Skip to content

Commit

Permalink
perf symbols: Support minimal build without libelf
Browse files Browse the repository at this point in the history
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>
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/1344228082-15569-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
  • Loading branch information
Namhyung Kim authored and Arnaldo Carvalho de Melo committed Aug 9, 2012
1 parent e5a1845 commit 393be2e
Show file tree
Hide file tree
Showing 7 changed files with 106 additions and 17 deletions.
57 changes: 43 additions & 14 deletions tools/perf/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down Expand Up @@ -450,34 +455,57 @@ 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);
Expand All @@ -488,6 +516,7 @@ 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
Expand Down
5 changes: 4 additions & 1 deletion tools/perf/builtin-inject.c
Original file line number Diff line number Diff line change
Expand Up @@ -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
}
}
}

Expand Down
2 changes: 1 addition & 1 deletion tools/perf/command-list.txt
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down
2 changes: 2 additions & 0 deletions tools/perf/perf.c
Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,9 @@ static struct cmd_struct commands[] = {
{ "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 },
Expand Down
15 changes: 15 additions & 0 deletions tools/perf/util/generate-cmdlist.sh
Original file line number Diff line number Diff line change
Expand Up @@ -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 "};"
3 changes: 2 additions & 1 deletion tools/perf/util/map.c
Original file line number Diff line number Diff line change
Expand Up @@ -156,6 +156,7 @@ 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);

Expand All @@ -168,7 +169,7 @@ 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;
}
/*
Expand Down
39 changes: 39 additions & 0 deletions tools/perf/util/symbol-minimal.c
Original file line number Diff line number Diff line change
@@ -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)
{
}

0 comments on commit 393be2e

Please sign in to comment.