The 'perf test bpf' was hooking a eBPF program on the SyS_epoll_wait()
kernel function, that was what the epoll_wait() glibc function ended up
calling, but since at least glibc 2.26, the one that comes with, for
instance, Fedora 27, glibc ends up calling SyS_epoll_pwait() when
epoll_wait() is used, causing this 'perf test' entry to fail.
So switch to using epoll_pwait() and hook the eBPF program to the
SyS_epoll_pwait() kernel function to make it work on a wider range of
glibc and kernel versions.
Tested-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-zynvquy63er8s5mrgsz65pto@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When failing on one of the BPF tests we were just stating:
BPF filter result incorrect
Add some more info to help figuring out the problem:
BPF filter result incorrect, expected 56, got 0 samples
This came out while investigating this failure, first seen after
updating the kernel to the 4.15.0-rc6 tag:
[root@jouet ~]# perf test bpf
39: BPF filter :
39.1: Basic BPF filtering : FAILED!
39.2: BPF pinning : Skip
39.3: BPF prologue generation: Skip
39.4: BPF relocation checker : Skip
[root@jouet ~]#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-403npu7daupv6b2bmxliv5pk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Having "test" in almost all test descriptions is redundant, simplify it
removing and rewriting tests with such descriptions.
End result:
# perf test
1: vmlinux symtab matches kallsyms : Ok
2: Detect openat syscall event : Ok
3: Detect openat syscall event on all cpus : Ok
4: Read samples using the mmap interface : Ok
5: Parse event definition strings : Ok
6: PERF_RECORD_* events & perf_sample fields : Ok
7: Parse perf pmu format : Ok
8: DSO data read : Ok
9: DSO data cache : Ok
10: DSO data reopen : Ok
11: Roundtrip evsel->name : Ok
12: Parse sched tracepoints fields : Ok
13: syscalls:sys_enter_openat event fields : Ok
14: Setup struct perf_event_attr : Ok
15: Match and link multiple hists : Ok
16: 'import perf' in python : Ok
17: Breakpoint overflow signal handler : Ok
18: Breakpoint overflow sampling : Ok
19: Number of exit events of a simple workload : Ok
20: Software clock events period values : Ok
21: Object code reading : Ok
22: Sample parsing : Ok
23: Use a dummy software event to keep tracking: Ok
24: Parse with no sample_id_all bit set : Ok
25: Filter hist entries : Ok
26: Lookup mmap thread : Ok
27: Share thread mg : Ok
28: Sort output of hist entries : Ok
29: Cumulate child hist entries : Ok
30: Track with sched_switch : Ok
31: Filter fds with revents mask in a fdarray : Ok
32: Add fd to a fdarray, making it autogrow : Ok
33: kmod_path__parse : Ok
34: Thread map : Ok
35: LLVM search and compile :
35.1: Basic BPF llvm compile : Ok
35.2: kbuild searching : Ok
35.3: Compile source for BPF prologue generation: Ok
35.4: Compile source for BPF relocation : Ok
36: Session topology : Ok
37: BPF filter :
37.1: Basic BPF filtering : Ok
37.2: BPF prologue generation : Ok
37.3: BPF relocation checker : Ok
38: Synthesize thread map : Ok
39: Synthesize cpu map : Ok
40: Synthesize stat config : Ok
41: Synthesize stat : Ok
42: Synthesize stat round : Ok
43: Synthesize attr update : Ok
44: Event times : Ok
45: Read backward ring buffer : Ok
46: Print cpu map : Ok
47: Probe SDT events : Ok
48: is_printable_array : Ok
49: Print bitmap : Ok
50: perf hooks : Ok
51: x86 rdpmc : Ok
52: Convert perf time to TSC : Ok
53: DWARF unwind : Ok
54: x86 instruction decoder - new instructions : Ok
55: Intel cqm nmi context read : Skip
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-rx2lbfcrrio2yx1fxcljqy0e@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The tools so far have been using the strerror_r() GNU variant, that
returns a string, be it the buffer passed or something else.
But that, besides being tricky in cases where we expect that the
function using strerror_r() returns the error formatted in a provided
buffer (we have to check if it returned something else and copy that
instead), breaks the build on systems not using glibc, like Alpine
Linux, where musl libc is used.
So, introduce yet another wrapper, str_error_r(), that has the GNU
interface, but uses the portable XSI variant of strerror_r(), so that
users rest asured that the provided buffer is used and it is what is
returned.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There's a bug in LLVM that it can generate unneeded relocation
information. See [1] and [2]. Libbpf should check the target section of
a relocation symbol.
This patch adds a testcase which references a global variable (BPF
doesn't support global variables). Before fixing libbpf, the new test
case can be loaded into kernel, the global variable acts like the first
map. It is incorrect.
Result:
# ~/perf test BPF
37: Test BPF filter :
37.1: Test basic BPF filtering : Ok
37.2: Test BPF prologue generation : Ok
37.3: Test BPF relocation checker : FAILED!
# ~/perf test -v BPF
...
libbpf: loading object '[bpf_relocation_test]' from buffer
libbpf: section .strtab, size 126, link 0, flags 0, type=3
libbpf: section .text, size 0, link 0, flags 6, type=1
libbpf: section .data, size 0, link 0, flags 3, type=1
libbpf: section .bss, size 0, link 0, flags 3, type=8
libbpf: section func=sys_write, size 104, link 0, flags 6, type=1
libbpf: found program func=sys_write
libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9
libbpf: section maps, size 16, link 0, flags 3, type=1
libbpf: maps in [bpf_relocation_test]: 16 bytes
libbpf: section license, size 4, link 0, flags 3, type=1
libbpf: license of [bpf_relocation_test] is GPL
libbpf: section version, size 4, link 0, flags 3, type=1
libbpf: kernel version of [bpf_relocation_test] is 40400
libbpf: section .symtab, size 144, link 1, flags 0, type=2
libbpf: map 0 is "my_table"
libbpf: collecting relocating info for: 'func=sys_write'
libbpf: relocation: insn_idx=7
Success unexpectedly: libbpf error when dealing with relocation
test child finished with -1
---- end ----
Test BPF filter subtest 2: FAILED!
[1] https://llvm.org/bugs/show_bug.cgi?id=26243
[2] https://patchwork.ozlabs.org/patch/571385/
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1453715801-7732-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch prints each sub-tests results for BPF testcases.
Before:
# ./perf test BPF
37: Test BPF filter : Ok
After:
# ./perf test BPF
37: Test BPF filter :
37.1: Test basic BPF filtering : Ok
37.2: Test BPF prologue generation : Ok
When a failure happens:
# cat ~/.perfconfig
[llvm]
clang-path = "/bin/false"
# ./perf test BPF
37: Test BPF filter :
37.1: Test basic BPF filtering : Skip
37.2: Test BPF prologue generation : Skip
Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447749170-175898-5-git-send-email-wangnan0@huawei.com
[ Fixed up not to use .func in an anonymous union ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Kan Liang
Arnaldo Carvalho de Melo
Wang Nan
Joe Stringer
Alexander Alemayhu
Colin Ian King