We have two printk tests reading trace_pipe in non blocking way,
with the very same code. Moving that in new read_trace_pipe_iter
function.
Current read_trace_pipe is used from samples/bpf and needs to
do blocking read and printf of the trace_pipe data, using new
read_trace_pipe_iter to implement that.
Both printk tests do early checks for the number of found messages
and can bail earlier, but I did not find any speed difference w/o
that condition, so I did not complicate the change more for that.
Some of the samples/bpf programs use read_trace_pipe function,
so I kept that interface untouched. I did not see any issues with
affected samples/bpf programs other than there's slight change in
read_trace_pipe output. The current code uses puts that adds new
line after the printed string, so we would occasionally see extra
new line. With this patch we read output per lines, so there's no
need to use puts and we can use just printf instead without extra
new line.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240410140952.292261-1-jolsa@kernel.org
These two functions allow selftests to do loading/searching
kallsyms based on their specific compare functions.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240326041513.1199440-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Refactor trace helper function load_kallsyms_local() such that
it invokes a common function with a compare function as input.
The common function will be used later for other local functions.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240326041508.1199239-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Static ksyms often have problems because the number of symbols exceeds the
MAX_SYMS limit. Like changing the MAX_SYMS from 300000 to 400000 in
commit e76a014334a6("selftests/bpf: Bump and validate MAX_SYMS") solves
the problem somewhat, but it's not the perfect way.
This commit uses dynamic memory allocation, which completely solves the
problem caused by the limitation of the number of kallsyms. At the same
time, add APIs:
load_kallsyms_local()
ksym_search_local()
ksym_get_addr_local()
free_kallsyms_local()
There are used to solve the problem of selftests/bpf updating kallsyms
after attach new symbols during testmod testing.
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/tencent_C9BDA68F9221F21BE4081566A55D66A9700A@qq.com
Adding read_build_id function that parses out build id from
specified binary.
It will replace extract_build_id and also be used in following
changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230331093157.1749137-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding load_kallsyms_refresh function to re-read symbols from
/proc/kallsyms file.
This will be needed to get proper functions addresses from
bpf_testmod.ko module, which is loaded/unloaded several times
during the tests run, so symbols might be already old when
we need to use them.
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20221025134148.3300700-6-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Fix how selftests determine relative offset of a function that is
uprobed. Previously, there was an assumption that uprobed function is
always in the first executable region, which is not always the case
(libbpf CI hits this case now). So get_base_addr() approach in isolation
doesn't work anymore. So teach get_uprobe_offset() to determine correct
memory mapping and calculate uprobe offset correctly.
While at it, I merged together two implementations of
get_uprobe_offset() helper, moving powerpc64-specific logic inside (had
to add extra {} block to avoid unused variable error for insn).
Also ensured that uprobed functions are never inlined, but are still
static (and thus local to each selftest), by using a no-op asm volatile
block internally. I didn't want to keep them global __weak, because some
tests use uprobe's ref counter offset (to test USDT-like logic) which is
not compatible with non-refcounted uprobe. So it's nicer to have each
test uprobe target local to the file and guaranteed to not be inlined or
skipped by the compiler (which can happen with static functions,
especially if compiling selftests with -O2).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220126193058.3390292-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Extend attach_probe selftests to specify ref_ctr_offset for uprobe/uretprobe
and validate that its value is incremented from zero.
Turns out that once uprobe is attached with ref_ctr_offset, uretprobe for the
same location/function *has* to use ref_ctr_offset as well, otherwise
perf_event_open() fails with -EINVAL. So this test uses ref_ctr_offset for
both uprobe and uretprobe, even though for the purpose of test uprobe would be
enough.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-17-andrii@kernel.org
Extract two helpers used for working with uprobes into trace_helpers.{c,h} to
be re-used between multiple uprobe-using selftests. Also rename get_offset()
into more appropriate get_uprobe_offset().
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-14-andrii@kernel.org
Selftests for typed ksyms. Tests two types of ksyms: one is a struct,
the other is a plain int. This tests two paths in the kernel. Struct
ksyms will be converted into PTR_TO_BTF_ID by the verifier while int
typed ksyms will be converted into PTR_TO_MEM.
Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-4-haoluo@google.com
To reduce the reliance of trace samples (trace*_user) on bpf_load,
move read_trace_pipe to trace_helpers. By moving this bpf_loader helper
elsewhere, trace functions can be easily migrated to libbbpf.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200321100424.1593964-2-danieltimlee@gmail.com
Fix all selftests to include libbpf header files with the bpf/ prefix, to
be consistent with external users of the library. Also ensure that all
includes of exported libbpf header files (those that are exported on 'make
install' of the library) use bracketed includes instead of quoted.
To not break the build, keep the old include path until everything has been
changed to the new one; a subsequent patch will remove that.
Fixes: 6910d7d386 ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560568.1683545.9649335788846513446.stgit@toke.dk
libbpf's perf_buffer API supersedes trace_helper.h's helpers.
Remove those helpers after all existing users were already moved to
perf_buffer API.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add two new helper functions to trace_helpers that supports polling
multiple perf file descriptors for events. These are used to the XDP
perf_event_output example, which needs to work with one perf fd per CPU.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Given a kernel function name, ksym_get_addr() will return the kernel
address for this function, or 0 if it cannot find this function name
in /proc/kallsyms. This function will be used later when a kernel
address is used to initiate a kprobe perf event.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
There are two copies of event reading loop - in bpftool and
trace_helpers "library". Consolidate them and move the code
to libbpf. Return codes from trace_helpers are kept, but
renamed to include LIBBPF prefix.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
There is no functionality change in this patch. The common-purpose
trace functions, including perf_event polling and ksym lookup,
are moved from trace_output_user.c and bpf_load.c to
selftests/bpf/trace_helpers.c so that these function can
be reused later in selftests.
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
