On 13/05/16 11:51, He Kuang wrote:
> 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 exsiting 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.
>
> Signed-off-by: He Kuang <heku...@huawei.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 44d440d..99f4a3d 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);
So if we have not yet added the 32-bit vdso but have added the 64-bit vdso,
we will return the wrong one.
Can we check it? e.g.
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);
> + if (!dso)
> + dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO,
> + true);
The x32 vdso is never called DSO__NAME_VDSO so this is not correct, but for
the same reason we don't need this __dsos__find() anyway.
> + 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;
>
