linux-dev/arch/s390/include/asm/perf_event.h, branch linus/master

s390: implement perf_arch_fetch_caller_regs

2019-11-30T09:52:44Z

On s390 bpf_get_stack_raw_tp() returns 0 entries for both kernel and user stacks. While there is no practical unwinding solution for userspace on s390 at this moment, there certainly is a kernel unwinder. However, it is not properly integrated with BPF. In order to start unwinding, bpf_get_stack_raw_tp() obtains the current kernel register values using perf_fetch_caller_regs(), which is not implemented for s390. The actual unwinding then happens by passing those registers to perf_callchain_kernel(). Implement perf_arch_fetch_caller_regs() for s390, where __builtin_frame_address(0) points to back_chain. Signed-off-by: Ilya Leoshkevich Acked-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/cpum_sf: Support ioctl PERF_EVENT_IOC_PERIOD

2019-09-19T10:56:07Z

A perf_event can be set up to deliver overflow notifications via SIGIO signal. The setup of the event is: 1. create event with perf_event_open() 2. assign it a signal for I/O notification with fcntl() 3. Install signal handler and consume samples The initial setup of perf_event_open() determines the period/frequency time span needed to elapse before each signal is delivered to the user process. While the event is active, system call ioctl(.., PERF_EVENT_IOC_PERIOD, value) can be used the change the frequency/period time span of the active event. The remaining signal handler invocations honour the new value. This does not work on s390. In fact the time span does not change regardless of ioctl's third argument 'value'. The call succeeds but the time span does not change. Support this behavior and make it common with other platforms. This is achieved by changing the interval value of the sampling control block accordingly and feed this new value every time the event is enabled using pmu_event_enable(). Before this change the interval value was set only once at pmu_event_add() and never changed. Signed-off-by: Thomas Richter Signed-off-by: Vasily Gorbik

s390/cpum_cf_diag: Add support for s390 counter facility diagnostic trace

2019-02-22T08:19:56Z

Introduce a PMU device named cpum_cf_diag. It extracts the values of all counters in all authorized counter sets and stores them as event raw data. This is done with the STORE CPU COUNTER MULTIPLE instruction to speed up access. All counter sets fit into one buffer. The values of each counter are taken when the event is started on the performance sub-system and when the event is stopped. This results in counter values available at the start and at the end of the measurement time frame. The difference is calculated for each counter. The differences of all counters are then saved as event raw data in the perf.data file. The counter values are accompanied by the time stamps when the counter set was started and when the counter set was stopped. This data is part of a trailer entry which describes the time frame, counter set version numbers, CPU speed, and machine type for later analysis. Signed-off-by: Thomas Richter Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky

s390/cpum_cf: move counter set controls to a new header file

2019-02-22T08:19:46Z

Move counter set specific controls and functions to the asm/cpu_mcf.h header file containg all counter facility support definitions. Also adapt few variable names and header file includes. No functional changes. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky

s390/bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type

2017-12-05T14:02:41Z

To mitigate and correct the broken uapi for the BPF_PROG_TYPE_PERF_EVENT program type, introduce a user_pt_regs structure (similar to arm64) that exports parts from the beginnig of the pt_regs structure. The export must start with the beginning of the pt_regs structure because to correctly calculate BPF prologues for perf (regs_query_register_offset()). For BPF_PROG_TYPE_PERF_EVENT program types, the BPF program is then passed a user_pt_regs structure. Note: Depending on future changes to the s390 pt_regs structure, consider the user_pt_regs structure to be stable for a particular kernel version only. (Of course, s390 tries to ensure keep it stable as much as possible.) Signed-off-by: Hendrik Brueckner Reviewed-and-tested-by: Thomas Richter Acked-by: Alexei Starovoitov Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Arnaldo Carvalho de Melo Cc: Daniel Borkmann Signed-off-by: Daniel Borkmann

s390/cpumf: remove raw event support in basic-only sampling mode

2017-11-16T14:06:09Z

Raw sample was implemented to export the diagnostic samples. With having this achieved with AUX buffers, there is no requirement for basic samples to export raw data. In particular, most basic sampling information are consumed for creating the perf event sample. Signed-off-by: Pu Hou Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

s390/cpum_cf: update counter numbers to ecctr limits

2017-03-31T05:53:26Z

Use the highest counter number that can be specified for the ecctr (extract CPU counter) instruction for perf. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky

s390/perf: remove perf_release/reserver_sampling functions

2016-06-28T07:32:25Z

Now that the oprofile sampling code is gone there is only one user of the sampling facility left. Therefore the reserve and release functions can be removed. Signed-off-by: Heiko Carstens Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky

s390: Fix misspellings in comments

2016-03-08T14:00:17Z

Signed-off-by: Adam Buchbinder Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky