[PATCH 04/16] perf bpf: Add BPF_PROLOGUE config options for further patches
From: Arnaldo Carvalho de Melo
Date: Tue Nov 17 2015 - 10:35:54 EST
From: Wang Nan <wangnan0@xxxxxxxxxx>
If both LIBBPF and DWARF are detected, it is possible to create prologue
for eBPF programs to help them access kernel data. HAVE_BPF_PROLOGUE and
CONFIG_BPF_PROLOGUE are added as flags for this feature.
PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET is introduced in commit
63ab024a5b6f295ca17a293ad81b7c728f49a89a ("perf tools:
regs_query_register_offset() infrastructure"), which indicates that 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@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Link: http://lkml.kernel.org/r/1447675815-166222-9-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/config/Makefile | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index de89ec574361..6eb9a956a408 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -318,6 +318,18 @@ 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
--
2.1.0
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