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 <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Brendan Gregg <[email protected]> Cc: Daniel Borkmann <[email protected]> Cc: David Ahern <[email protected]> Cc: He Kuang <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kaixu Xia <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Zefan Li <[email protected]> Cc: [email protected] Cc: Arnaldo Carvalho de Melo <[email protected]> Link: http://lkml.kernel.org/n/[email protected] [wawngnan: - Introduce new CFLAGS to control BPF prologue and arch_get_reg_info() separately. - Rename ARCH_GET_REG_INFO to ARCH_REGS_QUERY_REGISTER_OFFSET, arch_get_reg_info() to regs_query_register_offset(), change its API accordingly to make it similar to kernel's regs_query_register_offset(). ] --- tools/perf/config/Makefile | 17 +++++++++++++++++ tools/perf/util/include/dwarf-regs.h | 8 ++++++++ 2 files changed, 25 insertions(+) diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile index 38a4144..33785a1 100644 --- a/tools/perf/config/Makefile +++ b/tools/perf/config/Makefile @@ -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 +ifneq ($(origin PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET), undefined) + 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 $(call detected,CONFIG_LIBBPF) endif + + ifndef NO_DWARF + ifneq ($(origin PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET), undefined) + 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 diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h index 8f14965..07c644e 100644 --- a/tools/perf/util/include/dwarf-regs.h +++ b/tools/perf/util/include/dwarf-regs.h @@ -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 -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
