The BPF program for the snprintf selftest runs on all syscall entries.
On busy multicore systems this can cause concurrency issues.
For example it was observed that sometimes the userspace part of the
test reads " 4 0000" instead of " 4 000" (extra '0' at the end)
which seems to happen just before snprintf on another core sets
end[-1] = '\0'.
This patch adds a pid filter to the test to ensure that no
bpf_snprintf() will write over the test's output buffers while the
userspace reads the values.
Fixes: c2e39c6bdc ("selftests/bpf: Add a series of tests for bpf_snprintf")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210428152501.1024509-1-revest@chromium.org
Negative field existence cases for have a broken assumption that FIELD_EXISTS
CO-RE relo will fail for fields that match the name but have incompatible type
signature. That's not how CO-RE relocations generally behave. Types and fields
that match by name but not by expected type are treated as non-matching
candidates and are skipped. Error later is reported if no matching candidate
was found. That's what happens for most relocations, but existence relocations
(FIELD_EXISTS and TYPE_EXISTS) are more permissive and they are designed to
return 0 or 1, depending if a match is found. This allows to handle
name-conflicting but incompatible types in BPF code easily. Combined with
___flavor suffixes, it's possible to handle pretty much any structural type
changes in kernel within the compiled once BPF source code.
So, long story short, negative field existence test cases are invalid in their
assumptions, so this patch reworks them into a single consolidated positive
case that doesn't match any of the fields.
Fixes: c7566a6969 ("selftests/bpf: Add field existence CO-RE relocs tests")
Reported-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Lorenz Bauer <lmb@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210426192949.416837-5-andrii@kernel.org
Alexei Starovoitov says:
====================
pull-request: bpf-next 2021-04-23
The following pull-request contains BPF updates for your *net-next* tree.
We've added 69 non-merge commits during the last 22 day(s) which contain
a total of 69 files changed, 3141 insertions(+), 866 deletions(-).
The main changes are:
1) Add BPF static linker support for extern resolution of global, from Andrii.
2) Refine retval for bpf_get_task_stack helper, from Dave.
3) Add a bpf_snprintf helper, from Florent.
4) A bunch of miscellaneous improvements from many developers.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add selftest validating various aspects of statically linking BTF-defined map
definitions. Legacy map definitions do not support extern resolution between
object files. Some of the aspects validated:
- correct resolution of extern maps against concrete map definitions;
- extern maps can currently only specify map type and key/value size and/or
type information;
- weak concrete map definitions are resolved properly.
Static map definitions are not yet supported by libbpf, so they are not
explicitly tested, though manual testing showes that BPF linker handles them
properly.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-18-andrii@kernel.org
Add selftest validating various aspects of statically linking functions:
- no conflicts and correct resolution for name-conflicting static funcs;
- correct resolution of extern functions;
- correct handling of weak functions, both resolution itself and libbpf's
handling of unused weak function that "lost" (it leaves gaps in code with
no ELF symbols);
- correct handling of hidden visibility to turn global function into
"static" for the purpose of BPF verification.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-16-andrii@kernel.org
Conflicts:
MAINTAINERS
- keep Chandrasekar
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
- simple fix + trust the code re-added to param.c in -next is fine
include/linux/bpf.h
- trivial
include/linux/ethtool.h
- trivial, fix kdoc while at it
include/linux/skmsg.h
- move to relevant place in tcp.c, comment re-wrapped
net/core/skmsg.c
- add the sk = sk // sk = NULL around calls
net/tipc/crypto.c
- trivial
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
With a relatively recent clang master branch test_map skips a section,
libbpf: elf: skipping unrecognized data section(5) .rodata.str1.1
the cause is some pointless strings from bpf_printks in the BPF program
loaded during testing. After just removing the prints to fix above error
Daniel points out the program is a bit pointless and could be simply the
empty program returning SK_PASS.
Here we do just that and return simply SK_PASS. This program is used with
test_maps selftests to test insert/remove of a program into the sockmap
and sockhash maps. Its not testing actual functionality of the TCP
sockmap programs, these are tested from test_sockmap. So we shouldn't
lose in test coverage and fix above warnings. This original test was
added before test_sockmap existed and has been copied around ever since,
clean it up now.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/161731595664.74613.1603087410166945302.stgit@john-XPS-13-9370
This patch adds a few kernel function bpf_kfunc_call_test*() for the
selftest's test_run purpose. They will be allowed for tc_cls prog.
The selftest calling the kernel function bpf_kfunc_call_test*()
is also added in this patch.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015252.1551395-1-kafai@fb.com
This patch removes the bpf implementation of tcp_slow_start()
and tcp_cong_avoid_ai(). Instead, it directly uses the kernel
implementation.
It also replaces the bpf_cubic_undo_cwnd implementation by directly
calling tcp_reno_undo_cwnd(). bpf_dctcp also directly calls
tcp_reno_cong_avoid() instead.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015246.1551062-1-kafai@fb.com
Alexei Starovoitov says:
====================
pull-request: bpf-next 2021-03-24
The following pull-request contains BPF updates for your *net-next* tree.
We've added 37 non-merge commits during the last 15 day(s) which contain
a total of 65 files changed, 3200 insertions(+), 738 deletions(-).
The main changes are:
1) Static linking of multiple BPF ELF files, from Andrii.
2) Move drop error path to devmap for XDP_REDIRECT, from Lorenzo.
3) Spelling fixes from various folks.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Bpftool used to issue forward declarations for a struct used as part of
a pointer to array, which is invalid. Add a test to check that the
struct is fully defined in this case:
@@ -134,9 +134,9 @@
};
};
-struct struct_in_array {};
+struct struct_in_array;
-struct struct_in_array_typed {};
+struct struct_in_array_typed;
typedef struct struct_in_array_typed struct_in_array_t[2];
@@ -189,3 +189,7 @@
struct struct_with_embedded_stuff _14;
};
+struct struct_in_array {};
+
+struct struct_in_array_typed {};
+
...
#13/1 btf_dump: syntax:FAIL
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210319112554.794552-3-jean-philippe@linaro.org
Add Makefile infra to specify multi-file BPF object files (and derivative
skeletons). Add first selftest validating BPF static linker can merge together
successfully two independent BPF object files and resulting object and
skeleton are correct and usable.
Use the same F(F(F(X))) = F(F(X)) identity test on linked object files as for
the case of single BPF object files.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-13-andrii@kernel.org
When fixing the bpf test_tunnel.sh geneve failure. I only fixed the IPv4
part but forgot the IPv6 issue. Similar with the IPv4 fixes 557c223b64
("selftests/bpf: No need to drop the packet when there is no geneve opt"),
when there is no tunnel option and bpf_skb_get_tunnel_opt() returns error,
there is no need to drop the packets and break all geneve rx traffic.
Just set opt_class to 0 and keep returning TC_ACT_OK at the end.
Fixes: 557c223b64 ("selftests/bpf: No need to drop the packet when there is no geneve opt")
Fixes: 933a741e3b ("selftests/bpf: bpf tunnel test.")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: William Tu <u9012063@gmail.com>
Link: https://lore.kernel.org/bpf/20210309032214.2112438-1-liuhangbin@gmail.com
Alexei Starovoitov says:
====================
pull-request: bpf-next 2021-03-09
The following pull-request contains BPF updates for your *net-next* tree.
We've added 90 non-merge commits during the last 17 day(s) which contain
a total of 114 files changed, 5158 insertions(+), 1288 deletions(-).
The main changes are:
1) Faster bpf_redirect_map(), from Björn.
2) skmsg cleanup, from Cong.
3) Support for floating point types in BTF, from Ilya.
4) Documentation for sys_bpf commands, from Joe.
5) Support for sk_lookup in bpf_prog_test_run, form Lorenz.
6) Enable task local storage for tracing programs, from Song.
7) bpf_for_each_map_elem() helper, from Yonghong.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add missing return type to BPF_KPROBE definition. Without it, compiler
generates the following warning:
progs/loop6.c:68:12: warning: type specifier missing, defaults to 'int' [-Wimplicit-int]
BPF_KPROBE(trace_virtqueue_add_sgs, void *unused, struct scatterlist **sgs,
^
1 warning generated.
Fixes: 86a35af628 ("selftests/bpf: Add a verifier scale test with unknown bounded loop")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210309044322.3487636-1-andrii@kernel.org
Convert the selftests for sk_lookup narrow context access to use
PROG_TEST_RUN instead of creating actual sockets. This ensures that
ctx is populated correctly when using PROG_TEST_RUN.
Assert concrete values since we now control remote_ip and remote_port.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210303101816.36774-4-lmb@cloudflare.com
The original bcc pull request https://github.com/iovisor/bcc/pull/3270 exposed
a verifier failure with Clang 12/13 while Clang 4 works fine.
Further investigation exposed two issues:
Issue 1: LLVM may generate code which uses less refined value. The issue is
fixed in LLVM patch: https://reviews.llvm.org/D97479
Issue 2: Spills with initial value 0 are marked as precise which makes later
state pruning less effective. This is my rough initial analysis and
further investigation is needed to find how to improve verifier
pruning in such cases.
With the above LLVM patch, for the new loop6.c test, which has smaller loop
bound compared to original test, I got:
$ test_progs -s -n 10/16
...
stack depth 64
processed 390735 insns (limit 1000000) max_states_per_insn 87
total_states 8658 peak_states 964 mark_read 6
#10/16 loop6.o:OK
Use the original loop bound, i.e., commenting out "#define WORKAROUND", I got:
$ test_progs -s -n 10/16
...
BPF program is too large. Processed 1000001 insn
stack depth 64
processed 1000001 insns (limit 1000000) max_states_per_insn 91
total_states 23176 peak_states 5069 mark_read 6
...
#10/16 loop6.o:FAIL
The purpose of this patch is to provide a regression test for the above LLVM fix
and also provide a test case for further analyzing the verifier pruning issue.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Zhenwei Pi <pizhenwei@bytedance.com>
Link: https://lore.kernel.org/bpf/20210226223810.236472-1-yhs@fb.com
A test is added for arraymap and percpu arraymap. The test also
exercises the early return for the helper which does not
traverse all elements.
$ ./test_progs -n 45
#45/1 hash_map:OK
#45/2 array_map:OK
#45 for_each:OK
Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204934.3885756-1-yhs@fb.com
A test case is added for hashmap and percpu hashmap. The test
also exercises nested bpf_for_each_map_elem() calls like
bpf_prog:
bpf_for_each_map_elem(func1)
func1:
bpf_for_each_map_elem(func2)
func2:
$ ./test_progs -n 45
#45/1 hash_map:OK
#45 for_each:OK
Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204933.3885657-1-yhs@fb.com
Task local storage is enabled for tracing programs. Add two tests for
task local storage without CONFIG_BPF_LSM.
The first test stores a value in sys_enter and read it back in sys_exit.
The second test checks whether the kernel allows allocating task local
storage in exit_creds() (which it should not).
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210225234319.336131-4-songliubraving@fb.com
In bpf geneve tunnel test we set geneve option on tx side. On rx side we
only call bpf_skb_get_tunnel_opt(). Since commit 9c2e14b481 ("ip_tunnels:
Set tunnel option flag when tunnel metadata is present") geneve_rx() will
not add TUNNEL_GENEVE_OPT flag if there is no geneve option, which cause
bpf_skb_get_tunnel_opt() return ENOENT and _geneve_get_tunnel() in
test_tunnel_kern.c drop the packet.
As it should be valid that bpf_skb_get_tunnel_opt() return error when
there is not tunnel option, there is no need to drop the packet and
break all geneve rx traffic. Just set opt_class to 0 in this test and
keep returning TC_ACT_OK.
Fixes: 933a741e3b ("selftests/bpf: bpf tunnel test.")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: William Tu <u9012063@gmail.com>
Link: https://lore.kernel.org/bpf/20210224081403.1425474-1-liuhangbin@gmail.com
