[PATCHSET 0/6] perf tools: Minimal build without libelf dependency (v3)

[PATCHSET 0/6] perf tools: Minimal build without libelf dependency (v3)

[Namhyung Kim]

Hi,

This is my third version of the series. I removed RFC tag in subject
line since I think most of you seem to agree with the change. :)

Patch 1 and 2 are independent to the series and can be applied solely
(and possibly merged to one).

This patchset is based on Arnaldo's perf/core branch at 81e9b994bb20
("Merge tag 'libtraceevent-core-for-acme' of
git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf into
perf/core") and tested on x86_64 and ARM.

You can also get this set on perf/minimal-v3 branch on my tree (see
above) if you want.

Any comments are welcome.
Namhyung


v3:
 * drop already merged (cross-build related) patches
 * drop SYMBIND_* change (Arnaldo)

v2:
 * change make option name to NO_LIBELF
 * make it default when libelf doesn't exist (Ingo)
 * get rid of elf-minimal.h and use elf.h (Jiri)

The original description follows.

--- 

Current build procedure of perf tools requires a couple of external
libraries. Although most of them are optional, elfutils' libelf is
mandatory for resolving symbols and build-id of the binaries being
profiled. For some reason, it makes embedded guys' life harder who
want to build and run perf tools on their boards.

This patchset tries to fix the problem by letting the perf could
be built without the libelf. The initial intent was just providing
perf record command to gather performance events interested on the
system and copies perf.data to development box to be used by (full-
fledged) perf report for analysis.

However it's changed to have most of perf commands as is because
perf can resolve kernel symbols without libelf and many of perf
commands deal (mostly) with kernel events - so no need to restrict
capability of perf tools. Therefore, the end result is not so
minimalistic actually and the only thing it cannot do is "perf probe".

And there's a poor man's version of ELF parser only for parsing the
build-id info. While it's not absolutely needed, I think it's good to
have, just in case.

In addition, I changed my mind to keep unrelated configurations -
i.g. tui/gui and perf/python support - enabled by default so that
it can be configured by a find-grained config method in the future.

To build a minimal perf tools explicitly, pass NO_LIBELF=1 to make.
Or, if the system doesn't provide the elfutils it'll detect that
and converts to the minimal build mode automatically. The resulting
perf report will not display symbol names in userland:

 # Samples: 3K of event 'cycles'
 # Event count (approx.): 3740267998
 #
 # Overhead  Command      Shared Object                          Symbol
 # ........  .......  .................  ..............................
 #
     99.70%  noploop  noploop            [.] 0x000000000000066d        
      0.10%  noploop  [kernel.kallsyms]  [k] free_pgd_range            
      0.03%  noploop  [kernel.kallsyms]  [k] native_write_msr_safe     
      0.03%  noploop  [kernel.kallsyms]  [k] raise_softirq             
      0.03%  noploop  [kernel.kallsyms]  [k] rb_insert_color       
 
But perf buildid-list can show the build-id's:

 $ ./perf buildid-list --with-hits
 5eaf1839576cc801053e63300762def90a77a305 [kernel.kallsyms]
 43a7a2b399b6ee2ff29c6bdadbda6bff88712ed4 /home/namhyung/bin/noploop

So it can be packed using perf archive command and copied and
analized with full-fledged perf tools on a development machine.


Namhyung Kim (6):
  tools lib traceevent: Detect build environment changes
  tools lib traceevent: Ignore TRACEEVENT-CFLAGS file
  perf symbols: Introduce symbol__elf_init()
  perf tools: Split out util/symbol-elf.c
  perf tools: Support minimal build without libelf
  perf symbols: Implement poor man's ELF parser

 tools/lib/traceevent/.gitignore     |    1 +
 tools/lib/traceevent/Makefile       |   14 +-
 tools/perf/Makefile                 |   58 ++-
 tools/perf/builtin-buildid-list.c   |    4 +-
 tools/perf/builtin-inject.c         |    5 +-
 tools/perf/command-list.txt         |    2 +-
 tools/perf/perf.c                   |    2 +
 tools/perf/util/generate-cmdlist.sh |   15 +
 tools/perf/util/map.c               |   22 +-
 tools/perf/util/map.h               |    1 +
 tools/perf/util/symbol-elf.c        |  775 +++++++++++++++++++++++++++++++++
 tools/perf/util/symbol-minimal.c    |  267 ++++++++++++
 tools/perf/util/symbol.c            |  802 +----------------------------------
 tools/perf/util/symbol.h            |   16 +
 14 files changed, 1169 insertions(+), 815 deletions(-)
 create mode 100644 tools/lib/traceevent/.gitignore
 create mode 100644 tools/perf/util/symbol-elf.c
 create mode 100644 tools/perf/util/symbol-minimal.c

-- 
1.7.10.4

[PATCH 1/6] tools lib traceevent: Detect build environment changes

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

Cross compiling perf requires setting ARCH and CROSS_COMPILE
variables, but libtraceevent couldn't detect the changes so it ends up
believing no recompiling is required. Thus the linker failed like:

     LINK perf
 ../lib/traceevent//libtraceevent.a: member ../lib/traceevent//libtraceevent.a(event-parse.o) in archive is not an object
 collect2: ld returned 1 exit status
 make: *** [perf] Error 1

This patch fixes this by adding TRACEEVENT-CFLAGS file like
PERF-CFLAGS to track those changes.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/lib/traceevent/Makefile |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/tools/lib/traceevent/Makefile b/tools/lib/traceevent/Makefile
index 46c2f6b7b123..14131cb0522d 100644
--- a/tools/lib/traceevent/Makefile
+++ b/tools/lib/traceevent/Makefile
@@ -207,7 +207,7 @@ libtraceevent.so: $(PEVENT_LIB_OBJS)
 libtraceevent.a: $(PEVENT_LIB_OBJS)
 	$(Q)$(do_build_static_lib)
 
-$(PEVENT_LIB_OBJS): %.o: $(src)/%.c
+$(PEVENT_LIB_OBJS): %.o: $(src)/%.c TRACEEVENT-CFLAGS
 	$(Q)$(do_fpic_compile)
 
 define make_version.h
@@ -272,6 +272,16 @@ ifneq ($(dep_includes),)
  include $(dep_includes)
 endif
 
+### Detect environment changes
+TRACK_CFLAGS = $(subst ','\'',$(CFLAGS)):$(ARCH):$(CROSS_COMPILE)
+
+TRACEEVENT-CFLAGS: force
+	@FLAGS='$(TRACK_CFLAGS)'; \
+	    if test x"$$FLAGS" != x"`cat TRACEEVENT-CFLAGS 2>/dev/null`" ; then \
+		echo 1>&2 "    * new build flags or cross compiler"; \
+		echo "$$FLAGS" >TRACEEVENT-CFLAGS; \
+            fi
+
 tags:	force
 	$(RM) tags
 	find . -name '*.[ch]' | xargs ctags --extra=+f --c-kinds=+px \
@@ -297,7 +307,7 @@ install: install_lib
 
 clean:
 	$(RM) *.o *~ $(TARGETS) *.a *.so $(VERSION_FILES) .*.d
-	$(RM) tags TAGS
+	$(RM) TRACEEVENT-CFLAGS tags TAGS
 
 endif # skip-makefile
 
-- 
1.7.10.4

[PATCH 2/6] tools lib traceevent: Ignore TRACEEVENT-CFLAGS file

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The TRACEEVENT-CFLAGS file is used to detect any change on compiler
flags. Just ignore it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/lib/traceevent/.gitignore |    1 +
 1 file changed, 1 insertion(+)
 create mode 100644 tools/lib/traceevent/.gitignore

diff --git a/tools/lib/traceevent/.gitignore b/tools/lib/traceevent/.gitignore
new file mode 100644
index 000000000000..35f56be5a4cd
--- /dev/null
+++ b/tools/lib/traceevent/.gitignore
@@ -0,0 +1 @@
+TRACEEVENT-CFLAGS
-- 
1.7.10.4

[PATCH 3/6] perf symbols: Introduce symbol__elf_init()

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The symbol__elf_init() is for initializing internal libelf
data structure and getting rid of its dependency outside of
ELF/symboling handling code.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-buildid-list.c |    4 +---
 tools/perf/util/symbol.c          |    8 +++++++-
 tools/perf/util/symbol.h          |    1 +
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
index 6b2bcfbde150..7d6842826a0c 100644
--- a/tools/perf/builtin-buildid-list.c
+++ b/tools/perf/builtin-buildid-list.c
@@ -16,8 +16,6 @@
 #include "util/session.h"
 #include "util/symbol.h"
 
-#include <libelf.h>
-
 static const char *input_name;
 static bool force;
 static bool show_kernel;
@@ -71,7 +69,7 @@ static int perf_session__list_build_ids(void)
 {
 	struct perf_session *session;
 
-	elf_version(EV_CURRENT);
+	symbol__elf_init();
 
 	session = perf_session__new(input_name, O_RDONLY, force, false,
 				    &build_id__mark_dso_hit_ops);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 50958bbeb26a..ab22895482de 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1424,6 +1424,11 @@ out_close:
 	return err;
 }
 
+void symbol__elf_init(void)
+{
+	elf_version(EV_CURRENT);
+}
+
 static bool dso__build_id_equal(const struct dso *dso, u8 *build_id)
 {
 	return memcmp(dso->build_id, build_id, sizeof(dso->build_id)) == 0;
@@ -2694,7 +2699,8 @@ int symbol__init(void)
 
 	symbol_conf.priv_size = ALIGN(symbol_conf.priv_size, sizeof(u64));
 
-	elf_version(EV_CURRENT);
+	symbol__elf_init();
+
 	if (symbol_conf.sort_by_name)
 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
 					  sizeof(struct symbol));
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index a884b99017f0..9006b548546e 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -297,6 +297,7 @@ void machines__destroy_guest_kernel_maps(struct rb_root *machines);
 
 int symbol__init(void);
 void symbol__exit(void);
+void symbol__elf_init(void);
 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
 				    const struct addr_location *al, FILE *fp);
 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp);
-- 
1.7.10.4

[PATCH 4/6] perf tools: Split out util/symbol-elf.c

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

Factor out the dependency of ELF handling into separate symbol-elf.c
file. It is a preparation of building a minimalistic version perf
tools which doesn't depend on the elfutils.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Makefile          |    1 +
 tools/perf/util/map.c        |   19 +
 tools/perf/util/map.h        |    1 +
 tools/perf/util/symbol-elf.c |  775 ++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/symbol.c     |  804 +-----------------------------------------
 tools/perf/util/symbol.h     |   15 +
 6 files changed, 818 insertions(+), 797 deletions(-)
 create mode 100644 tools/perf/util/symbol-elf.c

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 75d74e5db8d5..c2d924b31033 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -354,6 +354,7 @@ LIB_OBJS += $(OUTPUT)util/usage.o
 LIB_OBJS += $(OUTPUT)util/wrapper.o
 LIB_OBJS += $(OUTPUT)util/sigchain.o
 LIB_OBJS += $(OUTPUT)util/symbol.o
+LIB_OBJS += $(OUTPUT)util/symbol-elf.o
 LIB_OBJS += $(OUTPUT)util/color.o
 LIB_OBJS += $(OUTPUT)util/pager.o
 LIB_OBJS += $(OUTPUT)util/header.o
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 35ae56864e4f..562a06af8658 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -84,6 +84,25 @@ out_delete:
 	return NULL;
 }
 
+/*
+ * Constructor variant for modules (where we know from /proc/modules where
+ * they are loaded) and for vmlinux, where only after we load all the
+ * symbols we'll know where it starts and ends.
+ */
+struct map *map__new2(u64 start, struct dso *dso, enum map_type type)
+{
+	struct map *map = calloc(1, (sizeof(*map) +
+				     (dso->kernel ? sizeof(struct kmap) : 0)));
+	if (map != NULL) {
+		/*
+		 * ->end will be filled after we load all the symbols
+		 */
+		map__init(map, type, start, 0, 0, dso);
+	}
+
+	return map;
+}
+
 void map__delete(struct map *self)
 {
 	free(self);
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index c14c665d9a25..ef29ba6e93e0 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -115,6 +115,7 @@ void map__init(struct map *self, enum map_type type,
 struct map *map__new(struct list_head *dsos__list, u64 start, u64 len,
 		     u64 pgoff, u32 pid, char *filename,
 		     enum map_type type);
+struct map *map__new2(u64 start, struct dso *dso, enum map_type type);
 void map__delete(struct map *self);
 struct map *map__clone(struct map *self);
 int map__overlap(struct map *l, struct map *r);
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
new file mode 100644
index 000000000000..753e56e7fe93
--- /dev/null
+++ b/tools/perf/util/symbol-elf.c
@@ -0,0 +1,775 @@
+#include <libelf.h>
+#include <gelf.h>
+#include <elf.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <inttypes.h>
+
+#include "symbol.h"
+#include "debug.h"
+
+#ifndef NT_GNU_BUILD_ID
+#define NT_GNU_BUILD_ID 3
+#endif
+
+/**
+ * elf_symtab__for_each_symbol - iterate thru all the symbols
+ *
+ * @syms: struct elf_symtab instance to iterate
+ * @idx: uint32_t idx
+ * @sym: GElf_Sym iterator
+ */
+#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
+	for (idx = 0, gelf_getsym(syms, idx, &sym);\
+	     idx < nr_syms; \
+	     idx++, gelf_getsym(syms, idx, &sym))
+
+static inline uint8_t elf_sym__type(const GElf_Sym *sym)
+{
+	return GELF_ST_TYPE(sym->st_info);
+}
+
+static inline int elf_sym__is_function(const GElf_Sym *sym)
+{
+	return elf_sym__type(sym) == STT_FUNC &&
+	       sym->st_name != 0 &&
+	       sym->st_shndx != SHN_UNDEF;
+}
+
+static inline bool elf_sym__is_object(const GElf_Sym *sym)
+{
+	return elf_sym__type(sym) == STT_OBJECT &&
+		sym->st_name != 0 &&
+		sym->st_shndx != SHN_UNDEF;
+}
+
+static inline int elf_sym__is_label(const GElf_Sym *sym)
+{
+	return elf_sym__type(sym) == STT_NOTYPE &&
+		sym->st_name != 0 &&
+		sym->st_shndx != SHN_UNDEF &&
+		sym->st_shndx != SHN_ABS;
+}
+
+static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
+{
+	switch (type) {
+	case MAP__FUNCTION:
+		return elf_sym__is_function(sym);
+	case MAP__VARIABLE:
+		return elf_sym__is_object(sym);
+	default:
+		return false;
+	}
+}
+
+static inline const char *elf_sym__name(const GElf_Sym *sym,
+					const Elf_Data *symstrs)
+{
+	return symstrs->d_buf + sym->st_name;
+}
+
+static inline const char *elf_sec__name(const GElf_Shdr *shdr,
+					const Elf_Data *secstrs)
+{
+	return secstrs->d_buf + shdr->sh_name;
+}
+
+static inline int elf_sec__is_text(const GElf_Shdr *shdr,
+					const Elf_Data *secstrs)
+{
+	return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
+}
+
+static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
+				    const Elf_Data *secstrs)
+{
+	return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
+}
+
+static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
+			  enum map_type type)
+{
+	switch (type) {
+	case MAP__FUNCTION:
+		return elf_sec__is_text(shdr, secstrs);
+	case MAP__VARIABLE:
+		return elf_sec__is_data(shdr, secstrs);
+	default:
+		return false;
+	}
+}
+
+static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
+{
+	Elf_Scn *sec = NULL;
+	GElf_Shdr shdr;
+	size_t cnt = 1;
+
+	while ((sec = elf_nextscn(elf, sec)) != NULL) {
+		gelf_getshdr(sec, &shdr);
+
+		if ((addr >= shdr.sh_addr) &&
+		    (addr < (shdr.sh_addr + shdr.sh_size)))
+			return cnt;
+
+		++cnt;
+	}
+
+	return -1;
+}
+
+static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
+				    GElf_Shdr *shp, const char *name,
+				    size_t *idx)
+{
+	Elf_Scn *sec = NULL;
+	size_t cnt = 1;
+
+	while ((sec = elf_nextscn(elf, sec)) != NULL) {
+		char *str;
+
+		gelf_getshdr(sec, shp);
+		str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
+		if (!strcmp(name, str)) {
+			if (idx)
+				*idx = cnt;
+			break;
+		}
+		++cnt;
+	}
+
+	return sec;
+}
+
+#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
+	for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
+	     idx < nr_entries; \
+	     ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
+
+#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
+	for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
+	     idx < nr_entries; \
+	     ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
+
+/*
+ * We need to check if we have a .dynsym, so that we can handle the
+ * .plt, synthesizing its symbols, that aren't on the symtabs (be it
+ * .dynsym or .symtab).
+ * And always look at the original dso, not at debuginfo packages, that
+ * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
+ */
+int dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map,
+				symbol_filter_t filter)
+{
+	uint32_t nr_rel_entries, idx;
+	GElf_Sym sym;
+	u64 plt_offset;
+	GElf_Shdr shdr_plt;
+	struct symbol *f;
+	GElf_Shdr shdr_rel_plt, shdr_dynsym;
+	Elf_Data *reldata, *syms, *symstrs;
+	Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
+	size_t dynsym_idx;
+	GElf_Ehdr ehdr;
+	char sympltname[1024];
+	Elf *elf;
+	int nr = 0, symidx, fd, err = 0;
+
+	fd = open(name, O_RDONLY);
+	if (fd < 0)
+		goto out;
+
+	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+	if (elf == NULL)
+		goto out_close;
+
+	if (gelf_getehdr(elf, &ehdr) == NULL)
+		goto out_elf_end;
+
+	scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym,
+					 ".dynsym", &dynsym_idx);
+	if (scn_dynsym == NULL)
+		goto out_elf_end;
+
+	scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
+					  ".rela.plt", NULL);
+	if (scn_plt_rel == NULL) {
+		scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
+						  ".rel.plt", NULL);
+		if (scn_plt_rel == NULL)
+			goto out_elf_end;
+	}
+
+	err = -1;
+
+	if (shdr_rel_plt.sh_link != dynsym_idx)
+		goto out_elf_end;
+
+	if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
+		goto out_elf_end;
+
+	/*
+	 * Fetch the relocation section to find the idxes to the GOT
+	 * and the symbols in the .dynsym they refer to.
+	 */
+	reldata = elf_getdata(scn_plt_rel, NULL);
+	if (reldata == NULL)
+		goto out_elf_end;
+
+	syms = elf_getdata(scn_dynsym, NULL);
+	if (syms == NULL)
+		goto out_elf_end;
+
+	scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
+	if (scn_symstrs == NULL)
+		goto out_elf_end;
+
+	symstrs = elf_getdata(scn_symstrs, NULL);
+	if (symstrs == NULL)
+		goto out_elf_end;
+
+	nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
+	plt_offset = shdr_plt.sh_offset;
+
+	if (shdr_rel_plt.sh_type == SHT_RELA) {
+		GElf_Rela pos_mem, *pos;
+
+		elf_section__for_each_rela(reldata, pos, pos_mem, idx,
+					   nr_rel_entries) {
+			symidx = GELF_R_SYM(pos->r_info);
+			plt_offset += shdr_plt.sh_entsize;
+			gelf_getsym(syms, symidx, &sym);
+			snprintf(sympltname, sizeof(sympltname),
+				 "%s@plt", elf_sym__name(&sym, symstrs));
+
+			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
+					STB_GLOBAL, sympltname);
+			if (!f)
+				goto out_elf_end;
+
+			if (filter && filter(map, f))
+				symbol__delete(f);
+			else {
+				symbols__insert(&dso->symbols[map->type], f);
+				++nr;
+			}
+		}
+	} else if (shdr_rel_plt.sh_type == SHT_REL) {
+		GElf_Rel pos_mem, *pos;
+		elf_section__for_each_rel(reldata, pos, pos_mem, idx,
+					  nr_rel_entries) {
+			symidx = GELF_R_SYM(pos->r_info);
+			plt_offset += shdr_plt.sh_entsize;
+			gelf_getsym(syms, symidx, &sym);
+			snprintf(sympltname, sizeof(sympltname),
+				 "%s@plt", elf_sym__name(&sym, symstrs));
+
+			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
+					STB_GLOBAL, sympltname);
+			if (!f)
+				goto out_elf_end;
+
+			if (filter && filter(map, f))
+				symbol__delete(f);
+			else {
+				symbols__insert(&dso->symbols[map->type], f);
+				++nr;
+			}
+		}
+	}
+
+	err = 0;
+out_elf_end:
+	elf_end(elf);
+out_close:
+	close(fd);
+
+	if (err == 0)
+		return nr;
+out:
+	pr_debug("%s: problems reading %s PLT info.\n",
+		 __func__, dso->long_name);
+	return 0;
+}
+
+/*
+ * Align offset to 4 bytes as needed for note name and descriptor data.
+ */
+#define NOTE_ALIGN(n) (((n) + 3) & -4U)
+
+static int elf_read_build_id(Elf *elf, void *bf, size_t size)
+{
+	int err = -1;
+	GElf_Ehdr ehdr;
+	GElf_Shdr shdr;
+	Elf_Data *data;
+	Elf_Scn *sec;
+	Elf_Kind ek;
+	void *ptr;
+
+	if (size < BUILD_ID_SIZE)
+		goto out;
+
+	ek = elf_kind(elf);
+	if (ek != ELF_K_ELF)
+		goto out;
+
+	if (gelf_getehdr(elf, &ehdr) == NULL) {
+		pr_err("%s: cannot get elf header.\n", __func__);
+		goto out;
+	}
+
+	/*
+	 * Check following sections for notes:
+	 *   '.note.gnu.build-id'
+	 *   '.notes'
+	 *   '.note' (VDSO specific)
+	 */
+	do {
+		sec = elf_section_by_name(elf, &ehdr, &shdr,
+					  ".note.gnu.build-id", NULL);
+		if (sec)
+			break;
+
+		sec = elf_section_by_name(elf, &ehdr, &shdr,
+					  ".notes", NULL);
+		if (sec)
+			break;
+
+		sec = elf_section_by_name(elf, &ehdr, &shdr,
+					  ".note", NULL);
+		if (sec)
+			break;
+
+		return err;
+
+	} while (0);
+
+	data = elf_getdata(sec, NULL);
+	if (data == NULL)
+		goto out;
+
+	ptr = data->d_buf;
+	while (ptr < (data->d_buf + data->d_size)) {
+		GElf_Nhdr *nhdr = ptr;
+		size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
+		       descsz = NOTE_ALIGN(nhdr->n_descsz);
+		const char *name;
+
+		ptr += sizeof(*nhdr);
+		name = ptr;
+		ptr += namesz;
+		if (nhdr->n_type == NT_GNU_BUILD_ID &&
+		    nhdr->n_namesz == sizeof("GNU")) {
+			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
+				size_t sz = min(size, descsz);
+				memcpy(bf, ptr, sz);
+				memset(bf + sz, 0, size - sz);
+				err = descsz;
+				break;
+			}
+		}
+		ptr += descsz;
+	}
+
+out:
+	return err;
+}
+
+int filename__read_build_id(const char *filename, void *bf, size_t size)
+{
+	int fd, err = -1;
+	Elf *elf;
+
+	if (size < BUILD_ID_SIZE)
+		goto out;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		goto out;
+
+	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+	if (elf == NULL) {
+		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
+		goto out_close;
+	}
+
+	err = elf_read_build_id(elf, bf, size);
+
+	elf_end(elf);
+out_close:
+	close(fd);
+out:
+	return err;
+}
+
+int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
+{
+	int fd, err = -1;
+
+	if (size < BUILD_ID_SIZE)
+		goto out;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		goto out;
+
+	while (1) {
+		char bf[BUFSIZ];
+		GElf_Nhdr nhdr;
+		size_t namesz, descsz;
+
+		if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
+			break;
+
+		namesz = NOTE_ALIGN(nhdr.n_namesz);
+		descsz = NOTE_ALIGN(nhdr.n_descsz);
+		if (nhdr.n_type == NT_GNU_BUILD_ID &&
+		    nhdr.n_namesz == sizeof("GNU")) {
+			if (read(fd, bf, namesz) != (ssize_t)namesz)
+				break;
+			if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
+				size_t sz = min(descsz, size);
+				if (read(fd, build_id, sz) == (ssize_t)sz) {
+					memset(build_id + sz, 0, size - sz);
+					err = 0;
+					break;
+				}
+			} else if (read(fd, bf, descsz) != (ssize_t)descsz)
+				break;
+		} else {
+			int n = namesz + descsz;
+			if (read(fd, bf, n) != n)
+				break;
+		}
+	}
+	close(fd);
+out:
+	return err;
+}
+
+int filename__read_debuglink(const char *filename, char *debuglink,
+			     size_t size)
+{
+	int fd, err = -1;
+	Elf *elf;
+	GElf_Ehdr ehdr;
+	GElf_Shdr shdr;
+	Elf_Data *data;
+	Elf_Scn *sec;
+	Elf_Kind ek;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		goto out;
+
+	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+	if (elf == NULL) {
+		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
+		goto out_close;
+	}
+
+	ek = elf_kind(elf);
+	if (ek != ELF_K_ELF)
+		goto out_close;
+
+	if (gelf_getehdr(elf, &ehdr) == NULL) {
+		pr_err("%s: cannot get elf header.\n", __func__);
+		goto out_close;
+	}
+
+	sec = elf_section_by_name(elf, &ehdr, &shdr,
+				  ".gnu_debuglink", NULL);
+	if (sec == NULL)
+		goto out_close;
+
+	data = elf_getdata(sec, NULL);
+	if (data == NULL)
+		goto out_close;
+
+	/* the start of this section is a zero-terminated string */
+	strncpy(debuglink, data->d_buf, size);
+
+	elf_end(elf);
+
+out_close:
+	close(fd);
+out:
+	return err;
+}
+
+static int dso__swap_init(struct dso *dso, unsigned char eidata)
+{
+	static unsigned int const endian = 1;
+
+	dso->needs_swap = DSO_SWAP__NO;
+
+	switch (eidata) {
+	case ELFDATA2LSB:
+		/* We are big endian, DSO is little endian. */
+		if (*(unsigned char const *)&endian != 1)
+			dso->needs_swap = DSO_SWAP__YES;
+		break;
+
+	case ELFDATA2MSB:
+		/* We are little endian, DSO is big endian. */
+		if (*(unsigned char const *)&endian != 0)
+			dso->needs_swap = DSO_SWAP__YES;
+		break;
+
+	default:
+		pr_err("unrecognized DSO data encoding %d\n", eidata);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int dso__load_sym(struct dso *dso, struct map *map, const char *name, int fd,
+		  symbol_filter_t filter, int kmodule, int want_symtab)
+{
+	struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
+	struct map *curr_map = map;
+	struct dso *curr_dso = dso;
+	Elf_Data *symstrs, *secstrs;
+	uint32_t nr_syms;
+	int err = -1;
+	uint32_t idx;
+	GElf_Ehdr ehdr;
+	GElf_Shdr shdr, opdshdr;
+	Elf_Data *syms, *opddata = NULL;
+	GElf_Sym sym;
+	Elf_Scn *sec, *sec_strndx, *opdsec;
+	Elf *elf;
+	int nr = 0;
+	size_t opdidx = 0;
+
+	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+	if (elf == NULL) {
+		pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
+		goto out_close;
+	}
+
+	if (gelf_getehdr(elf, &ehdr) == NULL) {
+		pr_debug("%s: cannot get elf header.\n", __func__);
+		goto out_elf_end;
+	}
+
+	if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
+		goto out_elf_end;
+
+	/* Always reject images with a mismatched build-id: */
+	if (dso->has_build_id) {
+		u8 build_id[BUILD_ID_SIZE];
+
+		if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
+			goto out_elf_end;
+
+		if (!dso__build_id_equal(dso, build_id))
+			goto out_elf_end;
+	}
+
+	sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
+	if (sec == NULL) {
+		if (want_symtab)
+			goto out_elf_end;
+
+		sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
+		if (sec == NULL)
+			goto out_elf_end;
+	}
+
+	opdsec = elf_section_by_name(elf, &ehdr, &opdshdr, ".opd", &opdidx);
+	if (opdshdr.sh_type != SHT_PROGBITS)
+		opdsec = NULL;
+	if (opdsec)
+		opddata = elf_rawdata(opdsec, NULL);
+
+	syms = elf_getdata(sec, NULL);
+	if (syms == NULL)
+		goto out_elf_end;
+
+	sec = elf_getscn(elf, shdr.sh_link);
+	if (sec == NULL)
+		goto out_elf_end;
+
+	symstrs = elf_getdata(sec, NULL);
+	if (symstrs == NULL)
+		goto out_elf_end;
+
+	sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
+	if (sec_strndx == NULL)
+		goto out_elf_end;
+
+	secstrs = elf_getdata(sec_strndx, NULL);
+	if (secstrs == NULL)
+		goto out_elf_end;
+
+	nr_syms = shdr.sh_size / shdr.sh_entsize;
+
+	memset(&sym, 0, sizeof(sym));
+	if (dso->kernel == DSO_TYPE_USER) {
+		dso->adjust_symbols = (ehdr.e_type == ET_EXEC ||
+				elf_section_by_name(elf, &ehdr, &shdr,
+						     ".gnu.prelink_undo",
+						     NULL) != NULL);
+	} else {
+		dso->adjust_symbols = 0;
+	}
+	elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
+		struct symbol *f;
+		const char *elf_name = elf_sym__name(&sym, symstrs);
+		char *demangled = NULL;
+		int is_label = elf_sym__is_label(&sym);
+		const char *section_name;
+
+		if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
+		    strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
+			kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
+
+		if (!is_label && !elf_sym__is_a(&sym, map->type))
+			continue;
+
+		/* Reject ARM ELF "mapping symbols": these aren't unique and
+		 * don't identify functions, so will confuse the profile
+		 * output: */
+		if (ehdr.e_machine == EM_ARM) {
+			if (!strcmp(elf_name, "$a") ||
+			    !strcmp(elf_name, "$d") ||
+			    !strcmp(elf_name, "$t"))
+				continue;
+		}
+
+		if (opdsec && sym.st_shndx == opdidx) {
+			u32 offset = sym.st_value - opdshdr.sh_addr;
+			u64 *opd = opddata->d_buf + offset;
+			sym.st_value = DSO__SWAP(dso, u64, *opd);
+			sym.st_shndx = elf_addr_to_index(elf, sym.st_value);
+		}
+
+		sec = elf_getscn(elf, sym.st_shndx);
+		if (!sec)
+			goto out_elf_end;
+
+		gelf_getshdr(sec, &shdr);
+
+		if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
+			continue;
+
+		section_name = elf_sec__name(&shdr, secstrs);
+
+		/* On ARM, symbols for thumb functions have 1 added to
+		 * the symbol address as a flag - remove it */
+		if ((ehdr.e_machine == EM_ARM) &&
+		    (map->type == MAP__FUNCTION) &&
+		    (sym.st_value & 1))
+			--sym.st_value;
+
+		if (dso->kernel != DSO_TYPE_USER || kmodule) {
+			char dso_name[PATH_MAX];
+
+			if (strcmp(section_name,
+				   (curr_dso->short_name +
+				    dso->short_name_len)) == 0)
+				goto new_symbol;
+
+			if (strcmp(section_name, ".text") == 0) {
+				curr_map = map;
+				curr_dso = dso;
+				goto new_symbol;
+			}
+
+			snprintf(dso_name, sizeof(dso_name),
+				 "%s%s", dso->short_name, section_name);
+
+			curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
+			if (curr_map == NULL) {
+				u64 start = sym.st_value;
+
+				if (kmodule)
+					start += map->start + shdr.sh_offset;
+
+				curr_dso = dso__new(dso_name);
+				if (curr_dso == NULL)
+					goto out_elf_end;
+				curr_dso->kernel = dso->kernel;
+				curr_dso->long_name = dso->long_name;
+				curr_dso->long_name_len = dso->long_name_len;
+				curr_map = map__new2(start, curr_dso,
+						     map->type);
+				if (curr_map == NULL) {
+					dso__delete(curr_dso);
+					goto out_elf_end;
+				}
+				curr_map->map_ip = identity__map_ip;
+				curr_map->unmap_ip = identity__map_ip;
+				curr_dso->symtab_type = dso->symtab_type;
+				map_groups__insert(kmap->kmaps, curr_map);
+				dsos__add(&dso->node, curr_dso);
+				dso__set_loaded(curr_dso, map->type);
+			} else
+				curr_dso = curr_map->dso;
+
+			goto new_symbol;
+		}
+
+		if (curr_dso->adjust_symbols) {
+			pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
+				  "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
+				  (u64)sym.st_value, (u64)shdr.sh_addr,
+				  (u64)shdr.sh_offset);
+			sym.st_value -= shdr.sh_addr - shdr.sh_offset;
+		}
+		/*
+		 * We need to figure out if the object was created from C++ sources
+		 * DWARF DW_compile_unit has this, but we don't always have access
+		 * to it...
+		 */
+		demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
+		if (demangled != NULL)
+			elf_name = demangled;
+new_symbol:
+		f = symbol__new(sym.st_value, sym.st_size,
+				GELF_ST_BIND(sym.st_info), elf_name);
+		free(demangled);
+		if (!f)
+			goto out_elf_end;
+
+		if (filter && filter(curr_map, f))
+			symbol__delete(f);
+		else {
+			symbols__insert(&curr_dso->symbols[curr_map->type], f);
+			nr++;
+		}
+	}
+
+	/*
+	 * For misannotated, zeroed, ASM function sizes.
+	 */
+	if (nr > 0) {
+		symbols__fixup_duplicate(&dso->symbols[map->type]);
+		symbols__fixup_end(&dso->symbols[map->type]);
+		if (kmap) {
+			/*
+			 * We need to fixup this here too because we create new
+			 * maps here, for things like vsyscall sections.
+			 */
+			__map_groups__fixup_end(kmap->kmaps, map->type);
+		}
+	}
+	err = nr;
+out_elf_end:
+	elf_end(elf);
+out_close:
+	return err;
+}
+
+void symbol__elf_init(void)
+{
+	elf_version(EV_CURRENT);
+}
+
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index ab22895482de..098fee475635 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -15,8 +15,6 @@
 #include "symbol.h"
 #include "strlist.h"
 
-#include <libelf.h>
-#include <gelf.h>
 #include <elf.h>
 #include <limits.h>
 #include <sys/utsname.h>
@@ -25,14 +23,6 @@
 #define KSYM_NAME_LEN 256
 #endif
 
-#ifndef NT_GNU_BUILD_ID
-#define NT_GNU_BUILD_ID 3
-#endif
-
-static bool dso__build_id_equal(const struct dso *dso, u8 *build_id);
-static int elf_read_build_id(Elf *elf, void *bf, size_t size);
-static void dsos__add(struct list_head *head, struct dso *dso);
-static struct map *map__new2(u64 start, struct dso *dso, enum map_type type);
 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
 				symbol_filter_t filter);
 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
@@ -144,7 +134,7 @@ static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
 		return SYMBOL_B;
 }
 
-static void symbols__fixup_duplicate(struct rb_root *symbols)
+void symbols__fixup_duplicate(struct rb_root *symbols)
 {
 	struct rb_node *nd;
 	struct symbol *curr, *next;
@@ -173,7 +163,7 @@ again:
 	}
 }
 
-static void symbols__fixup_end(struct rb_root *symbols)
+void symbols__fixup_end(struct rb_root *symbols)
 {
 	struct rb_node *nd, *prevnd = rb_first(symbols);
 	struct symbol *curr, *prev;
@@ -196,7 +186,7 @@ static void symbols__fixup_end(struct rb_root *symbols)
 		curr->end = roundup(curr->start, 4096);
 }
 
-static void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
+void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
 {
 	struct map *prev, *curr;
 	struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
@@ -226,8 +216,7 @@ static void map_groups__fixup_end(struct map_groups *mg)
 		__map_groups__fixup_end(mg, i);
 }
 
-static struct symbol *symbol__new(u64 start, u64 len, u8 binding,
-				  const char *name)
+struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
 {
 	size_t namelen = strlen(name) + 1;
 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
@@ -361,7 +350,7 @@ void dso__set_build_id(struct dso *dso, void *build_id)
 	dso->has_build_id = 1;
 }
 
-static void symbols__insert(struct rb_root *symbols, struct symbol *sym)
+void symbols__insert(struct rb_root *symbols, struct symbol *sym)
 {
 	struct rb_node **p = &symbols->rb_node;
 	struct rb_node *parent = NULL;
@@ -875,561 +864,7 @@ out_failure:
 	return -1;
 }
 
-/**
- * elf_symtab__for_each_symbol - iterate thru all the symbols
- *
- * @syms: struct elf_symtab instance to iterate
- * @idx: uint32_t idx
- * @sym: GElf_Sym iterator
- */
-#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
-	for (idx = 0, gelf_getsym(syms, idx, &sym);\
-	     idx < nr_syms; \
-	     idx++, gelf_getsym(syms, idx, &sym))
-
-static inline uint8_t elf_sym__type(const GElf_Sym *sym)
-{
-	return GELF_ST_TYPE(sym->st_info);
-}
-
-static inline int elf_sym__is_function(const GElf_Sym *sym)
-{
-	return elf_sym__type(sym) == STT_FUNC &&
-	       sym->st_name != 0 &&
-	       sym->st_shndx != SHN_UNDEF;
-}
-
-static inline bool elf_sym__is_object(const GElf_Sym *sym)
-{
-	return elf_sym__type(sym) == STT_OBJECT &&
-		sym->st_name != 0 &&
-		sym->st_shndx != SHN_UNDEF;
-}
-
-static inline int elf_sym__is_label(const GElf_Sym *sym)
-{
-	return elf_sym__type(sym) == STT_NOTYPE &&
-		sym->st_name != 0 &&
-		sym->st_shndx != SHN_UNDEF &&
-		sym->st_shndx != SHN_ABS;
-}
-
-static inline const char *elf_sec__name(const GElf_Shdr *shdr,
-					const Elf_Data *secstrs)
-{
-	return secstrs->d_buf + shdr->sh_name;
-}
-
-static inline int elf_sec__is_text(const GElf_Shdr *shdr,
-					const Elf_Data *secstrs)
-{
-	return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
-}
-
-static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
-				    const Elf_Data *secstrs)
-{
-	return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
-}
-
-static inline const char *elf_sym__name(const GElf_Sym *sym,
-					const Elf_Data *symstrs)
-{
-	return symstrs->d_buf + sym->st_name;
-}
-
-static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
-				    GElf_Shdr *shp, const char *name,
-				    size_t *idx)
-{
-	Elf_Scn *sec = NULL;
-	size_t cnt = 1;
-
-	while ((sec = elf_nextscn(elf, sec)) != NULL) {
-		char *str;
-
-		gelf_getshdr(sec, shp);
-		str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
-		if (!strcmp(name, str)) {
-			if (idx)
-				*idx = cnt;
-			break;
-		}
-		++cnt;
-	}
-
-	return sec;
-}
-
-#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
-	for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
-	     idx < nr_entries; \
-	     ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
-
-#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
-	for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
-	     idx < nr_entries; \
-	     ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
-
-/*
- * We need to check if we have a .dynsym, so that we can handle the
- * .plt, synthesizing its symbols, that aren't on the symtabs (be it
- * .dynsym or .symtab).
- * And always look at the original dso, not at debuginfo packages, that
- * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
- */
-static int
-dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map,
-			    symbol_filter_t filter)
-{
-	uint32_t nr_rel_entries, idx;
-	GElf_Sym sym;
-	u64 plt_offset;
-	GElf_Shdr shdr_plt;
-	struct symbol *f;
-	GElf_Shdr shdr_rel_plt, shdr_dynsym;
-	Elf_Data *reldata, *syms, *symstrs;
-	Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
-	size_t dynsym_idx;
-	GElf_Ehdr ehdr;
-	char sympltname[1024];
-	Elf *elf;
-	int nr = 0, symidx, fd, err = 0;
-
-	fd = open(name, O_RDONLY);
-	if (fd < 0)
-		goto out;
-
-	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
-	if (elf == NULL)
-		goto out_close;
-
-	if (gelf_getehdr(elf, &ehdr) == NULL)
-		goto out_elf_end;
-
-	scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym,
-					 ".dynsym", &dynsym_idx);
-	if (scn_dynsym == NULL)
-		goto out_elf_end;
-
-	scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
-					  ".rela.plt", NULL);
-	if (scn_plt_rel == NULL) {
-		scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
-						  ".rel.plt", NULL);
-		if (scn_plt_rel == NULL)
-			goto out_elf_end;
-	}
-
-	err = -1;
-
-	if (shdr_rel_plt.sh_link != dynsym_idx)
-		goto out_elf_end;
-
-	if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
-		goto out_elf_end;
-
-	/*
-	 * Fetch the relocation section to find the idxes to the GOT
-	 * and the symbols in the .dynsym they refer to.
-	 */
-	reldata = elf_getdata(scn_plt_rel, NULL);
-	if (reldata == NULL)
-		goto out_elf_end;
-
-	syms = elf_getdata(scn_dynsym, NULL);
-	if (syms == NULL)
-		goto out_elf_end;
-
-	scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
-	if (scn_symstrs == NULL)
-		goto out_elf_end;
-
-	symstrs = elf_getdata(scn_symstrs, NULL);
-	if (symstrs == NULL)
-		goto out_elf_end;
-
-	nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
-	plt_offset = shdr_plt.sh_offset;
-
-	if (shdr_rel_plt.sh_type == SHT_RELA) {
-		GElf_Rela pos_mem, *pos;
-
-		elf_section__for_each_rela(reldata, pos, pos_mem, idx,
-					   nr_rel_entries) {
-			symidx = GELF_R_SYM(pos->r_info);
-			plt_offset += shdr_plt.sh_entsize;
-			gelf_getsym(syms, symidx, &sym);
-			snprintf(sympltname, sizeof(sympltname),
-				 "%s@plt", elf_sym__name(&sym, symstrs));
-
-			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
-					STB_GLOBAL, sympltname);
-			if (!f)
-				goto out_elf_end;
-
-			if (filter && filter(map, f))
-				symbol__delete(f);
-			else {
-				symbols__insert(&dso->symbols[map->type], f);
-				++nr;
-			}
-		}
-	} else if (shdr_rel_plt.sh_type == SHT_REL) {
-		GElf_Rel pos_mem, *pos;
-		elf_section__for_each_rel(reldata, pos, pos_mem, idx,
-					  nr_rel_entries) {
-			symidx = GELF_R_SYM(pos->r_info);
-			plt_offset += shdr_plt.sh_entsize;
-			gelf_getsym(syms, symidx, &sym);
-			snprintf(sympltname, sizeof(sympltname),
-				 "%s@plt", elf_sym__name(&sym, symstrs));
-
-			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
-					STB_GLOBAL, sympltname);
-			if (!f)
-				goto out_elf_end;
-
-			if (filter && filter(map, f))
-				symbol__delete(f);
-			else {
-				symbols__insert(&dso->symbols[map->type], f);
-				++nr;
-			}
-		}
-	}
-
-	err = 0;
-out_elf_end:
-	elf_end(elf);
-out_close:
-	close(fd);
-
-	if (err == 0)
-		return nr;
-out:
-	pr_debug("%s: problems reading %s PLT info.\n",
-		 __func__, dso->long_name);
-	return 0;
-}
-
-static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
-{
-	switch (type) {
-	case MAP__FUNCTION:
-		return elf_sym__is_function(sym);
-	case MAP__VARIABLE:
-		return elf_sym__is_object(sym);
-	default:
-		return false;
-	}
-}
-
-static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
-			  enum map_type type)
-{
-	switch (type) {
-	case MAP__FUNCTION:
-		return elf_sec__is_text(shdr, secstrs);
-	case MAP__VARIABLE:
-		return elf_sec__is_data(shdr, secstrs);
-	default:
-		return false;
-	}
-}
-
-static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
-{
-	Elf_Scn *sec = NULL;
-	GElf_Shdr shdr;
-	size_t cnt = 1;
-
-	while ((sec = elf_nextscn(elf, sec)) != NULL) {
-		gelf_getshdr(sec, &shdr);
-
-		if ((addr >= shdr.sh_addr) &&
-		    (addr < (shdr.sh_addr + shdr.sh_size)))
-			return cnt;
-
-		++cnt;
-	}
-
-	return -1;
-}
-
-static int dso__swap_init(struct dso *dso, unsigned char eidata)
-{
-	static unsigned int const endian = 1;
-
-	dso->needs_swap = DSO_SWAP__NO;
-
-	switch (eidata) {
-	case ELFDATA2LSB:
-		/* We are big endian, DSO is little endian. */
-		if (*(unsigned char const *)&endian != 1)
-			dso->needs_swap = DSO_SWAP__YES;
-		break;
-
-	case ELFDATA2MSB:
-		/* We are little endian, DSO is big endian. */
-		if (*(unsigned char const *)&endian != 0)
-			dso->needs_swap = DSO_SWAP__YES;
-		break;
-
-	default:
-		pr_err("unrecognized DSO data encoding %d\n", eidata);
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static int dso__load_sym(struct dso *dso, struct map *map, const char *name,
-			 int fd, symbol_filter_t filter, int kmodule,
-			 int want_symtab)
-{
-	struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
-	struct map *curr_map = map;
-	struct dso *curr_dso = dso;
-	Elf_Data *symstrs, *secstrs;
-	uint32_t nr_syms;
-	int err = -1;
-	uint32_t idx;
-	GElf_Ehdr ehdr;
-	GElf_Shdr shdr, opdshdr;
-	Elf_Data *syms, *opddata = NULL;
-	GElf_Sym sym;
-	Elf_Scn *sec, *sec_strndx, *opdsec;
-	Elf *elf;
-	int nr = 0;
-	size_t opdidx = 0;
-
-	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
-	if (elf == NULL) {
-		pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
-		goto out_close;
-	}
-
-	if (gelf_getehdr(elf, &ehdr) == NULL) {
-		pr_debug("%s: cannot get elf header.\n", __func__);
-		goto out_elf_end;
-	}
-
-	if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
-		goto out_elf_end;
-
-	/* Always reject images with a mismatched build-id: */
-	if (dso->has_build_id) {
-		u8 build_id[BUILD_ID_SIZE];
-
-		if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
-			goto out_elf_end;
-
-		if (!dso__build_id_equal(dso, build_id))
-			goto out_elf_end;
-	}
-
-	sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
-	if (sec == NULL) {
-		if (want_symtab)
-			goto out_elf_end;
-
-		sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
-		if (sec == NULL)
-			goto out_elf_end;
-	}
-
-	opdsec = elf_section_by_name(elf, &ehdr, &opdshdr, ".opd", &opdidx);
-	if (opdshdr.sh_type != SHT_PROGBITS)
-		opdsec = NULL;
-	if (opdsec)
-		opddata = elf_rawdata(opdsec, NULL);
-
-	syms = elf_getdata(sec, NULL);
-	if (syms == NULL)
-		goto out_elf_end;
-
-	sec = elf_getscn(elf, shdr.sh_link);
-	if (sec == NULL)
-		goto out_elf_end;
-
-	symstrs = elf_getdata(sec, NULL);
-	if (symstrs == NULL)
-		goto out_elf_end;
-
-	sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
-	if (sec_strndx == NULL)
-		goto out_elf_end;
-
-	secstrs = elf_getdata(sec_strndx, NULL);
-	if (secstrs == NULL)
-		goto out_elf_end;
-
-	nr_syms = shdr.sh_size / shdr.sh_entsize;
-
-	memset(&sym, 0, sizeof(sym));
-	if (dso->kernel == DSO_TYPE_USER) {
-		dso->adjust_symbols = (ehdr.e_type == ET_EXEC ||
-				elf_section_by_name(elf, &ehdr, &shdr,
-						     ".gnu.prelink_undo",
-						     NULL) != NULL);
-	} else {
-		dso->adjust_symbols = 0;
-	}
-	elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
-		struct symbol *f;
-		const char *elf_name = elf_sym__name(&sym, symstrs);
-		char *demangled = NULL;
-		int is_label = elf_sym__is_label(&sym);
-		const char *section_name;
-
-		if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
-		    strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
-			kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
-
-		if (!is_label && !elf_sym__is_a(&sym, map->type))
-			continue;
-
-		/* Reject ARM ELF "mapping symbols": these aren't unique and
-		 * don't identify functions, so will confuse the profile
-		 * output: */
-		if (ehdr.e_machine == EM_ARM) {
-			if (!strcmp(elf_name, "$a") ||
-			    !strcmp(elf_name, "$d") ||
-			    !strcmp(elf_name, "$t"))
-				continue;
-		}
-
-		if (opdsec && sym.st_shndx == opdidx) {
-			u32 offset = sym.st_value - opdshdr.sh_addr;
-			u64 *opd = opddata->d_buf + offset;
-			sym.st_value = DSO__SWAP(dso, u64, *opd);
-			sym.st_shndx = elf_addr_to_index(elf, sym.st_value);
-		}
-
-		sec = elf_getscn(elf, sym.st_shndx);
-		if (!sec)
-			goto out_elf_end;
-
-		gelf_getshdr(sec, &shdr);
-
-		if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
-			continue;
-
-		section_name = elf_sec__name(&shdr, secstrs);
-
-		/* On ARM, symbols for thumb functions have 1 added to
-		 * the symbol address as a flag - remove it */
-		if ((ehdr.e_machine == EM_ARM) &&
-		    (map->type == MAP__FUNCTION) &&
-		    (sym.st_value & 1))
-			--sym.st_value;
-
-		if (dso->kernel != DSO_TYPE_USER || kmodule) {
-			char dso_name[PATH_MAX];
-
-			if (strcmp(section_name,
-				   (curr_dso->short_name +
-				    dso->short_name_len)) == 0)
-				goto new_symbol;
-
-			if (strcmp(section_name, ".text") == 0) {
-				curr_map = map;
-				curr_dso = dso;
-				goto new_symbol;
-			}
-
-			snprintf(dso_name, sizeof(dso_name),
-				 "%s%s", dso->short_name, section_name);
-
-			curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
-			if (curr_map == NULL) {
-				u64 start = sym.st_value;
-
-				if (kmodule)
-					start += map->start + shdr.sh_offset;
-
-				curr_dso = dso__new(dso_name);
-				if (curr_dso == NULL)
-					goto out_elf_end;
-				curr_dso->kernel = dso->kernel;
-				curr_dso->long_name = dso->long_name;
-				curr_dso->long_name_len = dso->long_name_len;
-				curr_map = map__new2(start, curr_dso,
-						     map->type);
-				if (curr_map == NULL) {
-					dso__delete(curr_dso);
-					goto out_elf_end;
-				}
-				curr_map->map_ip = identity__map_ip;
-				curr_map->unmap_ip = identity__map_ip;
-				curr_dso->symtab_type = dso->symtab_type;
-				map_groups__insert(kmap->kmaps, curr_map);
-				dsos__add(&dso->node, curr_dso);
-				dso__set_loaded(curr_dso, map->type);
-			} else
-				curr_dso = curr_map->dso;
-
-			goto new_symbol;
-		}
-
-		if (curr_dso->adjust_symbols) {
-			pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
-				  "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
-				  (u64)sym.st_value, (u64)shdr.sh_addr,
-				  (u64)shdr.sh_offset);
-			sym.st_value -= shdr.sh_addr - shdr.sh_offset;
-		}
-		/*
-		 * We need to figure out if the object was created from C++ sources
-		 * DWARF DW_compile_unit has this, but we don't always have access
-		 * to it...
-		 */
-		demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
-		if (demangled != NULL)
-			elf_name = demangled;
-new_symbol:
-		f = symbol__new(sym.st_value, sym.st_size,
-				GELF_ST_BIND(sym.st_info), elf_name);
-		free(demangled);
-		if (!f)
-			goto out_elf_end;
-
-		if (filter && filter(curr_map, f))
-			symbol__delete(f);
-		else {
-			symbols__insert(&curr_dso->symbols[curr_map->type], f);
-			nr++;
-		}
-	}
-
-	/*
-	 * For misannotated, zeroed, ASM function sizes.
-	 */
-	if (nr > 0) {
-		symbols__fixup_duplicate(&dso->symbols[map->type]);
-		symbols__fixup_end(&dso->symbols[map->type]);
-		if (kmap) {
-			/*
-			 * We need to fixup this here too because we create new
-			 * maps here, for things like vsyscall sections.
-			 */
-			__map_groups__fixup_end(kmap->kmaps, map->type);
-		}
-	}
-	err = nr;
-out_elf_end:
-	elf_end(elf);
-out_close:
-	return err;
-}
-
-void symbol__elf_init(void)
-{
-	elf_version(EV_CURRENT);
-}
-
-static bool dso__build_id_equal(const struct dso *dso, u8 *build_id)
+bool dso__build_id_equal(const struct dso *dso, u8 *build_id)
 {
 	return memcmp(dso->build_id, build_id, sizeof(dso->build_id)) == 0;
 }
@@ -1456,212 +891,6 @@ bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
 	return have_build_id;
 }
 
-/*
- * Align offset to 4 bytes as needed for note name and descriptor data.
- */
-#define NOTE_ALIGN(n) (((n) + 3) & -4U)
-
-static int elf_read_build_id(Elf *elf, void *bf, size_t size)
-{
-	int err = -1;
-	GElf_Ehdr ehdr;
-	GElf_Shdr shdr;
-	Elf_Data *data;
-	Elf_Scn *sec;
-	Elf_Kind ek;
-	void *ptr;
-
-	if (size < BUILD_ID_SIZE)
-		goto out;
-
-	ek = elf_kind(elf);
-	if (ek != ELF_K_ELF)
-		goto out;
-
-	if (gelf_getehdr(elf, &ehdr) == NULL) {
-		pr_err("%s: cannot get elf header.\n", __func__);
-		goto out;
-	}
-
-	/*
-	 * Check following sections for notes:
-	 *   '.note.gnu.build-id'
-	 *   '.notes'
-	 *   '.note' (VDSO specific)
-	 */
-	do {
-		sec = elf_section_by_name(elf, &ehdr, &shdr,
-					  ".note.gnu.build-id", NULL);
-		if (sec)
-			break;
-
-		sec = elf_section_by_name(elf, &ehdr, &shdr,
-					  ".notes", NULL);
-		if (sec)
-			break;
-
-		sec = elf_section_by_name(elf, &ehdr, &shdr,
-					  ".note", NULL);
-		if (sec)
-			break;
-
-		return err;
-
-	} while (0);
-
-	data = elf_getdata(sec, NULL);
-	if (data == NULL)
-		goto out;
-
-	ptr = data->d_buf;
-	while (ptr < (data->d_buf + data->d_size)) {
-		GElf_Nhdr *nhdr = ptr;
-		size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
-		       descsz = NOTE_ALIGN(nhdr->n_descsz);
-		const char *name;
-
-		ptr += sizeof(*nhdr);
-		name = ptr;
-		ptr += namesz;
-		if (nhdr->n_type == NT_GNU_BUILD_ID &&
-		    nhdr->n_namesz == sizeof("GNU")) {
-			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
-				size_t sz = min(size, descsz);
-				memcpy(bf, ptr, sz);
-				memset(bf + sz, 0, size - sz);
-				err = descsz;
-				break;
-			}
-		}
-		ptr += descsz;
-	}
-
-out:
-	return err;
-}
-
-int filename__read_build_id(const char *filename, void *bf, size_t size)
-{
-	int fd, err = -1;
-	Elf *elf;
-
-	if (size < BUILD_ID_SIZE)
-		goto out;
-
-	fd = open(filename, O_RDONLY);
-	if (fd < 0)
-		goto out;
-
-	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
-	if (elf == NULL) {
-		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
-		goto out_close;
-	}
-
-	err = elf_read_build_id(elf, bf, size);
-
-	elf_end(elf);
-out_close:
-	close(fd);
-out:
-	return err;
-}
-
-int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
-{
-	int fd, err = -1;
-
-	if (size < BUILD_ID_SIZE)
-		goto out;
-
-	fd = open(filename, O_RDONLY);
-	if (fd < 0)
-		goto out;
-
-	while (1) {
-		char bf[BUFSIZ];
-		GElf_Nhdr nhdr;
-		size_t namesz, descsz;
-
-		if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
-			break;
-
-		namesz = NOTE_ALIGN(nhdr.n_namesz);
-		descsz = NOTE_ALIGN(nhdr.n_descsz);
-		if (nhdr.n_type == NT_GNU_BUILD_ID &&
-		    nhdr.n_namesz == sizeof("GNU")) {
-			if (read(fd, bf, namesz) != (ssize_t)namesz)
-				break;
-			if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
-				size_t sz = min(descsz, size);
-				if (read(fd, build_id, sz) == (ssize_t)sz) {
-					memset(build_id + sz, 0, size - sz);
-					err = 0;
-					break;
-				}
-			} else if (read(fd, bf, descsz) != (ssize_t)descsz)
-				break;
-		} else {
-			int n = namesz + descsz;
-			if (read(fd, bf, n) != n)
-				break;
-		}
-	}
-	close(fd);
-out:
-	return err;
-}
-
-static int filename__read_debuglink(const char *filename,
-				    char *debuglink, size_t size)
-{
-	int fd, err = -1;
-	Elf *elf;
-	GElf_Ehdr ehdr;
-	GElf_Shdr shdr;
-	Elf_Data *data;
-	Elf_Scn *sec;
-	Elf_Kind ek;
-
-	fd = open(filename, O_RDONLY);
-	if (fd < 0)
-		goto out;
-
-	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
-	if (elf == NULL) {
-		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
-		goto out_close;
-	}
-
-	ek = elf_kind(elf);
-	if (ek != ELF_K_ELF)
-		goto out_close;
-
-	if (gelf_getehdr(elf, &ehdr) == NULL) {
-		pr_err("%s: cannot get elf header.\n", __func__);
-		goto out_close;
-	}
-
-	sec = elf_section_by_name(elf, &ehdr, &shdr,
-				  ".gnu_debuglink", NULL);
-	if (sec == NULL)
-		goto out_close;
-
-	data = elf_getdata(sec, NULL);
-	if (data == NULL)
-		goto out_close;
-
-	/* the start of this section is a zero-terminated string */
-	strncpy(debuglink, data->d_buf, size);
-
-	elf_end(elf);
-
-out_close:
-	close(fd);
-out:
-	return err;
-}
-
 char dso__symtab_origin(const struct dso *dso)
 {
 	static const char origin[] = {
@@ -1982,25 +1211,6 @@ static int machine__set_modules_path(struct machine *machine)
 	return map_groups__set_modules_path_dir(&machine->kmaps, modules_path);
 }
 
-/*
- * Constructor variant for modules (where we know from /proc/modules where
- * they are loaded) and for vmlinux, where only after we load all the
- * symbols we'll know where it starts and ends.
- */
-static struct map *map__new2(u64 start, struct dso *dso, enum map_type type)
-{
-	struct map *map = calloc(1, (sizeof(*map) +
-				     (dso->kernel ? sizeof(struct kmap) : 0)));
-	if (map != NULL) {
-		/*
-		 * ->end will be filled after we load all the symbols
-		 */
-		map__init(map, type, start, 0, 0, dso);
-	}
-
-	return map;
-}
-
 struct map *machine__new_module(struct machine *machine, u64 start,
 				const char *filename)
 {
@@ -2304,7 +1514,7 @@ out_try_fixup:
 	return err;
 }
 
-static void dsos__add(struct list_head *head, struct dso *dso)
+void dsos__add(struct list_head *head, struct dso *dso)
 {
 	list_add_tail(&dso->node, head);
 }
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 9006b548546e..41f3c9ca87e8 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -227,6 +227,7 @@ static inline void dso__set_loaded(struct dso *dso, enum map_type type)
 
 void dso__sort_by_name(struct dso *dso, enum map_type type);
 
+void dsos__add(struct list_head *head, struct dso *dso);
 struct dso *__dsos__findnew(struct list_head *head, const char *name);
 
 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter);
@@ -271,6 +272,7 @@ enum symtab_type {
 char dso__symtab_origin(const struct dso *dso);
 void dso__set_long_name(struct dso *dso, char *name);
 void dso__set_build_id(struct dso *dso, void *build_id);
+bool dso__build_id_equal(const struct dso *dso, u8 *build_id);
 void dso__read_running_kernel_build_id(struct dso *dso,
 				       struct machine *machine);
 struct map *dso__new_map(const char *name);
@@ -286,6 +288,8 @@ int build_id__sprintf(const u8 *build_id, int len, char *bf);
 int kallsyms__parse(const char *filename, void *arg,
 		    int (*process_symbol)(void *arg, const char *name,
 					  char type, u64 start, u64 end));
+int filename__read_debuglink(const char *filename, char *debuglink,
+			     size_t size);
 
 void machine__destroy_kernel_maps(struct machine *machine);
 int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel);
@@ -298,6 +302,7 @@ void machines__destroy_guest_kernel_maps(struct rb_root *machines);
 int symbol__init(void);
 void symbol__exit(void);
 void symbol__elf_init(void);
+struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name);
 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
 				    const struct addr_location *al, FILE *fp);
 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp);
@@ -305,4 +310,14 @@ bool symbol_type__is_a(char symbol_type, enum map_type map_type);
 
 size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp);
 
+void symbols__insert(struct rb_root *symbols, struct symbol *sym);
+void symbols__fixup_duplicate(struct rb_root *symbols);
+void symbols__fixup_end(struct rb_root *symbols);
+void __map_groups__fixup_end(struct map_groups *mg, enum map_type type);
+
+int dso__load_sym(struct dso *dso, struct map *map, const char *name, int fd,
+		  symbol_filter_t filter, int kmodule, int want_symtab);
+int dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map,
+				symbol_filter_t filter);
+
 #endif /* __PERF_SYMBOL */
-- 
1.7.10.4

[PATCH 5/6] perf tools: Support minimal build without libelf

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

Now we have isolated all ELF-specific stuff, it's possible to build
without libelf. The output binary can do most of jobs but lacks (user
level) symbol information - kernel symbols are still accessable thanks
to the kallsyms.

To build perf without libelf (elfutils), give NO_LIBELF=1 to make.

For now, only 'perf probe' command is removed since it depends on
libelf/libdw heavily.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Makefile                 |   57 ++++++++++++++++++++++++++---------
 tools/perf/builtin-inject.c         |    5 ++-
 tools/perf/command-list.txt         |    2 +-
 tools/perf/perf.c                   |    2 ++
 tools/perf/util/generate-cmdlist.sh |   15 +++++++++
 tools/perf/util/map.c               |    3 +-
 tools/perf/util/symbol-minimal.c    |   39 ++++++++++++++++++++++++
 7 files changed, 106 insertions(+), 17 deletions(-)
 create mode 100644 tools/perf/util/symbol-minimal.c

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index c2d924b31033..fab1c9f5837e 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -37,7 +37,12 @@ include config/utilities.mak
 #
 # Define NO_NEWT if you do not want TUI support.
 #
+# Define NO_GTK2 if you do not want GTK+ GUI support.
+#
 # Define NO_DEMANGLE if you do not want C++ symbol demangling.
+#
+# Define NO_LIBELF if you do not want libelf dependency (e.g. cross-builds)
+#
 
 $(OUTPUT)PERF-VERSION-FILE: .FORCE-PERF-VERSION-FILE
 	@$(SHELL_PATH) util/PERF-VERSION-GEN $(OUTPUT)
@@ -445,34 +450,57 @@ PYRF_OBJS += $(OUTPUT)util/xyarray.o
 -include config.mak.autogen
 -include config.mak
 
-ifndef NO_DWARF
-FLAGS_DWARF=$(ALL_CFLAGS) -ldw -lelf $(ALL_LDFLAGS) $(EXTLIBS)
-ifneq ($(call try-cc,$(SOURCE_DWARF),$(FLAGS_DWARF)),y)
-	msg := $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev);
+ifdef NO_LIBELF
 	NO_DWARF := 1
-endif # Dwarf support
-endif # NO_DWARF
-
--include arch/$(ARCH)/Makefile
-
-ifneq ($(OUTPUT),)
-	BASIC_CFLAGS += -I$(OUTPUT)
-endif
-
+	NO_DEMANGLE := 1
+else
 FLAGS_LIBELF=$(ALL_CFLAGS) $(ALL_LDFLAGS) $(EXTLIBS)
 ifneq ($(call try-cc,$(SOURCE_LIBELF),$(FLAGS_LIBELF)),y)
 	FLAGS_GLIBC=$(ALL_CFLAGS) $(ALL_LDFLAGS)
 	ifneq ($(call try-cc,$(SOURCE_GLIBC),$(FLAGS_GLIBC)),y)
 		msg := $(error No gnu/libc-version.h found, please install glibc-dev[el]/glibc-static);
 	else
-		msg := $(error No libelf.h/libelf found, please install libelf-dev/elfutils-libelf-devel);
+		NO_LIBELF := 1
+		NO_DWARF := 1
+		NO_DEMANGLE := 1
 	endif
 endif
+endif # NO_LIBELF
+
+-include arch/$(ARCH)/Makefile
+
+ifneq ($(OUTPUT),)
+	BASIC_CFLAGS += -I$(OUTPUT)
+endif
+
+ifdef NO_LIBELF
+BASIC_CFLAGS += -DNO_LIBELF_SUPPORT
+
+EXTLIBS := $(filter-out -lelf,$(EXTLIBS))
+
+# Remove ELF/DWARF dependent codes
+LIB_OBJS := $(filter-out $(OUTPUT)util/symbol-elf.o,$(LIB_OBJS))
+LIB_OBJS := $(filter-out $(OUTPUT)util/dwarf-aux.o,$(LIB_OBJS))
+LIB_OBJS := $(filter-out $(OUTPUT)util/probe-event.o,$(LIB_OBJS))
+LIB_OBJS := $(filter-out $(OUTPUT)util/probe-finder.o,$(LIB_OBJS))
+
+BUILTIN_OBJS := $(filter-out $(OUTPUT)builtin-probe.o,$(BUILTIN_OBJS))
+
+# Use minimal symbol handling
+LIB_OBJS += $(OUTPUT)util/symbol-minimal.o
+
+else # NO_LIBELF
 
 ifneq ($(call try-cc,$(SOURCE_ELF_MMAP),$(FLAGS_COMMON)),y)
 	BASIC_CFLAGS += -DLIBELF_NO_MMAP
 endif
 
+FLAGS_DWARF=$(ALL_CFLAGS) -ldw -lelf $(ALL_LDFLAGS) $(EXTLIBS)
+ifneq ($(call try-cc,$(SOURCE_DWARF),$(FLAGS_DWARF)),y)
+	msg := $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev);
+	NO_DWARF := 1
+endif # Dwarf support
+
 ifndef NO_DWARF
 ifeq ($(origin PERF_HAVE_DWARF_REGS), undefined)
 	msg := $(warning DWARF register mappings have not been defined for architecture $(ARCH), DWARF support disabled);
@@ -483,6 +511,7 @@ else
 	LIB_OBJS += $(OUTPUT)util/dwarf-aux.o
 endif # PERF_HAVE_DWARF_REGS
 endif # NO_DWARF
+endif # NO_LIBELF
 
 ifdef NO_NEWT
 	BASIC_CFLAGS += -DNO_NEWT_SUPPORT
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 3beab489afc5..64d8ba2fb7bc 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -191,10 +191,13 @@ static int perf_event__inject_buildid(struct perf_tool *tool,
 				 * If this fails, too bad, let the other side
 				 * account this as unresolved.
 				 */
-			} else
+			} else {
+#ifndef NO_LIBELF_SUPPORT
 				pr_warning("no symbols found in %s, maybe "
 					   "install a debug package?\n",
 					   al.map->dso->long_name);
+#endif
+			}
 		}
 	}
 
diff --git a/tools/perf/command-list.txt b/tools/perf/command-list.txt
index d695fe40fbff..0303ec692274 100644
--- a/tools/perf/command-list.txt
+++ b/tools/perf/command-list.txt
@@ -18,7 +18,7 @@ perf-stat			mainporcelain common
 perf-timechart			mainporcelain common
 perf-top			mainporcelain common
 perf-script			mainporcelain common
-perf-probe			mainporcelain common
+perf-probe			mainporcelain full
 perf-kmem			mainporcelain common
 perf-lock			mainporcelain common
 perf-kvm			mainporcelain common
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 2b2e225a4d4c..a1450ccac291 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -313,7 +313,9 @@ static void handle_internal_command(int argc, const char **argv)
 		{ "version",	cmd_version,	0 },
 		{ "script",	cmd_script,	0 },
 		{ "sched",	cmd_sched,	0 },
+#ifndef NO_LIBELF_SUPPORT
 		{ "probe",	cmd_probe,	0 },
+#endif
 		{ "kmem",	cmd_kmem,	0 },
 		{ "lock",	cmd_lock,	0 },
 		{ "kvm",	cmd_kvm,	0 },
diff --git a/tools/perf/util/generate-cmdlist.sh b/tools/perf/util/generate-cmdlist.sh
index f06f6fd148f8..389590c1ad21 100755
--- a/tools/perf/util/generate-cmdlist.sh
+++ b/tools/perf/util/generate-cmdlist.sh
@@ -21,4 +21,19 @@ do
 	    p
      }' "Documentation/perf-$cmd.txt"
 done
+
+echo "#ifndef NO_LIBELF_SUPPORT"
+sed -n -e 's/^perf-\([^ 	]*\)[ 	].* full.*/\1/p' command-list.txt |
+sort |
+while read cmd
+do
+     sed -n '
+     /^NAME/,/perf-'"$cmd"'/H
+     ${
+            x
+            s/.*perf-'"$cmd"' - \(.*\)/  {"'"$cmd"'", "\1"},/
+	    p
+     }' "Documentation/perf-$cmd.txt"
+done
+echo "#endif /* NO_LIBELF_SUPPORT */"
 echo "};"
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 562a06af8658..98f66dcb6ccb 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -154,6 +154,7 @@ int map__load(struct map *self, symbol_filter_t filter)
 		pr_warning(", continuing without symbols\n");
 		return -1;
 	} else if (nr == 0) {
+#ifndef NO_LIBELF_SUPPORT
 		const size_t len = strlen(name);
 		const size_t real_len = len - sizeof(DSO__DELETED);
 
@@ -166,7 +167,7 @@ int map__load(struct map *self, symbol_filter_t filter)
 			pr_warning("no symbols found in %s, maybe install "
 				   "a debug package?\n", name);
 		}
-
+#endif
 		return -1;
 	}
 	/*
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
new file mode 100644
index 000000000000..416ecf3bccf5
--- /dev/null
+++ b/tools/perf/util/symbol-minimal.c
@@ -0,0 +1,39 @@
+#include "symbol.h"
+
+
+int filename__read_build_id(const char *filename __used, void *bf __used,
+			    size_t size __used)
+{
+	return -1;
+}
+
+int sysfs__read_build_id(const char *filename __used, void *build_id __used,
+			 size_t size __used)
+{
+	return -1;
+}
+
+int filename__read_debuglink(const char *filename __used,
+			     char *debuglink __used, size_t size __used)
+{
+	return -1;
+}
+
+int dso__synthesize_plt_symbols(struct dso *dso __used, char *name __used,
+				struct map *map __used,
+				symbol_filter_t filter __used)
+{
+	return 0;
+}
+
+int dso__load_sym(struct dso *dso __used, struct map *map __used,
+		  const char *name __used, int fd __used,
+		  symbol_filter_t filter __used, int kmodule __used,
+		  int want_symtab __used)
+{
+	return 0;
+}
+
+void symbol__elf_init(void)
+{
+}
-- 
1.7.10.4

[PATCH 6/6] perf symbols: Implement poor man's ELF parser

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

Implement a minimal elf parser for getting build-id.  It assumes that
required elf.h header is provided by libc header on the system and the
parser only looks for PT_NOTE program header to check build-id.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/symbol-minimal.c |  242 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 235 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
index 416ecf3bccf5..bd8720b6780c 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -1,15 +1,71 @@
 #include "symbol.h"
 
+#include <elf.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <string.h>
+#include <byteswap.h>
+#include <sys/stat.h>
 
-int filename__read_build_id(const char *filename __used, void *bf __used,
-			    size_t size __used)
+
+static bool check_need_swap(int file_endian)
 {
-	return -1;
+	const int data = 1;
+	u8 *check = (u8 *)&data;
+	int host_endian;
+
+	if (check[0] == 1)
+		host_endian = ELFDATA2LSB;
+	else
+		host_endian = ELFDATA2MSB;
+
+	return host_endian != file_endian;
 }
 
-int sysfs__read_build_id(const char *filename __used, void *build_id __used,
-			 size_t size __used)
+#define NOTE_ALIGN(sz) (((sz) + 3) & ~3)
+
+#define NT_GNU_BUILD_ID	3
+
+static int read_build_id(void *note_data, size_t note_len, void *bf,
+			 size_t size, bool need_swap)
 {
+	struct {
+		u32 n_namesz;
+		u32 n_descsz;
+		u32 n_type;
+	} *nhdr;
+	void *ptr;
+
+	ptr = note_data;
+	while (ptr < (note_data + note_len)) {
+		const char *name;
+		size_t namesz, descsz;
+
+		nhdr = ptr;
+		if (need_swap) {
+			nhdr->n_namesz = bswap_32(nhdr->n_namesz);
+			nhdr->n_descsz = bswap_32(nhdr->n_descsz);
+			nhdr->n_type = bswap_32(nhdr->n_type);
+		}
+
+		namesz = NOTE_ALIGN(nhdr->n_namesz);
+		descsz = NOTE_ALIGN(nhdr->n_descsz);
+
+		ptr += sizeof(*nhdr);
+		name = ptr;
+		ptr += namesz;
+		if (nhdr->n_type == NT_GNU_BUILD_ID &&
+		    nhdr->n_namesz == sizeof("GNU")) {
+			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
+				size_t sz = min(size, descsz);
+				memcpy(bf, ptr, sz);
+				memset(bf + sz, 0, size - sz);
+				return 0;
+			}
+		}
+		ptr += descsz;
+	}
+
 	return -1;
 }
 
@@ -19,6 +75,172 @@ int filename__read_debuglink(const char *filename __used,
 	return -1;
 }
 
+/*
+ * Just try PT_NOTE header otherwise fails
+ */
+int filename__read_build_id(const char *filename, void *bf, size_t size)
+{
+	FILE *fp;
+	int ret = -1;
+	bool need_swap = false;
+	u8 e_ident[EI_NIDENT];
+	size_t buf_size;
+	void *buf;
+	int i;
+
+	fp = fopen(filename, "r");
+	if (fp == NULL)
+		return -1;
+
+	if (fread(e_ident, sizeof(e_ident), 1, fp) != 1)
+		goto out;
+
+	if (memcmp(e_ident, ELFMAG, SELFMAG) ||
+	    e_ident[EI_VERSION] != EV_CURRENT)
+		goto out;
+
+	need_swap = check_need_swap(e_ident[EI_DATA]);
+
+	/* for simplicity */
+	fseek(fp, 0, SEEK_SET);
+
+	if (e_ident[EI_CLASS] == ELFCLASS32) {
+		Elf32_Ehdr ehdr;
+		Elf32_Phdr *phdr;
+
+		if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
+			goto out;
+
+		if (need_swap) {
+			ehdr.e_phoff = bswap_32(ehdr.e_phoff);
+			ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
+			ehdr.e_phnum = bswap_16(ehdr.e_phnum);
+		}
+
+		buf_size = ehdr.e_phentsize * ehdr.e_phnum;
+		buf = malloc(buf_size);
+		if (buf == NULL)
+			goto out;
+
+		fseek(fp, ehdr.e_phoff, SEEK_SET);
+		if (fread(buf, buf_size, 1, fp) != 1)
+			goto out_free;
+
+		for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
+			void *tmp;
+
+			if (need_swap) {
+				phdr->p_type = bswap_32(phdr->p_type);
+				phdr->p_offset = bswap_32(phdr->p_offset);
+				phdr->p_filesz = bswap_32(phdr->p_filesz);
+			}
+
+			if (phdr->p_type != PT_NOTE)
+				continue;
+
+			buf_size = phdr->p_filesz;
+			tmp = realloc(buf, buf_size);
+			if (tmp == NULL)
+				goto out_free;
+
+			buf = tmp;
+			fseek(fp, phdr->p_offset, SEEK_SET);
+			if (fread(buf, buf_size, 1, fp) != 1)
+				goto out_free;
+
+			ret = read_build_id(buf, buf_size, bf, size, need_swap);
+			if (ret == 0)
+				ret = size;
+			break;
+		}
+	} else {
+		Elf64_Ehdr ehdr;
+		Elf64_Phdr *phdr;
+
+		if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
+			goto out;
+
+		if (need_swap) {
+			ehdr.e_phoff = bswap_64(ehdr.e_phoff);
+			ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
+			ehdr.e_phnum = bswap_16(ehdr.e_phnum);
+		}
+
+		buf_size = ehdr.e_phentsize * ehdr.e_phnum;
+		buf = malloc(buf_size);
+		if (buf == NULL)
+			goto out;
+
+		fseek(fp, ehdr.e_phoff, SEEK_SET);
+		if (fread(buf, buf_size, 1, fp) != 1)
+			goto out_free;
+
+		for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
+			void *tmp;
+
+			if (need_swap) {
+				phdr->p_type = bswap_32(phdr->p_type);
+				phdr->p_offset = bswap_64(phdr->p_offset);
+				phdr->p_filesz = bswap_64(phdr->p_filesz);
+			}
+
+			if (phdr->p_type != PT_NOTE)
+				continue;
+
+			buf_size = phdr->p_filesz;
+			tmp = realloc(buf, buf_size);
+			if (tmp == NULL)
+				goto out_free;
+
+			buf = tmp;
+			fseek(fp, phdr->p_offset, SEEK_SET);
+			if (fread(buf, buf_size, 1, fp) != 1)
+				goto out_free;
+
+			ret = read_build_id(buf, buf_size, bf, size, need_swap);
+			if (ret == 0)
+				ret = size;
+			break;
+		}
+	}
+out_free:
+	free(buf);
+out:
+	fclose(fp);
+	return ret;
+}
+
+int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
+{
+	int fd;
+	int ret = -1;
+	struct stat stbuf;
+	size_t buf_size;
+	void *buf;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return -1;
+
+	if (fstat(fd, &stbuf) < 0)
+		goto out;
+
+	buf_size = stbuf.st_size;
+	buf = malloc(buf_size);
+	if (buf == NULL)
+		goto out;
+
+	if (read(fd, buf, buf_size) != (ssize_t) buf_size)
+		goto out_free;
+
+	ret = read_build_id(buf, buf_size, build_id, size, false);
+out_free:
+	free(buf);
+out:
+	close(fd);
+	return ret;
+}
+
 int dso__synthesize_plt_symbols(struct dso *dso __used, char *name __used,
 				struct map *map __used,
 				symbol_filter_t filter __used)
@@ -26,11 +248,17 @@ int dso__synthesize_plt_symbols(struct dso *dso __used, char *name __used,
 	return 0;
 }
 
-int dso__load_sym(struct dso *dso __used, struct map *map __used,
-		  const char *name __used, int fd __used,
+int dso__load_sym(struct dso *dso, struct map *map __used,
+		  const char *name, int fd __used,
 		  symbol_filter_t filter __used, int kmodule __used,
 		  int want_symtab __used)
 {
+	unsigned char *build_id[BUILD_ID_SIZE];
+
+	if (filename__read_build_id(name, build_id, BUILD_ID_SIZE) > 0) {
+		dso__set_build_id(dso, build_id);
+		return 1;
+	}
 	return 0;
 }
 
-- 
1.7.10.4

[tip:perf/core] tools lib traceevent: Detect build environment changes

[tip-bot for Namhyung Kim]

Commit-ID:  52b5c0d485385d3c767d979496983ca2b6987f5c
Gitweb:     http://git.kernel.org/tip/52b5c0d485385d3c767d979496983ca2b6987f5c
Author:     Namhyung Kim <namhyung.kim@lge.com>
AuthorDate: Fri, 6 Jul 2012 16:21:32 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 25 Jul 2012 11:54:06 -0300

tools lib traceevent: Detect build environment changes

Cross compiling perf requires setting ARCH and CROSS_COMPILE variables,
but libtraceevent couldn't detect the changes so it ends up believing no
recompiling is required. Thus the linker failed like:

     LINK perf
 ../lib/traceevent//libtraceevent.a: member ../lib/traceevent//libtraceevent.a(event-parse.o) in archive is not an object
 collect2: ld returned 1 exit status
 make: *** [perf] Error 1

This patch fixes this by adding TRACEEVENT-CFLAGS file like
PERF-CFLAGS to track those changes.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1341559297-25725-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/lib/traceevent/Makefile |   14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/tools/lib/traceevent/Makefile b/tools/lib/traceevent/Makefile
index 46c2f6b..14131cb 100644
--- a/tools/lib/traceevent/Makefile
+++ b/tools/lib/traceevent/Makefile
@@ -207,7 +207,7 @@ libtraceevent.so: $(PEVENT_LIB_OBJS)
 libtraceevent.a: $(PEVENT_LIB_OBJS)
 	$(Q)$(do_build_static_lib)
 
-$(PEVENT_LIB_OBJS): %.o: $(src)/%.c
+$(PEVENT_LIB_OBJS): %.o: $(src)/%.c TRACEEVENT-CFLAGS
 	$(Q)$(do_fpic_compile)
 
 define make_version.h
@@ -272,6 +272,16 @@ ifneq ($(dep_includes),)
  include $(dep_includes)
 endif
 
+### Detect environment changes
+TRACK_CFLAGS = $(subst ','\'',$(CFLAGS)):$(ARCH):$(CROSS_COMPILE)
+
+TRACEEVENT-CFLAGS: force
+	@FLAGS='$(TRACK_CFLAGS)'; \
+	    if test x"$$FLAGS" != x"`cat TRACEEVENT-CFLAGS 2>/dev/null`" ; then \
+		echo 1>&2 "    * new build flags or cross compiler"; \
+		echo "$$FLAGS" >TRACEEVENT-CFLAGS; \
+            fi
+
 tags:	force
 	$(RM) tags
 	find . -name '*.[ch]' | xargs ctags --extra=+f --c-kinds=+px \
@@ -297,7 +307,7 @@ install: install_lib
 
 clean:
 	$(RM) *.o *~ $(TARGETS) *.a *.so $(VERSION_FILES) .*.d
-	$(RM) tags TAGS
+	$(RM) TRACEEVENT-CFLAGS tags TAGS
 
 endif # skip-makefile
 

[tip:perf/core] tools lib traceevent: Ignore TRACEEVENT-CFLAGS file

[tip-bot for Namhyung Kim]

Commit-ID:  52f18a2ff9b012a7efdbd520ca0dc0e118a8a837
Gitweb:     http://git.kernel.org/tip/52f18a2ff9b012a7efdbd520ca0dc0e118a8a837
Author:     Namhyung Kim <namhyung.kim@lge.com>
AuthorDate: Fri, 6 Jul 2012 16:21:33 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 25 Jul 2012 11:54:44 -0300

tools lib traceevent: Ignore TRACEEVENT-CFLAGS file

The TRACEEVENT-CFLAGS file is used to detect any change on compiler
flags. Just ignore it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1341559297-25725-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/lib/traceevent/.gitignore |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/tools/lib/traceevent/.gitignore b/tools/lib/traceevent/.gitignore
new file mode 100644
index 0000000..35f56be
--- /dev/null
+++ b/tools/lib/traceevent/.gitignore
@@ -0,0 +1 @@
+TRACEEVENT-CFLAGS