Em Mon, Dec 15, 2014 at 08:20:33PM +0530, Naveen N. Rao escreveu:
> If using the symbol table, symbol addresses are not being fixed up
> properly, resulting in probes being placed at wrong addresses:
>
> # perf probe do_fork
> Added new event:
> probe:do_fork (on do_fork)
>
> You can now use it in all perf tools, such as:
>
> perf record -e probe:do_fork -aR sleep 1
>
> # cat /sys/kernel/debug/tracing/kprobe_events
> p:probe/do_fork _text+635952
> # printf "%x" 635952
> 9b430
> # grep do_fork /boot/System.map
> c0000000000ab430 T .do_fork
>
> Fix by checking for ELF type ET_DYN used by ppc64 kernels.
Sorry if this was answered already, its been a while since this was
posted/discussed... Are you completely sure this is not a problem on
!ppc?
Woudln't it be more conservative to somehow only adjust symbols for this
ET_DYN type if the arch is ppc? I.e. something like moving that
adjust_symbols logic to be arch_adjust_symbols(), provide a default and
then override it for ppc to include also ET_DYN?
Looking at the other patches...
- Arnaldo
> Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
> ---
> tools/perf/util/symbol-elf.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 06fcd1b..7ac4e4c 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -683,7 +683,8 @@ int symsrc__init(struct symsrc *ss, struct dso *dso,
> const char *name,
> NULL) != NULL);
> } else {
> ss->adjust_symbols = ehdr.e_type == ET_EXEC ||
> - ehdr.e_type == ET_REL;
> + ehdr.e_type == ET_REL ||
> + ehdr.e_type == ET_DYN;
> }
>
> ss->name = strdup(name);
> --
> 2.1.3
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