| Message ID | 20230803023321.111078-1-tianruidong@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] coresight: tmc: Explicit type conversions to prevent integer overflow | expand |
On 03/08/2023 03:33, Ruidong Tian wrote: > Perf cs_etm session executed unexpectedly when AUX buffer > 1G. > > perf record -C 0 -m ,2G -e cs_etm// -- <workload> > [ perf record: Captured and wrote 2.615 MB perf.data ] > > Perf only collect about 2M perf data rather than 2G. This is becasuse > the operation, "nr_pages << PAGE_SHIFT", in coresight tmc driver, will > overflow when nr_pages >= 0x80000(correspond to 1G AUX buffer). The > overflow cause buffer allocation to fail, and TMC driver will alloc > minimal buffer size(1M). You can just get about 2M perf data(1M AUX > buffer + perf data header) at least. > > Explicit convert nr_pages to 64 bit to avoid overflow. > > Signed-off-by: Ruidong Tian <tianruidong@linux.alibaba.com> > Reviewed-by: James Clark <james.clark@arm.com> Fixes: 22f429f19c41 ("coresight: etm-perf: Add support for ETR backend") > --- > drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +- > drivers/hwtracing/coresight/coresight-tmc.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > index 766325de0e29..1425ecd1cf78 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > @@ -1267,7 +1267,7 @@ alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event, > * than the size requested via sysfs. > */ > if ((nr_pages << PAGE_SHIFT) > drvdata->size) { > - etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT), > + etr_buf = tmc_alloc_etr_buf(drvdata, ((ssize_t)nr_pages << PAGE_SHIFT), > 0, node, NULL); > if (!IS_ERR(etr_buf)) > goto done; > diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h > index b97da39652d2..0ee48c5ba764 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc.h > +++ b/drivers/hwtracing/coresight/coresight-tmc.h > @@ -325,7 +325,7 @@ ssize_t tmc_sg_table_get_data(struct tmc_sg_table *sg_table, > static inline unsigned long > tmc_sg_table_buf_size(struct tmc_sg_table *sg_table) > { > - return sg_table->data_pages.nr_pages << PAGE_SHIFT; > + return (unsigned long)sg_table->data_pages.nr_pages << PAGE_SHIFT; > } > > struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata); There are other places where such a fix is needed. e.g., $ git grep "nr_pages << PAGE_SHIFT" drivers/hwtracing/coresight/coresight-tmc* drivers/hwtracing/coresight/coresight-tmc-etf.c: head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1); drivers/hwtracing/coresight/coresight-tmc-etr.c:#define PERF_IDX2OFF(idx, buf) ((idx) % ((buf)->nr_pages << PAGE_SHIFT)) drivers/hwtracing/coresight/coresight-tmc-etr.c: if ((nr_pages << PAGE_SHIFT) > drvdata->size) { drivers/hwtracing/coresight/coresight-tmc-etr.c: etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT), drivers/hwtracing/coresight/coresight-tmc.h: return sg_table->data_pages.nr_pages << PAGE_SHIFT; Are you able to fix all of them ? Suzuki
Sure, I will put them all to patch v3. Ruidong On 2023/8/4 00:19, Suzuki K Poulose wrote: > On 03/08/2023 03:33, Ruidong Tian wrote: >> Perf cs_etm session executed unexpectedly when AUX buffer > 1G. >> >> perf record -C 0 -m ,2G -e cs_etm// -- <workload> >> [ perf record: Captured and wrote 2.615 MB perf.data ] >> >> Perf only collect about 2M perf data rather than 2G. This is becasuse >> the operation, "nr_pages << PAGE_SHIFT", in coresight tmc driver, will >> overflow when nr_pages >= 0x80000(correspond to 1G AUX buffer). The >> overflow cause buffer allocation to fail, and TMC driver will alloc >> minimal buffer size(1M). You can just get about 2M perf data(1M AUX >> buffer + perf data header) at least. >> >> Explicit convert nr_pages to 64 bit to avoid overflow. >> >> Signed-off-by: Ruidong Tian <tianruidong@linux.alibaba.com> >> Reviewed-by: James Clark <james.clark@arm.com> > > Fixes: 22f429f19c41 ("coresight: etm-perf: Add support for ETR backend") > > >> --- >> drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +- >> drivers/hwtracing/coresight/coresight-tmc.h | 2 +- >> 2 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c >> b/drivers/hwtracing/coresight/coresight-tmc-etr.c >> index 766325de0e29..1425ecd1cf78 100644 >> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c >> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c >> @@ -1267,7 +1267,7 @@ alloc_etr_buf(struct tmc_drvdata *drvdata, >> struct perf_event *event, >> * than the size requested via sysfs. >> */ >> if ((nr_pages << PAGE_SHIFT) > drvdata->size) { >> - etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT), >> + etr_buf = tmc_alloc_etr_buf(drvdata, ((ssize_t)nr_pages << >> PAGE_SHIFT), >> 0, node, NULL); >> if (!IS_ERR(etr_buf)) >> goto done; >> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h >> b/drivers/hwtracing/coresight/coresight-tmc.h >> index b97da39652d2..0ee48c5ba764 100644 >> --- a/drivers/hwtracing/coresight/coresight-tmc.h >> +++ b/drivers/hwtracing/coresight/coresight-tmc.h >> @@ -325,7 +325,7 @@ ssize_t tmc_sg_table_get_data(struct tmc_sg_table >> *sg_table, >> static inline unsigned long >> tmc_sg_table_buf_size(struct tmc_sg_table *sg_table) >> { >> - return sg_table->data_pages.nr_pages << PAGE_SHIFT; >> + return (unsigned long)sg_table->data_pages.nr_pages << PAGE_SHIFT; >> } >> struct coresight_device *tmc_etr_get_catu_device(struct >> tmc_drvdata *drvdata); > > There are other places where such a fix is needed. > e.g., > > $ git grep "nr_pages << PAGE_SHIFT" > drivers/hwtracing/coresight/coresight-tmc* > drivers/hwtracing/coresight/coresight-tmc-etf.c: head = > handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1); > drivers/hwtracing/coresight/coresight-tmc-etr.c:#define > PERF_IDX2OFF(idx, buf) ((idx) % ((buf)->nr_pages << PAGE_SHIFT)) > drivers/hwtracing/coresight/coresight-tmc-etr.c: if ((nr_pages > << PAGE_SHIFT) > drvdata->size) { > drivers/hwtracing/coresight/coresight-tmc-etr.c: etr_buf = > tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT), > drivers/hwtracing/coresight/coresight-tmc.h: return > sg_table->data_pages.nr_pages << PAGE_SHIFT; > > Are you able to fix all of them ? > > Suzuki
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 766325de0e29..1425ecd1cf78 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1267,7 +1267,7 @@ alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event, * than the size requested via sysfs. */ if ((nr_pages << PAGE_SHIFT) > drvdata->size) { - etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT), + etr_buf = tmc_alloc_etr_buf(drvdata, ((ssize_t)nr_pages << PAGE_SHIFT), 0, node, NULL); if (!IS_ERR(etr_buf)) goto done; diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index b97da39652d2..0ee48c5ba764 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -325,7 +325,7 @@ ssize_t tmc_sg_table_get_data(struct tmc_sg_table *sg_table, static inline unsigned long tmc_sg_table_buf_size(struct tmc_sg_table *sg_table) { - return sg_table->data_pages.nr_pages << PAGE_SHIFT; + return (unsigned long)sg_table->data_pages.nr_pages << PAGE_SHIFT; } struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata);