CoreSight November 2024

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[PATCH v11 0/8] Coresight for Kernel panic and watchdog reset

by Linu Cherian

This patch series is rebased on coresight-next-v6.12.rc4 * Patches 1 & 2 adds support for allocation of trace buffer pages from reserved RAM * Patches 3 & 4 adds support for saving metadata at the time of kernel panic * Patch 5 adds support for reading trace data captured at the time of panic * Patches 6 & 7 adds support for disabling coresight blocks at the time of panic * Patch 8: Gives the full description about this feature as part of documentation V10 is posted here, https://lore.kernel.org/linux-arm-kernel/20240916103437.226816-1-lcherian@m… Changelog from v10: * Converted all csdev_access_* to readl functions in tmc_panic_sync_* * Added "tmc" prefix for register snapshots in struct tmc_crash_metadata * Converted dev_info to dev_dbg in panic handlers * Converted dsb to dmb in panic handlers * Fixed marking metadata as invalid when a user is trying to use the reserved buffer. Earlier this was wrongly set at the time of reading reserved trace buffer. * Moved common validation checks to is_tmc_crashdata_valid and minor code rearrangements for efficiency * Got rid of sink specific prepare/unprepare invocations * Got rid of full from struct tmc_resrv_buf * While reading crashdata, size is now calculated from metdata instead of relying on reserved buffer size populated by dtb * Minor documenation fixes Changelog from v9: * Add common helper function of_tmc_get_reserved_resource_by_name for better code reuse * Reserved buffer validity and crashdata validity has been separated to avoid interdependence * New fields added to crash metadata: version, ffcr, ffsr, mode * Version checks added for metadata validation * Special file /dev/crash_tmc_xxx would be available only when crash metadata is valid * Removed READ_CRASHDATA mode meant for special casing crashdata reads. Instead, dedicated read function added for crashdata reads from reserved buffer which is common for both ETR and ETF sinks as well. * Documentation added to Documentation/tracing/coresight/panic.rst Changelog from v8: * Added missing exit path on error in __tmc_probe. * Few whitespace fixes, checkpatch fixes. * With perf sessions honouring stop_on_flush sysfs attribute, removed redundant variable stop_on_flush_en. Changelog from v7: * Fixed breakage on perf test -vvvv "arm coresight". No issues seen with and without "resrv" buffer mode * Moved the crashdev registration into a separate function. * Removed redundant variable in tmc_etr_setup_crashdata_buf * Avoided a redundant memcpy in tmc_panic_sync_etf. * Tested kernel panic with trace session started uisng perf. Please see the title "Perf based testing" below for details. For this, stop_on_flush sysfs attribute is taken into consideration while starting perf sessions as well. Changelog from v6: * Added special device files for reading crashdata, so that read_prevboot mode flag is removed. * Added new sysfs TMC device attribute, stop_on_flush. Stop on flush trigger event is disabled by default. User need to explicitly enable this from sysfs for panic stop to work. * Address parameter for panicstop ETM configuration is chosen as kernel "panic" address by default. * Added missing tmc_wait_for_tmcready during panic handling * Few other misc code rearrangements. Changelog from v5: * Fixed issues reported by CONFIG_DEBUG_ATOMIC_SLEEP * Fixed a memory leak while reading data from /dev/tmc_etrx in READ_PREVBOOT mode * Tested reading trace data from crashdump kernel Changelog from v4: * Device tree binding - Description is made more explicit on the usage of reserved memory region - Mismatch in memory region names in dts binding and driver fixed - Removed "mem" suffix from the memory region names * Rename "struct tmc_register_snapshot" -> "struct tmc_crash_metadata", since it contains more than register snapshot. Related variables are named accordingly. * Rename struct tmc_drvdata members resrv_buf -> crash_tbuf metadata -> crash_mdata * Size field in metadata refers to RSZ register and hence indicates the size in 32 bit words. ETR metadata follows this convention, the same has been extended to ETF metadata as well. * Added crc32 for more robust metadata and tracedata validation. * Added/modified dev_dbg messages during metadata validation * Fixed a typo in patch 5 commit description Changelog from v3: * Converted the Coresight ETM driver change to a named configuration. RFC tag has been removed with this change. * Fixed yaml issues reported by "make dt_binding_check" * Added names for reserved memory regions 0 and 1 * Added prevalidation checks for metadata processing * Fixed a regression introduced in RFC v3 - TMC Status register was getting saved wrongly * Reverted memremap attribute changes from _WB to _WC to match with the dma map attributes * Introduced reserved buffer mode specific .sync op. This fixes a possible crash when reserved buffer mode was used in normal trace capture, due to unwanted dma maintenance operations. Linu Cherian (8): dt-bindings: arm: coresight-tmc: Add "memory-region" property coresight: tmc-etr: Add support to use reserved trace memory coresight: core: Add provision for panic callbacks coresight: tmc: Enable panic sync handling coresight: tmc: Add support for reading crash data coresight: tmc: Stop trace capture on FlIn coresight: config: Add preloaded configuration Documentation: coresight: Panic support .../bindings/arm/arm,coresight-tmc.yaml | 26 ++ Documentation/trace/coresight/panic.rst | 356 ++++++++++++++++++ drivers/hwtracing/coresight/Makefile | 2 +- .../coresight/coresight-cfg-preload.c | 2 + .../coresight/coresight-cfg-preload.h | 2 + .../hwtracing/coresight/coresight-cfg-pstop.c | 83 ++++ drivers/hwtracing/coresight/coresight-core.c | 42 +++ .../hwtracing/coresight/coresight-tmc-core.c | 326 +++++++++++++++- .../hwtracing/coresight/coresight-tmc-etf.c | 92 ++++- .../hwtracing/coresight/coresight-tmc-etr.c | 181 ++++++++- drivers/hwtracing/coresight/coresight-tmc.h | 104 +++++ include/linux/coresight.h | 12 + 12 files changed, 1216 insertions(+), 12 deletions(-) create mode 100644 Documentation/trace/coresight/panic.rst create mode 100644 drivers/hwtracing/coresight/coresight-cfg-pstop.c -- 2.34.1

5 months, 1 week

[PATCH V11 0/2] arm-cs-trace-disasm.py/perf must accommodate non-zero DSO text offset

by Steve Clevenger

Changes in V11: - Corrected prefix. - Fixed compile-time error for perf debug build by substituting in the map__pgoff macro (trace_event_python.c). Changes in V10: - Removed errant space in patch file 0002. Passed 'git apply --check' at perf-tools-next, 6.11.0-rc6. - Added back missing prefixes. Changes in V9: - Removed V8 patch files 1/4 and 2/4. - Modified set_sym_in_dict (trace-event-python.c) to add map_pgoff in dictionary as-is without regard to MAPPING_IDENTITY. This patch file is now patch 2/2. Changes in V8: - in arm-cs-trace-disasm.py, ensure map_pgoff is not converted to string. - Remove map_pgoff integer conversion in dso not found print message. Changes in V7: - In arm-cs-trace-disasm.py, fix print message core dump resulting from mixed type arithmetic. - Modify CS_ETM_TRACE_ON filter to filter zero start_addr. The CS_ETM_TRACE_ON message is changed to print only in verbose mode. - Removed verbose mode only notification for start_addr/stop_addr outside of dso address range. Changes in V6: - In arm-cs-trace-disasm.py, zero map_pgoff for kernel files. Add map_pgoff to start/end address for dso not found message. - Added "Reviewed-by" trailer for patches 1-3 previously reviewed by Leo Yan in V4 and V5. Changes in V5: - In symbol-elf.c, branch to exit_close label if open file. - In trace_event_python.c, correct indentation. set_sym_in_dict call parameter "map_pgoff" renamed as "addr_map_pgoff" to match local naming. Changes in V4: - In trace-event-python.c, fixed perf-tools-next merge problem. Changes in V3: - Rebased to linux-perf-tools branch. - Squash symbol-elf.c and symbol.h into same commit. - In map.c, merge dso__is_pie() call into existing if statement. - In arm-cs-trace-disasm.py, remove debug artifacts. Changes in V2: - In dso__is_pie() (symbol-elf.c), Decrease indentation, add null pointer checks per Leo Yan review. Steve Clevenger (2): perf script cs_etm: Add map_pgoff to python dictionary perf script python: Adjust objdump start/end per map pgoff parameter tools/perf/scripts/python/arm-cs-trace-disasm.py | 16 +++++++++++----- .../util/scripting-engines/trace-event-python.c | 9 ++++++--- 2 files changed, 17 insertions(+), 8 deletions(-) -- 2.44.0

5 months, 1 week

Re: [PATCH V10 RESEND 1/2] perf util scripting-engines cs-etm: Add map_pgoff to python dictionary

by Steve Clevenger

On 11/7/2024 10:51 AM, Namhyung Kim wrote: > On Wed, Nov 06, 2024 at 04:51:10PM -0700, Steve Clevenger wrote: >> Add map_pgoff parameter to python dictionary so it can be seen by the >> python script. >> >> Signed-off-by: Steve Clevenger <scclevenger(a)os.amperecomputing.com> >> Reviewed-by: Leo Yan <leo.yan(a)arm.com> >> --- >> tools/perf/util/scripting-engines/trace-event-python.c | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c >> index d7183134b669..367132b3a51a 100644 >> --- a/tools/perf/util/scripting-engines/trace-event-python.c >> +++ b/tools/perf/util/scripting-engines/trace-event-python.c >> @@ -793,7 +793,8 @@ static int set_regs_in_dict(PyObject *dict, >> static void set_sym_in_dict(PyObject *dict, struct addr_location *al, >> const char *dso_field, const char *dso_bid_field, >> const char *dso_map_start, const char *dso_map_end, >> - const char *sym_field, const char *symoff_field) >> + const char *sym_field, const char *symoff_field, >> + const char *map_pgoff) >> { >> char sbuild_id[SBUILD_ID_SIZE]; >> >> @@ -809,6 +810,8 @@ static void set_sym_in_dict(PyObject *dict, struct addr_location *al, >> PyLong_FromUnsignedLong(map__start(al->map))); >> pydict_set_item_string_decref(dict, dso_map_end, >> PyLong_FromUnsignedLong(map__end(al->map))); >> + pydict_set_item_string_decref(dict, map_pgoff, >> + PyLong_FromUnsignedLongLong(al->map->pgoff)); > > Please use map__pgoff(al->map) instead. Otherwise you'll get this in > the debug build: > > util/scripting-engines/trace-event-python.c: In function 'set_sym_in_dict': > util/scripting-engines/trace-event-python.c:814:60: error: 'struct map' has no member named 'pgoff' > 814 | PyLong_FromUnsignedLongLong(al->map->pgoff)); > | ^~ > > Thanks, > Namhyung > Hi Namhyung, I do not see this compile error, and I typically build perf with debug. This make command works through 6.11.0-rc6: $ make -C tools/perf DEBUG=1 VF=1 CORESIGHT=1 PYTHON=python3 CONFIG_LIBPYTHON=y CSLIBS=/usr/lib CSINCLUDES=/usr/include install I can substitute in the map__pgoff() macro in any case. Thanks, Steve > >> } >> if (al->sym) { >> pydict_set_item_string_decref(dict, sym_field, >> @@ -895,7 +898,7 @@ static PyObject *get_perf_sample_dict(struct perf_sample *sample, >> pydict_set_item_string_decref(dict, "comm", >> _PyUnicode_FromString(thread__comm_str(al->thread))); >> set_sym_in_dict(dict, al, "dso", "dso_bid", "dso_map_start", "dso_map_end", >> - "symbol", "symoff"); >> + "symbol", "symoff", "map_pgoff"); >> >> pydict_set_item_string_decref(dict, "callchain", callchain); >> >> @@ -920,7 +923,7 @@ static PyObject *get_perf_sample_dict(struct perf_sample *sample, >> PyBool_FromLong(1)); >> set_sym_in_dict(dict_sample, addr_al, "addr_dso", "addr_dso_bid", >> "addr_dso_map_start", "addr_dso_map_end", >> - "addr_symbol", "addr_symoff"); >> + "addr_symbol", "addr_symoff", "addr_map_pgoff"); >> } >> >> if (sample->flags) >> -- >> 2.44.0 >>

5 months, 1 week

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CoreSight November 2024