[PATCH v2] perf: Support for Openembedded/Yocto -dbg packages

[Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>]

On OpenEmbedded the symbol files are located under a .debug folder on
the same folder as the binary file.

This patch adds support for such files.

Without this patch on perf top you can see:

no symbols found in /usr/lib/gstreamer-1.0/libtheoraenc.so.1.1.2, maybe install
a debug package?

84.56%  libtheoraenc.so.1.1.2       [.] 0x000000000000b346

With this patch symbols are shown:

19.06%  libtheoraenc.so.1.1.2       [.] oc_int_frag_satd_thresh_mmxext
9.76%   libtheoraenc.so.1.1.2       [.] oc_analyze_mb_mode_luma
5.58%   libtheoraenc.so.1.1.2       [.] oc_qii_state_advance
4.84%   libtheoraenc.so.1.1.2       [.] oc_enc_tokenize_ac
...

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---

v2: Changes proposed by Ingo Molnar

-Improve changeset
-Improve multi-snprintf readability
-Code Style

 tools/perf/util/dso.c    | 42 +++++++++++++++++++++++++++++-------------
 tools/perf/util/dso.h    |  1 +
 tools/perf/util/symbol.c |  1 +
 3 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index e3c1ff8..43481e5 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -7,19 +7,20 @@
 char dso__symtab_origin(const struct dso *dso)
 {
 	static const char origin[] = {
-		[DSO_BINARY_TYPE__KALLSYMS]		= 'k',
-		[DSO_BINARY_TYPE__VMLINUX]		= 'v',
-		[DSO_BINARY_TYPE__JAVA_JIT]		= 'j',
-		[DSO_BINARY_TYPE__DEBUGLINK]		= 'l',
-		[DSO_BINARY_TYPE__BUILD_ID_CACHE]	= 'B',
-		[DSO_BINARY_TYPE__FEDORA_DEBUGINFO]	= 'f',
-		[DSO_BINARY_TYPE__UBUNTU_DEBUGINFO]	= 'u',
-		[DSO_BINARY_TYPE__BUILDID_DEBUGINFO]	= 'b',
-		[DSO_BINARY_TYPE__SYSTEM_PATH_DSO]	= 'd',
-		[DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE]	= 'K',
-		[DSO_BINARY_TYPE__GUEST_KALLSYMS]	= 'g',
-		[DSO_BINARY_TYPE__GUEST_KMODULE]	= 'G',
-		[DSO_BINARY_TYPE__GUEST_VMLINUX]	= 'V',
+		[DSO_BINARY_TYPE__KALLSYMS]			= 'k',
+		[DSO_BINARY_TYPE__VMLINUX]			= 'v',
+		[DSO_BINARY_TYPE__JAVA_JIT]			= 'j',
+		[DSO_BINARY_TYPE__DEBUGLINK]			= 'l',
+		[DSO_BINARY_TYPE__BUILD_ID_CACHE]		= 'B',
+		[DSO_BINARY_TYPE__FEDORA_DEBUGINFO]		= 'f',
+		[DSO_BINARY_TYPE__UBUNTU_DEBUGINFO]		= 'u',
+		[DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO]	= 'o',
+		[DSO_BINARY_TYPE__BUILDID_DEBUGINFO]		= 'b',
+		[DSO_BINARY_TYPE__SYSTEM_PATH_DSO]		= 'd',
+		[DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE]		= 'K',
+		[DSO_BINARY_TYPE__GUEST_KALLSYMS]		= 'g',
+		[DSO_BINARY_TYPE__GUEST_KMODULE]		= 'G',
+		[DSO_BINARY_TYPE__GUEST_VMLINUX]		= 'V',
 	};
 
 	if (dso == NULL || dso->symtab_type == DSO_BINARY_TYPE__NOT_FOUND)
@@ -64,6 +65,21 @@ int dso__binary_type_file(struct dso *dso, enum dso_binary_type type,
 			 symbol_conf.symfs, dso->long_name);
 		break;
 
+	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:{
+		char *last_slash;
+
+		last_slash = dso->long_name + dso->long_name_len;
+		while (last_slash != dso->long_name && *last_slash != '/')
+			last_slash--;
+
+		size -= snprintf(file, MIN(size, strlen(symbol_conf.symfs) +
+				(last_slash - dso->long_name) + 2), "%s%s",
+				symbol_conf.symfs, dso->long_name);
+		snprintf(file + strlen(file), size, ".debug%s",
+				last_slash);
+		break;
+	}
+
 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
 		if (!dso->has_build_id) {
 			ret = -1;
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index b793053..dbd9241 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -23,6 +23,7 @@ enum dso_binary_type {
 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
 	DSO_BINARY_TYPE__KCORE,
 	DSO_BINARY_TYPE__GUEST_KCORE,
+	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
 	DSO_BINARY_TYPE__NOT_FOUND,
 };
 
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 7eb0362..cd1dcc4 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -51,6 +51,7 @@ static enum dso_binary_type binary_type_symtab[] = {
 	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
 	DSO_BINARY_TYPE__GUEST_KMODULE,
 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
+	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
 	DSO_BINARY_TYPE__NOT_FOUND,
 };
 
-- 
1.8.4.rc3