Messages in this thread Patch in this message | | | Date | Thu, 29 Oct 2015 19:45:38 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 14/31] perf tools: Add BPF_PROLOGUE config options for further patches |
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Em Wed, Oct 14, 2015 at 12:41:25PM +0000, Wang Nan escreveu: > If both LIBBPF and DWARF are detected, it is possible to create prologue > for eBPF programs to help them accessing kernel data. HAVE_BPF_PROLOGUE
what kernel data? you mean to be able to map from variable/function argument name to where they are in memory/registers?
> and CONFIG_BPF_PROLOGUE is added as flags for this feature. > > PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET indicates an architecture > supports converting name of a register to its offset in > 'struct pt_regs'. Without this support, BPF_PROLOGUE should be turned off. > > HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET is introduced as the corresponding > CFLAGS of PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET. > > Signed-off-by: Wang Nan <wangnan0@huawei.com> > Cc: Alexei Starovoitov <ast@plumgrid.com> > Cc: Brendan Gregg <brendan.d.gregg@gmail.com> > Cc: Daniel Borkmann <daniel@iogearbox.net> > Cc: David Ahern <dsahern@gmail.com> > Cc: He Kuang <hekuang@huawei.com> > Cc: Jiri Olsa <jolsa@kernel.org> > Cc: Kaixu Xia <xiakaixu@huawei.com> > Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> > Cc: Namhyung Kim <namhyung@kernel.org> > Cc: Paul Mackerras <paulus@samba.org> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> > Cc: Zefan Li <lizefan@huawei.com> > Cc: pi3orama@163.com > Cc: Arnaldo Carvalho de Melo <acme@redhat.com> > Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngkw86@git.kernel.org > --- > tools/perf/config/Makefile | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile > index de89ec5..6eb9a95 100644 > --- a/tools/perf/config/Makefile > +++ b/tools/perf/config/Makefile > @@ -318,6 +318,18 @@ ifndef NO_LIBELF > CFLAGS += -DHAVE_LIBBPF_SUPPORT > $(call detected,CONFIG_LIBBPF) > endif > + > + ifndef NO_DWARF > + ifdef PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET > + CFLAGS += -DHAVE_BPF_PROLOGUE > + $(call detected,CONFIG_BPF_PROLOGUE) > + else > + msg := $(warning BPF prologue is not supported by architecture $(ARCH), missing regs_query_register_offset()); > + endif > + else > + msg := $(warning DWARF support is off, BPF prologue is disabled); > + endif > + > endif # NO_LIBBPF > endif # NO_LIBELF > > -- > 1.8.3.4
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