Messages in this thread Patch in this message | | | From | Marti Raudsepp <> | Subject | Re: [PATCH] perf tools: add compatibility with libelf 0.8 and autodetect | Date | Sat, 24 Oct 2009 00:48:21 +0300 |
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On Sat, Oct 24, 2009 at 12:02 AM, Ingo Molnar <mingo@elte.hu> wrote: > Mind doing a small change: > > I think we want a small cleanup here: a perf_elf_begin() wrapper in a > header file to hide this #ifdef. (That's how Git wraps environmental > libraries as well.)
Ok, does this patch do what you had in mind? I wasn't quite sure how to implement; changing the cmd behind someone's back might be considered surprising.
Another take would be to #define our own ELF_C_READ_MMAP, but that would be lying, too...
> Also, this would be an urgent fix for v2.6.32 too, to make perf build on > Arch Linux, agreed?
Hopefully :)
Regards, Marti
[PATCH] perf tools: add compatibility with libelf 0.8 and autodetect
The Makefile now automatically defines LIBELF_NO_MMAP when libelf 0.8 is detected. libelf 0.8 is still maintained and some distributions such as Arch Linux use it instead of elfutils.
Signed-off-by: Marti Raudsepp <marti@juffo.org> --- tools/perf/Makefile | 6 +++++- tools/perf/util/symbol.c | 9 +++++---- tools/perf/util/symbol.h | 11 +++++++++++ 3 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/tools/perf/Makefile b/tools/perf/Makefile index 742a32e..46e877b 100644 --- a/tools/perf/Makefile +++ b/tools/perf/Makefile @@ -422,7 +422,11 @@ ifeq ($(uname_S),Darwin) PTHREAD_LIBS = endif -ifneq ($(shell sh -c "(echo '\#include <libelf.h>'; echo 'int main(void) { Elf * elf = elf_begin(0, ELF_C_READ_MMAP, 0); return (long)elf; }') | $(CC) -x c - $(ALL_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -o /dev/null $(ALL_LDFLAGS) > /dev/null 2>&1 && echo y"), y) +ifeq ($(shell sh -c "(echo '\#include <libelf.h>'; echo 'int main(void) { Elf * elf = elf_begin(0, ELF_C_READ, 0); return (long)elf; }') | $(CC) -x c - $(ALL_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -o /dev/null $(ALL_LDFLAGS) > /dev/null 2>&1 && echo y"), y) + ifneq ($(shell sh -c "(echo '\#include <libelf.h>'; echo 'int main(void) { Elf * elf = elf_begin(0, ELF_C_READ_MMAP, 0); return (long)elf; }') | $(CC) -x c - $(ALL_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -o /dev/null $(ALL_LDFLAGS) > /dev/null 2>&1 && echo y"), y) + BASIC_CFLAGS += -DLIBELF_NO_MMAP + endif +else msg := $(error No libelf.h/libelf found, please install libelf-dev/elfutils-libelf-devel and glibc-dev[el]); endif diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 47ea060..ec69c42 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -5,7 +5,6 @@ #include "debug.h" -#include <libelf.h> #include <gelf.h> #include <elf.h> @@ -413,7 +412,8 @@ static int dso__synthesize_plt_symbols(struct dso *self, int v) if (fd < 0) goto out; - elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); + elf = perf_elf_begin(fd, ELF_C_READ, NULL); + if (elf == NULL) goto out_close; @@ -533,7 +533,8 @@ static int dso__load_sym(struct dso *self, int fd, const char *name, Elf *elf; int nr = 0, kernel = !strcmp("[kernel]", self->name); - elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); + elf = perf_elf_begin(fd, ELF_C_READ, NULL); + if (elf == NULL) { if (v) fprintf(stderr, "%s: cannot read %s ELF file.\n", @@ -675,7 +676,7 @@ static char *dso__read_build_id(struct dso *self, int v) if (fd < 0) goto out; - elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); + elf = perf_elf_begin(fd, ELF_C_READ, NULL); if (elf == NULL) { if (v) fprintf(stderr, "%s: cannot read %s ELF file.\n", diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index 6e84907..50750e9 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -8,6 +8,8 @@ #include "module.h" #include "event.h" +#include <libelf.h> + #ifdef HAVE_CPLUS_DEMANGLE extern char *cplus_demangle(const char *, int); @@ -27,6 +29,15 @@ static inline char *bfd_demangle(void __used *v, const char __used *c, #endif #endif +static inline Elf *perf_elf_begin(int fd, Elf_Cmd cmd, Elf *ref) +{ +#ifndef LIBELF_NO_MMAP + if (cmd == ELF_C_READ) + cmd = ELF_C_READ_MMAP; +#endif + return elf_begin(fd, cmd, ref); +} + #ifndef DMGL_PARAMS #define DMGL_PARAMS (1 << 0) /* Include function args */ #define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */ -- 1.6.5.1
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