Messages in this thread | | | Date | Tue, 2 Jan 2018 15:59:17 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | perf test BPF failing on 4.15.0-rc6 |
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Hi Wang,
I just updated my machine to Fedora 27 and 4.15.0-rc6 and the only test failing for me is:
[root@jouet linux]# 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 linux]#
I haven't checked but perhaps the problem is that SyS_epoll_wait seems to now be inlined in three places and perhaps the eBPF proggie is being added to just one of them?
Seemingly relevant excerpt:
Open Debuginfo file: /lib/modules/4.15.0-rc6/build/vmlinux Try to find probe point from debuginfo. Matched function: SyS_epoll_wait [2f40eb7] found inline addr: 0xffffffff812b6ff1 Probe point found: compat_SyS_epoll_pwait+129 found inline addr: 0xffffffff812b6de7 Probe point found: SyS_epoll_pwait+135 found inline addr: 0xffffffff812b6c80 Probe point found: SyS_epoll_wait+0 Found 3 probe_trace_events.
- Arnaldo
P.S.: Full -v output:
[root@jouet linux]# uname -a Linux jouet 4.15.0-rc6 #4 SMP Tue Jan 2 14:30:53 -03 2018 x86_64 x86_64 x86_64 GNU/Linux [root@jouet linux]# gcc -v Using built-in specs. COLLECT_GCC=/usr/bin/gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/7/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-redhat-linux Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl --enable-libmpx --enable-offload-targets=nvptx-none --without-cuda-driver --enable-gnu-indirect-function --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix gcc version 7.2.1 20170915 (Red Hat 7.2.1-2) (GCC) [root@jouet linux]# clang -v clang version 6.0.0 (http://llvm.org/git/clang.git 56cc8f8880db2ebc433eeb6b6a707c101467a186) (http://llvm.org/git/llvm.git 3656d83960a4f3fedf6d8f19043abf52379f78c3) Target: x86_64-unknown-linux-gnu Thread model: posix InstalledDir: /usr/local/bin Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/7 Selected GCC installation: /usr/lib/gcc/x86_64-redhat-linux/7 Candidate multilib: .;@m64 Candidate multilib: 32;@m32 Selected multilib: .;@m64 [root@jouet linux]# perf test -v BPF 39: BPF filter : 39.1: Basic BPF filtering : --- start --- test child forked, pid 24304 Kernel build dir is set to /lib/modules/4.15.0-rc6/build set env: KBUILD_DIR=/lib/modules/4.15.0-rc6/build unset env: KBUILD_OPTS include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h set env: NR_CPUS=4 set env: LINUX_VERSION_CODE=0x40f00 set env: CLANG_EXEC=/usr/local/bin/clang set env: CLANG_OPTIONS=-xc set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h set env: WORKING_DIR=/lib/modules/4.15.0-rc6/build set env: CLANG_SOURCE=- llvm compiling command template: echo '/* * bpf-script-example.c * Test basic LLVM building */ #ifndef LINUX_VERSION_CODE # error Need LINUX_VERSION_CODE # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' #endif #define BPF_ANY 0 #define BPF_MAP_TYPE_ARRAY 2 #define BPF_FUNC_map_lookup_elem 1 #define BPF_FUNC_map_update_elem 2
static void *(*bpf_map_lookup_elem)(void *map, void *key) = (void *) BPF_FUNC_map_lookup_elem; static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) = (void *) BPF_FUNC_map_update_elem;
struct bpf_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; unsigned int max_entries; };
#define SEC(NAME) __attribute__((section(NAME), used)) struct bpf_map_def SEC("maps") flip_table = { .type = BPF_MAP_TYPE_ARRAY, .key_size = sizeof(int), .value_size = sizeof(int), .max_entries = 1, };
SEC("func=SyS_epoll_wait") int bpf_func__SyS_epoll_wait(void *ctx) { int ind =0; int *flag = bpf_map_lookup_elem(&flip_table, &ind); int new_flag; if (!flag) return 0; /* flip flag and store back */ new_flag = !*flag; bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY); return new_flag; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o - libbpf: loading object '[basic_bpf_test]' from buffer libbpf: section .strtab, size 120, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section func=SyS_epoll_wait, size 192, link 0, flags 6, type=1 libbpf: found program func=SyS_epoll_wait libbpf: section .relfunc=SyS_epoll_wait, size 32, link 8, flags 0, type=9 libbpf: section maps, size 16, link 0, flags 3, type=1 libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [basic_bpf_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [basic_bpf_test] is 40f00 libbpf: section .symtab, size 168, link 1, flags 0, type=2 libbpf: maps in [basic_bpf_test]: 1 maps in 16 bytes libbpf: map 0 is "flip_table" libbpf: collecting relocating info for: 'func=SyS_epoll_wait' libbpf: relocation: insn_idx=4 libbpf: relocation: find map 0 (flip_table) for insn 4 libbpf: relocation: insn_idx=17 libbpf: relocation: find map 0 (flip_table) for insn 17 bpf: config program 'func=SyS_epoll_wait' symbol:SyS_epoll_wait file:(null) line:0 offset:0 return:0 lazy:(null) bpf: config 'func=SyS_epoll_wait' is ok Looking at the vmlinux_path (8 entries long) Using /lib/modules/4.15.0-rc6/build/vmlinux for symbols Open Debuginfo file: /lib/modules/4.15.0-rc6/build/vmlinux Try to find probe point from debuginfo. Matched function: SyS_epoll_wait [2f40eb7] found inline addr: 0xffffffff812b6ff1 Probe point found: compat_SyS_epoll_pwait+129 found inline addr: 0xffffffff812b6de7 Probe point found: SyS_epoll_pwait+135 found inline addr: 0xffffffff812b6c80 Probe point found: SyS_epoll_wait+0 Found 3 probe_trace_events. Opening /sys/kernel/debug/tracing//kprobe_events write=1 Writing event: p:perf_bpf_probe/func _text+2846705 Writing event: p:perf_bpf_probe/func_1 _text+2846183 Writing event: p:perf_bpf_probe/func_2 _text+2845824 libbpf: create map flip_table: fd=3 add bpf event perf_bpf_probe:func and attach bpf program 4 registering plugin: /root/.traceevent/plugins/plugin_kvm.so registering plugin: /root/.traceevent/plugins/plugin_hrtimer.so registering plugin: /root/.traceevent/plugins/plugin_jbd2.so registering plugin: /root/.traceevent/plugins/plugin_kmem.so registering plugin: /root/.traceevent/plugins/plugin_scsi.so registering plugin: /root/.traceevent/plugins/plugin_sched_switch.so registering plugin: /root/.traceevent/plugins/plugin_function.so registering plugin: /root/.traceevent/plugins/plugin_xen.so registering plugin: /root/.traceevent/plugins/plugin_mac80211.so registering plugin: /root/.traceevent/plugins/plugin_cfg80211.so adding perf_bpf_probe:func adding perf_bpf_probe:func to 0x24e3850 add bpf event perf_bpf_probe:func_1 and attach bpf program 4 adding perf_bpf_probe:func_1 adding perf_bpf_probe:func_1 to 0x1965020 add bpf event perf_bpf_probe:func_2 and attach bpf program 4 adding perf_bpf_probe:func_2 adding perf_bpf_probe:func_2 to 0x19656a0 mmap size 1052672B BPF filter result incorrect, expected 56, got 0 samples Opening /sys/kernel/debug/tracing//kprobe_events write=1 Opening /sys/kernel/debug/tracing//uprobe_events write=1 Parsing probe_events: p:perf_bpf_probe/func _text+2846705 Group:perf_bpf_probe Event:func probe:p Parsing probe_events: p:perf_bpf_probe/func_1 _text+2846183 Group:perf_bpf_probe Event:func_1 probe:p Parsing probe_events: p:perf_bpf_probe/func_2 _text+2845824 Group:perf_bpf_probe Event:func_2 probe:p Writing event: -:perf_bpf_probe/func Opening /sys/kernel/debug/tracing//kprobe_events write=1 Opening /sys/kernel/debug/tracing//uprobe_events write=1 Parsing probe_events: p:perf_bpf_probe/func_1 _text+2846183 Group:perf_bpf_probe Event:func_1 probe:p Parsing probe_events: p:perf_bpf_probe/func_2 _text+2845824 Group:perf_bpf_probe Event:func_2 probe:p Writing event: -:perf_bpf_probe/func_1 Opening /sys/kernel/debug/tracing//kprobe_events write=1 Opening /sys/kernel/debug/tracing//uprobe_events write=1 Parsing probe_events: p:perf_bpf_probe/func_2 _text+2845824 Group:perf_bpf_probe Event:func_2 probe:p Writing event: -:perf_bpf_probe/func_2 test child finished with -1 ---- end ---- BPF filter subtest 0: FAILED! 39.2: BPF pinning : --- force skipped --- BPF filter subtest 1: Skip 39.3: BPF prologue generation : --- force skipped --- BPF filter subtest 2: Skip 39.4: BPF relocation checker : --- force skipped --- BPF filter subtest 3: Skip [root@jouet linux]# [root@jouet linux]#
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