Messages in this thread |  | | | Date | Fri, 23 Oct 2009 23:52:39 +0200 | | From | Ingo Molnar <> | | Subject | Re: [PATCH] perf tools: add compatibility with libelf 0.8 and autodetect |
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* Marti Raudsepp <marti@juffo.org> wrote:
> 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 */
Looks nice!
Mind adding a comment as well to document the version dependency?
Also, there's a few probably unintended whitespaces in the patch not matching surrounding style (which is the kernel coding style) - please run the patch through scripts/checkpatch.pl.
Ingo
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