In __start_server, it leaks a fd when setsockopt(SO_REUSEPORT) fails.
This patch fixes it.
Fixes: eed92afdd1 ("bpf: selftest: Test batching and bpf_(get|set)sockopt in bpf tcp iter")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20230316000726.1016773-2-martin.lau@linux.dev
In tcp_hdr_options test, it ensures the received tcp hdr option
and the sk local storage have the expected values. It uses memcmp
to check that. Testing the memcmp result with ASSERT_OK is confusing
because ASSERT_OK will print out the errno which is not set.
This patch uses ASSERT_EQ to check for 0 instead.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20230316000726.1016773-1-martin.lau@linux.dev
Adds a new test that tries to attach a program to fentry of two
functions of the same name, one located in vmlinux and the other in
bpf_testmod.
To avoid conflicts with existing tests, a new function
"bpf_fentry_shadow_test" was created both in vmlinux and in bpf_testmod.
The previous commit fixed a bug which caused this test to fail. The
verifier would always use the vmlinux function's address as the target
trampoline address, hence trying to create two trampolines for a single
address, which is forbidden.
The test (similarly to other fentry/fexit tests) is not working on arm64
at the moment.
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/5fe2f364190b6f79b085066ed7c5989c5bc475fa.1678432753.git.vmalik@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
LLVM commit https://reviews.llvm.org/D143726 introduced hoistMinMax optimization
that transformed
(i < VIRTIO_MAX_SGS) && (i < out_sgs)
into
i < MIN(VIRTIO_MAX_SGS, out_sgs)
and caused the verifier to stop recognizing such loop as bounded.
Which resulted in the following test failure:
libbpf: prog 'trace_virtqueue_add_sgs': BPF program load failed: Bad address
libbpf: prog 'trace_virtqueue_add_sgs': -- BEGIN PROG LOAD LOG --
The sequence of 8193 jumps is too complex.
verification time 789206 usec
stack depth 56
processed 156446 insns (limit 1000000) max_states_per_insn 7 total_states 1746 peak_states 1701 mark_read 12
-- END PROG LOAD LOG --
libbpf: prog 'trace_virtqueue_add_sgs': failed to load: -14
libbpf: failed to load object 'loop6.bpf.o'
Workaround the verifier limitation for now with inline asm that
prevents this particular optimization.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, the test relies on that only dropped ("xmitted") frames will
be recycled and if a frame became an skb, it will be freed later by the
stack and never come back to its page_pool.
So, it easily gets broken by trying to recycle skbs[0]:
test_xdp_do_redirect:PASS:pkt_count_xdp 0 nsec
test_xdp_do_redirect:FAIL:pkt_count_zero unexpected pkt_count_zero:
actual 9936 != expected 2
test_xdp_do_redirect:PASS:pkt_count_tc 0 nsec
That huge mismatch happened because after the TC ingress hook zeroes the
magic, the page gets recycled when skb is freed, not returned to the MM
layer. "Live frames" mode initializes only new pages and keeps the
recycled ones as is by design, so they appear with zeroed magic on the
Rx path again.
Expand the possible magic values from two: 0 (was "xmitted"/dropped or
did hit the TC hook) and 0x42 (hit the input XDP prog) to three: the new
one will mark frames hit the TC hook, so that they will elide both
@pkt_count_zero and @pkt_count_xdp. They can then be recycled to their
page_pool or returned to the page allocator, this won't affect the
counters anyhow. Just make sure to mark them as "input" (0x42) when they
appear on the Rx path again.
Also make an enum from those magics, so that they will be always visible
and can be changed in just one place anytime. This also eases adding any
new marks later on.
Link: https://github.com/kernel-patches/bpf/actions/runs/4386538411/jobs/7681081789
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/r/20230313215553.1045175-2-aleksander.lobakin@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The canonical location for the tracefs filesystem is at
/sys/kernel/tracing.
But, from Documentation/trace/ftrace.rst:
Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:
/sys/kernel/debug/tracing
Many tests in the bpf selftest code still refer to this older debugfs
path, so let's update them to avoid confusion.
Signed-off-by: Ross Zwisler <zwisler@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20230313205628.1058720-3-zwisler@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a new selftest, local_kptr_stash, which uses bpf_kptr_xchg to stash
a bpf_obj_new-allocated object in a map. Test the following scenarios:
* Stash two rb_nodes in an arraymap, don't unstash them, rely on map
free to destruct them
* Stash two rb_nodes in an arraymap, unstash the second one in a
separate program, rely on map free to destruct first
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230310230743.2320707-4-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch tests how many kmallocs is needed to create and free
a batch of UDP sockets and each socket has a 64bytes bpf storage.
It also measures how fast the UDP sockets can be created.
The result is from my qemu setup.
Before bpf_mem_cache_alloc/free:
./bench -p 1 local-storage-create
Setting up benchmark 'local-storage-create'...
Benchmark 'local-storage-create' started.
Iter 0 ( 73.193us): creates 213.552k/s (213.552k/prod), 3.09 kmallocs/create
Iter 1 (-20.724us): creates 211.908k/s (211.908k/prod), 3.09 kmallocs/create
Iter 2 ( 9.280us): creates 212.574k/s (212.574k/prod), 3.12 kmallocs/create
Iter 3 ( 11.039us): creates 213.209k/s (213.209k/prod), 3.12 kmallocs/create
Iter 4 (-11.411us): creates 213.351k/s (213.351k/prod), 3.12 kmallocs/create
Iter 5 ( -7.915us): creates 214.754k/s (214.754k/prod), 3.12 kmallocs/create
Iter 6 ( 11.317us): creates 210.942k/s (210.942k/prod), 3.12 kmallocs/create
Summary: creates 212.789 ± 1.310k/s (212.789k/prod), 3.12 kmallocs/create
After bpf_mem_cache_alloc/free:
./bench -p 1 local-storage-create
Setting up benchmark 'local-storage-create'...
Benchmark 'local-storage-create' started.
Iter 0 ( 68.265us): creates 243.984k/s (243.984k/prod), 1.04 kmallocs/create
Iter 1 ( 30.357us): creates 238.424k/s (238.424k/prod), 1.04 kmallocs/create
Iter 2 (-18.712us): creates 232.963k/s (232.963k/prod), 1.04 kmallocs/create
Iter 3 (-15.885us): creates 238.879k/s (238.879k/prod), 1.04 kmallocs/create
Iter 4 ( 5.590us): creates 237.490k/s (237.490k/prod), 1.04 kmallocs/create
Iter 5 ( 8.577us): creates 237.521k/s (237.521k/prod), 1.04 kmallocs/create
Iter 6 ( -6.263us): creates 238.508k/s (238.508k/prod), 1.04 kmallocs/create
Summary: creates 237.298 ± 2.198k/s (237.298k/prod), 1.04 kmallocs/create
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20230308065936.1550103-18-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch tweats the socket_bind bpf prog to test the
local_storage->smap == NULL case in the bpf_local_storage_free()
code path. The idea is to create the local_storage with
the sk_storage_map's selem first. Then add the sk_storage_map2's selem
and then delete the earlier sk_storeage_map's selem.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20230308065936.1550103-17-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The send_signal tracepoint tests are non-deterministically failing in
CI. The test works as follows:
1. Two pairs of file descriptors are created using the pipe() function.
One pair is used to communicate between a parent process -> child
process, and the other for the reverse direction.
2. A child is fork()'ed. The child process registers a signal handler,
notifies its parent that the signal handler is registered, and then
and waits for its parent to have enabled a BPF program that sends a
signal.
3. The parent opens and loads a BPF skeleton with programs that send
signals to the child process. The different programs are triggered by
different perf events (either NMI or normal perf), or by regular
tracepoints. The signal is delivered to the child whenever the child
triggers the program.
4. The child's signal handler is invoked, which sets a flag saying that
the signal handler was reached. The child then signals to the parent
that it received the signal, and the test ends.
The perf testcases (send_signal_perf{_thread} and
send_signal_nmi{_thread}) work 100% of the time, but the tracepoint
testcases fail non-deterministically because the tracepoint is not
always being fired for the child.
There are two tracepoint programs registered in the test:
'tracepoint/sched/sched_switch', and
'tracepoint/syscalls/sys_enter_nanosleep'. The child never intentionally
blocks, nor sleeps, so neither tracepoint is guaranteed to be triggered.
To fix this, we can have the child trigger the nanosleep program with a
usleep().
Before this patch, the test would fail locally every 2-3 runs. Now, it
doesn't fail after more than 1000 runs.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230310061909.1420887-1-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We recently added -Wuninitialized, but it's not enough to catch various
silly mistakes or omissions. Let's go all the way to -Wall, just like we
do for user-space code.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230309054015.4068562-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Once we enable -Wall for BPF sources, compiler will complain about lots
of unused variables, variables that are set but never read, etc.
Fix all these issues first before enabling -Wall in Makefile.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230309054015.4068562-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add __sink(expr) macro that forces compiler to believe that passed in
expression is both read and written. It used a simple embedded asm for
this. This is useful in a lot of tests where we assign value to some variable
to trigger some action, but later don't read variable, causing compiler
to complain (if corresponding compiler warnings are turned on, which
we'll do in the next patch).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230309054015.4068562-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
With latest llvm17, selftest fexit_bpf2bpf/func_replace_return_code
has the following verification failure:
0: R1=ctx(off=0,imm=0) R10=fp0
; int connect_v4_prog(struct bpf_sock_addr *ctx)
0: (bf) r7 = r1 ; R1=ctx(off=0,imm=0) R7_w=ctx(off=0,imm=0)
1: (b4) w6 = 0 ; R6_w=0
; memset(&tuple.ipv4.saddr, 0, sizeof(tuple.ipv4.saddr));
...
; return do_bind(ctx) ? 1 : 0;
179: (bf) r1 = r7 ; R1=ctx(off=0,imm=0) R7=ctx(off=0,imm=0)
180: (85) call pc+147
Func#3 is global and valid. Skipping.
181: R0_w=scalar()
181: (bc) w6 = w0 ; R0_w=scalar() R6_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
182: (05) goto pc-129
; }
54: (bc) w0 = w6 ; R0_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R6_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
55: (95) exit
At program exit the register R0 has value (0x0; 0xffffffff) should have been in (0x0; 0x1)
processed 281 insns (limit 1000000) max_states_per_insn 1 total_states 26 peak_states 26 mark_read 13
-- END PROG LOAD LOG --
libbpf: prog 'connect_v4_prog': failed to load: -22
The corresponding source code:
__attribute__ ((noinline))
int do_bind(struct bpf_sock_addr *ctx)
{
struct sockaddr_in sa = {};
sa.sin_family = AF_INET;
sa.sin_port = bpf_htons(0);
sa.sin_addr.s_addr = bpf_htonl(SRC_REWRITE_IP4);
if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
return 0;
return 1;
}
...
SEC("cgroup/connect4")
int connect_v4_prog(struct bpf_sock_addr *ctx)
{
...
return do_bind(ctx) ? 1 : 0;
}
Insn 180 is a call to 'do_bind'. The call's return value is also the return value
for the program. Since do_bind() returns 0/1, so it is legitimate for compiler to
optimize 'return do_bind(ctx) ? 1 : 0' to 'return do_bind(ctx)'. However, such
optimization breaks verifier as the return value of 'do_bind()' is marked as any
scalar which violates the requirement of prog return value 0/1.
There are two ways to fix this problem, (1) changing 'return 1' in do_bind() to
e.g. 'return 10' so the compiler has to do 'do_bind(ctx) ? 1 :0', or (2)
suggested by Andrii, marking do_bind() with __weak attribute so the compiler
cannot make any assumption on do_bind() return value.
This patch adopted adding __weak approach which is simpler and more resistant
to potential compiler optimizations.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230310012410.2920570-1-yhs@fb.com
There is a report that fib_lookup test is flaky when running in parallel.
A symptom of slowness or delay. An example:
Testing IPv6 stale neigh
set_lookup_params:PASS:inet_pton(IPV6_IFACE_ADDR) 0 nsec
test_fib_lookup:PASS:bpf_prog_test_run_opts 0 nsec
test_fib_lookup:FAIL:fib_lookup_ret unexpected fib_lookup_ret: actual 0 != expected 7
test_fib_lookup:FAIL:dmac not match unexpected dmac not match: actual 1 != expected 0
dmac expected 11:11:11:11:11:11 actual 00:00:00:00:00:00
[ Note that the "fib_lookup_ret unexpected fib_lookup_ret actual 0 ..."
is reversed in terms of expected and actual value. Fixing in this
patch also. ]
One possibility is the testing stale neigh entry was marked dead by the
gc (in neigh_periodic_work). The default gc_stale_time sysctl is 60s.
This patch increases it to 15 mins.
It also:
- fixes the reversed arg (actual vs expected) in one of the
ASSERT_EQ test
- removes the nodad command arg when adding v4 neigh entry which
currently has a warning.
Fixes: 168de02335 ("selftests/bpf: Add bpf_fib_lookup test")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230309060244.3242491-1-martin.lau@linux.dev
Implement a trivial iterator returning same specified integer value
N times as part of bpf_testmod kernel module. Add selftests to validate
everything works end to end.
We also reuse these tests as "verification-only" tests to validate that
kernel prints the state of custom kernel module-defined iterator correctly:
fp-16=iter_testmod_seq(ref_id=1,state=drained,depth=0)
"testmod_seq" part is an iterator type, and is coming from module's BTF
data dynamically at runtime.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add number iterator (bpf_iter_num_{new,next,destroy}()) tests,
validating the correct handling of various corner and common cases
*at runtime*.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add various tests for open-coded iterators. Some of them excercise
various possible coding patterns in C, some go down to low-level
assembly for more control over various conditions, especially invalid
ones.
We also make use of bpf_for(), bpf_for_each(), bpf_repeat() macros in
some of these tests.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-7-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add bpf_for_each(), bpf_for(), and bpf_repeat() macros that make writing
open-coded iterator-based loops much more convenient and natural. These
macros utilize cleanup attribute to ensure proper destruction of the
iterator and thanks to that manage to provide the ergonomics that is
very close to C language's for() construct. Typical loop would look like:
int i;
int arr[N];
bpf_for(i, 0, N) {
/* verifier will know that i >= 0 && i < N, so could be used to
* directly access array elements with no extra checks
*/
arr[i] = i;
}
bpf_repeat() is very similar, but it doesn't expose iteration number and
is meant as a simple "repeat action N times" loop:
bpf_repeat(N) { /* whatever, N times */ }
Note that `break` and `continue` statements inside the {} block work as
expected.
bpf_for_each() is a generalization over any kind of BPF open-coded
iterator allowing to use for-each-like approach instead of calling
low-level bpf_iter_<type>_{new,next,destroy}() APIs explicitly. E.g.:
struct cgroup *cg;
bpf_for_each(cgroup, cg, some, input, args) {
/* do something with each cg */
}
would call (not-yet-implemented) bpf_iter_cgroup_{new,next,destroy}()
functions to form a loop over cgroups, where `some, input, args` are
passed verbatim into constructor as
bpf_iter_cgroup_new(&it, some, input, args).
As a first demonstration, add pyperf variant based on the bpf_for() loop.
Also clean up a few tests that either included bpf_misc.h header
unnecessarily from the user-space, which is unsupported, or included it
before any common types are defined (and thus leading to unnecessary
compilation warnings, potentially).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit 62622dab0a ("ima: return IMA digest value only when IMA_COLLECTED
flag is set") caused bpf_ima_inode_hash() to refuse to give non-fresh
digests. IMA test #3 assumed the old behavior, that bpf_ima_inode_hash()
still returned also non-fresh digests.
Correct the test by accepting both cases. If the samples returned are 1,
assume that the commit above is applied and that the returned digest is
fresh. If the samples returned are 2, assume that the commit above is not
applied, and check both the non-fresh and fresh digest.
Fixes: 62622dab0a ("ima: return IMA digest value only when IMA_COLLECTED flag is set")
Reported-by: David Vernet <void@manifault.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Matt Bobrowski <mattbobrowski@google.com>
Link: https://lore.kernel.org/bpf/20230308103713.1681200-1-roberto.sassu@huaweicloud.com
In order to adapt to the older kernel, now we split the "attach_probe"
testing into multi subtests:
manual // manual attach tests for kprobe/uprobe
auto // auto-attach tests for kprobe and uprobe
kprobe-sleepable // kprobe sleepable test
uprobe-lib // uprobe tests for library function by name
uprobe-sleepable // uprobe sleepable test
uprobe-ref_ctr // uprobe ref_ctr test
As sleepable kprobe needs to set BPF_F_SLEEPABLE flag before loading,
we need to move it to a stand alone skel file, in case of it is not
supported by kernel and make the whole loading fail.
Therefore, we can only enable part of the subtests for older kernel.
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Biao Jiang <benbjiang@tencent.com>
Link: https://lore.kernel.org/bpf/20230306064833.7932-3-imagedong@tencent.com
Adjust log_fixup's expected buffer length to fix the test. It's pretty
finicky in its length expectation, but it doesn't break often. So just
adjust the length to work on current kernel and with follow up iterator
changes as well.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow to search for expected register state in all the verifier log
output that's related to specified instruction number.
See added comment for an example of possible situation that is happening
due to a simple enhancement done in the next patch, which fixes handling
of env->test_state_freq flag in state checkpointing logic.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Function verifier.c:convert_ctx_access() applies some rewrites to BPF
instructions that read or write BPF program context. This commit adds
machinery to allow test cases that inspect BPF program after these
rewrites are applied.
An example of a test case:
{
// Shorthand for field offset and size specification
N(CGROUP_SOCKOPT, struct bpf_sockopt, retval),
// Pattern generated for field read
.read = "$dst = *(u64 *)($ctx + bpf_sockopt_kern::current_task);"
"$dst = *(u64 *)($dst + task_struct::bpf_ctx);"
"$dst = *(u32 *)($dst + bpf_cg_run_ctx::retval);",
// Pattern generated for field write
.write = "*(u64 *)($ctx + bpf_sockopt_kern::tmp_reg) = r9;"
"r9 = *(u64 *)($ctx + bpf_sockopt_kern::current_task);"
"r9 = *(u64 *)(r9 + task_struct::bpf_ctx);"
"*(u32 *)(r9 + bpf_cg_run_ctx::retval) = $src;"
"r9 = *(u64 *)($ctx + bpf_sockopt_kern::tmp_reg);" ,
},
For each test case, up to three programs are created:
- One that uses BPF_LDX_MEM to read the context field.
- One that uses BPF_STX_MEM to write to the context field.
- One that uses BPF_ST_MEM to write to the context field.
The disassembly of each program is compared with the pattern specified
in the test case.
Kernel code for disassembly is reused (as is in the bpftool).
To keep Makefile changes to the minimum, symbolic links to
`kernel/bpf/disasm.c` and `kernel/bpf/disasm.h ` are added.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Check that verifier tracks pointer types for BPF_ST_MEM instructions
and reports error if pointer types do not match for different
execution branches.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Lift verifier restriction to use BPF_ST_MEM instructions to write to
context data structures. This requires the following changes:
- verifier.c:do_check() for BPF_ST updated to:
- no longer forbid writes to registers of type PTR_TO_CTX;
- track dst_reg type in the env->insn_aux_data[...].ptr_type field
(same way it is done for BPF_STX and BPF_LDX instructions).
- verifier.c:convert_ctx_access() and various callbacks invoked by
it are updated to handled BPF_ST instruction alongside BPF_STX.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_rcu_read_lock/unlock() are only available in clang compiled kernels. Lack
of such key mechanism makes it impossible for sleepable bpf programs to use RCU
pointers.
Allow bpf_rcu_read_lock/unlock() in GCC compiled kernels (though GCC doesn't
support btf_type_tag yet) and allowlist certain field dereferences in important
data structures like tast_struct, cgroup, socket that are used by sleepable
programs either as RCU pointer or full trusted pointer (which is valid outside
of RCU CS). Use BTF_TYPE_SAFE_RCU and BTF_TYPE_SAFE_TRUSTED macros for such
tagging. They will be removed once GCC supports btf_type_tag.
With that refactor check_ptr_to_btf_access(). Make it strict in enforcing
PTR_TRUSTED and PTR_UNTRUSTED while deprecating old PTR_TO_BTF_ID without
modifier flags. There is a chance that this strict enforcement might break
existing programs (especially on GCC compiled kernels), but this cleanup has to
start sooner than later. Note PTR_TO_CTX access still yields old deprecated
PTR_TO_BTF_ID. Once it's converted to strict PTR_TRUSTED or PTR_UNTRUSTED the
kfuncs and helpers will be able to default to KF_TRUSTED_ARGS. KF_RCU will
remain as a weaker version of KF_TRUSTED_ARGS where obj refcnt could be 0.
Adjust rcu_read_lock selftest to run on gcc and clang compiled kernels.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-7-alexei.starovoitov@gmail.com
Adjust cgroup kfunc test to dereference RCU protected cgroup pointer
as PTR_TRUSTED and pass into KF_TRUSTED_ARGS kfunc.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-6-alexei.starovoitov@gmail.com
The life time of certain kernel structures like 'struct cgroup' is protected by RCU.
Hence it's safe to dereference them directly from __kptr tagged pointers in bpf maps.
The resulting pointer is MEM_RCU and can be passed to kfuncs that expect KF_RCU.
Derefrence of other kptr-s returns PTR_UNTRUSTED.
For example:
struct map_value {
struct cgroup __kptr *cgrp;
};
SEC("tp_btf/cgroup_mkdir")
int BPF_PROG(test_cgrp_get_ancestors, struct cgroup *cgrp_arg, const char *path)
{
struct cgroup *cg, *cg2;
cg = bpf_cgroup_acquire(cgrp_arg); // cg is PTR_TRUSTED and ref_obj_id > 0
bpf_kptr_xchg(&v->cgrp, cg);
cg2 = v->cgrp; // This is new feature introduced by this patch.
// cg2 is PTR_MAYBE_NULL | MEM_RCU.
// When cg2 != NULL, it's a valid cgroup, but its percpu_ref could be zero
if (cg2)
bpf_cgroup_ancestor(cg2, level); // safe to do.
}
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-4-alexei.starovoitov@gmail.com
__kptr meant to store PTR_UNTRUSTED kernel pointers inside bpf maps.
The concept felt useful, but didn't get much traction,
since bpf_rdonly_cast() was added soon after and bpf programs received
a simpler way to access PTR_UNTRUSTED kernel pointers
without going through restrictive __kptr usage.
Rename __kptr_ref -> __kptr and __kptr -> __kptr_untrusted to indicate
its intended usage.
The main goal of __kptr_untrusted was to read/write such pointers
directly while bpf_kptr_xchg was a mechanism to access refcnted
kernel pointers. The next patch will allow RCU protected __kptr access
with direct read. At that point __kptr_untrusted will be deprecated.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-2-alexei.starovoitov@gmail.com
Add test for the absolute BPF timer under the existing timer tests. This
will run the timer two times with 1us expiration time, and then re-arm
the timer at ~35s in the future. At the end, it is verified that the
absolute timer expired exactly two times.
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Link: https://lore.kernel.org/r/20230302114614.2985072-3-tero.kristo@linux.intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Per C99 standard [0], Section 6.7.8, Paragraph 10:
If an object that has automatic storage duration is not initialized
explicitly, its value is indeterminate.
And in the same document, in appendix "J.2 Undefined behavior":
The behavior is undefined in the following circumstances:
[...]
The value of an object with automatic storage duration is used while
it is indeterminate (6.2.4, 6.7.8, 6.8).
This means that use of an uninitialized stack variable is undefined
behavior, and therefore that clang can choose to do a variety of scary
things, such as not generating bytecode for "bunch of useful code" in
the below example:
void some_func()
{
int i;
if (!i)
return;
// bunch of useful code
}
To add insult to injury, if some_func above is a helper function for
some BPF program, clang can choose to not generate an "exit" insn,
causing verifier to fail with "last insn is not an exit or jmp". Going
from that verification failure to the root cause of uninitialized use
is certain to be frustrating.
This patch adds -Wuninitialized to the cflags for selftest BPF progs and
fixes up existing instances of uninitialized use.
[0]: https://www.open-std.org/jtc1/sc22/WG14/www/docs/n1256.pdf
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Cc: David Vernet <void@manifault.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230303005500.1614874-1-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Extend __flag attribute by allowing to specify one of the following:
* BPF_F_STRICT_ALIGNMENT
* BPF_F_ANY_ALIGNMENT
* BPF_F_TEST_RND_HI32
* BPF_F_TEST_STATE_FREQ
* BPF_F_SLEEPABLE
* BPF_F_XDP_HAS_FRAGS
* Some numeric value
Extend __msg attribute by allowing to specify multiple exepcted messages.
All messages are expected to be present in the verifier log in the
order of application.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230301175417.3146070-2-eddyz87@gmail.com
[ Eduard: added commit message, formatting, comments ]
If target is bpf, there is no __loongarch__ definition, __BITS_PER_LONG
defaults to 32, __NR_nanosleep is not defined:
#if defined(__ARCH_WANT_TIME32_SYSCALLS) || __BITS_PER_LONG != 32
#define __NR_nanosleep 101
__SC_3264(__NR_nanosleep, sys_nanosleep_time32, sys_nanosleep)
#endif
Work around this problem, by explicitly setting __BITS_PER_LONG to
__loongarch_grlen which is defined by compiler as 64 for LA64.
This is similar with commit 36e70b9b06 ("selftests, bpf: Fix broken
riscv build").
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1677585781-21628-1-git-send-email-yangtiezhu@loongson.cn
Firstly, ensure programs successfully load when using all of the
supported maps. Then, extend existing tests to test more cases at
runtime. We are currently testing both the synchronous freeing of items
and asynchronous destruction when map is freed, but the code needs to be
adjusted a bit to be able to also accomodate support for percpu maps.
We now do a delete on the item (and update for array maps which has a
similar effect for kptrs) to perform a synchronous free of the kptr, and
test destruction both for the synchronous and asynchronous deletion.
Next time the program runs, it should observe the refcount as 1 since
all existing references should have been released by then. By running
the program after both possible paths freeing kptrs, we establish that
they correctly release resources. Next, we augment the existing test to
also test the same code path shared by all local storage maps using a
task local storage map.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230225154010.391965-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Test skb and xdp dynptr functionality in the following ways:
1) progs/test_cls_redirect_dynptr.c
* Rewrite "progs/test_cls_redirect.c" test to use dynptrs to parse
skb data
* This is a great example of how dynptrs can be used to simplify a
lot of the parsing logic for non-statically known values.
When measuring the user + system time between the original version
vs. using dynptrs, and averaging the time for 10 runs (using
"time ./test_progs -t cls_redirect"):
original version: 0.092 sec
with dynptrs: 0.078 sec
2) progs/test_xdp_dynptr.c
* Rewrite "progs/test_xdp.c" test to use dynptrs to parse xdp data
When measuring the user + system time between the original version
vs. using dynptrs, and averaging the time for 10 runs (using
"time ./test_progs -t xdp_attach"):
original version: 0.118 sec
with dynptrs: 0.094 sec
3) progs/test_l4lb_noinline_dynptr.c
* Rewrite "progs/test_l4lb_noinline.c" test to use dynptrs to parse
skb data
When measuring the user + system time between the original version
vs. using dynptrs, and averaging the time for 10 runs (using
"time ./test_progs -t l4lb_all"):
original version: 0.062 sec
with dynptrs: 0.081 sec
For number of processed verifier instructions:
original version: 6268 insns
with dynptrs: 2588 insns
4) progs/test_parse_tcp_hdr_opt_dynptr.c
* Add sample code for parsing tcp hdr opt lookup using dynptrs.
This logic is lifted from a real-world use case of packet parsing
in katran [0], a layer 4 load balancer. The original version
"progs/test_parse_tcp_hdr_opt.c" (not using dynptrs) is included
here as well, for comparison.
When measuring the user + system time between the original version
vs. using dynptrs, and averaging the time for 10 runs (using
"time ./test_progs -t parse_tcp_hdr_opt"):
original version: 0.031 sec
with dynptrs: 0.045 sec
5) progs/dynptr_success.c
* Add test case "test_skb_readonly" for testing attempts at writes
on a prog type with read-only skb ctx.
* Add "test_dynptr_skb_data" for testing that bpf_dynptr_data isn't
supported for skb progs.
6) progs/dynptr_fail.c
* Add test cases "skb_invalid_data_slice{1,2,3,4}" and
"xdp_invalid_data_slice{1,2}" for testing that helpers that modify the
underlying packet buffer automatically invalidate the associated
data slice.
* Add test cases "skb_invalid_ctx" and "xdp_invalid_ctx" for testing
that prog types that do not support bpf_dynptr_from_skb/xdp don't
have access to the API.
* Add test case "dynptr_slice_var_len{1,2}" for testing that
variable-sized len can't be passed in to bpf_dynptr_slice
* Add test case "skb_invalid_slice_write" for testing that writes to a
read-only data slice are rejected by the verifier.
* Add test case "data_slice_out_of_bounds_skb" for testing that
writes to an area outside the slice are rejected.
* Add test case "invalid_slice_rdwr_rdonly" for testing that prog
types that don't allow writes to packet data don't accept any calls
to bpf_dynptr_slice_rdwr.
[0] https://github.com/facebookincubator/katran/blob/main/katran/lib/bpf/pckt_parsing.h
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230301154953.641654-11-joannelkoong@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit bc292ab00f6c("mm: introduce vma->vm_flags wrapper functions")
turns the vm_flags into a const variable.
Added bpf_find_vma test in commit f108662b27c9("selftests/bpf: Add tests
for bpf_find_vma") to assign values to variables that declare const in
find_vma_fail1.c programs, which is an error to the compiler and does not
test BPF verifiers. It is better to replace 'const vm_flags_t vm_flags'
with 'unsigned long vm_start' for testing.
$ make -C tools/testing/selftests/bpf/ -j8
...
progs/find_vma_fail1.c:16:16: error: cannot assign to non-static data
member 'vm_flags' with const-qualified type 'const vm_flags_t' (aka
'const unsigned long')
vma->vm_flags |= 0x55;
~~~~~~~~~~~~~ ^
../tools/testing/selftests/bpf/tools/include/vmlinux.h:1898:20:
note: non-static data member 'vm_flags' declared const here
const vm_flags_t vm_flags;
~~~~~~~~~~~`~~~~~~^~~~~~~~
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/tencent_CB281722B3C1BD504C16CDE586CACC2BE706@qq.com
After commit 80d7da1cac ("asm-generic: Drop getrlimit and setrlimit
syscalls from default list"), new architectures won't need to include
getrlimit and setrlimit, they are superseded with prlimit64.
In order to maintain compatibility for the new architectures, such as
LoongArch which does not define __NR_getrlimit, it is better to use
__NR_prlimit64 instead of __NR_getrlimit in user_ringbuf test to fix
the following build error:
TEST-OBJ [test_progs] user_ringbuf.test.o
tools/testing/selftests/bpf/prog_tests/user_ringbuf.c: In function 'kick_kernel_cb':
tools/testing/selftests/bpf/prog_tests/user_ringbuf.c:593:17: error: '__NR_getrlimit' undeclared (first use in this function)
593 | syscall(__NR_getrlimit);
| ^~~~~~~~~~~~~~
tools/testing/selftests/bpf/prog_tests/user_ringbuf.c:593:17: note: each undeclared identifier is reported only once for each function it appears in
make: *** [Makefile:573: tools/testing/selftests/bpf/user_ringbuf.test.o] Error 1
make: Leaving directory 'tools/testing/selftests/bpf'
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1677235015-21717-4-git-send-email-yangtiezhu@loongson.cn
The current mptcp test is run in init netns. If the user or default
system config disabled mptcp, the test will fail. Let's run the mptcp
test in a dedicated netns to avoid none kernel default mptcp setting.
Suggested-by: Martin KaFai Lau <martin.lau@linux.dev>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/r/20230224061343.506571-3-liuhangbin@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
A lot of tests defined SYS() macro to run system calls with goto label.
Let's move this macro to test_progs.h and add configurable
"goto_label" as the first arg.
Suggested-by: Martin KaFai Lau <martin.lau@linux.dev>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20230224061343.506571-2-liuhangbin@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Kernel's flow dissector continues to parse the packet when
the (optional) IPv6 flow label is empty even when instructed
to stop (via BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL). Do
the same in our reference BPF reimplementation.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20230221180518.2139026-1-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Three testcases to make sure that stack reads from uninitialized
locations are accepted by verifier when executed in privileged mode:
- read from a fixed offset;
- read from a variable offset;
- passing a pointer to stack to a helper converts
STACK_INVALID to STACK_MISC.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230219200427.606541-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
