This patch series is to correct the pointer usages for the snapshot
mode.
Patch 01 allows the AUX trace in the free run mode and only syncs the
AUX ring buffer when taking snapshot.
Patch 02 is to polish code, it removes the redundant header maintained
in tmc-etr driver and directly uses pointer perf_output_handle::head.
Patch 03 removes the callback cs_etm_find_snapshot() which wrongly
calculates the buffer headers; we can simply use the perf's common
function __auxtrace_mmap__read() for headers calculation.
This patch can be cleanly applied on the mainline kernel with:
commit 97e5bf604b7a ("Merge branch 'for-5.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu")
And it has been tested on Arm64 Juno board.
Leo Yan (3):
coresight: etm-perf: Correct buffer syncing for snapshot
coresight: tmc-etr: Use perf_output_handle::head for AUX ring buffer
perf cs-etm: Remove callback cs_etm_find_snapshot()
.../hwtracing/coresight/coresight-etm-perf.c | 30 +++-
.../hwtracing/coresight/coresight-etm-perf.h | 2 +
.../hwtracing/coresight/coresight-tmc-etr.c | 10 +-
tools/perf/arch/arm/util/cs-etm.c | 133 ------------------
4 files changed, 32 insertions(+), 143 deletions(-)
--
2.25.1
Hello everyone,
I'm interested in performing data value tracing using CoreSight. Do
you know a board offering this feature?
So far I know that data value tracing is supported by CoreSight in
Cortex-A5 and Cortex-A7, although there might be other cores too
(probably 32 bits). In case you have not dealt with data value tracing
before, do you know a board with accessible CoreSight components
featuring either Cortex-A5 or Cortex-A7?
Any help will be greatly appreciated.
Regards,
Farzam
Hi Jon,
This series contain the remaining 8 patches I submitted at v3 that
weren't merged yet at -next.
This series is rebased on the top of your docs-next branch.
No changes here, except by some Reviewed/ack lines, and at the
name of the final patch (per PCI maintainer's request).
Mauro Carvalho Chehab (8):
docs: admin-guide: reporting-issues.rst: replace some characters
docs: trace: coresight: coresight-etm4x-reference.rst: replace some
characters
docs: driver-api: ioctl.rst: replace some characters
docs: usb: replace some characters
docs: vm: zswap.rst: replace some characters
docs: filesystems: ext4: blockgroup.rst: replace some characters
docs: networking: device_drivers: replace some characters
docs: PCI: Replace non-breaking spaces to avoid PDF issues
Documentation/PCI/acpi-info.rst | 18 +++++++++---------
Documentation/admin-guide/reporting-issues.rst | 2 +-
Documentation/driver-api/ioctl.rst | 8 ++++----
Documentation/filesystems/ext4/blockgroup.rst | 2 +-
.../device_drivers/ethernet/intel/i40e.rst | 6 +++---
.../device_drivers/ethernet/intel/iavf.rst | 2 +-
.../coresight/coresight-etm4x-reference.rst | 2 +-
Documentation/usb/ehci.rst | 2 +-
Documentation/usb/gadget_printer.rst | 2 +-
Documentation/vm/zswap.rst | 4 ++--
10 files changed, 24 insertions(+), 24 deletions(-)
--
2.31.1
(Maintainers bcc, to avoid too many recipient troubles)
As discussed at:
https://lore.kernel.org/linux-doc/871r9k6rmy.fsf@meer.lwn.net/
It is better to avoid using :doc:`foo` to refer to Documentation/foo.rst, as the
automarkup.py extension should handle it automatically, on most cases.
There are a couple of exceptions to this rule:
1. when :doc: tag is used to point to a kernel-doc DOC: markup;
2. when it is used with a named tag, e. g. :doc:`some name <foo>`;
On this series:
Patch 1 manually adjust the references inside driver-api/pm/devices.rst,
as there it uses :file:`foo` to refer to some Documentation/ files;
Patch 2 converts a table at Documentation/dev-tools/kunit/api/index.rst
into a list, carefully avoiding the
The remaining patches convert the other occurrences via a replace script.
They were manually edited, in order to honour 80-columns where possible.
This series based on docs-next branch. In order to avoid merge conflicts,
I rebased it internally against yesterday's linux-next, dropping a patch
and a hunk that would have caused conflicts there.
I'll re-send the remaining patch (plus another patch) with conflicting
changes, together with any other doc:`filename` reference that might
still be upstream by 5.14-rc1.
---
v2:
- dropped media patches (as I merged via my own tree);
- removed one patch that would conflict at linux-next (adm1177.rst);
- removed one hunk fron kunit patch that would also conflict at
linux-next.
Mauro Carvalho Chehab (29):
docs: devices.rst: better reference documentation docs
docs: dev-tools: kunit: don't use a table for docs name
docs: admin-guide: pm: avoid using ReST :doc:`foo` markup
docs: admin-guide: hw-vuln: avoid using ReST :doc:`foo` markup
docs: admin-guide: sysctl: avoid using ReST :doc:`foo` markup
docs: block: biodoc.rst: avoid using ReST :doc:`foo` markup
docs: bpf: bpf_lsm.rst: avoid using ReST :doc:`foo` markup
docs: core-api: avoid using ReST :doc:`foo` markup
docs: dev-tools: testing-overview.rst: avoid using ReST :doc:`foo`
markup
docs: dev-tools: kunit: avoid using ReST :doc:`foo` markup
docs: devicetree: bindings: submitting-patches.rst: avoid using ReST
:doc:`foo` markup
docs: doc-guide: avoid using ReST :doc:`foo` markup
docs: driver-api: avoid using ReST :doc:`foo` markup
docs: driver-api: gpio: using-gpio.rst: avoid using ReST :doc:`foo`
markup
docs: driver-api: surface_aggregator: avoid using ReST :doc:`foo`
markup
docs: driver-api: usb: avoid using ReST :doc:`foo` markup
docs: firmware-guide: acpi: avoid using ReST :doc:`foo` markup
docs: i2c: avoid using ReST :doc:`foo` markup
docs: kernel-hacking: hacking.rst: avoid using ReST :doc:`foo` markup
docs: networking: devlink: avoid using ReST :doc:`foo` markup
docs: PCI: endpoint: pci-endpoint-cfs.rst: avoid using ReST :doc:`foo`
markup
docs: PCI: pci.rst: avoid using ReST :doc:`foo` markup
docs: process: submitting-patches.rst: avoid using ReST :doc:`foo`
markup
docs: security: landlock.rst: avoid using ReST :doc:`foo` markup
docs: trace: coresight: coresight.rst: avoid using ReST :doc:`foo`
markup
docs: trace: ftrace.rst: avoid using ReST :doc:`foo` markup
docs: userspace-api: landlock.rst: avoid using ReST :doc:`foo` markup
docs: virt: kvm: s390-pv-boot.rst: avoid using ReST :doc:`foo` markup
docs: x86: avoid using ReST :doc:`foo` markup
.../PCI/endpoint/pci-endpoint-cfs.rst | 2 +-
Documentation/PCI/pci.rst | 6 +--
.../special-register-buffer-data-sampling.rst | 3 +-
Documentation/admin-guide/pm/intel_idle.rst | 16 +++++---
Documentation/admin-guide/pm/intel_pstate.rst | 9 +++--
Documentation/admin-guide/sysctl/abi.rst | 2 +-
Documentation/admin-guide/sysctl/kernel.rst | 37 ++++++++++---------
Documentation/block/biodoc.rst | 2 +-
Documentation/bpf/bpf_lsm.rst | 13 ++++---
.../core-api/bus-virt-phys-mapping.rst | 2 +-
Documentation/core-api/dma-api.rst | 5 ++-
Documentation/core-api/dma-isa-lpc.rst | 2 +-
Documentation/core-api/index.rst | 4 +-
Documentation/dev-tools/kunit/api/index.rst | 8 ++--
Documentation/dev-tools/kunit/faq.rst | 2 +-
Documentation/dev-tools/kunit/index.rst | 14 +++----
Documentation/dev-tools/kunit/start.rst | 4 +-
Documentation/dev-tools/kunit/tips.rst | 5 ++-
Documentation/dev-tools/kunit/usage.rst | 8 ++--
Documentation/dev-tools/testing-overview.rst | 16 ++++----
.../bindings/submitting-patches.rst | 11 +++---
Documentation/doc-guide/contributing.rst | 8 ++--
Documentation/driver-api/gpio/using-gpio.rst | 4 +-
Documentation/driver-api/ioctl.rst | 2 +-
Documentation/driver-api/pm/devices.rst | 8 ++--
.../surface_aggregator/clients/index.rst | 3 +-
.../surface_aggregator/internal.rst | 15 ++++----
.../surface_aggregator/overview.rst | 6 ++-
Documentation/driver-api/usb/dma.rst | 6 +--
.../acpi/dsd/data-node-references.rst | 3 +-
.../firmware-guide/acpi/dsd/graph.rst | 2 +-
.../firmware-guide/acpi/enumeration.rst | 7 ++--
Documentation/i2c/instantiating-devices.rst | 2 +-
Documentation/i2c/old-module-parameters.rst | 3 +-
Documentation/i2c/smbus-protocol.rst | 4 +-
Documentation/kernel-hacking/hacking.rst | 4 +-
.../networking/devlink/devlink-region.rst | 2 +-
.../networking/devlink/devlink-trap.rst | 4 +-
Documentation/process/submitting-patches.rst | 32 ++++++++--------
Documentation/security/landlock.rst | 3 +-
Documentation/trace/coresight/coresight.rst | 8 ++--
Documentation/trace/ftrace.rst | 2 +-
Documentation/userspace-api/landlock.rst | 11 +++---
Documentation/virt/kvm/s390-pv-boot.rst | 2 +-
Documentation/x86/boot.rst | 4 +-
Documentation/x86/mtrr.rst | 2 +-
46 files changed, 171 insertions(+), 147 deletions(-)
--
2.31.1
Hi,
We are a group of researchers from NYU trying to bring up Coresight ETM
interfaces on ThunderX2.
So we dug out this old thread (
https://lists.linaro.org/pipermail/coresight/2018-August/001626.html) and
trying to get things spinning. We are current on Linux 5.12.9 kernel, but
it seems some of the DTS entries are missing from the upstream.
Just to be sure, would it be possible that you could share the DTS scripts?
Thank you!
Zhenghao
Changes since RFC v4:
* Style and indentation fixes
* Add a warning when the buffer isn't found (suggested by Leo)
* Undo change to set 'etm->data_queued'
* Replace 'matchesCpuPid' with early exit when CPU/TID doesn't match
* Check more return value errors
* Remove TODOs from commit message and code
* Add motivation to commit message
James Clark (1):
perf cs-etm: Split Coresight decode by aux records
tools/perf/util/cs-etm.c | 158 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 157 insertions(+), 1 deletion(-)
--
2.28.0
Hardware assisted tracing families such as ARM Coresight, Intel PT
provides rich tracing capabilities including instruction level
tracing and accurate timestamps which are very useful for profiling
and also pose a significant security risk. One such example of
security risk is when kernel mode tracing is not excluded and these
hardware assisted tracing can be used to analyze cryptographic code
execution. In this case, even the root user must not be able to infer
anything.
To explain it more clearly in the words of a security team member
(credits: Mattias Nissler),
"Consider a system where disk contents are encrypted and the encryption
key is set up by the user when mounting the file system. From that point
on the encryption key resides in the kernel. It seems reasonable to
expect that the disk encryption key be protected from exfiltration even
if the system later suffers a root compromise (or even against insiders
that have root access), at least as long as the attacker doesn't
manage to compromise the kernel."
Here the idea is to protect such important information from all users
including root users since root privileges does not have to mean full
control over the kernel [1] and root compromise does not have to be
the end of the world.
But "Peter said even the regular counters can be used for full branch trace,
the information isn't as accurate as PT and friends and not easier but
is good enough to infer plenty". This would mean that a global tunable
config for all kernel mode pmu tracing is more appropriate than the one
targeting the hardware assisted instruction tracing.
Currently we can exclude kernel mode tracing via perf_event_paranoid
sysctl but it has following limitations,
* No option to restrict kernel mode instruction tracing by the
root user.
* Not possible to restrict kernel mode instruction tracing when the
hardware assisted tracing IPs like ARM Coresight ETMs use an
additional interface via sysfs for tracing in addition to perf
interface.
So introduce a new config CONFIG_EXCLUDE_KERNEL_PMU_TRACE to exclude
kernel mode pmu tracing for all users including root which will be
generic and applicable to all hardware tracing families and which
can also be used with other interfaces like sysfs in case of ETMs.
Patch 1 adds this new config and the support in perf core to exclude
all kernel mode PMU tracing.
Patch 2 adds the perf evsel warning message when the perf tool users
attempt to perform a kernel mode trace with the config enabled to
exclude the kernel mode tracing.
Patch 3 and Patch 4 adds the support for excluding kernel mode for
ARM Coresight ETM{4,3}XX sysfs mode using the newly introduced generic
config.
[1] https://lwn.net/Articles/796866/
Changes in v2:
* Move from kernel mode instruction tracing to all kernel level PMU tracing (Peter)
* Move the check and warning to the caller mode_store() (Doug)
Sai Prakash Ranjan (4):
perf/core: Add support to exclude kernel mode PMU tracing
perf evsel: Print warning for excluding kernel mode instruction
tracing
coresight: etm4x: Add support to exclude kernel mode tracing
coresight: etm3x: Add support to exclude kernel mode tracing
drivers/hwtracing/coresight/coresight-etm3x-core.c | 3 +++
drivers/hwtracing/coresight/coresight-etm3x-sysfs.c | 6 ++++++
drivers/hwtracing/coresight/coresight-etm4x-core.c | 6 +++++-
drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 6 ++++++
init/Kconfig | 11 +++++++++++
kernel/events/core.c | 3 +++
tools/perf/util/evsel.c | 3 ++-
7 files changed, 36 insertions(+), 2 deletions(-)
--
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