perf tools: Add feature detection for gelf_getnote()
That is not present on some libelf implementations, such as the one used
in Alpine Linux: libelf-0.8.13.
This ends up disabling the SDT code, that relies on this function.
One alternative would be to provide an weak fallback implementation or
the open coded variant used by the buildid sysfs notes reading code.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-82lh22ybedy9b9lych8xj12g@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index 97d4714..5ac4280 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -309,6 +309,12 @@
CFLAGS += -DHAVE_ELF_GETPHDRNUM_SUPPORT
endif
+ ifeq ($(feature-libelf-gelf_getnote), 1)
+ CFLAGS += -DHAVE_GELF_GETNOTE_SUPPORT
+ else
+ msg := $(warning gelf_getnote() not found on libelf, SDT support disabled);
+ endif
+
ifeq ($(feature-libelf-getshdrstrndx), 1)
CFLAGS += -DHAVE_ELF_GETSHDRSTRNDX_SUPPORT
endif
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index e1a1640..1e504e4 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -533,7 +533,7 @@
return ret;
}
-#ifdef HAVE_LIBELF_SUPPORT
+#if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
static int build_id_cache__add_sdt_cache(const char *sbuild_id,
const char *realname)
{
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 98398b5..e705a74 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -624,6 +624,7 @@
return ret;
}
+#ifdef HAVE_GELF_GETNOTE_SUPPORT
static unsigned long long sdt_note__get_addr(struct sdt_note *note)
{
return note->bit32 ? (unsigned long long)note->addr.a32[0]
@@ -682,6 +683,7 @@
cleanup_sdt_note_list(&sdtlist);
return ret;
}
+#endif
static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
{
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 79a6a19..cebf98e 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -1790,6 +1790,7 @@
unlink(kce->extract_filename);
}
+#ifdef HAVE_GELF_GETNOTE_SUPPORT
/**
* populate_sdt_note : Parse raw data and identify SDT note
* @elf: elf of the opened file
@@ -2041,6 +2042,7 @@
count++;
return count;
}
+#endif
void symbol__elf_init(void)
{