2020-02-03 01:55:01

by Leo Yan

Subject: [PATCH v3 5/5] perf cs-etm: Fix unsigned variable comparison to zero

The variable 'offset' in function cs_etm__sample() is u64 type, it's not
appropriate to check it with 'while (offset > 0)'; this patch changes to
'while (offset)'.

Signed-off-by: Leo Yan <[email protected]>
---
tools/perf/util/cs-etm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index dbddf1eec2be..720108bd8dba 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -945,7 +945,7 @@ static inline u64 cs_etm__instr_addr(struct cs_etm_queue *etmq,
if (packet->isa == CS_ETM_ISA_T32) {
u64 addr = packet->start_addr;

- while (offset > 0) {
+ while (offset) {
addr += cs_etm__t32_instr_size(etmq,
trace_chan_id, addr);
offset--;
--
2.17.1

2020-02-06 12:28:43

by Mike Leach

Subject: Re: [PATCH v3 5/5] perf cs-etm: Fix unsigned variable comparison to zero

Reviewed by: Mike Leach <[email protected]>

On Mon, 3 Feb 2020 at 01:53, Leo Yan <[email protected]> wrote:
>
> The variable 'offset' in function cs_etm__sample() is u64 type, it's not
> appropriate to check it with 'while (offset > 0)'; this patch changes to
> 'while (offset)'.
>
> Signed-off-by: Leo Yan <[email protected]>
> ---
> tools/perf/util/cs-etm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index dbddf1eec2be..720108bd8dba 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -945,7 +945,7 @@ static inline u64 cs_etm__instr_addr(struct cs_etm_queue *etmq,
> if (packet->isa == CS_ETM_ISA_T32) {
> u64 addr = packet->start_addr;
>
> - while (offset > 0) {
> + while (offset) {
> addr += cs_etm__t32_instr_size(etmq,
> trace_chan_id, addr);
> offset--;
> --
> 2.17.1
>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK