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2026-01-26perf unwind-libdw: Wire up e_flags for CSKYIan Rogers
Wire up the e_flags now it can be read for a thread. The e_flags encode the CSKY ABI level and this can impact which perf registers need setting up for unwinding. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Guo Ren <guoren@kernel.org> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Cc: Tianyou Li <tianyou.li@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf unwind-libdw: Don't discard loaded ELF/DWARF after every unwindIan Rogers
The unwind-libdw dwfl has ELF binaries associated with mmap addresses. Experimenting with using the per dso dwfl it is required to alter the address to be 0 based variant. Unfortunately libdwfl doesn't allow a single unwind and then an update to the return address to be 0 based as there are assertions that registers aren't updated once an unwind has started, etc. As removing the dwfl didn't prove possible, an alternative is to just not discard the dwfl when the unwind ends. The dwfl is valid for a process unless a dso is loaded at the same address as a previous one. So keep the dwfl with the maps, invalidate it if a map is removed (in case a new map replaces it) and recycle the dwfl in the unwinding code. A wrinkly in the implementation of this is that the attached thread argument is remembered by the dwfl and so it needs to be a pointer to memory that also persists with the dwfl (struct dwfl_ui_thread_info in the code). Recording 10 seconds of system wide data with --call-graph=dwarf and then processing with perf report shows a total runtime improvement from 41.583s to 2.279s (an 18x speedup). Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf dwarf-regs: Add MIPS perf to DWARF register number mapping functionsIan Rogers
Despite an unused function declaration, there was no unwind-libdw for MIPS but there is a perf_regs.h and a libdw implementation. Fill in the pieces so hopefully MIPS unwinding with libdw works. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf dwarf-regs: Add S390 perf to DWARF register number mapping functionsIan Rogers
These functions allow the generic initial register state code in unwind-libdw to be used. Now the non-generic code in unwind-libdw has no uses remove it. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf dwarf-regs: Add RISC-V perf to DWARF register number mapping functionsIan Rogers
These functions allow the generic initial register state code in unwind-libdw to be used. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf dwarf-regs: Add powerpc perf to DWARF register number mapping functionsIan Rogers
These functions allow the generic initial register state code in unwind-libdw to be used. Note, the link register was being coped to DWARF register 65 that the SysV ABI spec claims is FPSCR. It is corrected here to 108, but this is unlikely to matter as FPSCR has little to no impact on unwinding. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf dwarf-regs: Add loongarch perf to DWARF register number mapping functionsIan Rogers
These functions allow the generic initial register state code in unwind-libdw to be used. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf dwarf-regs: Add csky perf to dwarf register number mapping functionsIan Rogers
These functions allow the generic initial register state code in unwind-libdw to be used. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf dwarf-regs: Add ARM perf to dwarf register number mapping functionsIan Rogers
These functions allow the generic initial register state code in unwind-libdw to be used. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf dwarf-regs: Add get_dwarf_regnum_for_perf_regnum() and use for x86 ↵Ian Rogers
unwinding Add a utility to map a perf register number to a DWARF register number for a particular ELF machine type. Create a generic unwind-libdw initial register initialization routine that uses this function and thereby avoids arch specific initialization. The unwind-libdw code does: 1) compute the maximum DWARF register from the set of sampled user registers, 2) allocates a set of DWARF registers, 3) copies the sample registers into the appropriate DWARF registers. This generic solution is initially implemented for use with x86 as only get_dwarf_regnum_for_perf_regnum() support for x86 is currently present. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf unwind-libdw: Fix a cross-arch unwinding bugShimin Guo
The set_initial_registers field of Dwfl_Thread_Callbacks needs to be set according to the arch of the stack samples being analyzed, not the arch that perf itself is built for. Currently perf fails to unwind stack samples collected from archs different from that of the host perf is running on. This patch moves the arch-specific implementations of set_initial_registers from tools/perf/arch to tools/perf/utli/unwind-libdw-arch, similar to the way the perf-regs-arch folder contains arch-specific functions related to registers, and chooses the implementation based on the arch of the data being processed. Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Shimin Guo <shimin.guo@skydio.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-04-09perf unwind: Don't show unwind error messages when augmenting frame pointer ↵James Clark
stack Commit Fixes: b9f6fbb3b2c29736 ("perf arm64: Inject missing frames when using 'perf record --call-graph=fp'") intended to add a 'best effort' DWARF unwind that improved the frame pointer stack in most scenarios. It's expected that the unwind will fail sometimes, but this shouldn't be reported as an error. It only works when the return address can be determined from the contents of the link register alone. Fix the error shown when the unwinder requires extra registers by adding a new flag that suppresses error messages. This flag is not set in the normal --call-graph=dwarf unwind mode so that behavior is not changed. Fixes: b9f6fbb3b2c29736 ("perf arm64: Inject missing frames when using 'perf record --call-graph=fp'") Reported-by: John Garry <john.garry@huawei.com> Signed-off-by: James Clark <james.clark@arm.com> Tested-by: John Garry <john.garry@huawei.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Truong <alexandre.truong@arm.com> Cc: German Gomez <german.gomez@arm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20220406145651.1392529-1-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
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 <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-24perf tools: Use just forward declarations for struct thread where possibleArnaldo Carvalho de Melo
Removing various instances of unnecessary includes, reducing the maze of header dependencies. Link: http://lkml.kernel.org/n/tip-hwu6eyuok9pc57alookyzmsf@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-23perf callchain: Add order support for libdw DWARF unwinderJiri Olsa
As reported by Milian, currently for DWARF unwind (both libdw and libunwind) we display callchain in callee order only. Adding the support to follow callchain order setup to libdw DWARF unwinder, so we could get following output for report: $ perf record --call-graph dwarf ls ... $ perf report --no-children --stdio 21.12% ls libc-2.21.so [.] __strcoll_l | ---__strcoll_l mpsort_with_tmp mpsort_with_tmp mpsort_with_tmp sort_files main __libc_start_main _start $ perf report --stdio --no-children -g caller 21.12% ls libc-2.21.so [.] __strcoll_l | ---_start __libc_start_main main sort_files mpsort_with_tmp mpsort_with_tmp mpsort_with_tmp __strcoll_l Reported-and-Tested-by: Milian Wolff <milian.wolff@kdab.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Wang Nan <wangnan0@huawei.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jan Kratochvil <jkratoch@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20151119130119.GA26617@krava.brq.redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-02-24perf tools: Add libdw DWARF post unwind supportJiri Olsa
Adding libdw DWARF post unwind support, which is part of elfutils-devel/libdw-dev package from version 0.158. The new code is contained in unwin-libdw.c object, and implements unwind__get_entries unwind interface function. New Makefile variable NO_LIBDW_DWARF_UNWIND was added to control its compilation, and is marked as disabled now. It's factored with the rest of the Makefile unwind build code in the next patch. Arch specific code was added for x86. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jean Pihet <jean.pihet@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1392825179-5228-5-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>