From: He Kuang <heku...@huawei.com> There's a problem in machine__findnew_vdso(), vdso buildid generated by a 32-bit machine stores it with the name 'vdso', but when processing buildid on a 64-bit machine with the same 'perf.data', perf will search for vdso named as 'vdso32' and get failed.
This patch tries to find the existing dsos in machine->dsos by thread dso_type. 64-bit thread tries to find vdso with name 'vdso', because all 64-bit vdso is named as that. 32-bit thread first tries to find vdso with name 'vdso32' if this thread was run on 64-bit machine, if failed, then it tries 'vdso' which indicates that the thread was run on 32-bit machine when recording. Committer note: Additional explanation by Adrian Hunter: We match maps to builds ids using the file name - consider machine__findnew_[v]dso() called in map__new(). So in the context of a perf data file, we consider the file name to be unique. A vdso map does not have a file name - all we know is that it is vdso. We look at the thread to tell if it is 32-bit, 64-bit or x32. Then we need to get the build id which has been recorded using short name "[vdso]" or "[vdso32]" or "[vdsox32]". The problem is that on a 32-bit machine, we use the name "[vdso]". If you take a 32-bit perf data file to a 64-bit machine, it gets hard to figure out if "[vdso]" is 32-bit or 64-bit. This patch solves that problem. Signed-off-by: He Kuang <heku...@huawei.com> Acked-by: Adrian Hunter <adrian.hun...@intel.com> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Andi Kleen <a...@linux.intel.com> Cc: David Ahern <dsah...@gmail.com> Cc: Ekaterina Tumanova <tuman...@linux.vnet.ibm.com> Cc: Jiri Olsa <jo...@redhat.com> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Kan Liang <kan.li...@intel.com> Cc: Masami Hiramatsu <mhira...@kernel.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Pekka Enberg <penb...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Stephane Eranian <eran...@google.com> Cc: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com> Cc: Wang Nan <wangn...@huawei.com> Link: http://lkml.kernel.org/r/1463475894-163531-1-git-send-email-heku...@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/vdso.c | 40 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 37 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c index 44d440da15dc..8f81c415723d 100644 --- a/tools/perf/util/vdso.c +++ b/tools/perf/util/vdso.c @@ -134,8 +134,6 @@ static struct dso *__machine__addnew_vdso(struct machine *machine, const char *s return dso; } -#if BITS_PER_LONG == 64 - static enum dso_type machine__thread_dso_type(struct machine *machine, struct thread *thread) { @@ -156,6 +154,8 @@ static enum dso_type machine__thread_dso_type(struct machine *machine, return dso_type; } +#if BITS_PER_LONG == 64 + static int vdso__do_copy_compat(FILE *f, int fd) { char buf[4096]; @@ -283,8 +283,38 @@ static int __machine__findnew_vdso_compat(struct machine *machine, #endif +static struct dso *machine__find_vdso(struct machine *machine, + struct thread *thread) +{ + struct dso *dso = NULL; + enum dso_type dso_type; + + dso_type = machine__thread_dso_type(machine, thread); + switch (dso_type) { + case DSO__TYPE_32BIT: + dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO32, true); + if (!dso) { + dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, + true); + if (dso_type != dso__type(dso, machine)) + dso = NULL; + } + break; + case DSO__TYPE_X32BIT: + dso = __dsos__find(&machine->dsos, DSO__NAME_VDSOX32, true); + break; + case DSO__TYPE_64BIT: + case DSO__TYPE_UNKNOWN: + default: + dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true); + break; + } + + return dso; +} + struct dso *machine__findnew_vdso(struct machine *machine, - struct thread *thread __maybe_unused) + struct thread *thread) { struct vdso_info *vdso_info; struct dso *dso = NULL; @@ -297,6 +327,10 @@ struct dso *machine__findnew_vdso(struct machine *machine, if (!vdso_info) goto out_unlock; + dso = machine__find_vdso(machine, thread); + if (dso) + goto out_unlock; + #if BITS_PER_LONG == 64 if (__machine__findnew_vdso_compat(machine, thread, vdso_info, &dso)) goto out_unlock; -- 2.5.5
