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 <wangn...@huawei.com> Cc: Alexei Starovoitov <a...@plumgrid.com> Cc: Brendan Gregg <brendan.d.gr...@gmail.com> Cc: Daniel Borkmann <dan...@iogearbox.net> Cc: David Ahern <dsah...@gmail.com> Cc: He Kuang <heku...@huawei.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Kaixu Xia <xiaka...@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Link: http://lkml.kernel.org/n/1436445342-1402-33-git-send-email-wangn...@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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
