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]#
Unable to reproduce. In my kernel configuration, SyS_epoll_wait is not
inlined at all.
From the log you sent, it seems that all 3 instances are attached. This
testcase should work if the last one (SyS_epoll_wait) get probed correctly.
Could you please have a look if the 3rd kprobe event
(p:perf_bpf_probe/func_2 _text+2845824) works?
Thank you.
On 2018/1/3 2:59, Arnaldo Carvalho de Melo wrote:
> 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]#
And please check if the kprobe created by
$ perf probe -v SyS_epoll_wait
works for the test program used by this testcase:
#include <sys/epoll.h>
#include <stdlib.h>
#define NR_ITERS 100
static int epoll_wait_loop(void)
{
int i;
/* Should fail NR_ITERS times */
for (i = 0; i < NR_ITERS; i++)
epoll_wait(-(i + 1), NULL, 0, 0);
return 0;
}
int main()
{
epoll_wait_loop();
return 0;
}
In my configuration it gives 100 samples:
$ sudo ./perf record -e probe:SyS_epoll_wait /tmp/a.out
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.016 MB perf.data (100 samples) ]
I guess in your configuration you would get 3 tracepoints, and can get 0
sample from them.
Thank you.
On 2018/1/3 12:42, Wangnan (F) wrote:
> Unable to reproduce. In my kernel configuration, SyS_epoll_wait is not
> inlined at all.
>
> From the log you sent, it seems that all 3 instances are attached.
> This testcase should work if the last one (SyS_epoll_wait) get probed
> correctly.
>
> Could you please have a look if the 3rd kprobe event
> (p:perf_bpf_probe/func_2 _text+2845824) works?
>
> Thank you.
>
> On 2018/1/3 2:59, Arnaldo Carvalho de Melo wrote:
>> 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]#
>
Em Wed, Jan 03, 2018 at 12:58:26PM +0800, Wangnan (F) escreveu:
> And please check if the kprobe created by
>
> $ perf probe -v SyS_epoll_wait
[root@seventh ~]# perf probe -v SyS_epoll_wait
probe-definition(0): SyS_epoll_wait
symbol:SyS_epoll_wait file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /usr/lib/debug/lib/modules/4.14.8-300.fc27.x86_64/vmlinux for symbols
Open Debuginfo file: /usr/lib/debug/lib/modules/4.14.8-300.fc27.x86_64/vmlinux
Try to find probe point from debuginfo.
Matched function: SyS_epoll_wait [314b563]
found inline addr: 0xffffffff812d8087
Probe point found: compat_SyS_epoll_pwait+151
found inline addr: 0xffffffff812d7e5a
Probe point found: SyS_epoll_pwait+138
found inline addr: 0xffffffff812d7cf0
Probe point found: SyS_epoll_wait+0
Found 3 probe_trace_events.
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: p:probe/SyS_epoll_wait _text+2982023
Writing event: p:probe/SyS_epoll_wait_1 _text+2981466
Writing event: p:probe/SyS_epoll_wait_2 _text+2981104
Added new events:
probe:SyS_epoll_wait (on SyS_epoll_wait)
probe:SyS_epoll_wait_1 (on SyS_epoll_wait)
probe:SyS_epoll_wait_2 (on SyS_epoll_wait)
You can now use it in all perf tools, such as:
perf record -e probe:SyS_epoll_wait_2 -aR sleep 1
[root@seventh ~]#
Then, with your proggie, it seems its glibc that now maps epoll_wait()
to a different syscall than in older systems:
[root@seventh ~]# trace -e probe:SyS_epoll_wait* ~acme/epoll
0.018 ( 0.001 ms): epoll/20444 brk( ) = 0x2600000
0.029 ( 0.004 ms): epoll/20444 access(filename: 0xe874ec0, mode: R ) = -1 ENOENT No such file or directory
0.035 ( 0.003 ms): epoll/20444 openat(dfd: CWD, filename: 0xe872726, flags: CLOEXEC ) = 3
0.040 ( 0.002 ms): epoll/20444 fstat(fd: 3, statbuf: 0x7fffcc37b830 ) = 0
0.042 ( 0.002 ms): epoll/20444 mmap(len: 109538, prot: READ, flags: PRIVATE, fd: 3 ) = 0x7fc50ea5d000
0.045 ( 0.001 ms): epoll/20444 close(fd: 3 ) = 0
0.052 ( 0.003 ms): epoll/20444 openat(dfd: CWD, filename: 0xea7ace0, flags: CLOEXEC ) = 3
0.056 ( 0.001 ms): epoll/20444 read(fd: 3, buf: 0x7fffcc37b9f8, count: 832 ) = 832
0.059 ( 0.001 ms): epoll/20444 fstat(fd: 3, statbuf: 0x7fffcc37b890 ) = 0
0.060 ( 0.002 ms): epoll/20444 mmap(len: 8192, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS, fd: -1 ) = 0x7fc50ea5b000
0.065 ( 0.003 ms): epoll/20444 mmap(len: 4074112, prot: EXEC|READ, flags: PRIVATE|DENYWRITE, fd: 3 ) = 0x7fc50e46e000
0.068 ( 0.004 ms): epoll/20444 mprotect(start: 0x7fc50e648000, len: 2093056 ) = 0
0.073 ( 0.004 ms): epoll/20444 mmap(addr: 0x7fc50e847000, len: 24576, prot: READ|WRITE, flags: PRIVATE|DENYWRITE|FIXED, fd: 3, off: 1937408) = 0x7fc50e847000
0.079 ( 0.002 ms): epoll/20444 mmap(addr: 0x7fc50e84d000, len: 14976, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS|FIXED, fd: -1) = 0x7fc50e84d000
0.085 ( 0.001 ms): epoll/20444 close(fd: 3 ) = 0
0.093 ( 0.001 ms): epoll/20444 arch_prctl(option: 4098, arg2: 140484331029696 ) = 0
0.128 ( 0.003 ms): epoll/20444 mprotect(start: 0x7fc50e847000, len: 16384, prot: READ ) = 0
0.133 ( 0.002 ms): epoll/20444 mprotect(start: 0x600000, len: 4096, prot: READ ) = 0
0.137 ( 0.002 ms): epoll/20444 mprotect(start: 0x7fc50ea78000, len: 4096, prot: READ ) = 0
0.140 ( 0.005 ms): epoll/20444 munmap(addr: 0x7fc50ea5d000, len: 109538 ) = 0
0.159 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -1, sigsetsize: 8 ) = -22
0.160 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -2, sigsetsize: 8 ) = -22
0.162 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -3, sigsetsize: 8 ) = -22
0.163 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -4, sigsetsize: 8 ) = -22
0.165 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -5, sigsetsize: 8 ) = -22
<SNIP>
0.279 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -85, sigsetsize: 8 ) = -22
0.280 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -86, sigsetsize: 8 ) = -22
0.282 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -87, sigsetsize: 8 ) = -22
0.283 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -88, sigsetsize: 8 ) = -22
0.284 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -89, sigsetsize: 8 ) = -22
0.286 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -90, sigsetsize: 8 ) = -22
0.287 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -91, sigsetsize: 8 ) = -22
0.289 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -92, sigsetsize: 8 ) = -22
0.290 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -93, sigsetsize: 8 ) = -22
0.292 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -94, sigsetsize: 8 ) = -22
0.293 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -95, sigsetsize: 8 ) = -22
0.294 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -96, sigsetsize: 8 ) = -22
0.296 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -97, sigsetsize: 8 ) = -22
0.297 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -98, sigsetsize: 8 ) = -22
0.299 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -99, sigsetsize: 8 ) = -22
0.300 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -100, sigsetsize: 8 ) = -22
0.305 ( ? ): epoll/20444 exit_group( )
[root@seventh ~]#
This is on a Fedora 27 system, that has glibc 2.26, while on a RHEL7
machine, that has glibc 2.17, it still uses epoll_wait() and we get:
[root@felicio ~]# trace ./epoll
0.018 ( 0.001 ms): epoll/2818 brk( ) = 0x8e5000
0.033 ( 0.002 ms): epoll/2818 mmap(len: 4096, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS ) = 0x7f3f738e3000
0.041 ( 0.004 ms): epoll/2818 access(filename: 0x736e2160, mode: R ) = -1 ENOENT No such file or directory
0.051 ( 0.003 ms): epoll/2818 open(filename: 0x736e0a58, flags: CLOEXEC ) = 3
0.056 ( 0.001 ms): epoll/2818 fstat(fd: 3, statbuf: 0x7fff8b35f5b0 ) = 0
0.057 ( 0.002 ms): epoll/2818 mmap(len: 78559, prot: READ, flags: PRIVATE, fd: 3 ) = 0x7f3f738cf000
0.060 ( 0.001 ms): epoll/2818 close(fd: 3 ) = 0
0.070 ( 0.005 ms): epoll/2818 open(filename: 0x738e3640, flags: CLOEXEC ) = 3
0.076 ( 0.001 ms): epoll/2818 read(fd: 3, buf: 0x7fff8b35f770, count: 832 ) = 832
0.079 ( 0.001 ms): epoll/2818 fstat(fd: 3, statbuf: 0x7fff8b35f610 ) = 0
0.082 ( 0.003 ms): epoll/2818 mmap(len: 3932672, prot: EXEC|READ, flags: PRIVATE|DENYWRITE, fd: 3 ) = 0x7f3f73304000
0.086 ( 0.005 ms): epoll/2818 mprotect(start: 0x7f3f734bb000, len: 2093056 ) = 0
0.091 ( 0.005 ms): epoll/2818 mmap(addr: 0x7f3f736ba000, len: 24576, prot: READ|WRITE, flags: PRIVATE|DENYWRITE|FIXED, fd: 3, off: 1794048) = 0x7f3f736ba000
0.100 ( 0.003 ms): epoll/2818 mmap(addr: 0x7f3f736c0000, len: 16896, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS|FIXED) = 0x7f3f736c0000
0.106 ( 0.001 ms): epoll/2818 close(fd: 3 ) = 0
0.115 ( 0.002 ms): epoll/2818 mmap(len: 4096, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS ) = 0x7f3f738ce000
0.119 ( 0.002 ms): epoll/2818 mmap(len: 8192, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS ) = 0x7f3f738cc000
0.123 ( 0.001 ms): epoll/2818 arch_prctl(option: 4098, arg2: 139910498273088, arg3: 139910498275408, arg4: 34, arg5: -1) = 0
0.181 ( 0.003 ms): epoll/2818 mprotect(start: 0x7f3f736ba000, len: 16384, prot: READ ) = 0
0.186 ( 0.002 ms): epoll/2818 mprotect(start: 0x600000, len: 4096, prot: READ ) = 0
0.190 ( 0.002 ms): epoll/2818 mprotect(start: 0x7f3f738e4000, len: 4096, prot: READ ) = 0
0.193 ( 0.004 ms): epoll/2818 munmap(addr: 0x7f3f738cf000, len: 78559 ) = 0
0.218 ( 0.001 ms): epoll/2818 epoll_wait(epfd: -1 ) = -1 EINVAL Invalid argument
0.220 ( 0.000 ms): epoll/2818 epoll_wait(epfd: -2 ) = -1 EINVAL Invalid argument
0.221 ( 0.000 ms): epoll/2818 epoll_wait(epfd: -3 ) = -1 EINVAL Invalid argument
0.221 ( 0.000 ms): epoll/2818 epoll_wait(epfd: -4 ) = -1 EINVAL Invalid argument
0.222 ( 0.000 ms): epoll/2818 epoll_wait(epfd: -5 ) = -1 EINVAL Invalid argument
<SNIP>
It thought that this part would cover it:
Probe point found: SyS_epoll_pwait+138
found inline addr: 0xffffffff812d7cf0
Continuing investigation...
- Arnaldo
> works for the test program used by this testcase:
>
> #include <sys/epoll.h>
> #include <stdlib.h>
>
> #define NR_ITERS 100
>
> static int epoll_wait_loop(void)
> {
> int i;
>
> /* Should fail NR_ITERS times */
> for (i = 0; i < NR_ITERS; i++)
> epoll_wait(-(i + 1), NULL, 0, 0);
> return 0;
> }
>
> int main()
> {
> epoll_wait_loop();
> return 0;
> }
>
> In my configuration it gives 100 samples:
>
> $ sudo ./perf record -e probe:SyS_epoll_wait /tmp/a.out
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.016 MB perf.data (100 samples) ]
>
> I guess in your configuration you would get 3 tracepoints, and can get 0
> sample from them.
>
> Thank you.
>
> On 2018/1/3 12:42, Wangnan (F) wrote:
> > Unable to reproduce. In my kernel configuration, SyS_epoll_wait is not
> > inlined at all.
> >
> > From the log you sent, it seems that all 3 instances are attached. This
> > testcase should work if the last one (SyS_epoll_wait) get probed
> > correctly.
> >
> > Could you please have a look if the 3rd kprobe event
> > (p:perf_bpf_probe/func_2 _text+2845824) works?
> >
> > Thank you.
> >
> > On 2018/1/3 2:59, Arnaldo Carvalho de Melo wrote:
> > > 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]#
> >
>
Em Wed, Jan 03, 2018 at 01:58:44PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Wed, Jan 03, 2018 at 12:58:26PM +0800, Wangnan (F) escreveu:
> > And please check if the kprobe created by
> >
> > $ perf probe -v SyS_epoll_wait
>
> [root@seventh ~]# perf probe -v SyS_epoll_wait
> probe-definition(0): SyS_epoll_wait
> symbol:SyS_epoll_wait file:(null) line:0 offset:0 return:0 lazy:(null)
> 0 arguments
> Looking at the vmlinux_path (8 entries long)
> Using /usr/lib/debug/lib/modules/4.14.8-300.fc27.x86_64/vmlinux for symbols
> Open Debuginfo file: /usr/lib/debug/lib/modules/4.14.8-300.fc27.x86_64/vmlinux
> Try to find probe point from debuginfo.
> Matched function: SyS_epoll_wait [314b563]
> found inline addr: 0xffffffff812d8087
> Probe point found: compat_SyS_epoll_pwait+151
> found inline addr: 0xffffffff812d7e5a
> Probe point found: SyS_epoll_pwait+138
> found inline addr: 0xffffffff812d7cf0
> Probe point found: SyS_epoll_wait+0
> Found 3 probe_trace_events.
> Opening /sys/kernel/debug/tracing//kprobe_events write=1
> Writing event: p:probe/SyS_epoll_wait _text+2982023
> Writing event: p:probe/SyS_epoll_wait_1 _text+2981466
> Writing event: p:probe/SyS_epoll_wait_2 _text+2981104
> Added new events:
> probe:SyS_epoll_wait (on SyS_epoll_wait)
> probe:SyS_epoll_wait_1 (on SyS_epoll_wait)
> probe:SyS_epoll_wait_2 (on SyS_epoll_wait)
>
> You can now use it in all perf tools, such as:
>
> perf record -e probe:SyS_epoll_wait_2 -aR sleep 1
>
> [root@seventh ~]#
>
> Then, with your proggie, it seems its glibc that now maps epoll_wait()
> to a different syscall than in older systems:
>
> [root@seventh ~]# trace -e probe:SyS_epoll_wait* ~acme/epoll
> 0.018 ( 0.001 ms): epoll/20444 brk( ) = 0x2600000
> 0.029 ( 0.004 ms): epoll/20444 access(filename: 0xe874ec0, mode: R ) = -1 ENOENT No such file or directory
> 0.035 ( 0.003 ms): epoll/20444 openat(dfd: CWD, filename: 0xe872726, flags: CLOEXEC ) = 3
> 0.040 ( 0.002 ms): epoll/20444 fstat(fd: 3, statbuf: 0x7fffcc37b830 ) = 0
> 0.042 ( 0.002 ms): epoll/20444 mmap(len: 109538, prot: READ, flags: PRIVATE, fd: 3 ) = 0x7fc50ea5d000
> 0.045 ( 0.001 ms): epoll/20444 close(fd: 3 ) = 0
> 0.052 ( 0.003 ms): epoll/20444 openat(dfd: CWD, filename: 0xea7ace0, flags: CLOEXEC ) = 3
> 0.056 ( 0.001 ms): epoll/20444 read(fd: 3, buf: 0x7fffcc37b9f8, count: 832 ) = 832
> 0.059 ( 0.001 ms): epoll/20444 fstat(fd: 3, statbuf: 0x7fffcc37b890 ) = 0
> 0.060 ( 0.002 ms): epoll/20444 mmap(len: 8192, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS, fd: -1 ) = 0x7fc50ea5b000
> 0.065 ( 0.003 ms): epoll/20444 mmap(len: 4074112, prot: EXEC|READ, flags: PRIVATE|DENYWRITE, fd: 3 ) = 0x7fc50e46e000
> 0.068 ( 0.004 ms): epoll/20444 mprotect(start: 0x7fc50e648000, len: 2093056 ) = 0
> 0.073 ( 0.004 ms): epoll/20444 mmap(addr: 0x7fc50e847000, len: 24576, prot: READ|WRITE, flags: PRIVATE|DENYWRITE|FIXED, fd: 3, off: 1937408) = 0x7fc50e847000
> 0.079 ( 0.002 ms): epoll/20444 mmap(addr: 0x7fc50e84d000, len: 14976, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS|FIXED, fd: -1) = 0x7fc50e84d000
> 0.085 ( 0.001 ms): epoll/20444 close(fd: 3 ) = 0
> 0.093 ( 0.001 ms): epoll/20444 arch_prctl(option: 4098, arg2: 140484331029696 ) = 0
> 0.128 ( 0.003 ms): epoll/20444 mprotect(start: 0x7fc50e847000, len: 16384, prot: READ ) = 0
> 0.133 ( 0.002 ms): epoll/20444 mprotect(start: 0x600000, len: 4096, prot: READ ) = 0
> 0.137 ( 0.002 ms): epoll/20444 mprotect(start: 0x7fc50ea78000, len: 4096, prot: READ ) = 0
> 0.140 ( 0.005 ms): epoll/20444 munmap(addr: 0x7fc50ea5d000, len: 109538 ) = 0
> 0.159 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -1, sigsetsize: 8 ) = -22
> 0.160 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -2, sigsetsize: 8 ) = -22
> 0.162 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -3, sigsetsize: 8 ) = -22
> 0.163 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -4, sigsetsize: 8 ) = -22
> 0.165 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -5, sigsetsize: 8 ) = -22
> <SNIP>
> 0.279 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -85, sigsetsize: 8 ) = -22
> 0.280 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -86, sigsetsize: 8 ) = -22
> 0.282 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -87, sigsetsize: 8 ) = -22
> 0.283 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -88, sigsetsize: 8 ) = -22
> 0.284 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -89, sigsetsize: 8 ) = -22
> 0.286 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -90, sigsetsize: 8 ) = -22
> 0.287 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -91, sigsetsize: 8 ) = -22
> 0.289 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -92, sigsetsize: 8 ) = -22
> 0.290 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -93, sigsetsize: 8 ) = -22
> 0.292 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -94, sigsetsize: 8 ) = -22
> 0.293 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -95, sigsetsize: 8 ) = -22
> 0.294 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -96, sigsetsize: 8 ) = -22
> 0.296 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -97, sigsetsize: 8 ) = -22
> 0.297 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -98, sigsetsize: 8 ) = -22
> 0.299 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -99, sigsetsize: 8 ) = -22
> 0.300 ( 0.001 ms): epoll/20444 epoll_pwait(epfd: -100, sigsetsize: 8 ) = -22
> 0.305 ( ? ): epoll/20444 exit_group( )
> [root@seventh ~]#
>
> This is on a Fedora 27 system, that has glibc 2.26, while on a RHEL7
> machine, that has glibc 2.17, it still uses epoll_wait() and we get:
>
> [root@felicio ~]# trace ./epoll
> 0.018 ( 0.001 ms): epoll/2818 brk( ) = 0x8e5000
> 0.033 ( 0.002 ms): epoll/2818 mmap(len: 4096, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS ) = 0x7f3f738e3000
> 0.041 ( 0.004 ms): epoll/2818 access(filename: 0x736e2160, mode: R ) = -1 ENOENT No such file or directory
> 0.051 ( 0.003 ms): epoll/2818 open(filename: 0x736e0a58, flags: CLOEXEC ) = 3
> 0.056 ( 0.001 ms): epoll/2818 fstat(fd: 3, statbuf: 0x7fff8b35f5b0 ) = 0
> 0.057 ( 0.002 ms): epoll/2818 mmap(len: 78559, prot: READ, flags: PRIVATE, fd: 3 ) = 0x7f3f738cf000
> 0.060 ( 0.001 ms): epoll/2818 close(fd: 3 ) = 0
> 0.070 ( 0.005 ms): epoll/2818 open(filename: 0x738e3640, flags: CLOEXEC ) = 3
> 0.076 ( 0.001 ms): epoll/2818 read(fd: 3, buf: 0x7fff8b35f770, count: 832 ) = 832
> 0.079 ( 0.001 ms): epoll/2818 fstat(fd: 3, statbuf: 0x7fff8b35f610 ) = 0
> 0.082 ( 0.003 ms): epoll/2818 mmap(len: 3932672, prot: EXEC|READ, flags: PRIVATE|DENYWRITE, fd: 3 ) = 0x7f3f73304000
> 0.086 ( 0.005 ms): epoll/2818 mprotect(start: 0x7f3f734bb000, len: 2093056 ) = 0
> 0.091 ( 0.005 ms): epoll/2818 mmap(addr: 0x7f3f736ba000, len: 24576, prot: READ|WRITE, flags: PRIVATE|DENYWRITE|FIXED, fd: 3, off: 1794048) = 0x7f3f736ba000
> 0.100 ( 0.003 ms): epoll/2818 mmap(addr: 0x7f3f736c0000, len: 16896, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS|FIXED) = 0x7f3f736c0000
> 0.106 ( 0.001 ms): epoll/2818 close(fd: 3 ) = 0
> 0.115 ( 0.002 ms): epoll/2818 mmap(len: 4096, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS ) = 0x7f3f738ce000
> 0.119 ( 0.002 ms): epoll/2818 mmap(len: 8192, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS ) = 0x7f3f738cc000
> 0.123 ( 0.001 ms): epoll/2818 arch_prctl(option: 4098, arg2: 139910498273088, arg3: 139910498275408, arg4: 34, arg5: -1) = 0
> 0.181 ( 0.003 ms): epoll/2818 mprotect(start: 0x7f3f736ba000, len: 16384, prot: READ ) = 0
> 0.186 ( 0.002 ms): epoll/2818 mprotect(start: 0x600000, len: 4096, prot: READ ) = 0
> 0.190 ( 0.002 ms): epoll/2818 mprotect(start: 0x7f3f738e4000, len: 4096, prot: READ ) = 0
> 0.193 ( 0.004 ms): epoll/2818 munmap(addr: 0x7f3f738cf000, len: 78559 ) = 0
> 0.218 ( 0.001 ms): epoll/2818 epoll_wait(epfd: -1 ) = -1 EINVAL Invalid argument
> 0.220 ( 0.000 ms): epoll/2818 epoll_wait(epfd: -2 ) = -1 EINVAL Invalid argument
> 0.221 ( 0.000 ms): epoll/2818 epoll_wait(epfd: -3 ) = -1 EINVAL Invalid argument
> 0.221 ( 0.000 ms): epoll/2818 epoll_wait(epfd: -4 ) = -1 EINVAL Invalid argument
> 0.222 ( 0.000 ms): epoll/2818 epoll_wait(epfd: -5 ) = -1 EINVAL Invalid argument
> <SNIP>
>
> It thought that this part would cover it:
>
> Probe point found: SyS_epoll_pwait+138
> found inline addr: 0xffffffff812d7cf0
>
> Continuing investigation...
After applying the fallback patch to allow new tools to work with older
kernels:
[root@felicio ~]# perf test bpf
39: BPF filter :
39.1: Basic BPF filtering : Ok
39.2: BPF pinning : Ok
39.3: BPF prologue generation : Ok
39.4: BPF relocation checker : Ok
[root@felicio ~]# uname -a
Linux felicio.ghostprotocols.net 4.13.0-rc7+ #1 SMP Mon Sep 11 13:56:18 -03 2017 x86_64 x86_64 x86_64 GNU/Linux
[root@felicio ~]# rpm -q glibc
glibc-2.17-157.el7_3.2.x86_64
[root@felicio ~]#
After applying the patch below I get to, which is what I am trying to
fix now:
[root@jouet ~]# perf test bpf
39: BPF filter :
39.1: Basic BPF filtering : Ok
39.2: BPF pinning : Ok
39.3: BPF prologue generation : FAILED!
39.4: BPF relocation checker : Skip
[root@jouet ~]#
Its related to:
<stdin>:11:10: fatal error: 'uapi/linux/fs.h' file not found
#include <uapi/linux/fs.h>
^~~~~~~~~~~~~~~~~
1 error generated.
ERROR: unable to compile -
Hint: Check error message shown above.
Hint: You can also pre-compile it into .o using:
clang -target bpf -O2 -c -
with proper -I and -D options.
Failed to compile test case: 'Compile source for BPF prologue generation'
Unable to get BPF object, fix kbuild first
test child finished with -1
---- end ----
BPF filter subtest 2: FAILED!
- Arnaldo
diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c
index 268e5f8e4aa2..d1e67e271675 100644
--- a/tools/perf/tests/bpf-script-example.c
+++ b/tools/perf/tests/bpf-script-example.c
@@ -31,7 +31,7 @@ struct bpf_map_def SEC("maps") flip_table = {
.max_entries = 1,
};
-SEC("func=SyS_epoll_wait")
+SEC("func=SyS_epoll_pwait")
int bpf_func__SyS_epoll_wait(void *ctx)
{
int ind =0;
Em Wed, Jan 03, 2018 at 03:27:01PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Continuing investigation...
>
> After applying the fallback patch to allow new tools to work with older
> kernels:
>
> [root@felicio ~]# perf test bpf
> 39: BPF filter :
> 39.1: Basic BPF filtering : Ok
> 39.2: BPF pinning : Ok
> 39.3: BPF prologue generation : Ok
> 39.4: BPF relocation checker : Ok
> [root@felicio ~]# uname -a
> Linux felicio.ghostprotocols.net 4.13.0-rc7+ #1 SMP Mon Sep 11 13:56:18 -03 2017 x86_64 x86_64 x86_64 GNU/Linux
> [root@felicio ~]# rpm -q glibc
> glibc-2.17-157.el7_3.2.x86_64
> [root@felicio ~]#
>
> After applying the patch below I get to, which is what I am trying to
> fix now:
>
> [root@jouet ~]# perf test bpf
> 39: BPF filter :
> 39.1: Basic BPF filtering : Ok
> 39.2: BPF pinning : Ok
> 39.3: BPF prologue generation : FAILED!
> 39.4: BPF relocation checker : Skip
> [root@jouet ~]#
Update the patch to the one at the end of this message to make it work
with older glibcs, so that we ask for epoll_pwait() and hook into that
as well().
Now checking why 39.3 fails...
- Arnaldo
diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c
index 268e5f8e4aa2..d1e67e271675 100644
--- a/tools/perf/tests/bpf-script-example.c
+++ b/tools/perf/tests/bpf-script-example.c
@@ -31,7 +31,7 @@ struct bpf_map_def SEC("maps") flip_table = {
.max_entries = 1,
};
-SEC("func=SyS_epoll_wait")
+SEC("func=SyS_epoll_pwait")
int bpf_func__SyS_epoll_wait(void *ctx)
{
int ind =0;
diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
index 0512f1b5bfdb..7c04e2d5b60b 100644
--- a/tools/perf/tests/bpf.c
+++ b/tools/perf/tests/bpf.c
@@ -25,7 +25,7 @@ static int epoll_wait_loop(void)
/* Should fail NR_ITERS times */
for (i = 0; i < NR_ITERS; i++)
- epoll_wait(-(i + 1), NULL, 0, 0);
+ epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
return 0;
}
Em Wed, Jan 03, 2018 at 03:33:07PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Wed, Jan 03, 2018 at 03:27:01PM -0300, Arnaldo Carvalho de Melo escreveu:
> > > Continuing investigation...
> >
> > After applying the fallback patch to allow new tools to work with older
> > kernels:
> >
> > [root@felicio ~]# perf test bpf
> > 39: BPF filter :
> > 39.1: Basic BPF filtering : Ok
> > 39.2: BPF pinning : Ok
> > 39.3: BPF prologue generation : Ok
> > 39.4: BPF relocation checker : Ok
> > [root@felicio ~]# uname -a
> > Linux felicio.ghostprotocols.net 4.13.0-rc7+ #1 SMP Mon Sep 11 13:56:18 -03 2017 x86_64 x86_64 x86_64 GNU/Linux
> > [root@felicio ~]# rpm -q glibc
> > glibc-2.17-157.el7_3.2.x86_64
> > [root@felicio ~]#
> >
> > After applying the patch below I get to, which is what I am trying to
> > fix now:
> >
> > [root@jouet ~]# perf test bpf
> > 39: BPF filter :
> > 39.1: Basic BPF filtering : Ok
> > 39.2: BPF pinning : Ok
> > 39.3: BPF prologue generation : FAILED!
> > 39.4: BPF relocation checker : Skip
> > [root@jouet ~]#
>
> Update the patch to the one at the end of this message to make it work
> with older glibcs, so that we ask for epoll_pwait() and hook into that
> as well().
>
> Now checking why 39.3 fails...
Couldn't reproduce after fixing up some kernel build problems, the patch
below is all I need to have this working with both Fedora 27 and RHEL7,
please take a look and see if it continues to work on your systems,
- Arnaldo
> - Arnaldo
>
> diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c
> index 268e5f8e4aa2..d1e67e271675 100644
> --- a/tools/perf/tests/bpf-script-example.c
> +++ b/tools/perf/tests/bpf-script-example.c
> @@ -31,7 +31,7 @@ struct bpf_map_def SEC("maps") flip_table = {
> .max_entries = 1,
> };
>
> -SEC("func=SyS_epoll_wait")
> +SEC("func=SyS_epoll_pwait")
> int bpf_func__SyS_epoll_wait(void *ctx)
> {
> int ind =0;
> diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
> index 0512f1b5bfdb..7c04e2d5b60b 100644
> --- a/tools/perf/tests/bpf.c
> +++ b/tools/perf/tests/bpf.c
> @@ -25,7 +25,7 @@ static int epoll_wait_loop(void)
>
> /* Should fail NR_ITERS times */
> for (i = 0; i < NR_ITERS; i++)
> - epoll_wait(-(i + 1), NULL, 0, 0);
> + epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
> return 0;
> }
>
On 2018/1/4 4:13, Arnaldo Carvalho de Melo wrote:
> Em Wed, Jan 03, 2018 at 03:33:07PM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Wed, Jan 03, 2018 at 03:27:01PM -0300, Arnaldo Carvalho de Melo escreveu:
>>>> Continuing investigation...
>>> After applying the fallback patch to allow new tools to work with older
>>> kernels:
>>>
>>> [root@felicio ~]# perf test bpf
>>> 39: BPF filter :
>>> 39.1: Basic BPF filtering : Ok
>>> 39.2: BPF pinning : Ok
>>> 39.3: BPF prologue generation : Ok
>>> 39.4: BPF relocation checker : Ok
>>> [root@felicio ~]# uname -a
>>> Linux felicio.ghostprotocols.net 4.13.0-rc7+ #1 SMP Mon Sep 11 13:56:18 -03 2017 x86_64 x86_64 x86_64 GNU/Linux
>>> [root@felicio ~]# rpm -q glibc
>>> glibc-2.17-157.el7_3.2.x86_64
>>> [root@felicio ~]#
>>>
>>> After applying the patch below I get to, which is what I am trying to
>>> fix now:
>>>
>>> [root@jouet ~]# perf test bpf
>>> 39: BPF filter :
>>> 39.1: Basic BPF filtering : Ok
>>> 39.2: BPF pinning : Ok
>>> 39.3: BPF prologue generation : FAILED!
>>> 39.4: BPF relocation checker : Skip
>>> [root@jouet ~]#
>> Update the patch to the one at the end of this message to make it work
>> with older glibcs, so that we ask for epoll_pwait() and hook into that
>> as well().
>>
>> Now checking why 39.3 fails...
> Couldn't reproduce after fixing up some kernel build problems, the patch
> below is all I need to have this working with both Fedora 27 and RHEL7,
> please take a look and see if it continues to work on your systems,
It works for me. Thank you.
Since we test epoll_pwait, we'd better correct function names:
diff --git a/tools/perf/tests/bpf-script-example.c
b/tools/perf/tests/bpf-script-example.c
index 268e5f8..e4123c1 100644
--- a/tools/perf/tests/bpf-script-example.c
+++ b/tools/perf/tests/bpf-script-example.c
@@ -31,8 +31,8 @@ struct bpf_map_def SEC("maps") flip_table = {
.max_entries = 1,
};
-SEC("func=SyS_epoll_wait")
-int bpf_func__SyS_epoll_wait(void *ctx)
+SEC("func=SyS_epoll_pwait")
+int bpf_func__SyS_epoll_pwait(void *ctx)
{
int ind =0;
int *flag = bpf_map_lookup_elem(&flip_table, &ind);
diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
index 34c22cd..a8f9095 100644
--- a/tools/perf/tests/bpf.c
+++ b/tools/perf/tests/bpf.c
@@ -19,13 +19,13 @@
#ifdef HAVE_LIBBPF_SUPPORT
-static int epoll_wait_loop(void)
+static int epoll_pwait_loop(void)
{
int i;
/* Should fail NR_ITERS times */
for (i = 0; i < NR_ITERS; i++)
- epoll_wait(-(i + 1), NULL, 0, 0);
+ epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
return 0;
}
@@ -68,7 +68,7 @@ static struct {
"[basic_bpf_test]",
"fix 'perf test LLVM' first",
"load bpf object failed",
- &epoll_wait_loop,
+ &epoll_pwait_loop,
(NR_ITERS + 1) / 2,
false,
},
@@ -78,7 +78,7 @@ static struct {
"[bpf_pinning]",
"fix kbuild first",
"check your vmlinux setting?",
- &epoll_wait_loop,
+ &epoll_pwait_loop,
(NR_ITERS + 1) / 2,
true,
},
Em Thu, Jan 04, 2018 at 09:37:35AM +0800, Wangnan (F) escreveu:
>
>
> On 2018/1/4 4:13, Arnaldo Carvalho de Melo wrote:
> > Em Wed, Jan 03, 2018 at 03:33:07PM -0300, Arnaldo Carvalho de Melo escreveu:
> > > Em Wed, Jan 03, 2018 at 03:27:01PM -0300, Arnaldo Carvalho de Melo escreveu:
> > > > > Continuing investigation...
> > > > After applying the fallback patch to allow new tools to work with older
> > > > kernels:
> > > >
> > > > [root@felicio ~]# perf test bpf
> > > > 39: BPF filter :
> > > > 39.1: Basic BPF filtering : Ok
> > > > 39.2: BPF pinning : Ok
> > > > 39.3: BPF prologue generation : Ok
> > > > 39.4: BPF relocation checker : Ok
> > > > [root@felicio ~]# uname -a
> > > > Linux felicio.ghostprotocols.net 4.13.0-rc7+ #1 SMP Mon Sep 11 13:56:18 -03 2017 x86_64 x86_64 x86_64 GNU/Linux
> > > > [root@felicio ~]# rpm -q glibc
> > > > glibc-2.17-157.el7_3.2.x86_64
> > > > [root@felicio ~]#
> > > >
> > > > After applying the patch below I get to, which is what I am trying to
> > > > fix now:
> > > >
> > > > [root@jouet ~]# perf test bpf
> > > > 39: BPF filter :
> > > > 39.1: Basic BPF filtering : Ok
> > > > 39.2: BPF pinning : Ok
> > > > 39.3: BPF prologue generation : FAILED!
> > > > 39.4: BPF relocation checker : Skip
> > > > [root@jouet ~]#
> > > Update the patch to the one at the end of this message to make it work
> > > with older glibcs, so that we ask for epoll_pwait() and hook into that
> > > as well().
> > >
> > > Now checking why 39.3 fails...
> > Couldn't reproduce after fixing up some kernel build problems, the patch
> > below is all I need to have this working with both Fedora 27 and RHEL7,
> > please take a look and see if it continues to work on your systems,
>
> It works for me. Thank you.
>
> Since we test epoll_pwait, we'd better correct function names:
Right, that wasn't strictly needed, so I tried to restrict my changes to
focus on the fix.
Now that we agree on it, I'm doing what you suggest, to make it less
confusing.
I'm adding your Tested-by, thanks!
- Arnaldo
>
> diff --git a/tools/perf/tests/bpf-script-example.c
> b/tools/perf/tests/bpf-script-example.c
> index 268e5f8..e4123c1 100644
> --- a/tools/perf/tests/bpf-script-example.c
> +++ b/tools/perf/tests/bpf-script-example.c
> @@ -31,8 +31,8 @@ struct bpf_map_def SEC("maps") flip_table = {
> .max_entries = 1,
> };
>
> -SEC("func=SyS_epoll_wait")
> -int bpf_func__SyS_epoll_wait(void *ctx)
> +SEC("func=SyS_epoll_pwait")
> +int bpf_func__SyS_epoll_pwait(void *ctx)
> {
> int ind =0;
> int *flag = bpf_map_lookup_elem(&flip_table, &ind);
> diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
> index 34c22cd..a8f9095 100644
> --- a/tools/perf/tests/bpf.c
> +++ b/tools/perf/tests/bpf.c
> @@ -19,13 +19,13 @@
>
> #ifdef HAVE_LIBBPF_SUPPORT
>
> -static int epoll_wait_loop(void)
> +static int epoll_pwait_loop(void)
> {
> int i;
>
> /* Should fail NR_ITERS times */
> for (i = 0; i < NR_ITERS; i++)
> - epoll_wait(-(i + 1), NULL, 0, 0);
> + epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
> return 0;
> }
>
> @@ -68,7 +68,7 @@ static struct {
> "[basic_bpf_test]",
> "fix 'perf test LLVM' first",
> "load bpf object failed",
> - &epoll_wait_loop,
> + &epoll_pwait_loop,
> (NR_ITERS + 1) / 2,
> false,
> },
> @@ -78,7 +78,7 @@ static struct {
> "[bpf_pinning]",
> "fix kbuild first",
> "check your vmlinux setting?",
> - &epoll_wait_loop,
> + &epoll_pwait_loop,
> (NR_ITERS + 1) / 2,
> true,
> },
>
>