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>
Make sure to set BPF_F_TEST_SANITY_STRICT program flag by default across
most verifier tests (and a bunch of others that set custom prog flags).
There are currently two tests that do fail validation, if enforced
strictly: verifier_bounds/crossing_64_bit_signed_boundary_2 and
verifier_bounds/crossing_32_bit_signed_boundary_2. To accommodate them,
we teach test_loader a flag negation:
__flag(!<flagname>) will *clear* specified flag, allowing easy opt-out.
We apply __flag(!BPF_F_TEST_SANITY_STRICT) to these to tests.
Also sprinkle BPF_F_TEST_SANITY_STRICT everywhere where we already set
test-only BPF_F_TEST_RND_HI32 flag, for completeness.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231112010609.848406-12-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add random cases generation to reg_bounds.c and run them without
SLOW_TESTS=1 to increase a chance of BPF CI catching latent issues.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231112010609.848406-11-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Now that verifier supports range vs range bounds adjustments, validate
that by checking each generated range against every other generated
range, across all supported operators (everything by JSET).
We also add few cases that were problematic during development either
for verifier or for selftest's range tracking implementation.
Note that we utilize the same trick with splitting everything into
multiple independent parallelizable tests, but init_t and cond_t. This
brings down verification time in parallel mode from more than 8 hours
down to less that 1.5 hours. 106 million cases were successfully
validate for range vs range logic, in addition to about 7 million range
vs const cases, added in earlier patch.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231112010609.848406-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add test to validate BPF verifier's register range bounds tracking logic.
The main bulk is a lot of auto-generated tests based on a small set of
seed values for lower and upper 32 bits of full 64-bit values.
Currently we validate only range vs const comparisons, but the idea is
to start validating range over range comparisons in subsequent patch set.
When setting up initial register ranges we treat registers as one of
u64/s64/u32/s32 numeric types, and then independently perform conditional
comparisons based on a potentially different u64/s64/u32/s32 types. This
tests lots of tricky cases of deriving bounds information across
different numeric domains.
Given there are lots of auto-generated cases, we guard them behind
SLOW_TESTS=1 envvar requirement, and skip them altogether otherwise.
With current full set of upper/lower seed value, all supported
comparison operators and all the combinations of u64/s64/u32/s32 number
domains, we get about 7.7 million tests, which run in about 35 minutes
on my local qemu instance without parallelization. But we also split
those tests by init/cond numeric types, which allows to rely on
test_progs's parallelization of tests with `-j` option, getting run time
down to about 5 minutes on 8 cores. It's still something that shouldn't
be run during normal test_progs run. But we can run it a reasonable
time, and so perhaps a nightly CI test run (once we have it) would be
a good option for this.
We also add a small set of tricky conditions that came up during
development and triggered various bugs or corner cases in either
selftest's reimplementation of range bounds logic or in verifier's logic
itself. These are fast enough to be run as part of normal test_progs
test run and are great for a quick sanity checking.
Let's take a look at test output to understand what's going on:
$ sudo ./test_progs -t reg_bounds_crafted
#191/1 reg_bounds_crafted/(u64)[0; 0xffffffff] (u64)< 0:OK
...
#191/115 reg_bounds_crafted/(u64)[0; 0x17fffffff] (s32)< 0:OK
...
#191/137 reg_bounds_crafted/(u64)[0xffffffff; 0x100000000] (u64)== 0:OK
Each test case is uniquely and fully described by this generated string.
E.g.: "(u64)[0; 0x17fffffff] (s32)< 0". This means that we
initialize a register (R6) in such a way that verifier knows that it can
have a value in [(u64)0; (u64)0x17fffffff] range. Another
register (R7) is also set up as u64, but this time a constant (zero in
this case). They then are compared using 32-bit signed < operation.
Resulting TRUE/FALSE branches are evaluated (including cases where it's
known that one of the branches will never be taken, in which case we
validate that verifier also determines this as a dead code). Test
validates that verifier's final register state matches expected state
based on selftest's own reg_state logic, implemented from scratch for
cross-checking purposes.
These test names can be conveniently used for further debugging, and if -vv
verboseness is requested we can get a corresponding verifier log (with
mark_precise logs filtered out as irrelevant and distracting). Example below is
slightly redacted for brevity, omitting irrelevant register output in
some places, marked with [...].
$ sudo ./test_progs -a 'reg_bounds_crafted/(u32)[0; U32_MAX] (s32)< -1' -vv
...
VERIFIER LOG:
========================
func#0 @0
0: R1=ctx(off=0,imm=0) R10=fp0
0: (05) goto pc+2
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (bc) w6 = w0 ; R0_w=scalar() R6_w=scalar(smin=0,smax=umax=4294967295,var_off=(0x0; 0xffffffff))
5: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
6: (bc) w7 = w0 ; R0_w=scalar() R7_w=scalar(smin=0,smax=umax=4294967295,var_off=(0x0; 0xffffffff))
7: (b4) w1 = 0 ; R1_w=0
8: (b4) w2 = -1 ; R2=4294967295
9: (ae) if w6 < w1 goto pc-9
9: R1=0 R6=scalar(smin=0,smax=umax=4294967295,var_off=(0x0; 0xffffffff))
10: (2e) if w6 > w2 goto pc-10
10: R2=4294967295 R6=scalar(smin=0,smax=umax=4294967295,var_off=(0x0; 0xffffffff))
11: (b4) w1 = -1 ; R1_w=4294967295
12: (b4) w2 = -1 ; R2_w=4294967295
13: (ae) if w7 < w1 goto pc-13 ; R1_w=4294967295 R7=4294967295
14: (2e) if w7 > w2 goto pc-14
14: R2_w=4294967295 R7=4294967295
15: (bc) w0 = w6 ; [...] R6=scalar(id=1,smin=0,smax=umax=4294967295,var_off=(0x0; 0xffffffff))
16: (bc) w0 = w7 ; [...] R7=4294967295
17: (ce) if w6 s< w7 goto pc+3 ; R6=scalar(id=1,smin=0,smax=umax=4294967295,smin32=-1,var_off=(0x0; 0xffffffff)) R7=4294967295
18: (bc) w0 = w6 ; [...] R6=scalar(id=1,smin=0,smax=umax=4294967295,smin32=-1,var_off=(0x0; 0xffffffff))
19: (bc) w0 = w7 ; [...] R7=4294967295
20: (95) exit
from 17 to 21: [...]
21: (bc) w0 = w6 ; [...] R6=scalar(id=1,smin=umin=umin32=2147483648,smax=umax=umax32=4294967294,smax32=-2,var_off=(0x80000000; 0x7fffffff))
22: (bc) w0 = w7 ; [...] R7=4294967295
23: (95) exit
from 13 to 1: [...]
1: [...]
1: (b7) r0 = 0 ; R0_w=0
2: (95) exit
processed 24 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
=====================
Verifier log above is for `(u32)[0; U32_MAX] (s32)< -1` use cases, where u32
range is used for initialization, followed by signed < operator. Note
how we use w6/w7 in this case for register initialization (it would be
R6/R7 for 64-bit types) and then `if w6 s< w7` for comparison at
instruction #17. It will be `if R6 < R7` for 64-bit unsigned comparison.
Above example gives a good impression of the overall structure of a BPF
programs generated for reg_bounds tests.
In the future, this "framework" can be extended to test not just
conditional jumps, but also arithmetic operations. Adding randomized
testing is another possibility.
Some implementation notes. We basically have our own generics-like
operations on numbers, where all the numbers are stored in u64, but how
they are interpreted is passed as runtime argument enum num_t. Further,
`struct range` represents a bounds range, and those are collected
together into a minimal `struct reg_state`, which collects range bounds
across all four numberical domains: u64, s64, u32, s64.
Based on these primitives and `enum op` representing possible
conditional operation (<, <=, >, >=, ==, !=), there is a set of generic
helpers to perform "range arithmetics", which is used to maintain struct
reg_state. We simulate what verifier will do for reg bounds of R6 and R7
registers using these range and reg_state primitives. Simulated
information is used to determine branch taken conclusion and expected
exact register state across all four number domains.
Implementation of "range arithmetics" is more generic than what verifier
is currently performing: it allows range over range comparisons and
adjustments. This is the intended end goal of this patch set overall and verifier
logic is enhanced in subsequent patches in this series to handle range
vs range operations, at which point selftests are extended to validate
these conditions as well. For now it's range vs const cases only.
Note that tests are split into multiple groups by their numeric types
for initialization of ranges and for comparison operation. This allows
to use test_progs's -j parallelization to speed up tests, as we now have
16 groups of parallel running tests. Overall reduction of running time
that allows is pretty good, we go down from more than 30 minutes to
slightly less than 5 minutes running time.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20231112010609.848406-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add selftests for cgroup1 hierarchy.
The result as follows,
$ tools/testing/selftests/bpf/test_progs --name=cgroup1_hierarchy
#36/1 cgroup1_hierarchy/test_cgroup1_hierarchy:OK
#36/2 cgroup1_hierarchy/test_root_cgid:OK
#36/3 cgroup1_hierarchy/test_invalid_level:OK
#36/4 cgroup1_hierarchy/test_invalid_cgid:OK
#36/5 cgroup1_hierarchy/test_invalid_hid:OK
#36/6 cgroup1_hierarchy/test_invalid_cgrp_name:OK
#36/7 cgroup1_hierarchy/test_invalid_cgrp_name2:OK
#36/8 cgroup1_hierarchy/test_sleepable_prog:OK
#36 cgroup1_hierarchy:OK
Summary: 1/8 PASSED, 0 SKIPPED, 0 FAILED
Besides, I also did some stress test similar to the patch #2 in this
series, as follows (with CONFIG_PROVE_RCU_LIST enabled):
- Continuously mounting and unmounting named cgroups in some tasks,
for example:
cgrp_name=$1
while true
do
mount -t cgroup -o none,name=$cgrp_name none /$cgrp_name
umount /$cgrp_name
done
- Continuously run this selftest concurrently,
while true; do ./test_progs --name=cgroup1_hierarchy; done
They can ran successfully without any RCU warnings in dmesg.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231111090034.4248-7-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A new cgroup helper function, get_cgroup1_hierarchy_id(), has been
introduced to obtain the ID of a cgroup1 hierarchy based on the provided
cgroup name. This cgroup name can be obtained from the /proc/self/cgroup
file.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231111090034.4248-6-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Include the current pid in the classid cgroup path. This way, different
testers relying on classid-based configurations will have distinct classid
cgroup directories, enabling them to run concurrently. Additionally, we
leverage the current pid as the classid, ensuring unique identification.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231111090034.4248-4-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
If the net_cls subsystem is already mounted, attempting to mount it again
in setup_classid_environment() will result in a failure with the error code
EBUSY. Despite this, tmpfs will have been successfully mounted at
/sys/fs/cgroup/net_cls. Consequently, the /sys/fs/cgroup/net_cls directory
will be empty, causing subsequent setup operations to fail.
Here's an error log excerpt illustrating the issue when net_cls has already
been mounted at /sys/fs/cgroup/net_cls prior to running
setup_classid_environment():
- Before that change
$ tools/testing/selftests/bpf/test_progs --name=cgroup_v1v2
test_cgroup_v1v2:PASS:server_fd 0 nsec
test_cgroup_v1v2:PASS:client_fd 0 nsec
test_cgroup_v1v2:PASS:cgroup_fd 0 nsec
test_cgroup_v1v2:PASS:server_fd 0 nsec
run_test:PASS:skel_open 0 nsec
run_test:PASS:prog_attach 0 nsec
test_cgroup_v1v2:PASS:cgroup-v2-only 0 nsec
(cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup.procs
(cgroup_helpers.c:540: errno: No such file or directory) Opening cgroup classid: /sys/fs/cgroup/net_cls/cgroup-test-work-dir/net_cls.classid
run_test:PASS:skel_open 0 nsec
run_test:PASS:prog_attach 0 nsec
(cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup-test-work-dir/cgroup.procs
run_test:FAIL:join_classid unexpected error: 1 (errno 2)
test_cgroup_v1v2:FAIL:cgroup-v1v2 unexpected error: -1 (errno 2)
(cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup.procs
#44 cgroup_v1v2:FAIL
Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED
- After that change
$ tools/testing/selftests/bpf/test_progs --name=cgroup_v1v2
#44 cgroup_v1v2:OK
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231111090034.4248-3-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This is a follow up to:
commit b8e3a87a62 ("bpf: Add crosstask check to __bpf_get_stack").
This test ensures that the task iterator only gets a single
user stack (for the current task).
Signed-off-by: Jordan Rome <linux@jordanrome.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20231112023010.144675-1-linux@jordanrome.com
With latest clang18 (main branch of llvm-project repo), when building bpf selftests,
[~/work/bpf-next (master)]$ make -C tools/testing/selftests/bpf LLVM=1 -j
The following compilation error happens:
fatal error: error in backend: Branch target out of insn range
...
Stack dump:
0. Program arguments: clang -g -Wall -Werror -D__TARGET_ARCH_x86 -mlittle-endian
-I/home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/include
-I/home/yhs/work/bpf-next/tools/testing/selftests/bpf -I/home/yhs/work/bpf-next/tools/include/uapi
-I/home/yhs/work/bpf-next/tools/testing/selftests/usr/include -idirafter
/home/yhs/work/llvm-project/llvm/build.18/install/lib/clang/18/include -idirafter /usr/local/include
-idirafter /usr/include -Wno-compare-distinct-pointer-types -DENABLE_ATOMICS_TESTS -O2 --target=bpf
-c progs/pyperf180.c -mcpu=v3 -o /home/yhs/work/bpf-next/tools/testing/selftests/bpf/pyperf180.bpf.o
1. <eof> parser at end of file
2. Code generation
...
The compilation failure only happens to cpu=v2 and cpu=v3. cpu=v4 is okay
since cpu=v4 supports 32-bit branch target offset.
The above failure is due to upstream llvm patch [1] where some inlining behavior
are changed in clang18.
To workaround the issue, previously all 180 loop iterations are fully unrolled.
The bpf macro __BPF_CPU_VERSION__ (implemented in clang18 recently) is used to avoid
unrolling changes if cpu=v4. If __BPF_CPU_VERSION__ is not available and the
compiler is clang18, the unrollng amount is unconditionally reduced.
[1] 1a2e77cf9e
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20231110193644.3130906-1-yonghong.song@linux.dev
This patch demonstrates that verifier changes earlier in this series
result in bpf_refcount_acquire(mapval->stashed_kptr) passing
verification. The added test additionally validates that stashing a kptr
in mapval and - in a separate BPF program - refcount_acquiring the kptr
without unstashing works as expected at runtime.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20231107085639.3016113-7-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The test added in this patch exercises the logic fixed in the previous
patch in this series. Before the previous patch's changes,
bpf_refcount_acquire accepts MAYBE_NULL local kptrs; after the change
the verifier correctly rejects the such a call.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20231107085639.3016113-3-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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>
Building an arm64 kernel and seftests/bpf with defconfig +
selftests/bpf/config and selftests/bpf/config.aarch64 the fragment
CONFIG_DEBUG_INFO_REDUCED is enabled in arm64's defconfig, it should be
disabled in file sefltests/bpf/config.aarch64 since if its not disabled
CONFIG_DEBUG_INFO_BTF wont be enabled.
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231103220912.333930-1-anders.roxell@linaro.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Those configs are needed to be able to run VM somewhat consistently.
For instance, ATM, s390x is missing the `CONFIG_VIRTIO_CONSOLE` which
prevents s390x kernels built in CI to leverage qemu-guest-agent.
By moving them to `config,vm`, we should have selftest kernels which are
equal in term of VM functionalities when they include this file.
The set of config unabled were picked using
grep -h -E '(_9P|_VIRTIO)' config.x86_64 config | sort | uniq
added to `config.vm` and then
grep -vE '(_9P|_VIRTIO)' config.{x86_64,aarch64,s390x}
as a side-effect, some config may have disappeared to the aarch64 and
s390x kernels, but they should not be needed. CI will tell.
Signed-off-by: Manu Bretelle <chantr4@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231031212717.4037892-1-chantr4@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
BPF CI failed due to map_percpu_stats_percpu_hash from time to time [1].
It seems that the failure reason is per-cpu bpf memory allocator may not
be able to allocate per-cpu pointer successfully and it can not refill
free llist timely, and bpf_map_update_elem() will return -ENOMEM.
So mitigate the problem by retrying the update operation for
non-preallocated per-cpu map.
[1]: https://github.com/kernel-patches/bpf/actions/runs/6713177520/job/18244865326?pr=5909
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231101032455.3808547-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Export map_update_retriable() to make it usable for other map_test
cases. These cases may only need retry for specific errno, so add
a new callback parameter to let map_update_retriable() decide whether or
not the errno is retriable.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231101032455.3808547-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When updating per-cpu map in map_percpu_stats test, patch_map_thread()
only passes 4-bytes-sized value to bpf_map_update_elem(). The expected
size of the value is 8 * num_possible_cpus(), so fix it by passing a
value with enough-size for per-cpu map update.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231101032455.3808547-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Some compilers complain about get_pprint_mapv_size() not returning value
in some code paths. Fix with explicit return.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231102033759.2541186-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Compiler complains about malloc(). We also don't need to dynamically
allocate anything, so make the life easier by using statically sized
buffer.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231102033759.2541186-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since some malloc calls in bpf_iter may at times fail,
this patch adds the appropriate fail checks, and ensures that
any previously allocated resource is appropriately destroyed
before returning the function.
Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/DB3PR10MB6835F0ECA792265FA41FC39BE8A3A@DB3PR10MB6835.EURPRD10.PROD.OUTLOOK.COM
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit f49843afde (selftests/bpf: Add tests for css_task iter combining
with cgroup iter) added a test which demonstrates how css_task iter can be
combined with cgroup iter. That test used bpf_cgroup_from_id() to convert
bpf_iter__cgroup->cgroup to a trusted ptr which is pointless now, since
with the previous fix, we can get a trusted cgroup directly from
bpf_iter__cgroup.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231107132204.912120-3-zhouchuyi@bytedance.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
There are architectures where char is not signed. If so, the following
error is triggered:
| xdp_hw_metadata.c:435:42: error: result of comparison of constant -1 \
| with expression of type 'char' is always true \
| [-Werror,-Wtautological-constant-out-of-range-compare]
| 435 | while ((opt = getopt(argc, argv, "mh")) != -1) {
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~
| 1 error generated.
Correct by changing the char to int.
Fixes: bb6a88885f ("selftests/bpf: Add options and frags to xdp_hw_metadata")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Larysa Zaremba <larysa.zaremba@intel.com>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Link: https://lore.kernel.org/r/20231102103537.247336-1-bjorn@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
As seen from previous commit that fix backtracking for BPF_ALU | BPF_TO_BE
| BPF_END, both BPF_NEG and BPF_END require special handling. Add tests
written with inline assembly to check that the verifier does not incorrecly
use the src_reg field of BPF_NEG and BPF_END (including bswap added in v4).
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20231102053913.12004-4-shung-hsi.yu@suse.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This Patch add a test to prove css_task iter can be used in normal
sleepable progs.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231031050438.93297-4-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds a test which demonstrates how css_task iter can be combined
with cgroup iter and it won't cause deadlock, though cgroup iter is not
sleepable.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231031050438.93297-3-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The newly added open-coded css_task iter would try to hold the global
css_set_lock in bpf_iter_css_task_new, so the bpf side has to be careful in
where it allows to use this iter. The mainly concern is dead locking on
css_set_lock. check_css_task_iter_allowlist() in verifier enforced css_task
can only be used in bpf_lsm hooks and sleepable bpf_iter.
This patch relax the allowlist for css_task iter. Any lsm and any iter
(even non-sleepable) and any sleepable are safe since they would not hold
the css_set_lock before entering BPF progs context.
This patch also fixes the misused BPF_TRACE_ITER in
check_css_task_iter_allowlist which compared bpf_prog_type with
bpf_attach_type.
Fixes: 9c66dc94b6 ("bpf: Introduce css_task open-coded iterator kfuncs")
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231031050438.93297-2-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Not all uses of __diag_ignore_all(...) in BPF-related code in order to
suppress warnings are wrapping kfunc definitions. Some "hook point"
definitions - small functions meant to be used as attach points for
fentry and similar BPF progs - need to suppress -Wmissing-declarations.
We could use __bpf_kfunc_{start,end}_defs added in the previous patch in
such cases, but this might be confusing to someone unfamiliar with BPF
internals. Instead, this patch adds __bpf_hook_{start,end} macros,
currently having the same effect as __bpf_kfunc_{start,end}_defs, then
uses them to suppress warnings for two hook points in the kernel itself
and some bpf_testmod hook points as well.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231031215625.2343848-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Merge tag 'for-6.7/io_uring-sockopt-2023-10-30' of git://git.kernel.dk/linux
Pull io_uring {get,set}sockopt support from Jens Axboe:
"This adds support for using getsockopt and setsockopt via io_uring.
The main use cases for this is to enable use of direct descriptors,
rather than first instantiating a normal file descriptor, doing the
option tweaking needed, then turning it into a direct descriptor. With
this support, we can avoid needing a regular file descriptor
completely.
The net and bpf bits have been signed off on their side"
* tag 'for-6.7/io_uring-sockopt-2023-10-30' of git://git.kernel.dk/linux:
selftests/bpf/sockopt: Add io_uring support
io_uring/cmd: Introduce SOCKET_URING_OP_SETSOCKOPT
io_uring/cmd: Introduce SOCKET_URING_OP_GETSOCKOPT
io_uring/cmd: return -EOPNOTSUPP if net is disabled
selftests/net: Extract uring helpers to be reusable
tools headers: Grab copy of io_uring.h
io_uring/cmd: Pass compat mode in issue_flags
net/socket: Break down __sys_getsockopt
net/socket: Break down __sys_setsockopt
bpf: Add sockptr support for setsockopt
bpf: Add sockptr support for getsockopt
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Merge tag 'for-netdev' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2023-10-26
We've added 51 non-merge commits during the last 10 day(s) which contain
a total of 75 files changed, 5037 insertions(+), 200 deletions(-).
The main changes are:
1) Add open-coded task, css_task and css iterator support.
One of the use cases is customizable OOM victim selection via BPF,
from Chuyi Zhou.
2) Fix BPF verifier's iterator convergence logic to use exact states
comparison for convergence checks, from Eduard Zingerman,
Andrii Nakryiko and Alexei Starovoitov.
3) Add BPF programmable net device where bpf_mprog defines the logic
of its xmit routine. It can operate in L3 and L2 mode,
from Daniel Borkmann and Nikolay Aleksandrov.
4) Batch of fixes for BPF per-CPU kptr and re-enable unit_size checking
for global per-CPU allocator, from Hou Tao.
5) Fix libbpf which eagerly assumed that SHT_GNU_verdef ELF section
was going to be present whenever a binary has SHT_GNU_versym section,
from Andrii Nakryiko.
6) Fix BPF ringbuf correctness to fold smp_mb__before_atomic() into
atomic_set_release(), from Paul E. McKenney.
7) Add a warning if NAPI callback missed xdp_do_flush() under
CONFIG_DEBUG_NET which helps checking if drivers were missing
the former, from Sebastian Andrzej Siewior.
8) Fix missed RCU read-lock in bpf_task_under_cgroup() which was throwing
a warning under sleepable programs, from Yafang Shao.
9) Avoid unnecessary -EBUSY from htab_lock_bucket by disabling IRQ before
checking map_locked, from Song Liu.
10) Make BPF CI linked_list failure test more robust,
from Kumar Kartikeya Dwivedi.
11) Enable samples/bpf to be built as PIE in Fedora, from Viktor Malik.
12) Fix xsk starving when multiple xsk sockets were associated with
a single xsk_buff_pool, from Albert Huang.
13) Clarify the signed modulo implementation for the BPF ISA standardization
document that it uses truncated division, from Dave Thaler.
14) Improve BPF verifier's JEQ/JNE branch taken logic to also consider
signed bounds knowledge, from Andrii Nakryiko.
15) Add an option to XDP selftests to use multi-buffer AF_XDP
xdp_hw_metadata and mark used XDP programs as capable to use frags,
from Larysa Zaremba.
16) Fix bpftool's BTF dumper wrt printing a pointer value and another
one to fix struct_ops dump in an array, from Manu Bretelle.
* tag 'for-netdev' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (51 commits)
netkit: Remove explicit active/peer ptr initialization
selftests/bpf: Fix selftests broken by mitigations=off
samples/bpf: Allow building with custom bpftool
samples/bpf: Fix passing LDFLAGS to libbpf
samples/bpf: Allow building with custom CFLAGS/LDFLAGS
bpf: Add more WARN_ON_ONCE checks for mismatched alloc and free
selftests/bpf: Add selftests for netkit
selftests/bpf: Add netlink helper library
bpftool: Extend net dump with netkit progs
bpftool: Implement link show support for netkit
libbpf: Add link-based API for netkit
tools: Sync if_link uapi header
netkit, bpf: Add bpf programmable net device
bpf: Improve JEQ/JNE branch taken logic
bpf: Fold smp_mb__before_atomic() into atomic_set_release()
bpf: Fix unnecessary -EBUSY from htab_lock_bucket
xsk: Avoid starving the xsk further down the list
bpf: print full verifier states on infinite loop detection
selftests/bpf: test if state loops are detected in a tricky case
bpf: correct loop detection for iterators convergence
...
====================
Link: https://lore.kernel.org/r/20231026150509.2824-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When we configure the kernel command line with 'mitigations=off' and set
the sysctl knob 'kernel.unprivileged_bpf_disabled' to 0, the commit
bc5bc309db ("bpf: Inherit system settings for CPU security mitigations")
causes issues in the execution of `test_progs -t verifier`. This is
because 'mitigations=off' bypasses Spectre v1 and Spectre v4 protections.
Currently, when a program requests to run in unprivileged mode
(kernel.unprivileged_bpf_disabled = 0), the BPF verifier may prevent
it from running due to the following conditions not being enabled:
- bypass_spec_v1
- bypass_spec_v4
- allow_ptr_leaks
- allow_uninit_stack
While 'mitigations=off' enables the first two conditions, it does not
enable the latter two. As a result, some test cases in
'test_progs -t verifier' that were expected to fail to run may run
successfully, while others still fail but with different error messages.
This makes it challenging to address them comprehensively.
Moreover, in the future, we may introduce more fine-grained control over
CPU mitigations, such as enabling only bypass_spec_v1 or bypass_spec_v4.
Given the complexity of the situation, rather than fixing each broken test
case individually, it's preferable to skip them when 'mitigations=off' is
in effect and introduce specific test cases for the new 'mitigations=off'
scenario. For instance, we can introduce new BTF declaration tags like
'__failure__nospec', '__failure_nospecv1' and '__failure_nospecv4'.
In this patch, the approach is to simply skip the broken test cases when
'mitigations=off' is enabled. The result of `test_progs -t verifier` as
follows after this commit,
Before this commit
==================
- without 'mitigations=off'
- kernel.unprivileged_bpf_disabled = 2
Summary: 74/948 PASSED, 388 SKIPPED, 0 FAILED
- kernel.unprivileged_bpf_disabled = 0
Summary: 74/1336 PASSED, 0 SKIPPED, 0 FAILED <<<<
- with 'mitigations=off'
- kernel.unprivileged_bpf_disabled = 2
Summary: 74/948 PASSED, 388 SKIPPED, 0 FAILED
- kernel.unprivileged_bpf_disabled = 0
Summary: 63/1276 PASSED, 0 SKIPPED, 11 FAILED <<<< 11 FAILED
After this commit
=================
- without 'mitigations=off'
- kernel.unprivileged_bpf_disabled = 2
Summary: 74/948 PASSED, 388 SKIPPED, 0 FAILED
- kernel.unprivileged_bpf_disabled = 0
Summary: 74/1336 PASSED, 0 SKIPPED, 0 FAILED <<<<
- with this patch, with 'mitigations=off'
- kernel.unprivileged_bpf_disabled = 2
Summary: 74/948 PASSED, 388 SKIPPED, 0 FAILED
- kernel.unprivileged_bpf_disabled = 0
Summary: 74/948 PASSED, 388 SKIPPED, 0 FAILED <<<< SKIPPED
Fixes: bc5bc309db ("bpf: Inherit system settings for CPU security mitigations")
Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Closes: https://lore.kernel.org/bpf/CAADnVQKUBJqg+hHtbLeeC2jhoJAWqnmRAzXW3hmUCNSV9kx4sQ@mail.gmail.com
Link: https://lore.kernel.org/bpf/20231025031144.5508-1-laoar.shao@gmail.com
Add a minimal netlink helper library for the BPF selftests. This has been
taken and cut down and cleaned up from iproute2. This covers basics such
as netdevice creation which we need for BPF selftests / BPF CI given
iproute2 package cannot cover it yet.
Stanislav Fomichev suggested that this could be replaced in future by ynl
tool generated C code once it has RTNL support to create devices. Once we
get to this point the BPF CI would also need to add libmnl. If no further
extensions are needed, a second option could be that we remove this code
again once iproute2 package has support.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20231024214904.29825-7-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
A convoluted test case for iterators convergence logic that
demonstrates that states with branch count equal to 0 might still be
a part of not completely explored loop.
E.g. consider the following state diagram:
initial Here state 'succ' was processed first,
| it was eventually tracked to produce a
V state identical to 'hdr'.
.---------> hdr All branches from 'succ' had been explored
| | and thus 'succ' has its .branches == 0.
| V
| .------... Suppose states 'cur' and 'succ' correspond
| | | to the same instruction + callsites.
| V V In such case it is necessary to check
| ... ... whether 'succ' and 'cur' are identical.
| | | If 'succ' and 'cur' are a part of the same loop
| V V they have to be compared exactly.
| succ <- cur
| |
| V
| ...
| |
'----'
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
These test cases try to hide read and precision marks from loop
convergence logic: marks would only be assigned on subsequent loop
iterations or after exploring states pushed to env->head stack first.
Without verifier fix to use exact states comparison logic for
iterators convergence these tests (except 'triple_continue') would be
errorneously marked as safe.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Convergence for open coded iterators is computed in is_state_visited()
by examining states with branches count > 1 and using states_equal().
states_equal() computes sub-state relation using read and precision marks.
Read and precision marks are propagated from children states,
thus are not guaranteed to be complete inside a loop when branches
count > 1. This could be demonstrated using the following unsafe program:
1. r7 = -16
2. r6 = bpf_get_prandom_u32()
3. while (bpf_iter_num_next(&fp[-8])) {
4. if (r6 != 42) {
5. r7 = -32
6. r6 = bpf_get_prandom_u32()
7. continue
8. }
9. r0 = r10
10. r0 += r7
11. r8 = *(u64 *)(r0 + 0)
12. r6 = bpf_get_prandom_u32()
13. }
Here verifier would first visit path 1-3, create a checkpoint at 3
with r7=-16, continue to 4-7,3 with r7=-32.
Because instructions at 9-12 had not been visitied yet existing
checkpoint at 3 does not have read or precision mark for r7.
Thus states_equal() would return true and verifier would discard
current state, thus unsafe memory access at 11 would not be caught.
This commit fixes this loophole by introducing exact state comparisons
for iterator convergence logic:
- registers are compared using regs_exact() regardless of read or
precision marks;
- stack slots have to have identical type.
Unfortunately, this is too strict even for simple programs like below:
i = 0;
while(iter_next(&it))
i++;
At each iteration step i++ would produce a new distinct state and
eventually instruction processing limit would be reached.
To avoid such behavior speculatively forget (widen) range for
imprecise scalar registers, if those registers were not precise at the
end of the previous iteration and do not match exactly.
This a conservative heuristic that allows to verify wide range of
programs, however it precludes verification of programs that conjure
an imprecise value on the first loop iteration and use it as precise
on the second.
Test case iter_task_vma_for_each() presents one of such cases:
unsigned int seen = 0;
...
bpf_for_each(task_vma, vma, task, 0) {
if (seen >= 1000)
break;
...
seen++;
}
Here clang generates the following code:
<LBB0_4>:
24: r8 = r6 ; stash current value of
... body ... 'seen'
29: r1 = r10
30: r1 += -0x8
31: call bpf_iter_task_vma_next
32: r6 += 0x1 ; seen++;
33: if r0 == 0x0 goto +0x2 <LBB0_6> ; exit on next() == NULL
34: r7 += 0x10
35: if r8 < 0x3e7 goto -0xc <LBB0_4> ; loop on seen < 1000
<LBB0_6>:
... exit ...
Note that counter in r6 is copied to r8 and then incremented,
conditional jump is done using r8. Because of this precision mark for
r6 lags one state behind of precision mark on r8 and widening logic
kicks in.
Adding barrier_var(seen) after conditional is sufficient to force
clang use the same register for both counting and conditional jump.
This issue was discussed in the thread [1] which was started by
Andrew Werner <awerner32@gmail.com> demonstrating a similar bug
in callback functions handling. The callbacks would be addressed
in a followup patch.
[1] https://lore.kernel.org/bpf/97a90da09404c65c8e810cf83c94ac703705dc0e.camel@gmail.com/
Co-developed-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Co-developed-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
It delivers current TCP time stamp in ms unit, and is used
in place of confusing tcp_time_stamp_raw()
It is the same family than tcp_clock_ns() and tcp_clock_ms().
tcp_time_stamp_raw() will be replaced later for TSval
contexts with a more descriptive name.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the following 3 test cases for bpf memory allocator:
1) Do allocation in bpf program and free through map free
2) Do batch per-cpu allocation and per-cpu free in bpf program
3) Do per-cpu allocation in bpf program and free through map free
For per-cpu allocation, because per-cpu allocation can not refill timely
sometimes, so test 2) and test 3) consider it is OK for
bpf_percpu_obj_new_impl() to return NULL.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-8-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The linked list failure test 'pop_front_off' and 'pop_back_off'
currently rely on matching exact instruction and register values. The
purpose of the test is to ensure the offset is correctly incremented for
the returned pointers from list pop helpers, which can then be used with
container_of to obtain the real object. Hence, somehow obtaining the
information that the offset is 48 will work for us. Make the test more
robust by relying on verifier error string of bpf_spin_lock and remove
dependence on fragile instruction index or register number, which can be
affected by different clang versions used to build the selftests.
Fixes: 300f19dcdb ("selftests/bpf: Add BPF linked list API tests")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231020144839.2734006-1-memxor@gmail.com
This patch adds 4 subtests to demonstrate these patterns and validating
correctness.
subtest1:
1) We use task_iter to iterate all process in the system and search for the
current process with a given pid.
2) We create some threads in current process context, and use
BPF_TASK_ITER_PROC_THREADS to iterate all threads of current process. As
expected, we would find all the threads of current process.
3) We create some threads and use BPF_TASK_ITER_ALL_THREADS to iterate all
threads in the system. As expected, we would find all the threads which was
created.
subtest2:
We create a cgroup and add the current task to the cgroup. In the
BPF program, we would use bpf_for_each(css_task, task, css) to iterate all
tasks under the cgroup. As expected, we would find the current process.
subtest3:
1) We create a cgroup tree. In the BPF program, we use
bpf_for_each(css, pos, root, XXX) to iterate all descendant under the root
with pre and post order. As expected, we would find all descendant and the
last iterating cgroup in post-order is root cgroup, the first iterating
cgroup in pre-order is root cgroup.
2) We wse BPF_CGROUP_ITER_ANCESTORS_UP to traverse the cgroup tree starting
from leaf and root separately, and record the height. The diff of the
hights would be the total tree-high - 1.
subtest4:
Add some failure testcase when using css_task, task and css iters, e.g,
unlock when using task-iters to iterate tasks.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Link: https://lore.kernel.org/r/20231018061746.111364-9-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The newly-added struct bpf_iter_task has a name collision with a selftest
for the seq_file task iter's bpf skel, so the selftests/bpf/progs file is
renamed in order to avoid the collision.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-8-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This Patch adds kfuncs bpf_iter_css_{new,next,destroy} which allow
creation and manipulation of struct bpf_iter_css in open-coded iterator
style. These kfuncs actually wrapps css_next_descendant_{pre, post}.
css_iter can be used to:
1) iterating a sepcific cgroup tree with pre/post/up order
2) iterating cgroup_subsystem in BPF Prog, like
for_each_mem_cgroup_tree/cpuset_for_each_descendant_pre in kernel.
The API design is consistent with cgroup_iter. bpf_iter_css_new accepts
parameters defining iteration order and starting css. Here we also reuse
BPF_CGROUP_ITER_DESCENDANTS_PRE, BPF_CGROUP_ITER_DESCENDANTS_POST,
BPF_CGROUP_ITER_ANCESTORS_UP enums.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-5-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
