Hey Yonghong,
On 12/06/2017 11:07 PM, Yonghong Song wrote:
> Commit e87c6bc3852b ("bpf: permit multiple bpf attachments
> for a single perf event") added support to attach multiple
> bpf programs to a single perf event. Given a perf event
> (kprobe, uprobe, or kernel tracepoint), the perf ioctl interface
> is used to query bpf programs attached to the same trace event.
>
> There already exists a BPF_PROG_QUERY command for introspection
> currently used by cgroup+bpf. We did have an implementation for
> querying tracepoint+bpf through the same interface. However, it
> looks cleaner to use ioctl() style of api here, since attaching
> bpf prog to tracepoint/kuprobe is also done via ioctl.
>
> Patch #1 had the core implementation and patch #2 added
> a test case in tools bpf selftests suite.
>
> Changelogs:
> v2 -> v3:
> - Change uapi structure perf_event_query_bpf to be more
> clearer based on Peter's suggestion, and adjust
> other codes accordingly.
> v1 -> v2:
> - Rebase on top of net-next.
> - Use existing bpf_prog_array_length function instead of
> implementing the same functionality in function
> bpf_prog_array_copy_info.
>
> Yonghong Song (2):
> bpf/tracing: allow user space to query prog array on the same tp
> bpf/tracing: add a bpf test for new ioctl query interface
v3 doesn't build cleanly, could you take a look & fix?
Thanks,
Daniel
$ make -j4 kernel/trace/
CHK include/config/kernel.release
HOSTCC scripts/basic/fixdep
CHK include/generated/uapi/linux/version.h
DESCEND objtool
CHK include/generated/utsrelease.h
HOSTCC /home/darkstar/trees/bpf-next/tools/objtool/fixdep.o
HOSTCC scripts/basic/bin2c
HOSTLD /home/darkstar/trees/bpf-next/tools/objtool/fixdep-in.o
LINK /home/darkstar/trees/bpf-next/tools/objtool/fixdep
CC /home/darkstar/trees/bpf-next/tools/objtool/builtin-check.o
CC /home/darkstar/trees/bpf-next/tools/objtool/arch/x86/decode.o
CC /home/darkstar/trees/bpf-next/tools/objtool/builtin-orc.o
CC /home/darkstar/trees/bpf-next/tools/objtool/exec-cmd.o
CC /home/darkstar/trees/bpf-next/tools/objtool/help.o
CC /home/darkstar/trees/bpf-next/tools/objtool/pager.o
CC /home/darkstar/trees/bpf-next/tools/objtool/parse-options.o
CC /home/darkstar/trees/bpf-next/tools/objtool/run-command.o
CC /home/darkstar/trees/bpf-next/tools/objtool/sigchain.o
CC /home/darkstar/trees/bpf-next/tools/objtool/subcmd-config.o
LD /home/darkstar/trees/bpf-next/tools/objtool/arch/x86/objtool-in.o
CC /home/darkstar/trees/bpf-next/tools/objtool/check.o
HOSTCC arch/x86/tools/relocs_32.o
HOSTCC arch/x86/tools/relocs_64.o
CC /home/darkstar/trees/bpf-next/tools/objtool/orc_gen.o
HOSTCC arch/x86/tools/relocs_common.o
LD /home/darkstar/trees/bpf-next/tools/objtool/libsubcmd-in.o
AR /home/darkstar/trees/bpf-next/tools/objtool/libsubcmd.a
HOSTLD arch/x86/tools/relocs
CC /home/darkstar/trees/bpf-next/tools/objtool/orc_dump.o
CC scripts/mod/empty.o
HOSTCC scripts/mod/mk_elfconfig
CC arch/x86/purgatory/purgatory.o
AS arch/x86/purgatory/stack.o
CC scripts/mod/devicetable-offsets.s
AS arch/x86/purgatory/setup-x86_64.o
HOSTCC scripts/kallsyms
CC arch/x86/purgatory/sha256.o
MKELF scripts/mod/elfconfig.h
CHK scripts/mod/devicetable-offsets.h
HOSTCC scripts/mod/sumversion.o
HOSTCC scripts/pnmtologo
HOSTCC scripts/mod/modpost.o
AS arch/x86/purgatory/entry64.o
CC arch/x86/purgatory/string.o
CC /home/darkstar/trees/bpf-next/tools/objtool/elf.o
LD arch/x86/purgatory/purgatory.ro
HOSTCC scripts/conmakehash
BIN2C arch/x86/purgatory/kexec-purgatory.c
CC kernel/bounds.s
CHK include/generated/timeconst.h
CHK include/generated/bounds.h
CC arch/x86/kernel/asm-offsets.s
HOSTCC scripts/recordmcount
CC /home/darkstar/trees/bpf-next/tools/objtool/special.o
CC /home/darkstar/trees/bpf-next/tools/objtool/objtool.o
CC /home/darkstar/trees/bpf-next/tools/objtool/libstring.o
CC /home/darkstar/trees/bpf-next/tools/objtool/str_error_r.o
LD /home/darkstar/trees/bpf-next/tools/objtool/objtool-in.o
HOSTCC scripts/mod/file2alias.o
Warning: synced file at 'tools/objtool/arch/x86/lib/x86-opcode-map.txt' differs
from latest kernel version at 'arch/x86/lib/x86-opcode-map.txt'
LINK /home/darkstar/trees/bpf-next/tools/objtool/objtool
HOSTCC scripts/sortextable
CHK include/generated/asm-offsets.h
HOSTCC scripts/asn1_compiler
CALL scripts/checksyscalls.sh
HOSTCC scripts/sign-file
HOSTCC scripts/extract-cert
HOSTLD scripts/mod/modpost
CC kernel/trace/trace_clock.o
CC kernel/trace/ftrace.o
CC kernel/trace/ring_buffer.o
CC kernel/trace/trace.o
CC kernel/trace/trace_output.o
CC kernel/trace/trace_seq.o
CC kernel/trace/trace_stat.o
CC kernel/trace/trace_printk.o
CC kernel/trace/trace_sched_switch.o
CC kernel/trace/trace_functions.o
CC kernel/trace/trace_nop.o
CC kernel/trace/trace_functions_graph.o
CC kernel/trace/blktrace.o
CC kernel/trace/trace_events.o
CC kernel/trace/trace_export.o
CC kernel/trace/trace_syscalls.o
CC kernel/trace/trace_event_perf.o
CC kernel/trace/trace_events_filter.o
CC kernel/trace/trace_events_trigger.o
CC kernel/trace/bpf_trace.o
CC kernel/trace/trace_kprobe.o
kernel/trace/bpf_trace.c: In function ‘bpf_event_query_prog_array’:
kernel/trace/bpf_trace.c:839:12: error: passing argument 2 of
‘bpf_prog_array_copy_info’ from incompatible pointer type
[-Werror=incompatible-pointer-types]
&uquery->ids,
^
In file included from kernel/trace/bpf_trace.c:11:0:
./include/linux/bpf.h:289:5: note: expected ‘__u32 * {aka unsigned int *}’ but
argument is of type ‘__u32 (*)[]’
int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array,
^~~~~~~~~~~~~~~~~~~~~~~~
CC kernel/trace/power-traces.o
CC kernel/trace/rpm-traces.o
cc1: some warnings being treated as errors
scripts/Makefile.build:310: recipe for target 'kernel/trace/bpf_trace.o' failed
make[1]: *** [kernel/trace/bpf_trace.o] Error 1
make[1]: *** Waiting for unfinished jobs....
Makefile:1674: recipe for target 'kernel/trace/' failed
make: *** [kernel/trace/] Error 2
