[tip:perf/core] perf jit: Enable jitdump support without dwarf

From: tip-bot for Maciej Debski
Date: Mon Oct 24 2016 - 14:59:12 EST


Commit-ID: 621cb4e7837e39d25a5af5a785ad282cdd2b4ce8
Gitweb: http://git.kernel.org/tip/621cb4e7837e39d25a5af5a785ad282cdd2b4ce8
Author: Maciej Debski <maciejd@xxxxxxxxxx>
AuthorDate: Thu, 13 Oct 2016 03:59:36 -0700
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 24 Oct 2016 11:07:37 -0300

perf jit: Enable jitdump support without dwarf

This patch modifies the build dependencies on the jitdump support in
perf. As it stands jitdump was wrongfully made dependent 100% on using
DWARF. However, the dwarf dependency, only exist if generating the
source line table in genelf_debug.c. The rest of the support does not
need DWARF.

This patch removes the dependency on DWARF for the entire jitdump
support. It keeps it only for the genelf_debug.c support.

Signed-off-by: Maciej Debski <maciejd@xxxxxxxxxx>
Reviewed-by: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Anton Blanchard <anton@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1476356383-30100-3-git-send-email-eranian@xxxxxxxxxx
Fixes: e12b202f8fb9 ("perf jitdump: Build only on supported archs")
[ Make it build only if NO_LIBELF isn't defined, as jitdump.o will only be built in that case ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Makefile.config | 2 +-
tools/perf/util/Build | 2 +-
tools/perf/util/genelf.c | 9 +++++++--
tools/perf/util/genelf.h | 2 ++
4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 72edf83..cffdd9c 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -366,7 +366,7 @@ ifndef NO_SDT
endif

ifdef PERF_HAVE_JITDUMP
- ifndef NO_DWARF
+ ifndef NO_LIBELF
$(call detected,CONFIG_JITDUMP)
CFLAGS += -DHAVE_JITDUMP
endif
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index eb60e61..1dc67ef 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -120,7 +120,7 @@ libperf-y += demangle-rust.o
ifdef CONFIG_JITDUMP
libperf-$(CONFIG_LIBELF) += jitdump.o
libperf-$(CONFIG_LIBELF) += genelf.o
-libperf-$(CONFIG_LIBELF) += genelf_debug.o
+libperf-$(CONFIG_DWARF) += genelf_debug.o
endif

CFLAGS_config.o += -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
diff --git a/tools/perf/util/genelf.c b/tools/perf/util/genelf.c
index 8a2995e..30dece3 100644
--- a/tools/perf/util/genelf.c
+++ b/tools/perf/util/genelf.c
@@ -19,7 +19,9 @@
#include <limits.h>
#include <fcntl.h>
#include <err.h>
+#ifdef HAVE_DWARF_SUPPORT
#include <dwarf.h>
+#endif

#include "perf.h"
#include "genelf.h"
@@ -161,7 +163,7 @@ gen_build_id(struct buildid_note *note, unsigned long load_addr, const void *cod
int
jit_write_elf(int fd, uint64_t load_addr, const char *sym,
const void *code, int csize,
- void *debug, int nr_debug_entries)
+ void *debug __maybe_unused, int nr_debug_entries __maybe_unused)
{
Elf *e;
Elf_Data *d;
@@ -390,11 +392,14 @@ jit_write_elf(int fd, uint64_t load_addr, const char *sym,
shdr->sh_size = sizeof(bnote);
shdr->sh_entsize = 0;

+#ifdef HAVE_DWARF_SUPPORT
if (debug && nr_debug_entries) {
retval = jit_add_debug_info(e, load_addr, debug, nr_debug_entries);
if (retval)
goto error;
- } else {
+ } else
+#endif
+ {
if (elf_update(e, ELF_C_WRITE) < 0) {
warnx("elf_update 4 failed");
goto error;
diff --git a/tools/perf/util/genelf.h b/tools/perf/util/genelf.h
index 2fbeb59..5c933ac 100644
--- a/tools/perf/util/genelf.h
+++ b/tools/perf/util/genelf.h
@@ -4,8 +4,10 @@
/* genelf.c */
int jit_write_elf(int fd, uint64_t code_addr, const char *sym,
const void *code, int csize, void *debug, int nr_debug_entries);
+#ifdef HAVE_DWARF_SUPPORT
/* genelf_debug.c */
int jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries);
+#endif

#if defined(__arm__)
#define GEN_ELF_ARCH EM_ARM