CoreSight November 2020

coresight@lists.linaro.org

26 participants
36 discussions

[PATCH v4 0/2] Make sysFS functional on topologies with per core sink

by Linu Cherian

This patch series tries to fix the sysfs breakage on topologies with per core sink. Changes since v3: - References to coresight_get_enabled_sink in perf interface has been removed and marked deprecated as a new patch. - To avoid changes to coresight_find_sink for ease of maintenance, search function specific to sysfs usage has been added. - Sysfs being the only user for coresight_get_enabled sink, reset option is removed as well. Changes since v2: - Fixed checkpatch issue Changes since v1: - Misc fixes in commit message Applies on https://git.linaro.org/kernel/coresight.git/log/?h=next Linu Cherian (2): coresight: etm: perf: Sink selection using sysfs is deprecated coresight: Make sysFS functional on topologies with per core sink .../hwtracing/coresight/coresight-etm-perf.c | 2 - drivers/hwtracing/coresight/coresight-priv.h | 3 +- drivers/hwtracing/coresight/coresight.c | 58 +++++++++---------- 3 files changed, 29 insertions(+), 34 deletions(-) base-commit: 17f17c8f02a35a746376c2ecd054386575835b8b -- 2.25.1

6 years

perf cs-etm: Multi-thread support

by Andrea Brunato

Good morning, Is tracing a multi-threaded program a supported use case for perf cs-etm? If yes, are there any flags that should be specified with perf? Thanks, Andrea IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

6 years

[PATCH RESEND 1/2] perf test: Fix a typo in cs-etm testing

by Leo Yan

Fix a typo: s/devce_name/device_name. Fixes: fe0aed19b266 ("perf test: Introduce script for Arm CoreSight testing") Signed-off-by: Leo Yan <leo.yan(a)linaro.org> --- Resend patches for adding "Fixes" tags. tools/perf/tests/shell/test_arm_coresight.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/tests/shell/test_arm_coresight.sh b/tools/perf/tests/shell/test_arm_coresight.sh index 8d84fdbed6a6..59d847d4981d 100755 --- a/tools/perf/tests/shell/test_arm_coresight.sh +++ b/tools/perf/tests/shell/test_arm_coresight.sh @@ -105,7 +105,7 @@ arm_cs_iterate_devices() { # `> device_name = 'tmc_etf0' device_name=$(basename $path) - if is_device_sink $path $devce_name; then + if is_device_sink $path $device_name; then record_touch_file $device_name $2 && perf_script_branch_samples touch && -- 2.17.1

6 years

[PATCH v3 00/26] coresight: Support for ETM system instructions

by Suzuki K Poulose

CoreSight ETMv4.4 obsoletes memory mapped access to ETM and mandates the system instructions for registers. This also implies that they may not be on the amba bus. Right now all the CoreSight components are accessed via memory map. Also, we have some common routines in coresight generic code driver (e.g, CS_LOCK, claim/disclaim), which assume the mmio. In order to preserve the generic algorithms at a single place and to allow dynamic switch for ETMs, this series introduces an abstraction layer for accessing a coresight device. It is designed such that the mmio access are fast tracked (i.e, without an indirect function call). This will also help us to get rid of the driver+attribute specific sysfs show/store routines and replace them with a single routine to access a given register offset (which can be embedded in the dev_ext_attribute). This is not currently implemented in the series, but can be achieved. Further we switch the generic routines to work with the abstraction. With this in place, we refactor the etm4x code a bit to allow for supporting the system instructions with very little new code. The changes also switch to using the system instructions by default even when we may have an MMIO. We use TRCDEVARCH for the detection of the ETM component, which is a standard register as per CoreSight architecture, rather than the etm specific id register TRCIDR1. This is for making sure that we are able to detect the ETM via system instructions accurately, when the the trace unit could be anything (etm or a custom trace unit). To keep the backward compatibility for any existing broken impelementation which may not implement TRCDEVARCH, we fall back to TRCIDR1. Also this covers us for the changes in the future architecture [0]. The series has been mildly tested on a model for system instructions. I would really appreciate any testing on real hardware. Applies on coresight/next. [0] https://developer.arm.com/docs/ddi0601/g/aarch64-system-registers/trcidr1 Known issues: Checkpatch failure for "coresight: etm4x: Add sysreg access helpers" : ERROR: Macros with complex values should be enclosed in parentheses #121: FILE: drivers/hwtracing/coresight/coresight-etm4x.h:153: +#define CASE_READ(res, x) \ + case (x): { (res) = read_etm4x_sysreg_const_offset((x)); break; } I don't know how to fix that without breaking the build ! Suggestions welcome. Changes since V2: - Several fixes to the ETM register accesses. Access a register when it is present. - Add support for TRCIDR3.NUMPROCS for v4.2+ - Drop OS lock detection. Use software lock only in case of mmio. - Fix issues with the Exception level masks (Mike Leach) - Fall back to using TRCIDR1 when TRCDEVARCH is not "present" - Use a generic notion of ETM architecture (rather than using the encoding as in registers) - Fixed some checkpatch issues. - Add support for Self Hosted tracing Arm v8.4 extensions. (Mike Leach) Originally written by Jonathan, refactored and cleaned up. - Changed the dts compatible string to "arm,coresight-etm-sysreg" (Mike Leach) Changes since V1: - Flip the switch for iomem from no_iomem to io_mem in csdev_access. - Split patches for claim/disclaim and CS_LOCK/UNLOCK conversions. - Move device access initialisation for etm4x to the target CPU - Cleanup secure exception level mask handling. - Switch to use TRCDEVARCH for ETM component discovery. This is for making - Check the availability of OS/Software Locks before using them. Suzuki K Poulose (26): coresight: etm4x: Fix accesses to TRCVMIDCTLR1 coresight: etm4x: Fix accesses to TRCCIDCTLR1 coresight: etm4x: Update TRCIDR3.NUMPROCS handling to match v4.2 coresight: etm4x: Fix accesses to TRCPROCSELR coresight: etm4x: Handle TRCVIPCSSCTLR accesses coresight: etm4x: Handle access to TRCSSPCICRn coresight: Introduce device access abstraction coresight: tpiu: Prepare for using coresight device access abstraction coresight: Convert coresight_timeout to use access abstraction coresight: Convert claim/disclaim operations to use access wrappers coresight: etm4x: Always read the registers on the host CPU coresight: etm4x: Convert all register accesses coresight: etm4x: Add commentary on the registers coresight: etm4x: Add sysreg access helpers coresight: etm4x: Define DEVARCH register fields coresight: etm4x: Check for Software Lock coresight: etm4x: Cleanup secure exception level masks coresight: etm4x: Clean up exception level masks coresight: etm4x: Detect access early on the target CPU coresight: etm4x: Handle ETM architecture version coresight: etm4x: Use TRCDEVARCH for component discovery coresight: etm4x: Add necessary synchronization for sysreg access coresight: etm4x: Detect system instructions support coresight: etm4x: Refactor probing routine coresight: etm4x: Add support for sysreg only devices dts: bindings: coresight: ETM system register access only units .../devicetree/bindings/arm/coresight.txt | 5 +- drivers/hwtracing/coresight/coresight-catu.c | 12 +- drivers/hwtracing/coresight/coresight-core.c | 130 ++- .../hwtracing/coresight/coresight-cti-core.c | 18 +- drivers/hwtracing/coresight/coresight-etb10.c | 10 +- .../coresight/coresight-etm3x-core.c | 9 +- .../coresight/coresight-etm4x-core.c | 758 +++++++++++------- .../coresight/coresight-etm4x-sysfs.c | 44 +- drivers/hwtracing/coresight/coresight-etm4x.h | 501 +++++++++++- .../hwtracing/coresight/coresight-funnel.c | 7 +- .../coresight/coresight-replicator.c | 17 +- drivers/hwtracing/coresight/coresight-stm.c | 4 +- .../hwtracing/coresight/coresight-tmc-core.c | 16 +- .../hwtracing/coresight/coresight-tmc-etf.c | 10 +- .../hwtracing/coresight/coresight-tmc-etr.c | 4 +- drivers/hwtracing/coresight/coresight-tpiu.c | 31 +- include/linux/coresight.h | 230 +++++- 17 files changed, 1376 insertions(+), 430 deletions(-) -- 2.24.1

6 years

[PATCH v2] coresight: tmc-etr: Assign boolean values to a bool variable

by xiakaixu1987＠gmail.com

From: Kaixu Xia <kaixuxia(a)tencent.com> Fix the following coccinelle warnings: ./drivers/hwtracing/coresight/coresight-tmc-etr.c:957:2-15: WARNING: Assignment of 0/1 to bool variable Fix them by assigning boolean values. Reported-by: Tosk Robot <tencent_os_robot(a)tencent.com> Signed-off-by: Kaixu Xia <kaixuxia(a)tencent.com> --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 714f9e867e5f..525f0ecc129c 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -954,11 +954,11 @@ static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata) dev_dbg(&drvdata->csdev->dev, "tmc memory error detected, truncating buffer\n"); etr_buf->len = 0; - etr_buf->full = 0; + etr_buf->full = false; return; } - etr_buf->full = status & TMC_STS_FULL; + etr_buf->full = !!(status & TMC_STS_FULL); WARN_ON(!etr_buf->ops || !etr_buf->ops->sync); -- 2.20.0

6 years

[PATCH 1/2] perf test: Fix a typo in cs-etm testing

by Leo Yan

Fix a typo: s/devce_name/device_name. Signed-off-by: Leo Yan <leo.yan(a)linaro.org> --- tools/perf/tests/shell/test_arm_coresight.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/tests/shell/test_arm_coresight.sh b/tools/perf/tests/shell/test_arm_coresight.sh index 8d84fdbed6a6..59d847d4981d 100755 --- a/tools/perf/tests/shell/test_arm_coresight.sh +++ b/tools/perf/tests/shell/test_arm_coresight.sh @@ -105,7 +105,7 @@ arm_cs_iterate_devices() { # `> device_name = 'tmc_etf0' device_name=$(basename $path) - if is_device_sink $path $devce_name; then + if is_device_sink $path $device_name; then record_touch_file $device_name $2 && perf_script_branch_samples touch && -- 2.17.1

6 years

Demo of using etm traces on arm for instructions and functions recording and reverse debugging

by Zied Guermazi

hi all, to demonstrate extending gdb to use etm traces for implementing btrace on arm processors, I have made this video available on youtube https://youtu.be/ptKbJRNUqUI users can then have access to process record and replay, on instructions and functions level (https://sourceware.org/gdb/current/onlinedocs/gdb/Process-Record-and-Replay…) and reverse debugging(https://www.gnu.org/software/gdb/news/reversible.html) we have all functionalities available for intel PT except tracing multi-threaded applications. In this demo I have "reconstructed" the cspr register to enable setting breakpoints in reverse debugging. it is still dirty (adds arm specific register to an architecture agnostic structure) but it shows that it works when implemented properly Kind Regards Zied Guermazi

6 years

[PATCH] coresight: tmc-etr: Assign boolean values to a bool variable

by xiakaixu1987＠gmail.com

From: Kaixu Xia <kaixuxia(a)tencent.com> Fix the following coccinelle warnings: ./drivers/hwtracing/coresight/coresight-tmc-etr.c:957:2-15: WARNING: Assignment of 0/1 to bool variable Signed-off-by: Kaixu Xia <kaixuxia(a)tencent.com> --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 714f9e867e5f..c86f8f2a2526 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -954,11 +954,11 @@ static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata) dev_dbg(&drvdata->csdev->dev, "tmc memory error detected, truncating buffer\n"); etr_buf->len = 0; - etr_buf->full = 0; + etr_buf->full = false; return; } - etr_buf->full = status & TMC_STS_FULL; + etr_buf->full = (status & TMC_STS_FULL ? true : false); WARN_ON(!etr_buf->ops || !etr_buf->ops->sync); -- 2.20.0

6 years

[PATCH v5 0/9] perf cs-etm: Support thread stack and callchain

by Leo Yan

This patch series adds support for thread stack and callchain; this patch set depends on the instruction sample fix patch set [1]. This patch set get more complex, so before divide into small groups, I'd like to use this patch set version to include all relevant patches, hope this can give whole context for related code change. Briefly, this patch can be divided into three parts, which also can be reviewed separately for every part: Patches 01, 02 are used to fix samples for one corner case is for accessing the branch's target address and trigger an exception. Essentially, an extra branch sample is added to reflect this mediate branch between the previous branch and exception entry. Patches 03, 04, 05, 06 are coming from patch v4, which are used to support thread stack and callchain. Patches 07, 08, 09 are used to fixup for exception entry and exit. This is mainly used to fix two cases, one part is to fixup the thread stack and callchain for the case when access branch target address and trigger exception; another part is to fixup the thread stack for instruction emulation (and other single step cases). This patch set has been tested on Juno-r2 after applied on perf/core branch with latest commit 85fc95d75970 ("perf maps: Add missing unlock to maps__insert() error case"), and this patch set is also applied on top of instruction sample fix patch set [1]. Test for option '-F,+callindent': # perf script -F,+callindent main 3258 1 branches: main ffffad684d20 __libc_start_main+0xe0 (/usr/lib/aarch64-linux-gnu/libc-2.28.so) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) main 3258 1 branches: _dl_fixup ffffad811b4c _dl_runtime_resolve+0x40 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: _dl_lookup_symbol_x ffffad80c078 _dl_fixup+0xb8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: do_lookup_x ffffad80849c _dl_lookup_symbol_x+0x104 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: check_match ffffad807bf0 do_lookup_x+0x238 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: strcmp ffffad807888 check_match+0x70 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) [...] Test for option '--itrace=g': # perf script --itrace=g16l64i100 main 3258 100 instructions: ffffad816a80 memcpy+0x70 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad809468 _dl_new_object+0xa8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad801840 dl_main+0x778 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad81384c _dl_sysdep_start+0x36c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800884 _dl_start_final+0xac (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800b00 _dl_start+0x200 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800048 _start+0x8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 100 instructions: ffffad80952c _dl_new_object+0x16c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad801840 dl_main+0x778 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad81384c _dl_sysdep_start+0x36c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800884 _dl_start_final+0xac (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800b00 _dl_start+0x200 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800048 _start+0x8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 100 instructions: ffffad8018dc dl_main+0x814 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad81384c _dl_sysdep_start+0x36c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800884 _dl_start_final+0xac (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800b00 _dl_start+0x200 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800048 _start+0x8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 100 instructions: ffff8000100878d0 el0_sync_handler+0x168 ([kernel.kallsyms]) ffff800010082d00 el0_sync+0x140 ([kernel.kallsyms]) ffffad801910 dl_main+0x848 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad81384c _dl_sysdep_start+0x36c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800884 _dl_start_final+0xac (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800b00 _dl_start+0x200 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800048 _start+0x8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) [...] Changes from v4: * Addressed Mike's suggestion for performance improvement for function cs_etm__instr_addr() for quick calculation for non T32; * Removed the patch 'perf cs-etm: Synchronize instruction sample with the thread stack' (Mike); * Fixed the issue for exception is taken for branch target address accessing, for the branch sample and stack thread handling, the related patches are 01, 02, 07; * Fixed the stack thread handling for instruction emulation and single step with patches 08, 09. Changes from v3: * Split out separate patch set for instruction samples fixing. * Rebased on latest perf/core branch. Changes from v2: * Added patch 01 to fix the unsigned variable comparison to zero (Suzuki). * Refined commit logs. Changes from v1: * Added comments for task thread handling (Mathieu). * Split patch 02 into two patches, one is for support thread stack and another is for callchain support (Mathieu). * Added a new patch to support branch filter. [1] https://lkml.org/lkml/2020/2/18/1406 Leo Yan (9): perf cs-etm: Defer to assign exception sample flag perf cs-etm: Reflect branch prior to exception perf cs-etm: Refactor instruction size handling perf cs-etm: Support thread stack perf cs-etm: Support branch filter perf cs-etm: Support callchain for instruction sample perf cs-etm: Fixup exception entry for thread stack perf thread: Add helper to get top return address perf cs-etm: Fixup exception exit for thread stack .../perf/util/cs-etm-decoder/cs-etm-decoder.c | 1 + tools/perf/util/cs-etm.c | 290 ++++++++++++++++-- tools/perf/util/thread-stack.c | 10 + tools/perf/util/thread-stack.h | 1 + 4 files changed, 268 insertions(+), 34 deletions(-) -- 2.17.1

6 years

GDB: status of branch tracing on arm processors using coresight etm traces

by Zied Guermazi

hi all I am announcing updates in the implementation of branch tracing using coresight etm in GDB. in this update, functions and instruction history are running successfully on single threaded applications. reverse debugging is basically working with the limitation that sometimes cspr register (register 25) is required but current implementation does not provide it. the feature requires linux kernel v 4.19 or higher with manual etm sink setup. 5.9.1 or higher for automatic sink selection. GDB gdb.btrace test suite was adapted to run on arm processors. here is the summary of the gdb.btrace test results executed on an STM32MP157 (ARM cortex A7) with Linux kernel 5.9.1 === gdb Summary === # of expected passes 390 # of unexpected failures 119 # of unsupported tests 4 following tests are 100% successful: - buffer-size - enable - instruction_history - function_call_history - data - delta - cpu - gcore - record_goto-step - dlopen - vdso - segv GDB source code is available on https://github.com/gzied/binutils-gdb/tree/gdb_arm_coresight many thanks to GDB and linaro communities for their support Kind Regards Zied Guermazi

6 years

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CoreSight November 2020