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2021-09-29selftests: arm64: More comprehensively test the SVE ptrace interfaceMark Brown
Currently the selftest for the SVE register set is not quite as thorough as is desirable - it only validates that the value of a single Z register is not modified by a partial write to a lower numbered Z register after having previously been set through the FPSIMD regset. Make this more thorough: - Test the ability to set vector lengths and enumerate those supported in the system. - Validate data in all Z and P registers, plus FPSR and FPCR. - Test reads via the FPSIMD regset after set via the SVE regset. There's still some oversights, the main one being that due to the need to generate a pattern in FFR and the fact that this rewrite is primarily motivated by SME's streaming SVE which doesn't have FFR we don't currently test FFR. Update the TODO to reflect those that occurred to me (and fix an adjacent typo in there). Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210913125505.52619-8-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-09-29selftests: arm64: Verify interoperation of SVE and FPSIMD register setsMark Brown
After setting the FPSIMD registers via the SVE register set read them back via the FPSIMD register set, validating that the two register sets are interoperating and that the values we thought we set made it into the child process. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210913125505.52619-7-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-09-29selftests: arm64: Clarify output when verifying SVE register setMark Brown
When verifying setting a Z register via ptrace we check each byte by hand, iterating over the buffer using a pointer called p and treating each register value written as a test. This creates output referring to "p[X]" which is confusing since SVE also has predicate registers Pn. Tweak the output to avoid confusion here. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210913125505.52619-6-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-09-29selftests: arm64: Document what the SVE ptrace test is doingMark Brown
Before we go modifying it further let's add some comments and output clarifications explaining what this test is actually doing. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210913125505.52619-5-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-09-29selftests: arm64: Remove extraneous register setting codeMark Brown
For some reason the SVE ptrace test code starts off by setting values in some of the SVE vector registers in the parent process which it then never interacts with when verifying the ptrace interfaces. This is not especially relevant to what's being tested and somewhat confusing when reading the code so let's remove it. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210913125505.52619-4-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-09-29selftests: arm64: Don't log child creation as a test in SVE ptrace testMark Brown
Currently we log the creation of the child process as a test but it's not really relevant to what we're trying to test and can make the output a little confusing so don't do that. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210913125505.52619-3-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-09-29selftests: arm64: Use a define for the number of SVE ptrace tests to be runMark Brown
Partly in preparation for future refactoring move from hard coding the number of tests in main() to putting #define at the top of the source instead. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210913125505.52619-2-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-09-28selftests/bpf: Fix probe_user test failure with clang build kernelYonghong Song
clang build kernel failed the selftest probe_user. $ ./test_progs -t probe_user $ ... $ test_probe_user:PASS:get_kprobe_res 0 nsec $ test_probe_user:FAIL:check_kprobe_res wrong kprobe res from probe read: 0.0.0.0:0 $ #94 probe_user:FAIL The test attached to kernel function __sys_connect(). In net/socket.c, we have int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen) { ...... } ... SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr, int, addrlen) { return __sys_connect(fd, uservaddr, addrlen); } The gcc compiler (8.5.0) does not inline __sys_connect() in syscall entry function. But latest clang trunk did the inlining. So the bpf program is not triggered. To make the test more reliable, let us kprobe the syscall entry function instead. Note that x86_64, arm64 and s390 have syscall wrappers and they have to be handled specially. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210929033000.3711921-1-yhs@fb.com
2021-09-28bpftool: Avoid using "?: " in generated codeYucong Sun
"?:" is a GNU C extension, some environment has warning flags for its use, or even prohibit it directly. This patch avoid triggering these problems by simply expand it to its full form, no functionality change. Signed-off-by: Yucong Sun <fallentree@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210928184221.1545079-1-fallentree@fb.com
2021-09-28selftests/bpf: Switch sk_lookup selftests to strict SEC("sk_lookup") useAndrii Nakryiko
Update "sk_lookup/" definition to be a stand-alone type specifier, with backwards-compatible prefix match logic in non-libbpf-1.0 mode. Currently in selftests all the "sk_lookup/<whatever>" uses just use <whatever> for duplicated unique name encoding, which is redundant as BPF program's name (C function name) uniquely and descriptively identifies the intended use for such BPF programs. With libbpf's SEC_DEF("sk_lookup") definition updated, switch existing sk_lookup programs to use "unqualified" SEC("sk_lookup") section names, with no random text after it. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20210928161946.2512801-11-andrii@kernel.org
2021-09-28libbpf: Add opt-in strict BPF program section name handling logicAndrii Nakryiko
Implement strict ELF section name handling for BPF programs. It utilizes `libbpf_set_strict_mode()` framework and adds new flag: LIBBPF_STRICT_SEC_NAME. If this flag is set, libbpf will enforce exact section name matching for a lot of program types that previously allowed just partial prefix match. E.g., if previously SEC("xdp_whatever_i_want") was allowed, now in strict mode only SEC("xdp") will be accepted, which makes SEC("") definitions cleaner and more structured. SEC() now won't be used as yet another way to uniquely encode BPF program identifier (for that C function name is better and is guaranteed to be unique within bpf_object). Now SEC() is strictly BPF program type and, depending on program type, extra load/attach parameter specification. Libbpf completely supports multiple BPF programs in the same ELF section, so multiple BPF programs of the same type/specification easily co-exist together within the same bpf_object scope. Additionally, a new (for now internal) convention is introduced: section name that can be a stand-alone exact BPF program type specificator, but also could have extra parameters after '/' delimiter. An example of such section is "struct_ops", which can be specified by itself, but also allows to specify the intended operation to be attached to, e.g., "struct_ops/dctcp_init". Note, that "struct_ops_some_op" is not allowed. Such section definition is specified as "struct_ops+". This change is part of libbpf 1.0 effort ([0], [1]). [0] Closes: https://github.com/libbpf/libbpf/issues/271 [1] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#stricter-and-more-uniform-bpf-program-section-name-sec-handling Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20210928161946.2512801-10-andrii@kernel.org
2021-09-28libbpf: Complete SEC() table unification for BPF_APROG_SEC/BPF_EAPROG_SECAndrii Nakryiko
Complete SEC() table refactoring towards unified form by rewriting BPF_APROG_SEC and BPF_EAPROG_SEC definitions with SEC_DEF(SEC_ATTACHABLE_OPT) (for optional expected_attach_type) and SEC_DEF(SEC_ATTACHABLE) (mandatory expected_attach_type), respectively. Drop BPF_APROG_SEC, BPF_EAPROG_SEC, and BPF_PROG_SEC_IMPL macros after that, leaving SEC_DEF() macro as the only one used. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20210928161946.2512801-9-andrii@kernel.org
2021-09-28libbpf: Refactor ELF section handler definitionsAndrii Nakryiko
Refactor ELF section handler definitions table to use a set of flags and unified SEC_DEF() macro. This allows for more succinct and table-like set of definitions, and allows to more easily extend the logic without adding more verbosity (this is utilized in later patches in the series). This approach is also making libbpf-internal program pre-load callback not rely on bpf_sec_def definition, which demonstrates that future pluggable ELF section handlers will be able to achieve similar level of integration without libbpf having to expose extra types and APIs. For starters, update SEC_DEF() definitions and make them more succinct. Also convert BPF_PROG_SEC() and BPF_APROG_COMPAT() definitions to a common SEC_DEF() use. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20210928161946.2512801-8-andrii@kernel.org
2021-09-28libbpf: Reduce reliance of attach_fns on sec_def internalsAndrii Nakryiko
Move closer to not relying on bpf_sec_def internals that won't be part of public API, when pluggable SEC() handlers will be allowed. Drop pre-calculated prefix length, and in various helpers don't rely on this prefix length availability. Also minimize reliance on knowing bpf_sec_def's prefix for few places where section prefix shortcuts are supported (e.g., tp vs tracepoint, raw_tp vs raw_tracepoint). Given checking some string for having a given string-constant prefix is such a common operation and so annoying to be done with pure C code, add a small macro helper, str_has_pfx(), and reuse it throughout libbpf.c where prefix comparison is performed. With __builtin_constant_p() it's possible to have a convenient helper that checks some string for having a given prefix, where prefix is either string literal (or compile-time known string due to compiler optimization) or just a runtime string pointer, which is quite convenient and saves a lot of typing and string literal duplication. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20210928161946.2512801-7-andrii@kernel.org
2021-09-28libbpf: Refactor internal sec_def handling to enable pluggabilityAndrii Nakryiko
Refactor internals of libbpf to allow adding custom SEC() handling logic easily from outside of libbpf. To that effect, each SEC()-handling registration sets mandatory program type/expected attach type for a given prefix and can provide three callbacks called at different points of BPF program lifetime: - init callback for right after bpf_program is initialized and prog_type/expected_attach_type is set. This happens during bpf_object__open() step, close to the very end of constructing bpf_object, so all the libbpf APIs for querying and updating bpf_program properties should be available; - pre-load callback is called right before BPF_PROG_LOAD command is called in the kernel. This callbacks has ability to set both bpf_program properties, as well as program load attributes, overriding and augmenting the standard libbpf handling of them; - optional auto-attach callback, which makes a given SEC() handler support auto-attachment of a BPF program through bpf_program__attach() API and/or BPF skeletons <skel>__attach() method. Each callbacks gets a `long cookie` parameter passed in, which is specified during SEC() handling. This can be used by callbacks to lookup whatever additional information is necessary. This is not yet completely ready to be exposed to the outside world, mainly due to non-public nature of struct bpf_prog_load_params. Instead of making it part of public API, we'll wait until the planned low-level libbpf API improvements for BPF_PROG_LOAD and other typical bpf() syscall APIs, at which point we'll have a public, probably OPTS-based, way to fully specify BPF program load parameters, which will be used as an interface for custom pre-load callbacks. But this change itself is already a good first step to unify the BPF program hanling logic even within the libbpf itself. As one example, all the extra per-program type handling (sleepable bit, attach_btf_id resolution, unsetting optional expected attach type) is now more obvious and is gathered in one place. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20210928161946.2512801-6-andrii@kernel.org
2021-09-28selftests/bpf: Normalize all the rest SEC() usesAndrii Nakryiko
Normalize all the other non-conforming SEC() usages across all selftests. This is in preparation for libbpf to start to enforce stricter SEC() rules in libbpf 1.0 mode. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20210928161946.2512801-5-andrii@kernel.org
2021-09-28selftests/bpf: Switch SEC("classifier*") usage to a strict SEC("tc")Andrii Nakryiko
Convert all SEC("classifier*") uses to a new and strict SEC("tc") section name. In reference_tracking selftests switch from ambiguous searching by program title (section name) to non-ambiguous searching by name in some selftests, getting closer to completely removing bpf_object__find_program_by_title(). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210928161946.2512801-4-andrii@kernel.org
2021-09-28selftests/bpf: Normalize XDP section names in selftestsAndrii Nakryiko
Convert almost all SEC("xdp_blah") uses to strict SEC("xdp") to comply with strict libbpf 1.0 logic of exact section name match for XDP program types. There is only one exception, which is only tested through iproute2 and defines multiple XDP programs within the same BPF object. Given iproute2 still works in non-strict libbpf mode and it doesn't have means to specify XDP programs by its name (not section name/title), leave that single file alone for now until iproute2 gains lookup by function/program name. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20210928161946.2512801-3-andrii@kernel.org
2021-09-28libbpf: Add "tc" SEC_DEF which is a better name for "classifier"Andrii Nakryiko
As argued in [0], add "tc" ELF section definition for SCHED_CLS BPF program type. "classifier" is a misleading terminology and should be migrated away from. [0] https://lore.kernel.org/bpf/270e27b1-e5be-5b1c-b343-51bd644d0747@iogearbox.net/ Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210928161946.2512801-2-andrii@kernel.org
2021-09-28perf vendor events arm64: Revise hip08 uncore eventsJohn Garry
To improve alias matching, remove the PMU name prefix from the EventName. This will mean that the pmu code will merge aliases, such that we no longer get a huge list of per-PMU events - see perf_pmu_merge_alias(). Also make the following associated changes: - Use "ConfigCode" rather than "EventCode", so the pmu code is not so disagreeable about inconsistent event codes - Add undocumented HHA event codes to allow alias merging (for those events) Signed-off-by: John Garry <john.garry@huawei.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linuxarm@huawei.com Cc: liuqi115@huawei.com Link: https://lore.kernel.org/r/1631795665-240946-6-git-send-email-john.garry@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf test: Add pmu-event test for event described as "config="John Garry
Add a new test event for a system event whose event member is in form "config=". Signed-off-by: John Garry <john.garry@huawei.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linuxarm@huawei.com Cc: liuqi115@huawei.com Link: https://lore.kernel.org/r/1631795665-240946-5-git-send-email-john.garry@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf test: Verify more event members in pmu-events testJohn Garry
Function compare_pmu_events() does not compare all struct pmu-events members, so add tests for missing members "name", "event", "aggr_mod", "event", "metric_constraint", and "metric_group", and re-order the tests to match current struct pmu-events member ordering. Also fix uncore_hisi_l3c_rd_hit_cpipe.event member, now that we're actually testing it. Signed-off-by: John Garry <john.garry@huawei.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linuxarm@huawei.com Cc: liuqi115@huawei.com Link: https://lore.kernel.org/r/1631795665-240946-4-git-send-email-john.garry@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf jevents: Support ConfigCodeJohn Garry
Some PMUs use "config=XXX" for eventcodes, like: more /sys/bus/event_source/devices/hisi_sccl1_ddrc3/events/act_cmd config=0x5 However jevents would give an alias with .event field "event=0x5" for this event. This is handled without issue by the parse events code, but the pmu alias code gets a bit confused, as it warns about assigning "event=0x5" over "config=0x5" in perf_pmu_assign_str() when merging aliases: ./perf stat -v -e act_cmd ... alias act_cmd differs in field 'value' ... To make things a bit more straightforward, allow jevents to support "config=XXX" as well, by supporting a "ConfigCode" field. Signed-off-by: John Garry <john.garry@huawei.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linuxarm@huawei.com Cc: liuqi115@huawei.com Link: https://lore.kernel.org/r/1631795665-240946-3-git-send-email-john.garry@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf parse-events: Set numeric term configJohn Garry
For numeric terms, the config field may be NULL as it is not set from the l+y parsing. Fix by setting the term config from the term type name. Also fix up the pmu-events test to set the alias strings to set the period term properly, and fix up parse-events test to check the term config string. Signed-off-by: John Garry <john.garry@huawei.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linuxarm@huawei.com Cc: liuqi115@huawei.com Link: https://lore.kernel.org/r/1631795665-240946-2-git-send-email-john.garry@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28libtraceevent: Increase libtraceevent logging when verboseIan Rogers
libtraceevent has added more levels of debug printout and with changes like: https://lore.kernel.org/linux-trace-devel/20210507095022.1079364-3-tz.stoyanov@gmail.com previously generated output like "registering plugin" is no longer displayed. This change makes it so that if perf's verbose debug output is enabled then the debug and info libtraceevent messages can be displayed. The code is conditionally enabled based on the libtraceevent version as discussed in the RFC: https://lore.kernel.org/lkml/20210610060643.595673-1-irogers@google.com/ v2. Is a rebase and handles the case of building without LIBTRACEEVENT_DYNAMIC. Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Cc: linux-trace-devel@vger.kernel.org Link: http://lore.kernel.org/lkml/20210923001024.550263-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf tools: Add define for libtracefs versionIan Rogers
This will allow version specific support of libtracefs. Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Cc: linux-trace-devel@vger.kernel.org Link: http://lore.kernel.org/lkml/20210923001024.550263-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf tools: Add define for libtraceevent versionIan Rogers
The definition is derived from pkg-config as discussed in: https://lore.kernel.org/lkml/20210610155915.20a252d3@oasis.local.home/ The definition is computed using expr rather than passed to be computed in C code, this avoids complications with quote in the variable expansions. For example see the target python/perf.so in Makefile.perf. Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Cc: linux-trace-devel@vger.kernel.org Link: http://lore.kernel.org/lkml/20210923001024.550263-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf tools: Enable libtracefs dynamic linkingIan Rogers
Currently libtracefs isn't used by perf, but there are potential improvements by using it as identified Steven Rostedt's e-mail: https://lore.kernel.org/lkml/20210610154759.1ef958f0@oasis.local.home/ This change is modelled on the dynamic libtraceevent patch by Michael Petlan: https://lore.kernel.org/linux-perf-users/20210428092023.4009-1-mpetlan@redhat.com/ v3. Adds file missed in v1 and v2 spotted by Jiri Olsa. Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Cc: linux-trace-devel@vger.kernel.org Link: http://lore.kernel.org/lkml/20210923001024.550263-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf test: Workload test of all PMUsIan Rogers
Iterate over the list of PMUs and run the 'true' workload on them. If the event isn't printed then run the large 'perf bench internals synthesize' workload and check the event is counted. On a Skylake this test takes 1m15s mainly running the 'true' workload. Suggested-by: John Garry <john.garry@huawei.com> Signed-off-by: Ian Rogers <irogers@google.com> Reviewed-by: John Garry <john.garry@huawei.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jin Yao <yao.jin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Clarke <pc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20210917184240.2181186-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf test: Workload test of metric and metricgroupsIan Rogers
Test every metric and metricgroup with 'true' as a workload. For metrics, check that we see the metric printed or get unsupported. If the 'true' workload executes too quickly retry with 'perf bench internals synthesize'. v3. Fix test condition (thanks to Paul A. Clarke <pc@us.ibm.com>). Add a fallback case of a larger workload so that we don't ignore "<not counted>". v2. Switched the workload to something faster. Signed-off-by: Ian Rogers <irogers@google.com> Reviewed-by: John Garry <john.garry@huawei.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jin Yao <yao.jin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Clarke <pc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20210917184240.2181186-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-28perf jevents: Add __maybe_unused attribute to unused function argArnaldo Carvalho de Melo
The tools/perf/pmu-events/jevents.c file isn't being compiled with -Werror and -Wextra, which will be the case soon, so before we turn those compiler flags on, fix what it would flag. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Like Xu <like.xu.linux@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> To: John Garry <john.garry@huawei.com>
2021-09-28selftests: KVM: Don't clobber XMM register when readOliver Upton
There is no need to clobber a register that is only being read from. Oops. Drop the XMM register from the clobbers list. Signed-off-by: Oliver Upton <oupton@google.com> Message-Id: <20210927223621.50178-1-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf 2021-09-28 The following pull-request contains BPF updates for your *net* tree. We've added 10 non-merge commits during the last 14 day(s) which contain a total of 11 files changed, 139 insertions(+), 53 deletions(-). The main changes are: 1) Fix MIPS JIT jump code emission for too large offsets, from Piotr Krysiuk. 2) Fix x86 JIT atomic/fetch emission when dst reg maps to rax, from Johan Almbladh. 3) Fix cgroup_sk_alloc corner case when called from interrupt, from Daniel Borkmann. 4) Fix segfault in libbpf's linker for objects without BTF, from Kumar Kartikeya Dwivedi. 5) Fix bpf_jit_charge_modmem for applications with CAP_BPF, from Lorenz Bauer. 6) Fix return value handling for struct_ops BPF programs, from Hou Tao. 7) Various fixes to BPF selftests, from Jiri Benc. ==================== Signed-off-by: David S. Miller <davem@davemloft.net> ,
2021-09-28selftests, bpf: test_lwt_ip_encap: Really disable rp_filterJiri Benc
It's not enough to set net.ipv4.conf.all.rp_filter=0, that does not override a greater rp_filter value on the individual interfaces. We also need to set net.ipv4.conf.default.rp_filter=0 before creating the interfaces. That way, they'll also get their own rp_filter value of zero. Fixes: 0fde56e4385b0 ("selftests: bpf: add test_lwt_ip_encap selftest") Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/b1cdd9d469f09ea6e01e9c89a6071c79b7380f89.1632386362.git.jbenc@redhat.com
2021-09-28selftests, bpf: Fix makefile dependencies on libbpfJiri Benc
When building bpf selftest with make -j, I'm randomly getting build failures such as this one: In file included from progs/bpf_flow.c:19: [...]/tools/testing/selftests/bpf/tools/include/bpf/bpf_helpers.h:11:10: fatal error: 'bpf_helper_defs.h' file not found #include "bpf_helper_defs.h" ^~~~~~~~~~~~~~~~~~~ The file that fails the build varies between runs but it's always in the progs/ subdir. The reason is a missing make dependency on libbpf for the .o files in progs/. There was a dependency before commit 3ac2e20fba07e but that commit removed it to prevent unneeded rebuilds. However, that only works if libbpf has been built already; the 'wildcard' prerequisite does not trigger when there's no bpf_helper_defs.h generated yet. Keep the libbpf as an order-only prerequisite to satisfy both goals. It is always built before the progs/ objects but it does not trigger unnecessary rebuilds by itself. Fixes: 3ac2e20fba07e ("selftests/bpf: BPF object files should depend only on libbpf headers") Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/ee84ab66436fba05a197f952af23c98d90eb6243.1632758415.git.jbenc@redhat.com
2021-09-28libbpf: Fix segfault in static linker for objects without BTFKumar Kartikeya Dwivedi
When a BPF object is compiled without BTF info (without -g), trying to link such objects using bpftool causes a SIGSEGV due to btf__get_nr_types accessing obj->btf which is NULL. Fix this by checking for the NULL pointer, and return error. Reproducer: $ cat a.bpf.c extern int foo(void); int bar(void) { return foo(); } $ cat b.bpf.c int foo(void) { return 0; } $ clang -O2 -target bpf -c a.bpf.c $ clang -O2 -target bpf -c b.bpf.c $ bpftool gen obj out a.bpf.o b.bpf.o Segmentation fault (core dumped) After fix: $ bpftool gen obj out a.bpf.o b.bpf.o libbpf: failed to find BTF info for object 'a.bpf.o' Error: failed to link 'a.bpf.o': Unknown error -22 (-22) Fixes: a46349227cd8 (libbpf: Add linker extern resolution support for functions and global variables) Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210924023725.70228-1-memxor@gmail.com
2021-09-27libbpf: Ignore STT_SECTION symbols in 'maps' sectionToke Høiland-Jørgensen
When parsing legacy map definitions, libbpf would error out when encountering an STT_SECTION symbol. This becomes a problem because some versions of binutils will produce SECTION symbols for every section when processing an ELF file, so BPF files run through 'strip' will end up with such symbols, making libbpf refuse to load them. There's not really any reason why erroring out is strictly necessary, so change libbpf to just ignore SECTION symbols when parsing the ELF. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210927205810.715656-1-toke@redhat.com
2021-09-28selftests: xsk: Add frame_headroom testMagnus Karlsson
Add a test for the frame_headroom feature that can be set on the umem. The logic added validates that all offsets in all tests and packets are valid, not just the ones that have a specifically configured frame_headroom. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210922075613.12186-14-magnus.karlsson@gmail.com
2021-09-28selftests: xsk: Change interleaving of packets in unaligned modeMagnus Karlsson
Change the interleaving of packets in unaligned mode. With the current buffer addresses in the packet stream, the last buffer in the umem could not be used as a large packet could potentially write over the end of the umem. The kernel correctly threw this buffer address away and refused to use it. This is perfectly fine for all regular packet streams, but the ones used for unaligned mode have every other packet being at some different offset. As we will add checks for correct offsets in the next patch, this needs to be fixed. Just start these page-boundary straddling buffers one page earlier so that the last one is not on the last page of the umem, making all buffers valid. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210922075613.12186-13-magnus.karlsson@gmail.com
2021-09-28selftests: xsk: Add single packet testMagnus Karlsson
Add a test where a single packet is sent and received. This might sound like a silly test, but since many of the interfaces in xsk are batched, it is important to be able to validate that we did not break something as fundamental as just receiving single packets, instead of batches of packets at high speed. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210922075613.12186-12-magnus.karlsson@gmail.com
2021-09-28selftests: xsk: Introduce pacing of trafficMagnus Karlsson
Introduce pacing of traffic so that the Tx thread can never send more packets than the receiver has processed plus the number of packets it can have in its umem. So at any point in time, the number of in flight packets (not processed by the Rx thread) are less than or equal to the number of packets that can be held in the Rx thread's umem. The batch size is also increased to improve running time. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210922075613.12186-11-magnus.karlsson@gmail.com
2021-09-28selftests: xsk: Fix socket creation retryMagnus Karlsson
The socket creation retry unnecessarily registered the umem once for every retry. No reason to do this. It wastes memory and it might lead to too many pages being locked at some point and the failure of a test. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210922075613.12186-10-magnus.karlsson@gmail.com
2021-09-28selftests: xsk: Put the same buffer only once in the fill ringMagnus Karlsson
Fix a problem where the fill ring was populated with too many entries. If number of buffers in the umem was smaller than the fill ring size, the code used to loop over from the beginning of the umem and start putting the same buffers in again. This is racy indeed as a later packet can be received overwriting an earlier one before the Rx thread manages to validate it. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210922075613.12186-9-magnus.karlsson@gmail.com
2021-09-28selftests: xsk: Fix missing initializationMagnus Karlsson
Fix missing initialization of the member rx_pkt_nb in the packet stream. This leads to some tests declaring success too early as the test thought all packets had already been received. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210922075613.12186-8-magnus.karlsson@gmail.com
2021-09-27Merge tag 'perf-tools-fixes-for-v5.15-2021-09-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux Pull more perf tools fixes from Arnaldo Carvalho de Melo: - Fix 'perf test' DWARF unwind for optimized builds. - Fix 'perf test' 'Object code reading' when dealing with samples in @plt symbols. - Fix off-by-one directory paths in the ARM support code. - Fix error message to eliminate confusion in 'perf config' when first creating a config file. - 'perf iostat' fix for system wide operation. - Fix printing of metrics when 'perf iostat' is used with one or more iio_root_ports and unconnected cpus (using -C). - Fix several typos in the documentation files. - Fix spelling mistake "icach" -> "icache" in the power8 JSON vendor files. * tag 'perf-tools-fixes-for-v5.15-2021-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: perf iostat: Fix Segmentation fault from NULL 'struct perf_counts_values *' perf iostat: Use system-wide mode if the target cpu_list is unspecified perf config: Refine error message to eliminate confusion perf doc: Fix typos all over the place perf arm: Fix off-by-one directory paths. perf vendor events powerpc: Fix spelling mistake "icach" -> "icache" perf tests: Fix flaky test 'Object code reading' perf test: Fix DWARF unwind for optimized builds.
2021-09-27Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "A bit late... I got sidetracked by back-from-vacation routines and conferences. But most of these patches are already a few weeks old and things look more calm on the mailing list than what this pull request would suggest. x86: - missing TLB flush - nested virtualization fixes for SMM (secure boot on nested hypervisor) and other nested SVM fixes - syscall fuzzing fixes - live migration fix for AMD SEV - mirror VMs now work for SEV-ES too - fixes for reset - possible out-of-bounds access in IOAPIC emulation - fix enlightened VMCS on Windows 2022 ARM: - Add missing FORCE target when building the EL2 object - Fix a PMU probe regression on some platforms Generic: - KCSAN fixes selftests: - random fixes, mostly for clang compilation" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (43 commits) selftests: KVM: Explicitly use movq to read xmm registers selftests: KVM: Call ucall_init when setting up in rseq_test KVM: Remove tlbs_dirty KVM: X86: Synchronize the shadow pagetable before link it KVM: X86: Fix missed remote tlb flush in rmap_write_protect() KVM: x86: nSVM: don't copy virt_ext from vmcb12 KVM: x86: nSVM: test eax for 4K alignment for GP errata workaround KVM: x86: selftests: test simultaneous uses of V_IRQ from L1 and L0 KVM: x86: nSVM: restore int_vector in svm_clear_vintr kvm: x86: Add AMD PMU MSRs to msrs_to_save_all[] KVM: x86: nVMX: re-evaluate emulation_required on nested VM exit KVM: x86: nVMX: don't fail nested VM entry on invalid guest state if !from_vmentry KVM: x86: VMX: synthesize invalid VM exit when emulating invalid guest state KVM: x86: nSVM: refactor svm_leave_smm and smm_enter_smm KVM: x86: SVM: call KVM_REQ_GET_NESTED_STATE_PAGES on exit from SMM mode KVM: x86: reset pdptrs_from_userspace when exiting smm KVM: x86: nSVM: restore the L1 host state prior to resuming nested guest on SMM exit KVM: nVMX: Filter out all unsupported controls when eVMCS was activated KVM: KVM: Use cpumask_available() to check for NULL cpumask when kicking vCPUs KVM: Clean up benign vcpu->cpu data races when kicking vCPUs ...
2021-09-27selftests: drivers/dma-buf: Fix implicit declaration warnsShuah Khan
udmabuf has the following implicit declaration warns: udmabuf.c:30:10: warning: implicit declaration of function 'open'; udmabuf.c:42:8: warning: implicit declaration of function 'fcntl' These are caused due to not including fcntl.h and including just linux/fcntl.h. Fix it to include fcntl.h which will bring in the linux/fcntl.h. In addition, define __EXPORTED_HEADERS__ to bring in F_ADD_SEALS and F_SEAL_SHRINK defines and fix the following error that show up when just fcntl.h is included. udmabuf.c:45:21: error: 'F_ADD_SEALS' undeclared 45 | ret = fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK); | ^~~~~~~~~~~ udmabuf.c:45:34: error: 'F_SEAL_SHRINK' undeclared 45 | ret = fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK); | ^~~~~~~~~~~~~ Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2021-09-27perf iostat: Fix Segmentation fault from NULL 'struct perf_counts_values *'Like Xu
If the 'perf iostat' user specifies two or more iio_root_ports and also specifies the cpu(s) by -C which is not *connected to all* the above iio ports, the iostat_print_metric() will run into trouble: For example: $ perf iostat list S0-uncore_iio_0<0000:16> S1-uncore_iio_0<0000:97> # <--- CPU 1 is located in the socket S0 $ perf iostat 0000:16,0000:97 -C 1 -- ls port Inbound Read(MB) Inbound Write(MB) Outbound Read(MB) Outbound Write(MB) ../perf-iostat: line 12: 104418 Segmentation fault (core dumped) perf stat --iostat$DELIMITER$* The core-dump stack says, in the above corner case, the returned (struct perf_counts_values *) count will be NULL, and the caller iostat_print_metric() apparently doesn't not handle this case. 433 struct perf_counts_values *count = perf_counts(evsel->counts, die, 0); 434 435 if (count->run && count->ena) { (gdb) p count $1 = (struct perf_counts_values *) 0x0 The deeper reason is that there are actually no statistics from the user specified pair "iostat 0000:X, -C (disconnected) Y ", but let's fix it with minimum cost by adding a NULL check in the user space. Fixes: f9ed693e8bc0e7de ("perf stat: Enable iostat mode for x86 platforms") Signed-off-by: Like Xu <likexu@tencent.com> Cc: Alexander Antonov <alexander.antonov@linux.intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20210927081115.39568-2-likexu@tencent.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-27perf iostat: Use system-wide mode if the target cpu_list is unspecifiedLike Xu
An iostate use case like "perf iostat 0000:16,0000:97 -- ls" should be implemented to work in system-wide mode to ensure that the output from print_header() is consistent with the user documentation perf-iostat.txt, rather than incorrectly assuming that the kernel does not support it: Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) \ for event (uncore_iio_0/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/). /bin/dmesg | grep -i perf may provide additional information. This error is easily fixed by assigning system-wide mode by default for IOSTAT_RUN only when the target cpu_list is unspecified. Fixes: f07952b179697771 ("perf stat: Basic support for iostat in perf") Signed-off-by: Like Xu <likexu@tencent.com> Cc: Alexander Antonov <alexander.antonov@linux.intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20210927081115.39568-1-likexu@tencent.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-27perf annotate: Add riscv64 supportWilliam Cohen
This patch adds basic arch initialization and instruction associate support for the riscv64 CPU architecture. Example output: $ perf annotate --stdio2 Samples: 122K of event 'task-clock:u', 4000 Hz, Event count (approx.): 30637250000, [percent: local period] strcmp() /usr/lib64/libc-2.32.so Percent Disassembly of section .text: 0000000000069a30 <strcmp>: __GI_strcmp(): const unsigned char *s2 = (const unsigned char *) p2; unsigned char c1, c2; do { c1 = (unsigned char) *s1++; 37.30 lbu a5,0(a0) c2 = (unsigned char) *s2++; 1.23 addi a1,a1,1 c1 = (unsigned char) *s1++; 18.68 addi a0,a0,1 c2 = (unsigned char) *s2++; 1.37 lbu a4,-1(a1) if (c1 == '\0') 18.71 ↓ beqz a5,18 return c1 - c2; } Signed-off-by: William Cohen <wcohen@redhat.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-riscv@lists.infradead.org Link: http://lore.kernel.org/lkml/20210927005115.610264-1-wcohen@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>