can be flexibly combined with asc/desc orders.

Here's an example of ordering results first by verdict match/mismatch (or n/a
if one of the sides is missing; n/a is always considered to be the lowest
value), and within each match/mismatch/n/a group further sort by number of
instructions in B side. In this case we don't have MISMATCH cases, but N/A are
split from MATCH, demonstrating this custom ordering.

$ ./veristat -e file,prog,verdict,insns -s verdict_diff,insns_b_ -C ~/base.csv ~/comp.csv
File Program Verdict (A) Verdict (B) Verdict (DIFF) Insns (A) Insns (B) Insns (DIFF)
------------------ ------------------------------ ----------- ----------- -------------- --------- --------- --------------
bpf_xdp.o tail_lb_ipv6 N/A success N/A N/A 151895 N/A
bpf_xdp.o tail_nodeport_nat_egress_ipv4 N/A success N/A N/A 15619 N/A
bpf_xdp.o tail_nodeport_ipv6_dsr N/A success N/A N/A 1206 N/A
bpf_xdp.o tail_nodeport_ipv4_dsr N/A success N/A N/A 1162 N/A
bpf_alignchecker.o tail_icmp6_send_echo_reply N/A failure N/A N/A 74 N/A
bpf_alignchecker.o __send_drop_notify success N/A N/A 53 N/A N/A
bpf_host.o __send_drop_notify success N/A N/A 53 N/A N/A
bpf_host.o cil_from_host success N/A N/A 762 N/A N/A
bpf_xdp.o tail_lb_ipv4 success success MATCH 71736 73430 +1694 (+2.36%)
bpf_xdp.o tail_handle_nat_fwd_ipv4 success success MATCH 21547 20920 -627 (-2.91%)
bpf_xdp.o tail_rev_nodeport_lb6 success success MATCH 17954 17905 -49 (-0.27%)
bpf_xdp.o tail_handle_nat_fwd_ipv6 success success MATCH 16974 17039 +65 (+0.38%)
bpf_xdp.o tail_nodeport_nat_ingress_ipv4 success success MATCH 7658 7713 +55 (+0.72%)
bpf_xdp.o tail_rev_nodeport_lb4 success success MATCH 7126 6934 -192 (-2.69%)
bpf_xdp.o tail_nodeport_nat_ingress_ipv6 success success MATCH 6405 6397 -8 (-0.12%)
bpf_xdp.o tail_nodeport_nat_ipv6_egress failure failure MATCH 752 752 +0 (+0.00%)
bpf_xdp.o cil_xdp_entry success success MATCH 423 423 +0 (+0.00%)
bpf_xdp.o __send_drop_notify success success MATCH 151 151 +0 (+0.00%)
bpf_alignchecker.o tail_icmp6_handle_ns failure failure MATCH 33 33 +0 (+0.00%)
------------------ ------------------------------ ----------- ----------- -------------- --------- --------- --------------

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: handle missing records in comparison mode better in veristat

When comparing two datasets, if either side is missing corresponding
record with the same file and prog name, currently veristat emits
misleading zeros/failures, and even tried to calculate a difference,
even though there is no data to compare against.

This patch improves internal logic of handling such situations. Now
we'll emit "N/A" in places where data is missing and comparison is
non-sensical.

As an example, in an artificially truncated and mismatched Cilium
results, the output looks like below:

$ ./veristat -e file,prog,verdict,insns -C ~/base.csv ~/comp.csv
File Program Verdict (A) Verdict (B) Verdict (DIFF) Insns (A) Insns (B) Insns (DIFF)
------------------ ------------------------------ ----------- ----------- -------------- --------- --------- --------------
bpf_alignchecker.o __send_drop_notify success N/A N/A 53 N/A N/A
bpf_alignchecker.o tail_icmp6_handle_ns failure failure MATCH 33 33 +0 (+0.00%)
bpf_alignchecker.o tail_icmp6_send_echo_reply N/A failure N/A N/A 74 N/A
bpf_host.o __send_drop_notify success N/A N/A 53 N/A N/A
bpf_host.o cil_from_host success N/A N/A 762 N/A N/A
bpf_xdp.o __send_drop_notify success success MATCH 151 151 +0 (+0.00%)
bpf_xdp.o cil_xdp_entry success success MATCH 423 423 +0 (+0.00%)
bpf_xdp.o tail_handle_nat_fwd_ipv4 success success MATCH 21547 20920 -627 (-2.91%)
bpf_xdp.o tail_handle_nat_fwd_ipv6 success success MATCH 16974 17039 +65 (+0.38%)
bpf_xdp.o tail_lb_ipv4 success success MATCH 71736 73430 +1694 (+2.36%)
bpf_xdp.o tail_lb_ipv6 N/A success N/A N/A 151895 N/A
bpf_xdp.o tail_nodeport_ipv4_dsr N/A success N/A N/A 1162 N/A
bpf_xdp.o tail_nodeport_ipv6_dsr N/A success N/A N/A 1206 N/A
bpf_xdp.o tail_nodeport_nat_egress_ipv4 N/A success N/A N/A 15619 N/A
bpf_xdp.o tail_nodeport_nat_ingress_ipv4 success success MATCH 7658 7713 +55 (+0.72%)
bpf_xdp.o tail_nodeport_nat_ingress_ipv6 success success MATCH 6405 6397 -8 (-0.12%)
bpf_xdp.o tail_nodeport_nat_ipv6_egress failure failure MATCH 752 752 +0 (+0.00%)
bpf_xdp.o tail_rev_nodeport_lb4 success success MATCH 7126 6934 -192 (-2.69%)
bpf_xdp.o tail_rev_nodeport_lb6 success success MATCH 17954 17905 -49 (-0.27%)
------------------ ------------------------------ ----------- ----------- -------------- --------- --------- --------------

Internally veristat now separates joining two datasets and remembering the
join, and actually emitting a comparison view. This will come handy when we add
support for filtering and custom ordering in comparison mode.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: make veristat emit all stats in CSV mode by default

Make veristat distinguish between table and CSV output formats and use
different default set of stats (columns) that are emitted. While for
human-readable table output it doesn't make sense to output all known
stats, it is very useful for CSV mode to record all possible data, so
that it can later be queried and filtered in replay or comparison mode.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: support simple filtering of stats in veristat

Define simple expressions to filter not just by file and program name,
but also by resulting values of collected stats. Support usual
equality and inequality operators. Verdict, which is a boolean-like
field can be also filtered either as 0/1, failure/success (with f/s,
fail/succ, and failure/success aliases) symbols, or as false/true (f/t).
Aliases are case insensitive.

Currently this filtering is honored only in verification and replay
modes. Comparison mode support will be added in next patch.

Here's an example of verifying a bunch of BPF object files and emitting
only results for successfully validated programs that have more than 100
total instructions processed by BPF verifier, sorted by number of
instructions in ascending order:

$ sudo ./veristat *.bpf.o -s insns^ -f 'insns>100'

There can be many filters (both allow and deny flavors), all of them are
combined.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-7-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: allow to define asc/desc ordering for sort specs in veristat

Allow to specify '^' at the end of stat name to designate that it should
be sorted in ascending order. Similarly, allow any of 'v', 'V', '.',
'!', or '_' suffix "symbols" to designate descending order. It's such
a zoo for descending order because there is no single intuitive symbol
that could be used (using 'v' looks pretty weird in practice), so few
symbols that are "downwards leaning or pointing" were chosen. Either
way, it shouldn't cause any troubles in practice.

This new feature allows to customize sortering order to match user's
needs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: ensure we always have non-ambiguous sorting in veristat

Always fall back to unique file/prog comparison if user's custom order
specs are ambiguous. This ensures stable output no matter what.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: consolidate and improve file/prog filtering in veristat

Slightly change rules of specifying file/prog glob filters. In practice
it's quite often inconvenient to do `*/<prog-glob>` if that program glob
is unique enough and won't accidentally match any file names.

This patch changes the rules so that `-f <glob>` will apply specified
glob to both file and program names. User still has all the control by
doing '*/<prog-only-glob>' or '<file-only-glob/*'. We also now allow
'/<prog-glob>' and '<file-glob/' (all matching wildcard is assumed if
missing).

Also, internally unify file-only and file+prog checks
(should_process_file and should_process_prog are now
should_process_file_prog that can handle prog name as optional). This
makes maintaining and extending this code easier.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: shorten "Total insns/states" column names in veristat

In comparison mode the "Total " part is pretty useless, but takes
a considerable amount of horizontal space. Drop the "Total " parts.

Also make sure that table headers for numerical columns are aligned in
the same fashion as integer values in those columns. This looks better
and is now more obvious with shorter "Insns" and "States" column
headers.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: add veristat replay mode

Replay mode allow to parse previously stored CSV file with verification
results and present it in desired output (presumable human-readable
table, but CSV to CSV convertion is supported as well). While doing
that, it's possible to use veristat's sorting rules, specify subset of
columns, and filter by file and program name.

In subsequent patches veristat's filtering capabilities will just grow
making replay mode even more useful in practice for post-processing
results.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221103055304.2904589-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: add BPF object fixup step to veristat

Add a step to attempt to "fix up" BPF object file to make it possible to
successfully load it. E.g., set non-zero size for BPF maps that expect
max_entries set, but BPF object file itself doesn't have declarative
max_entries values specified.

Another issue was with automatic map pinning. Pinning has no effect on
BPF verification process itself but can interfere when validating
multiple related programs and object files, so veristat disabled all the
pinning explicitly.

In the future more such fix up heuristics could be added to accommodate
common patterns encountered in practice.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221005161450.1064469-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: avoid reporting +100% difference in veristat for actual 0%

In special case when both base and comparison values are 0, veristat
currently reports "+0 (+100%)" difference, which is quite confusing. Fix
it up to be "+0 (+0%)".

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221005161450.1064469-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: allow to adjust BPF verifier log level in veristat

Add -l (--log-level) flag to override default BPF verifier log lever.
This only matters in verbose mode, which is the mode in which veristat
emits verifier log for each processed BPF program.

This is important because for successfully verified BPF programs
log_level 1 is empty, as BPF verifier truncates all the successfully
verified paths. So -l2 is the only way to actually get BPF verifier log
in practice. It looks sometihng like this:

[vmuser@archvm bpf]$ sudo ./veristat xdp_tx.bpf.o -vl2
Processing 'xdp_tx.bpf.o'...
PROCESSING xdp_tx.bpf.o/xdp_tx, DURATION US: 19, VERDICT: success, VERIFIER LOG:
func#0 @0
0: R1=ctx(off=0,imm=0) R10=fp0
; return XDP_TX;
0: (b4) w0 = 3 ; R0_w=3
1: (95) exit
verification time 19 usec
stack depth 0
processed 2 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0

File Program Verdict Duration (us) Total insns Total states Peak states
------------ ------- ------- ------------- ----------- ------------ -----------
xdp_tx.bpf.o xdp_tx success 19 2 0 0
------------ ------- ------- ------------- ----------- ------------ -----------
Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220923175913.3272430-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: emit processing progress and add quiet mode to veristat

Emit "Processing <filepath>..." for each BPF object file to be
processed, to show progress. But also add -q (--quiet) flag to silence
such messages. Doing something more clever (like overwriting same output
line) is to cumbersome and easily breakable if there is any other
console output (e.g., errors from libbpf).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220923175913.3272430-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: make veristat skip non-BPF and failing-to-open BPF objects

Make veristat ignore non-BPF object files. This allows simpler
mass-verification (e.g., `sudo ./veristat *.bpf.o` in selftests/bpf
directory). Note that `sudo ./veristat *.o` would also work, but with
selftests's multiple copies of BPF object files (.bpf.o and
.bpf.linked{1,2,3}.o) it's 4x slower.

Also, given some of BPF object files could be incomplete in the sense
that they are meant to be statically linked into final BPF object file
(like linked_maps, linked_funcs, linked_vars), note such instances in
stderr, but proceed anyways. This seems like a better trade off between
completely silently ignoring BPF object file and aborting
mass-verification altogether.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220923175913.3272430-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: make veristat's verifier log parsing faster and more robust

Make sure veristat doesn't spend ridiculous amount of time parsing
verifier stats from verifier log, especially for very large logs or
truncated logs (e.g., when verifier returns -ENOSPC due to too small
buffer). For this, parse lines from the end of the log and make sure we
parse only up to 100 last lines, where stats should be, if at all.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220923175913.3272430-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: add ability to filter programs in veristat

Add -f (--filter) argument which accepts glob-based filters for
narrowing down what BPF object files and programs within them should be
processed by veristat. This filtering applies both to comparison and
main (verification) mode.

Filter can be of two forms:
- file (object) filter: 'strobemeta*'; in this case all the programs
within matching files are implicitly allowed (or denied, depending
if it's positive or negative rule, see below);
- file and prog filter: 'strobemeta*/*unroll*' will further filter
programs within matching files to only allow those program names that
match '*unroll*' glob.

As mentioned, filters can be positive (allowlisting) and negative
(denylisting). Negative filters should start with '!': '!strobemeta*'
will deny any filename which basename starts with "strobemeta".

Further, one extra special syntax is supported to allow more convenient
use in practice. Instead of specifying rule on the command line,
veristat allows to specify file that contains rules, both positive and
negative, one line per one filter. This is achieved with -f @<filepath>
use, where <filepath> points to a text file containing rules (negative
and positive rules can be mixed). For convenience empty lines and lines
starting with '#' are ignored. This feature is useful to have some
pre-canned list of object files and program names that are tested
repeatedly, allowing to check in a list of rules and quickly specify
them on the command line.

As a demonstration (and a short cut for nearest future), create a small
list of "interesting" BPF object files from selftests/bpf and commit it
as veristat.cfg. It currently includes 73 programs, most of which are
the most complex and largest BPF programs in selftests, as judged by
total verified instruction count and verifier states total.

If there is overlap between positive or negative filters, negative
filter takes precedence (denylisting is stronger than allowlisting). If
no allow filter is specified, veristat implicitly assumes '*/*' rule. If
no deny rule is specified, veristat (logically) assumes no negative
filters.

Also note that -f (just like -e and -s) can be specified multiple times
and their effect is cumulative.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220921164254.3630690-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: add comparison mode to veristat

Add ability to compare and contrast two veristat runs, previously
recorded with veristat using CSV output format.

When veristat is called with -C (--compare) flag, veristat expects
exactly two input files specified, both should be in CSV format.
Expectation is that it's output from previous veristat runs, but as long
as column names and formats match, it should just work. First CSV file
is designated as a "baseline" provided, and the second one is
comparison (experiment) data set. Establishing baseline matters later
when calculating difference percentages, see below.

Veristat parses these two CSV files and "reconstructs" verifier stats
(it could be just a subset of all possible stats). File and program
names are mandatory as they are used as joining key (these two "stats"
are designated as "key stats" in the code).

Veristat currently enforces that the set of stats recorded in both CSV
has to exactly match, down to exact order. This is just a simplifying
condition which can be lifted with a bit of additional pre-processing to
reorded stat specs internally, which I didn't bother doing, yet.

For all the non-key stats, veristat will output three columns: one for
baseline data, one for comparison data, and one with an absolute and
relative percentage difference. If either baseline or comparison values
are missing (that is, respective CSV file doesn't have a row with
*exactly* matching file and program name), those values are assumed to
be empty or zero. In such case relative percentages are forced to +100%
or -100% output, for consistency with a typical case.

Veristat's -e (--emit) and -s (--sort) specs still apply, so even if CSV
contains lots of stats, user can request to compare only a subset of
them (and specify desired column order as well). Similarly, both CSV and
human-readable table output is honored. Note that input is currently
always expected to be CSV.

Here's an example shell session, recording data for biosnoop tool on two
different kernels and comparing them afterwards, outputting data in table
format.

# on slightly older production kernel
$ sudo ./veristat biosnoop_bpf.o
File Program Verdict Duration (us) Total insns Total states Peak states
-------------- ------------------------ ------- ------------- ----------- ------------ -----------
biosnoop_bpf.o blk_account_io_merge_bio success 37 24 1 1
biosnoop_bpf.o blk_account_io_start failure 0 0 0 0
biosnoop_bpf.o block_rq_complete success 76 104 6 6
biosnoop_bpf.o block_rq_insert success 83 85 7 7
biosnoop_bpf.o block_rq_issue success 79 85 7 7
-------------- ------------------------ ------- ------------- ----------- ------------ -----------
Done. Processed 1 object files, 5 programs.
$ sudo ./veristat ~/local/tmp/fbcode-bpf-objs/biosnoop_bpf.o -o csv > baseline.csv
$ cat baseline.csv
file_name,prog_name,verdict,duration,total_insns,total_states,peak_states
biosnoop_bpf.o,blk_account_io_merge_bio,success,36,24,1,1
biosnoop_bpf.o,blk_account_io_start,failure,0,0,0,0
biosnoop_bpf.o,block_rq_complete,success,82,104,6,6
biosnoop_bpf.o,block_rq_insert,success,78,85,7,7
biosnoop_bpf.o,block_rq_issue,success,74,85,7,7

# on latest bpf-next kernel
$ sudo ./veristat biosnoop_bpf.o
File Program Verdict Duration (us) Total insns Total states Peak states
-------------- ------------------------ ------- ------------- ----------- ------------ -----------
biosnoop_bpf.o blk_account_io_merge_bio success 31 24 1 1
biosnoop_bpf.o blk_account_io_start failure 0 0 0 0
biosnoop_bpf.o block_rq_complete success 76 104 6 6
biosnoop_bpf.o block_rq_insert success 83 91 7 7
biosnoop_bpf.o block_rq_issue success 74 91 7 7
-------------- ------------------------ ------- ------------- ----------- ------------ -----------
Done. Processed 1 object files, 5 programs.
$ sudo ./veristat biosnoop_bpf.o -o csv > comparison.csv
$ cat comparison.csv
file_name,prog_name,verdict,duration,total_insns,total_states,peak_states
biosnoop_bpf.o,blk_account_io_merge_bio,success,71,24,1,1
biosnoop_bpf.o,blk_account_io_start,failure,0,0,0,0
biosnoop_bpf.o,block_rq_complete,success,82,104,6,6
biosnoop_bpf.o,block_rq_insert,success,83,91,7,7
biosnoop_bpf.o,block_rq_issue,success,87,91,7,7

# now let's compare with human-readable output (note that no sudo needed)
# we also ignore verification duration in this case to shortned output
$ ./veristat -C baseline.csv comparison.csv -e file,prog,verdict,insns
File Program Verdict (A) Verdict (B) Verdict (DIFF) Total insns (A) Total insns (B) Total insns (DIFF)
-------------- ------------------------ ----------- ----------- -------------- --------------- --------------- ------------------
biosnoop_bpf.o blk_account_io_merge_bio success success MATCH 24 24 +0 (+0.00%)
biosnoop_bpf.o blk_account_io_start failure failure MATCH 0 0 +0 (+100.00%)
biosnoop_bpf.o block_rq_complete success success MATCH 104 104 +0 (+0.00%)
biosnoop_bpf.o block_rq_insert success success MATCH 91 85 -6 (-6.59%)
biosnoop_bpf.o block_rq_issue success success MATCH 91 85 -6 (-6.59%)
-------------- ------------------------ ----------- ----------- -------------- --------------- --------------- ------------------

While not particularly exciting example (it turned out to be kind of hard to
quickly find a nice example with significant difference just because of kernel
version bump), it should demonstrate main features.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220921164254.3630690-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: add CSV output mode for veristat

Teach veristat to output results as CSV table for easier programmatic
processing. Change what was --output/-o argument to now be --emit/-e.
And then use --output-format/-o <fmt> to specify output format.
Currently "table" and "csv" is supported, table being default.

For CSV output mode veristat is using spec identifiers as column names.
E.g., instead of "Total states" veristat uses "total_states" as a CSV
header name.

Internally veristat recognizes three formats, one of them
(RESFMT_TABLE_CALCLEN) is a special format instructing veristat to
calculate column widths for table output. This felt a bit cleaner and
more uniform than either creating separate functions just for this.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220921164254.3630690-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: fix double bpf_object__close() in veristate

bpf_object__close(obj) is called twice for BPF object files with single
BPF program in it. This causes crash. Fix this by not calling
bpf_object__close() unnecessarily.

Fixes: c8bc5e050976 ("selftests/bpf: Add veristat tool for mass-verifying BPF object files")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220921164254.3630690-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add veristat tool for mass-verifying BPF object files

Add a small tool, veristat, that allows mass-verification of
a set of *libbpf-compatible* BPF ELF object files. For each such object
file, veristat will attempt to verify each BPF program *individually*.
Regardless of success or failure, it parses BPF verifier stats and
outputs them in human-readable table format. In the future we can also
add CSV and JSON output for more scriptable post-processing, if necessary.

veristat allows to specify a set of stats that should be output and
ordering between multiple objects and files (e.g., so that one can
easily order by total instructions processed, instead of default file
name, prog name, verdict, total instructions order).

This tool should be useful for validating various BPF verifier changes
or even validating different kernel versions for regressions.

Here's an example for some of the heaviest selftests/bpf BPF object
files:

$ sudo ./veristat -s insns,file,prog {pyperf,loop,test_verif_scale,strobemeta,test_cls_redirect,profiler}*.linked3.o
File Program Verdict Duration, us Total insns Total states Peak states
------------------------------------ ------------------------------------ ------- ------------ ----------- ------------ -----------
loop3.linked3.o while_true failure 350990 1000001 9663 9663
test_verif_scale3.linked3.o balancer_ingress success 115244 845499 8636 2141
test_verif_scale2.linked3.o balancer_ingress success 77688 773445 3048 788
pyperf600.linked3.o on_event success 2079872 624585 30335 30241
pyperf600_nounroll.linked3.o on_event success 353972 568128 37101 2115
strobemeta.linked3.o on_event success 455230 557149 15915 13537
test_verif_scale1.linked3.o balancer_ingress success 89880 554754 8636 2141
strobemeta_nounroll2.linked3.o on_event success 433906 501725 17087 1912
loop6.linked3.o trace_virtqueue_add_sgs success 282205 398057 8717 919
loop1.linked3.o nested_loops success 125630 361349 5504 5504
pyperf180.linked3.o on_event success 2511740 160398 11470 11446
pyperf100.linked3.o on_event success 744329 87681 6213 6191
test_cls_redirect.linked3.o cls_redirect success 54087 78925 4782 903
strobemeta_subprogs.linked3.o on_event success 57898 65420 1954 403
test_cls_redirect_subprogs.linked3.o cls_redirect success 54522 64965 4619 958
strobemeta_nounroll1.linked3.o on_event success 43313 57240 1757 382
pyperf50.linked3.o on_event success 194355 46378 3263 3241
profiler2.linked3.o tracepoint__syscalls__sys_enter_kill success 23869 43372 1423 542
pyperf_subprogs.linked3.o on_event success 29179 36358 2499 2499
profiler1.linked3.o tracepoint__syscalls__sys_enter_kill success 13052 27036 1946 936
profiler3.linked3.o tracepoint__syscalls__sys_enter_kill success 21023 26016 2186 915
profiler2.linked3.o kprobe__vfs_link success 5255 13896 303 271
profiler1.linked3.o kprobe__vfs_link success 7792 12687 1042 1041
profiler3.linked3.o kprobe__vfs_link success 7332 10601 865 865
profiler2.linked3.o kprobe_ret__do_filp_open success 3417 8900 216 199
profiler2.linked3.o kprobe__vfs_symlink success 3548 8775 203 186
pyperf_global.linked3.o on_event success 10007 7563 520 520
profiler3.linked3.o kprobe_ret__do_filp_open success 4708 6464 532 532
profiler1.linked3.o kprobe_ret__do_filp_open success 3090 6445 508 508
profiler3.linked3.o kprobe__vfs_symlink success 4477 6358 521 521
profiler1.linked3.o kprobe__vfs_symlink success 3381 6347 507 507
profiler2.linked3.o raw_tracepoint__sched_process_exec success 2464 5874 292 189
profiler3.linked3.o raw_tracepoint__sched_process_exec success 2677 4363 397 283
profiler2.linked3.o kprobe__proc_sys_write success 1800 4355 143 138
profiler1.linked3.o raw_tracepoint__sched_process_exec success 1649 4019 333 240
pyperf600_bpf_loop.linked3.o on_event success 2711 3966 306 306
profiler2.linked3.o raw_tracepoint__sched_process_exit success 1234 3138 83 66
profiler3.linked3.o kprobe__proc_sys_write success 1755 2623 223 223
profiler1.linked3.o kprobe__proc_sys_write success 1222 2456 193 193
loop2.linked3.o while_true success 608 1783 57 30
profiler3.linked3.o raw_tracepoint__sched_process_exit success 789 1680 146 146
profiler1.linked3.o raw_tracepoint__sched_process_exit success 592 1526 133 133
strobemeta_bpf_loop.linked3.o on_event success 1015 1512 106 106
loop4.linked3.o combinations success 165 524 18 17
profiler3.linked3.o raw_tracepoint__sched_process_fork success 196 299 25 25
profiler1.linked3.o raw_tracepoint__sched_process_fork success 109 265 19 19
profiler2.linked3.o raw_tracepoint__sched_process_fork success 111 265 19 19
loop5.linked3.o while_true success 47 84 9 9
------------------------------------ ------------------------------------ ------- ------------ ----------- ------------ -----------

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220909193053.577111-4-andrii@kernel.org