Messages in this thread Patch in this message | | | From | Wang Nan <> | Subject | [PATCH 20/29] perf tools: Add BPF_PROLOGUE config options for further patches | Date | Fri, 21 Aug 2015 10:09:21 +0000 |
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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 and CONFIG_BPF_PROLOGUE is added as flags for this feature.
PERF_HAVE_ARCH_GET_REG_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.
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/1436445342-1402-33-git-send-email-wangnan0@huawei.com --- tools/perf/config/Makefile | 12 ++++++++++++ tools/perf/util/include/dwarf-regs.h | 7 +++++++ 2 files changed, 19 insertions(+)
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile index 38a4144..d46765b7 100644 --- a/tools/perf/config/Makefile +++ b/tools/perf/config/Makefile @@ -314,6 +314,18 @@ ifndef NO_LIBELF CFLAGS += -DHAVE_LIBBPF_SUPPORT $(call detected,CONFIG_LIBBPF) endif + + ifndef NO_DWARF + ifneq ($(origin PERF_HAVE_ARCH_GET_REG_INFO), undefined) + CFLAGS += -DHAVE_BPF_PROLOGUE + $(call detected,CONFIG_BPF_PROLOGUE) + else + msg := $(warning BPF prologue is not supported by architecture $(ARCH)); + endif + else + msg := $(warning DWARF support is off, BPF prologue is disabled); + endif + endif # NO_LIBBPF endif # NO_LIBELF diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h index 8f14965..3dda083 100644 --- a/tools/perf/util/include/dwarf-regs.h +++ b/tools/perf/util/include/dwarf-regs.h @@ -5,4 +5,11 @@ const char *get_arch_regstr(unsigned int n); #endif +#ifdef HAVE_BPF_PROLOGUE +/* + * Arch should support fetching the offset of a register in pt_regs + * by its name. + */ +int arch_get_reg_info(const char *name, int *offset); +#endif #endif -- 2.1.0
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