On Tue, Sep 01, 2015 at 06:59:48AM +0000, Wang Nan wrote: > 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 <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 > [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)
Why not just using 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 > $(call detected,CONFIG_LIBBPF) > endif > + > + ifndef NO_DWARF > + ifneq ($(origin PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET), undefined) Ditto. Thanks, Namhyung > + 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 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/
