CoreSight

coresight@lists.linaro.org

5 participants
2515 discussions

[PATCH v2 0/1] perf: Set build-id using build-id header on new mmap records

by James Clark

Changes since v1: * Add read lock around dso find * Bracket style fix Hi, We are seeing an issue with doing Coresight decode off target where initially the correct dso from ~/.debug is used, but after a new thread in the perf.data file is passed with its mmap record, the local version of the dso is picked up instead. This happens if the binary exists in the same path on both devices, for example /bin/ls. Initially when parsing the build-ids in the header, the dso for /bin/ls will be created, and the file will correctly point to ~/.debug/bin/ls/2f15ad836be3339dec0e2e6a3c637e08e48aacbd/elf, but for any new threads or mmaps that are also for /bin/ls, they will not have a build-id set so they point to /bin/ls on the local machine rather than the debug folder. To fix this I made it possible to look up which existing dsos have build id's set that originate from the header and then copy that build-id onto the new dso if the name matches. Another way to do it would be to stop comparing the mmap id so it matches on filename only, but I think we do want to differentiate between different mmaps, even if they have the same name, which is how it works in this version. Applies to perf/core 56dce8681 James Clark (1): perf: Set build-id using build-id header on new mmap records tools/perf/util/dso.h | 1 + tools/perf/util/header.c | 1 + tools/perf/util/map.c | 20 +++++++++++++++++--- 3 files changed, 19 insertions(+), 3 deletions(-) -- 2.28.0

3 years, 8 months

Re: [PATCH 1/1] perf: Set build-id using build-id header on new mmap records

by James Clark

On 27/02/2022 22:50, Jiri Olsa wrote: > On Thu, Feb 24, 2022 at 05:19:55PM +0000, James Clark wrote: >> MMAP records that occur after the build-id header is parsed do not have >> their build-id set even if the filename matches an entry from the >> header. Set the build-id on these dsos as long as the MMAP record >> doesn't have its own build-id set. >> >> This fixes an issue with off target analysis where the local version of >> a dso is loaded rather than one from ~/.debug via a build-id. > > nice catch :) > >> >> Reported-by: Denis Nikitin <denik(a)chromium.org> >> Signed-off-by: James Clark <james.clark(a)arm.com> >> --- >> tools/perf/util/dso.h | 1 + >> tools/perf/util/header.c | 1 + >> tools/perf/util/map.c | 16 ++++++++++++++-- >> 3 files changed, 16 insertions(+), 2 deletions(-) >> >> diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h >> index 011da3924fc1..3a9fd4d389b5 100644 >> --- a/tools/perf/util/dso.h >> +++ b/tools/perf/util/dso.h >> @@ -167,6 +167,7 @@ struct dso { >> enum dso_load_errno load_errno; >> u8 adjust_symbols:1; >> u8 has_build_id:1; >> + u8 header_build_id:1; >> u8 has_srcline:1; >> u8 hit:1; >> u8 annotate_warned:1; >> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c >> index 6da12e522edc..571d73d4f976 100644 >> --- a/tools/perf/util/header.c >> +++ b/tools/perf/util/header.c >> @@ -2200,6 +2200,7 @@ static int __event_process_build_id(struct perf_record_header_build_id *bev, >> >> build_id__init(&bid, bev->data, size); >> dso__set_build_id(dso, &bid); >> + dso->header_build_id = 1; >> >> if (dso_space != DSO_SPACE__USER) { >> struct kmod_path m = { .name = NULL, }; >> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c >> index 1803d3887afe..4ae91e491e23 100644 >> --- a/tools/perf/util/map.c >> +++ b/tools/perf/util/map.c >> @@ -127,7 +127,7 @@ struct map *map__new(struct machine *machine, u64 start, u64 len, >> >> if (map != NULL) { >> char newfilename[PATH_MAX]; >> - struct dso *dso; >> + struct dso *dso, *header_bid_dso; >> int anon, no_dso, vdso, android; >> >> android = is_android_lib(filename); >> @@ -185,7 +185,19 @@ struct map *map__new(struct machine *machine, u64 start, u64 len, >> >> if (build_id__is_defined(bid)) >> dso__set_build_id(dso, bid); >> - >> + else { > > nit please add { } to the if clause as well > >> + /* >> + * If the mmap event had no build ID, search for an existing dso from the >> + * build ID header by name. Otherwise only the dso loaded at the time of >> + * reading the header will have the build ID set and all future mmaps will >> + * have it missing. >> + */ >> + header_bid_dso = __dsos__find(&machine->dsos, filename, false); > > is this 'perf top' safe? I think dso should be added in the > same thread, but please check and add comment why we don't > need locking in here Seems like there are multiple synthesize_threads_workers using the same machine->dsos object so I think locking is needed. At first I thought of doing this: diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index 4ae91e491e23..b87b81e3d41c 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -192,7 +192,9 @@ struct map *map__new(struct machine *machine, u64 start, u64 len, * reading the header will have the build ID set and all future mmaps will * have it missing. */ + down_read(&machine->dsos.lock); header_bid_dso = __dsos__find(&machine->dsos, filename, false); + up_read(&machine->dsos.lock); if (header_bid_dso && header_bid_dso->header_build_id) { dso__set_build_id(dso, &header_bid_dso->bid); dso->header_build_id = 1; But then I was wondering why it doesn't need a write lock all the way from machine__findnew_dso_id() to dso__put()? At the moment there are writes to the dso like dso__set_loaded(), dso->nsinfo = nsi and dso__set_build_id(), so another thread could find the dso in a partially constructed state. Not sure if this is an issue currently without my patch, but at least with it they would have to be found with header_build_id already set to 1 otherwise it will mess things up. Extending the write lock outside of machine__findnew_dso_id() is difficult because it already releases it before it returns. Does it need to be changed so that machine__findnew_dso_id() takes all the arguments needed to construct it inside the lock? James > > thanks, > jirka > >> + if (header_bid_dso && header_bid_dso->header_build_id) { >> + dso__set_build_id(dso, &header_bid_dso->bid); >> + dso->header_build_id = 1; >> + } >> + } >> dso__put(dso); >> } >> return map; >> -- >> 2.28.0 >>

3 years, 8 months

Re: [PATCH] coresight: core: Fix coresight device probe failure issue

by Suzuki K Poulose

On 02/03/2022 08:01, Mao Jinlong wrote: > It is possibe that probe failure issue happens when the device > and its child_device's probe happens at the same time. > In coresight_make_links, has_conns_grp is true for parent, but > has_conns_grp is false for child device as has_conns_grp is set > to true in coresight_create_conns_sysfs_group. The probe of parent > device will fail at this condition. Add has_conns_grp check for > child device before make the links and make the process from > device_register to connection_create be atomic to avoid this > probe failure issue. > > Suggested-by: Suzuki K Poulose <suzuki.poulose(a)arm.com> > Suggested-by: Mike Leach <mike.leach(a)linaro.org> > Signed-off-by: Mao Jinlong <quic_jinlmao(a)quicinc.com> > --- > drivers/hwtracing/coresight/coresight-core.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c > index 88653d1c06a4..7ce78dddfe31 100644 > --- a/drivers/hwtracing/coresight/coresight-core.c > +++ b/drivers/hwtracing/coresight/coresight-core.c > @@ -1382,7 +1382,7 @@ static int coresight_fixup_device_conns(struct coresight_device *csdev) > continue; > conn->child_dev = > coresight_find_csdev_by_fwnode(conn->child_fwnode); > - if (conn->child_dev) { > + if (conn->child_dev && conn->child_dev->has_conns_grp) { > ret = coresight_make_links(csdev, conn, > conn->child_dev); > if (ret) > @@ -1619,6 +1619,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) > csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev)); > dev_set_name(&csdev->dev, "%s", desc->name); > > + mutex_lock(&coresight_mutex); > ret = device_register(&csdev->dev); > if (ret) { > put_device(&csdev->dev); > @@ -1645,8 +1646,6 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) > } > } > > - mutex_lock(&coresight_mutex); > - > ret = coresight_create_conns_sysfs_group(csdev); > if (!ret) > ret = coresight_fixup_device_conns(csdev); > @@ -1666,6 +1665,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) > err_free_csdev: > kfree(csdev); > err_out: > + mutex_unlock(&coresight_mutex); This appears to be wrong. We may do an unlock when we didn't lock it in the first place. Please could you double check. Also, I think it may be neater to move the kfree(csdev) to the only user and return straight away from there. Cheers Suzuki > /* Cleanup the connection information */ > coresight_release_platform_data(NULL, desc->pdata); > return ERR_PTR(ret);

3 years, 8 months

Re: [PATCH] coresight: Defer probe when the child dev is not probed

by Suzuki K Poulose

Hi On 01/03/2022 13:30, Jinlong Mao wrote: > Hi Mike, > > On 3/1/2022 9:15 PM, Mike Leach wrote: >> Hi, >> >> On Tue, 1 Mar 2022 at 11:42, Jinlong Mao <quic_jinlmao(a)quicinc.com> >> wrote: >>> On 2/28/2022 10:51 PM, Suzuki K Poulose wrote: >>> ... >>> >>> Hi Suzuki, >>> >>> This issue happens when race condition happens. >>> The condition is that the device and its child_device's probe happens >>> at the same time. >>> >>> For example: device0 and its child device device1. >>> Both of them are calling coresight_register function. device0 is >>> calling coresight_fixup_device_conns. >>> device1 is waiting for device0 to release the coresight_mutex. >>> Because device1's csdev node is allocated, >>> coresight_make_links will be called for device0. Then in >>> coresight_add_sysfs_link, has_conns_grp is true >>> for device0, but has_conns_grp is false for device1 as has_conns_grp >>> is set to true in coresight_create_conns_sysfs_group . >>> The probe of device0 will fail for at this condition. >>> >>> >>> struct coresight_device *coresight_register(struct coresight_desc *desc) >>> { >>> ......... >>> mutex_lock(&coresight_mutex); >>> >>> ret = coresight_create_conns_sysfs_group(csdev); >>> if (!ret) >>> ret = coresight_fixup_device_conns(csdev); >>> if (!ret) >>> ret = coresight_fixup_orphan_conns(csdev); >>> if (!ret && cti_assoc_ops && cti_assoc_ops->add) >>> cti_assoc_ops->add(csdev); >>> >>> mutex_unlock(&coresight_mutex); >>> >>> ......... >>> >>> } >>> >>> static int coresight_fixup_device_conns(struct coresight_device *csdev) >>> { >>> .......... >>> conn->child_dev = >>> coresight_find_csdev_by_fwnode(conn->child_fwnode); >> The issue appears to be a constraint hidden in the lower layers of the >> code. >> Would a better solution not be to alter the code here: >> >> if (conn->child_dev && conn->child_dev->has_conns_grp) { >> ... >> } else { >> csdev->orphan = true; >> } >> >> which would mean that the connection attempt would drop through to >> label the connection as an orphan, to be cleaned up by the child >> itself when it runs coresight_fixup_orphan_conns() >> Tnanks Mike, I think that is a good solution. Alternatively, we could make sure that device_register() and the fixup following that are atomic. i.e. mutex_lock() device_register() fixup_connections() create_sysfs() mutex_unlock(); The fix may be a bit invasive than Mike's proposal, but it makes sure we don't end up with half baked device on the coresight-bus. Suzuki

3 years, 8 months

Re: [PATCH] coresight: Defer probe when the child dev is not probed

by Mike Leach

Hi, On Tue, 1 Mar 2022 at 11:42, Jinlong Mao <quic_jinlmao(a)quicinc.com> wrote: > > On 2/28/2022 10:51 PM, Suzuki K Poulose wrote: > > Hi Jinlong > > On 28/02/2022 13:31, Mao Jinlong wrote: > > From: Mao Jinlong <jinlmao(a)qti.qualcomm.com> > > It is possible that when device probe, its child device is not > probed. Then it will fail when add sysfs connection for the device. > Make device defer probe when the child device is not probed. > > > Please could you a bit a more specific on the exact issue ? > I don't see a problem with probe deferral right now, with > coresight/next. > > For e.g., > > root@juno-server:~# lsmod > Module Size Used by > coresight 73728 0 > root@juno-server:~# ls /sys/bus/coresight/devices/ > root@juno-server:~# modprobe coresight-etm4x > root@juno-server:~# lsmod > Module Size Used by > coresight_etm4x 81920 0 > coresight 73728 1 coresight_etm4x > root@juno-server:~# ls /sys/bus/coresight/devices/ > etm0 etm1 > > -- Note etm2-etm5 doesn't appear -- > > root@juno-server:~# modprobe coresight-funnel > root@juno-server:~# lsmod > Module Size Used by > coresight_funnel 20480 0 > coresight_etm4x 81920 0 > coresight 73728 2 coresight_etm4x,coresight_funnel > root@juno-server:~# ls /sys/bus/coresight/devices/ > etm0 etm1 > > -- Still don't appear --- > > root@juno-server:~# modprobe coresight-replicator > root@juno-server:~# ls /sys/bus/coresight/devices/ > etm0 etm1 > root@juno-server:~# modprobe coresight-tmc > > -- At this stage, the devices automatically get probed and appear -- > root@juno-server:~# ls /sys/bus/coresight/devices/ > etm0 etm1 etm2 etm3 etm4 etm5 funnel0 funnel1 funnel2 tmc_etf0 tmc_etr0 > > > root@juno-server:~# lsmod > Module Size Used by > coresight_tmc 40960 0 > coresight_replicator 20480 0 > coresight_funnel 20480 0 > coresight_etm4x 81920 0 > coresight 73728 4 coresight_tmc,coresight_etm4x,coresight_replicator,coresight_funnel > > So, my question is, what is this patch trying to solve ? > > > Cheers > Suzuki > > Hi Suzuki, > > This issue happens when race condition happens. > The condition is that the device and its child_device's probe happens at the same time. > > For example: device0 and its child device device1. > Both of them are calling coresight_register function. device0 is calling coresight_fixup_device_conns. > device1 is waiting for device0 to release the coresight_mutex. Because device1's csdev node is allocated, > coresight_make_links will be called for device0. Then in coresight_add_sysfs_link, has_conns_grp is true > for device0, but has_conns_grp is false for device1 as has_conns_grp is set to true in coresight_create_conns_sysfs_group . > The probe of device0 will fail for at this condition. > > > struct coresight_device *coresight_register(struct coresight_desc *desc) > { > ......... > mutex_lock(&coresight_mutex); > > ret = coresight_create_conns_sysfs_group(csdev); > if (!ret) > ret = coresight_fixup_device_conns(csdev); > if (!ret) > ret = coresight_fixup_orphan_conns(csdev); > if (!ret && cti_assoc_ops && cti_assoc_ops->add) > cti_assoc_ops->add(csdev); > > mutex_unlock(&coresight_mutex); > > ......... > > } > > static int coresight_fixup_device_conns(struct coresight_device *csdev) > { > .......... > conn->child_dev = > coresight_find_csdev_by_fwnode(conn->child_fwnode); The issue appears to be a constraint hidden in the lower layers of the code. Would a better solution not be to alter the code here: if (conn->child_dev && conn->child_dev->has_conns_grp) { ... } else { csdev->orphan = true; } which would mean that the connection attempt would drop through to label the connection as an orphan, to be cleaned up by the child itself when it runs coresight_fixup_orphan_conns() Regards Mike > if (conn->child_dev) { > ret = coresight_make_links(csdev, conn, > > conn->child_dev); > > .......... > > } > > > int coresight_add_sysfs_link(struct coresight_sysfs_link *info) > { > ................ > if (!info->orig->has_conns_grp || !info->target->has_conns_grp) > return -EINVAL; > > > > The probe fail issue is reproduced with reboot stress test on our internal device. > > With the patch, the probe fail issue is not reproduced. > > Thanks > > Jinlong Mao > > > > Signed-off-by: Mao Jinlong <jinlmao(a)qti.qualcomm.com> > --- > drivers/hwtracing/coresight/coresight-sysfs.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c > index 34d2a2d31d00..7df9eb59bf2c 100644 > --- a/drivers/hwtracing/coresight/coresight-sysfs.c > +++ b/drivers/hwtracing/coresight/coresight-sysfs.c > @@ -73,8 +73,10 @@ int coresight_add_sysfs_link(struct coresight_sysfs_link *info) > if (!info->orig || !info->target || > !info->orig_name || !info->target_name) > return -EINVAL; > - if (!info->orig->has_conns_grp || !info->target->has_conns_grp) > + if (!info->orig->has_conns_grp) > return -EINVAL; > + if (!info->target->has_conns_grp) > + return -EPROBE_DEFER; > /* first link orig->target */ > ret = sysfs_add_link_to_group(&info->orig->dev.kobj, > > -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK

3 years, 8 months

OpenCSD Release v1.2.1

by Mike Leach

OpenCSD v1.2.1 has been released. This contains a bugfix affecting the sequencing of output packets around context updates - which can affect clients ability to provide correct memory images to the library in certain circumstances. Mike -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK

3 years, 8 months

[PATCH] coresight: Drop unused 'none' enum value for each component

by Anshuman Khandual

CORESIGHT_DEV_TYPE_NONE/CORESIGHT_DEV_SUBTYPE_XXXX_NONE values are not used any where. Actual enumeration can start from 0. Just drop these unused enum values. Cc: Mathieu Poirier <mathieu.poirier(a)linaro.org> Cc: Suzuki K Poulose <suzuki.poulose(a)arm.com> Cc: Mike Leach <mike.leach(a)linaro.org> Cc: Leo Yan <leo.yan(a)linaro.org> Cc: coresight(a)lists.linaro.org Cc: linux-arm-kernel(a)lists.infradead.org Cc: linux-kernel(a)vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khandual(a)arm.com> --- drivers/hwtracing/coresight/coresight-core.c | 3 --- include/linux/coresight.h | 5 ----- 2 files changed, 8 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 88653d1c06a4..af00dca8d1ac 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -1278,9 +1278,6 @@ static struct attribute *coresight_source_attrs[] = { ATTRIBUTE_GROUPS(coresight_source); static struct device_type coresight_dev_type[] = { - { - .name = "none", - }, { .name = "sink", .groups = coresight_sink_groups, diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 93a2922b7653..9f445f09fcfe 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -36,7 +36,6 @@ extern struct bus_type coresight_bustype; enum coresight_dev_type { - CORESIGHT_DEV_TYPE_NONE, CORESIGHT_DEV_TYPE_SINK, CORESIGHT_DEV_TYPE_LINK, CORESIGHT_DEV_TYPE_LINKSINK, @@ -46,7 +45,6 @@ enum coresight_dev_type { }; enum coresight_dev_subtype_sink { - CORESIGHT_DEV_SUBTYPE_SINK_NONE, CORESIGHT_DEV_SUBTYPE_SINK_PORT, CORESIGHT_DEV_SUBTYPE_SINK_BUFFER, CORESIGHT_DEV_SUBTYPE_SINK_SYSMEM, @@ -54,21 +52,18 @@ enum coresight_dev_subtype_sink { }; enum coresight_dev_subtype_link { - CORESIGHT_DEV_SUBTYPE_LINK_NONE, CORESIGHT_DEV_SUBTYPE_LINK_MERG, CORESIGHT_DEV_SUBTYPE_LINK_SPLIT, CORESIGHT_DEV_SUBTYPE_LINK_FIFO, }; enum coresight_dev_subtype_source { - CORESIGHT_DEV_SUBTYPE_SOURCE_NONE, CORESIGHT_DEV_SUBTYPE_SOURCE_PROC, CORESIGHT_DEV_SUBTYPE_SOURCE_BUS, CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE, }; enum coresight_dev_subtype_helper { - CORESIGHT_DEV_SUBTYPE_HELPER_NONE, CORESIGHT_DEV_SUBTYPE_HELPER_CATU, }; -- 2.20.1

3 years, 8 months

Re: [PATCH] coresight: Defer probe when the child dev is not probed

by Suzuki K Poulose

Hi Jinlong On 28/02/2022 13:31, Mao Jinlong wrote: > From: Mao Jinlong <jinlmao(a)qti.qualcomm.com> > > It is possible that when device probe, its child device is not > probed. Then it will fail when add sysfs connection for the device. > Make device defer probe when the child device is not probed. Please could you a bit a more specific on the exact issue ? I don't see a problem with probe deferral right now, with coresight/next. For e.g., root@juno-server:~# lsmod Module Size Used by coresight 73728 0 root@juno-server:~# ls /sys/bus/coresight/devices/ root@juno-server:~# modprobe coresight-etm4x root@juno-server:~# lsmod Module Size Used by coresight_etm4x 81920 0 coresight 73728 1 coresight_etm4x root@juno-server:~# ls /sys/bus/coresight/devices/ etm0 etm1 -- Note etm2-etm5 doesn't appear -- root@juno-server:~# modprobe coresight-funnel root@juno-server:~# lsmod Module Size Used by coresight_funnel 20480 0 coresight_etm4x 81920 0 coresight 73728 2 coresight_etm4x,coresight_funnel root@juno-server:~# ls /sys/bus/coresight/devices/ etm0 etm1 -- Still don't appear --- root@juno-server:~# modprobe coresight-replicator root@juno-server:~# ls /sys/bus/coresight/devices/ etm0 etm1 root@juno-server:~# modprobe coresight-tmc -- At this stage, the devices automatically get probed and appear -- root@juno-server:~# ls /sys/bus/coresight/devices/ etm0 etm1 etm2 etm3 etm4 etm5 funnel0 funnel1 funnel2 tmc_etf0 tmc_etr0 root@juno-server:~# lsmod Module Size Used by coresight_tmc 40960 0 coresight_replicator 20480 0 coresight_funnel 20480 0 coresight_etm4x 81920 0 coresight 73728 4 coresight_tmc,coresight_etm4x,coresight_replicator,coresight_funnel So, my question is, what is this patch trying to solve ? Cheers Suzuki > > Signed-off-by: Mao Jinlong <jinlmao(a)qti.qualcomm.com> > --- > drivers/hwtracing/coresight/coresight-sysfs.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c > index 34d2a2d31d00..7df9eb59bf2c 100644 > --- a/drivers/hwtracing/coresight/coresight-sysfs.c > +++ b/drivers/hwtracing/coresight/coresight-sysfs.c > @@ -73,8 +73,10 @@ int coresight_add_sysfs_link(struct coresight_sysfs_link *info) > if (!info->orig || !info->target || > !info->orig_name || !info->target_name) > return -EINVAL; > - if (!info->orig->has_conns_grp || !info->target->has_conns_grp) > + if (!info->orig->has_conns_grp) > return -EINVAL; > + if (!info->target->has_conns_grp) > + return -EPROBE_DEFER; > > /* first link orig->target */ > ret = sysfs_add_link_to_group(&info->orig->dev.kobj,

3 years, 8 months

[PATCH v2 RESEND 0/4] coresight: etm: Correct PID tracing for non-root namespace

by Leo Yan

If a profiling program runs in a non-root PID namespace and CoreSight driver enables PID tracing (with contextID), it can lead to mismatching issue between the context ID traced in hardware (from the root namespace) and the PIDs gathered by profiling tool (e.g. perf) in its non-root namespace. CoreSight driver has tried to address this issue for the contextID related interfaces under sysfs, but it misses to prevent user to set VMID (virtual contextID) for kernel runs in EL2 with VHE; furthermore, it misses to handle the case when the profiling tool runs in the non-root PID namespace. For this reason, this patch series is to correct contextID tracing for non-root namespace. After applied this patchset, patch 02 doesn't permit users to access virtual contextID via sysfs nodes in the non-root PID namespace, patch 03 and 04 stop to trace PID packet for non-root PID namespace. This patch series has been rebased on the mainline kernel and applied cleanly on latest commit dcb85f85fa6f ("gcc-plugins/stackleak: Use noinstr in favor of notrace"). Leo Yan (4): coresight: etm4x: Add lock for reading virtual context ID comparator coresight: etm4x: Don't use virtual contextID for non-root PID namespace coresight: etm4x: Don't trace PID for non-root PID namespace coresight: etm3x: Don't trace PID for non-root PID namespace .../coresight/coresight-etm3x-core.c | 4 +++ .../coresight/coresight-etm4x-core.c | 10 +++++-- .../coresight/coresight-etm4x-sysfs.c | 30 +++++++++++++++++++ 3 files changed, 42 insertions(+), 2 deletions(-) -- 2.25.1

3 years, 8 months

Re: [PATCH v2 01/15] coresight: Make ETM4x TRCIDR0 register accesses consistent with sysreg.h

by Suzuki K Poulose

On 07/02/2022 05:44, Anshuman Khandual wrote: > Hi James, > > These are all ETM4X specific changes. Something like this might be cleaner > and also more compact. Also would suggest to follow the same for subsequent > patches as well. > > coresight: etm4x: Cleanup TRCIDR0 register accesses > > Consistency with sysreg.h could be mentioned in the commit message itself. > > On 2/3/22 5:35 PM, James Clark wrote: >> This is a no-op change for style and consistency and has no effect on the >> binary produced by gcc-11. > > This patch adds register definitions, helper macros as well. Please expand > the commit message to add more details. This is too short, for the change > it creates. BTW why is it necessary to mention GCC version number here. > >> >> Signed-off-by: James Clark <james.clark(a)arm.com> >> --- >> .../coresight/coresight-etm4x-core.c | 36 +++++-------------- >> drivers/hwtracing/coresight/coresight-etm4x.h | 17 +++++++++ >> drivers/hwtracing/coresight/coresight-priv.h | 5 +++ >> 3 files changed, 30 insertions(+), 28 deletions(-) >> >> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c >> index e2eebd865241..107e81948f76 100644 >> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c >> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c >> @@ -1091,41 +1091,21 @@ static void etm4_init_arch_data(void *info) >> etmidr0 = etm4x_relaxed_read32(csa, TRCIDR0); >> >> /* INSTP0, bits[2:1] P0 tracing support field */ >> - if (BMVAL(etmidr0, 1, 2) == 0b11) >> - drvdata->instrp0 = true; >> - else >> - drvdata->instrp0 = false; >> - >> + drvdata->instrp0 = !!(REG_VAL(etmidr0, TRCIDR0_INSTP0) == 0b11); >> /* TRCBB, bit[5] Branch broadcast tracing support bit */ >> - if (BMVAL(etmidr0, 5, 5)) >> - drvdata->trcbb = true; >> - else >> - drvdata->trcbb = false; >> - >> + drvdata->trcbb = !!(etmidr0 & TRCIDR0_TRCBB); >> /* TRCCOND, bit[6] Conditional instruction tracing support bit */ >> - if (BMVAL(etmidr0, 6, 6)) >> - drvdata->trccond = true; >> - else >> - drvdata->trccond = false; >> - >> + drvdata->trccond = !!(etmidr0 & TRCIDR0_TRCCOND); >> /* TRCCCI, bit[7] Cycle counting instruction bit */ >> - if (BMVAL(etmidr0, 7, 7)) >> - drvdata->trccci = true; >> - else >> - drvdata->trccci = false; >> - >> + drvdata->trccci = !!(etmidr0 & TRCIDR0_TRCCCI); >> /* RETSTACK, bit[9] Return stack bit */ >> - if (BMVAL(etmidr0, 9, 9)) >> - drvdata->retstack = true; >> - else >> - drvdata->retstack = false; >> - >> + drvdata->retstack = !!(etmidr0 & TRCIDR0_RETSTACK); >> /* NUMEVENT, bits[11:10] Number of events field */ >> - drvdata->nr_event = BMVAL(etmidr0, 10, 11); >> + drvdata->nr_event = REG_VAL(etmidr0, TRCIDR0_NUMEVENT); >> /* QSUPP, bits[16:15] Q element support field */ >> - drvdata->q_support = BMVAL(etmidr0, 15, 16); >> + drvdata->q_support = REG_VAL(etmidr0, TRCIDR0_QSUPP); >> /* TSSIZE, bits[28:24] Global timestamp size field */ >> - drvdata->ts_size = BMVAL(etmidr0, 24, 28); >> + drvdata->ts_size = REG_VAL(etmidr0, TRCIDR0_TSSIZE); >> >> /* maximum size of resources */ >> etmidr2 = etm4x_relaxed_read32(csa, TRCIDR2); >> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h >> index 3c4d69b096ca..2bd8ad953b8e 100644 >> --- a/drivers/hwtracing/coresight/coresight-etm4x.h >> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h >> @@ -130,6 +130,23 @@ >> >> #define TRCRSR_TA BIT(12) >> >> +/* >> + * Bit positions of registers that are defined above, in the sysreg.h style >> + * of _MASK, _SHIFT and BIT(). >> + */ > > ^^^ not really necessary. Instead the format requirement for below mentioned > CORESIGHT_REG_VAL() macro might be relevant and should be mentioned. > >> +#define TRCIDR0_INSTP0_SHIFT 1 >> +#define TRCIDR0_INSTP0_MASK GENMASK(1, 0) >> +#define TRCIDR0_TRCBB BIT(5) >> +#define TRCIDR0_TRCCOND BIT(6) >> +#define TRCIDR0_TRCCCI BIT(7) >> +#define TRCIDR0_RETSTACK BIT(9) >> +#define TRCIDR0_NUMEVENT_SHIFT 10 >> +#define TRCIDR0_NUMEVENT_MASK GENMASK(1, 0) >> +#define TRCIDR0_QSUPP_SHIFT 15 >> +#define TRCIDR0_QSUPP_MASK GENMASK(1, 0) >> +#define TRCIDR0_TSSIZE_SHIFT 24 >> +#define TRCIDR0_TSSIZE_MASK GENMASK(4, 0) >> + >> /* >> * System instructions to access ETM registers. >> * See ETMv4.4 spec ARM IHI0064F section 4.3.6 System instructions >> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h >> index ff1dd2092ac5..1452c6038421 100644 >> --- a/drivers/hwtracing/coresight/coresight-priv.h >> +++ b/drivers/hwtracing/coresight/coresight-priv.h >> @@ -36,6 +36,11 @@ >> >> #define TIMEOUT_US 100 >> #define BMVAL(val, lsb, msb) ((val & GENMASK(msb, lsb)) >> lsb) >> +/* >> + * Extract a field from a register where field is #defined in the form >> + * <register_name>_<field_name>_MASK and <register_name>_<field_name>_SHIFT >> + */ > > Looking at the usage, <register_name> is already embedded in <filed_name>. So > it requires <field_name>_SHIFT and <field_name>_MASK instead. Unless register > name should be passed as separate argument (which actually might be better). > > REG_VAL(etmidr0, TRCIDR0_TSSIZE) ----> REG_VAL(etmidr0, TRCIDR0, TSSIZE) I don't see much difference here. So I am fine either way. > > with some restructuring in the comment .. > > /* > * Extract a field from a coresight register > * > * Required fields are defined as macros like the following > * > * <register_name>_<field_name>_MASK and <register_name>_<field_name>_SHIFT > */ > >> +#define REG_VAL(val, field) ((val & (field##_MASK << field##_SHIFT)) >> field##_SHIFT) > > This is too generic to be in a coresight header or it should just be > named CORESIGHT_REG_VAL() instead, making it more specific for here. > > The build should fail in case any required macro definition is absent. > I guess no more fortification is required in case macros are missing. > > However CORESIGHT_REG_VAL() is better placed in <coresight-etm4x.h> > just before all the dependent SHIFT/MASK register field definition > starts. Not necessarily. CORESIGHT_REG_VAL() is a generic function and doesn't have anything specific to do with etm4x. We could reuse that for cleaning up other drivers in CoreSight. Cheers Suzuki

3 years, 8 months

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

CoreSight