@@ -110,6 +110,11 @@ FEATURE_CHECK_CFLAGS-bpf = -I. -I$(srctree)/tools/include -I$(srctree)/arch/$(AR
# include ARCH specific config
-include $(src-perf)/arch/$(ARCH)/Makefile
+ifdef PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
+ CFLAGS += -DHAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
+endif
+
+
include $(src-perf)/config/utilities.mak
ifeq ($(call get-executable,$(FLEX)),)
@@ -314,6 +319,18 @@ 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
@@ -5,4 +5,12 @@
const char *get_arch_regstr(unsigned int n);
#endif
+#ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
+/*
+ * Arch should support fetching the offset of a register in pt_regs
+ * by its name. See kernel's regs_query_register_offset in
+ * arch/xxx/kernel/ptrace.c.
+ */
+int regs_query_register_offset(const char *name);
+#endif
#endif
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_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/1441090789-108382-2-git-send-email-wangnan0@huawei.com [wangnan: - Simplify Makefile based on Namhyung Kim's suggestion. ] --- tools/perf/config/Makefile | 17 +++++++++++++++++ tools/perf/util/include/dwarf-regs.h | 8 ++++++++ 2 files changed, 25 insertions(+)