builtin-test.c

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/*
 * builtin-test.c
 *
 * Builtin regression testing command: ever growing number of sanity tests
 */
#include "builtin.h"

#include "util/cache.h"
#include "util/debug.h"
#include "util/debugfs.h"
#include "util/evlist.h"
#include "util/parse-options.h"
#include "util/parse-events.h"
#include "util/symbol.h"
#include "util/thread_map.h"
#include "util/pmu.h"
#include "event-parse.h"
#include <linux/hw_breakpoint.h>

#include <sys/mman.h>

static int vmlinux_matches_kallsyms_filter(struct map *map __maybe_unused,
                       struct symbol *sym)
{
    bool *visited = symbol__priv(sym);
    *visited = true;
    return 0;
}

static int test__vmlinux_matches_kallsyms(void)
{
    int err = -1;
    struct rb_node *nd;
    struct symbol *sym;
    struct map *kallsyms_map, *vmlinux_map;
    struct machine kallsyms, vmlinux;
    enum map_type type = MAP__FUNCTION;
    long page_size = sysconf(_SC_PAGE_SIZE);
    struct ref_reloc_sym ref_reloc_sym = { .name = "_stext", };

    /*
     * Step 1:
     *
     * Init the machines that will hold kernel, modules obtained from
     * both vmlinux + .ko files and from /proc/kallsyms split by modules.
     */
    machine__init(&kallsyms, "", HOST_KERNEL_ID);
    machine__init(&vmlinux, "", HOST_KERNEL_ID);

    /*
     * Step 2:
     *
     * Create the kernel maps for kallsyms and the DSO where we will then
     * load /proc/kallsyms. Also create the modules maps from /proc/modules
     * and find the .ko files that match them in /lib/modules/`uname -r`/.
     */
    if (machine__create_kernel_maps(&kallsyms) < 0) {
        pr_debug("machine__create_kernel_maps ");
        return -1;
    }

    /*
     * Step 3:
     *
     * Load and split /proc/kallsyms into multiple maps, one per module.
     */
    if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, NULL) <= 0) {
        pr_debug("dso__load_kallsyms ");
        goto out;
    }

    /*
     * Step 4:
     *
     * kallsyms will be internally on demand sorted by name so that we can
     * find the reference relocation * symbol, i.e. the symbol we will use
     * to see if the running kernel was relocated by checking if it has the
     * same value in the vmlinux file we load.
     */
    kallsyms_map = machine__kernel_map(&kallsyms, type);

    sym = map__find_symbol_by_name(kallsyms_map, ref_reloc_sym.name, NULL);
    if (sym == NULL) {
        pr_debug("dso__find_symbol_by_name ");
        goto out;
    }

    ref_reloc_sym.addr = sym->start;

    /*
     * Step 5:
     *
     * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
     */
    if (machine__create_kernel_maps(&vmlinux) < 0) {
        pr_debug("machine__create_kernel_maps ");
        goto out;
    }

    vmlinux_map = machine__kernel_map(&vmlinux, type);
    map__kmap(vmlinux_map)->ref_reloc_sym = &ref_reloc_sym;

    /*
     * Step 6:
     *
     * Locate a vmlinux file in the vmlinux path that has a buildid that
     * matches the one of the running kernel.
     *
     * While doing that look if we find the ref reloc symbol, if we find it
     * we'll have its ref_reloc_symbol.unrelocated_addr and then
     * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
     * to fixup the symbols.
     */
    if (machine__load_vmlinux_path(&vmlinux, type,
                       vmlinux_matches_kallsyms_filter) <= 0) {
        pr_debug("machine__load_vmlinux_path ");
        goto out;
    }

    err = 0;
    /*
     * Step 7:
     *
     * Now look at the symbols in the vmlinux DSO and check if we find all of them
     * in the kallsyms dso. For the ones that are in both, check its names and
     * end addresses too.
     */
    for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
        struct symbol *pair, *first_pair;
        bool backwards = true;

        sym  = rb_entry(nd, struct symbol, rb_node);

        if (sym->start == sym->end)
            continue;

        first_pair = machine__find_kernel_symbol(&kallsyms, type, sym->start, NULL, NULL);
        pair = first_pair;

        if (pair && pair->start == sym->start) {
next_pair:
            if (strcmp(sym->name, pair->name) == 0) {
                /*
                 * kallsyms don't have the symbol end, so we
                 * set that by using the next symbol start - 1,
                 * in some cases we get this up to a page
                 * wrong, trace_kmalloc when I was developing
                 * this code was one such example, 2106 bytes
                 * off the real size. More than that and we
                 * _really_ have a problem.
                 */
                s64 skew = sym->end - pair->end;
                if (llabs(skew) < page_size)
                    continue;

                pr_debug("%#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n",
                     sym->start, sym->name, sym->end, pair->end);
            } else {
                struct rb_node *nnd;
detour:
                nnd = backwards ? rb_prev(&pair->rb_node) :
                          rb_next(&pair->rb_node);
                if (nnd) {
                    struct symbol *next = rb_entry(nnd, struct symbol, rb_node);

                    if (next->start == sym->start) {
                        pair = next;
                        goto next_pair;
                    }
                }

                if (backwards) {
                    backwards = false;
                    pair = first_pair;
                    goto detour;
                }

                pr_debug("%#" PRIx64 ": diff name v: %s k: %s\n",
                     sym->start, sym->name, pair->name);
            }
        } else
            pr_debug("%#" PRIx64 ": %s not on kallsyms\n", sym->start, sym->name);

        err = -1;
    }

    if (!verbose)
        goto out;

    pr_info("Maps only in vmlinux:\n");

    for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
        struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
        /*
         * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
         * the kernel will have the path for the vmlinux file being used,
         * so use the short name, less descriptive but the same ("[kernel]" in
         * both cases.
         */
        pair = map_groups__find_by_name(&kallsyms.kmaps, type,
                        (pos->dso->kernel ?
                            pos->dso->short_name :
                            pos->dso->name));
        if (pair)
            pair->priv = 1;
        else
            map__fprintf(pos, stderr);
    }

    pr_info("Maps in vmlinux with a different name in kallsyms:\n");

    for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
        struct map *pos = rb_entry(nd, struct map, rb_node), *pair;

        pair = map_groups__find(&kallsyms.kmaps, type, pos->start);
        if (pair == NULL || pair->priv)
            continue;

        if (pair->start == pos->start) {
            pair->priv = 1;
            pr_info(" %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as",
                pos->start, pos->end, pos->pgoff, pos->dso->name);
            if (pos->pgoff != pair->pgoff || pos->end != pair->end)
                pr_info(": \n*%" PRIx64 "-%" PRIx64 " %" PRIx64 "",
                    pair->start, pair->end, pair->pgoff);
            pr_info(" %s\n", pair->dso->name);
            pair->priv = 1;
        }
    }

    pr_info("Maps only in kallsyms:\n");

    for (nd = rb_first(&kallsyms.kmaps.maps[type]);
         nd; nd = rb_next(nd)) {
        struct map *pos = rb_entry(nd, struct map, rb_node);

        if (!pos->priv)
            map__fprintf(pos, stderr);
    }
out:
    return err;
}

#include "util/cpumap.h"
#include "util/evsel.h"
#include <sys/types.h>

static int trace_event__id(const char *evname)
{
    char *filename;
    int err = -1, fd;

    if (asprintf(&filename,
             "%s/syscalls/%s/id",
             tracing_events_path, evname) < 0)
        return -1;

    fd = open(filename, O_RDONLY);
    if (fd >= 0) {
        char id[16];
        if (read(fd, id, sizeof(id)) > 0)
            err = atoi(id);
        close(fd);
    }

    free(filename);
    return err;
}

static int test__open_syscall_event(void)
{
    int err = -1, fd;
    struct thread_map *threads;
    struct perf_evsel *evsel;
    struct perf_event_attr attr;
    unsigned int nr_open_calls = 111, i;
    int id = trace_event__id("sys_enter_open");

    if (id < 0) {
        pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
        return -1;
    }

    threads = thread_map__new(-1, getpid(), UINT_MAX);
    if (threads == NULL) {
        pr_debug("thread_map__new\n");
        return -1;
    }

    memset(&attr, 0, sizeof(attr));
    attr.type = PERF_TYPE_TRACEPOINT;
    attr.config = id;
    evsel = perf_evsel__new(&attr, 0);
    if (evsel == NULL) {
        pr_debug("perf_evsel__new\n");
        goto out_thread_map_delete;
    }

    if (perf_evsel__open_per_thread(evsel, threads) < 0) {
        pr_debug("failed to open counter: %s, "
             "tweak /proc/sys/kernel/perf_event_paranoid?\n",
             strerror(errno));
        goto out_evsel_delete;
    }

    for (i = 0; i < nr_open_calls; ++i) {
        fd = open("/etc/passwd", O_RDONLY);
        close(fd);
    }

    if (perf_evsel__read_on_cpu(evsel, 0, 0) < 0) {
        pr_debug("perf_evsel__read_on_cpu\n");
        goto out_close_fd;
    }

    if (evsel->counts->cpu[0].val != nr_open_calls) {
        pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls, got %" PRIu64 "\n",
             nr_open_calls, evsel->counts->cpu[0].val);
        goto out_close_fd;
    }
    
    err = 0;
out_close_fd:
    perf_evsel__close_fd(evsel, 1, threads->nr);
out_evsel_delete:
    perf_evsel__delete(evsel);
out_thread_map_delete:
    thread_map__delete(threads);
    return err;
}

#include <sched.h>

static int test__open_syscall_event_on_all_cpus(void)
{
    int err = -1, fd, cpu;
    struct thread_map *threads;
    struct cpu_map *cpus;
    struct perf_evsel *evsel;
    struct perf_event_attr attr;
    unsigned int nr_open_calls = 111, i;
    cpu_set_t cpu_set;
    int id = trace_event__id("sys_enter_open");

    if (id < 0) {
        pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
        return -1;
    }

    threads = thread_map__new(-1, getpid(), UINT_MAX);
    if (threads == NULL) {
        pr_debug("thread_map__new\n");
        return -1;
    }

    cpus = cpu_map__new(NULL);
    if (cpus == NULL) {
        pr_debug("cpu_map__new\n");
        goto out_thread_map_delete;
    }


    CPU_ZERO(&cpu_set);

    memset(&attr, 0, sizeof(attr));
    attr.type = PERF_TYPE_TRACEPOINT;
    attr.config = id;
    evsel = perf_evsel__new(&attr, 0);
    if (evsel == NULL) {
        pr_debug("perf_evsel__new\n");
        goto out_thread_map_delete;
    }

    if (perf_evsel__open(evsel, cpus, threads) < 0) {
        pr_debug("failed to open counter: %s, "
             "tweak /proc/sys/kernel/perf_event_paranoid?\n",
             strerror(errno));
        goto out_evsel_delete;
    }

    for (cpu = 0; cpu < cpus->nr; ++cpu) {
        unsigned int ncalls = nr_open_calls + cpu;
        /*
         * XXX eventually lift this restriction in a way that
         * keeps perf building on older glibc installations
         * without CPU_ALLOC. 1024 cpus in 2010 still seems
         * a reasonable upper limit tho :-)
         */
        if (cpus->map[cpu] >= CPU_SETSIZE) {
            pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
            continue;
        }

        CPU_SET(cpus->map[cpu], &cpu_set);
        if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
            pr_debug("sched_setaffinity() failed on CPU %d: %s ",
                 cpus->map[cpu],
                 strerror(errno));
            goto out_close_fd;
        }
        for (i = 0; i < ncalls; ++i) {
            fd = open("/etc/passwd", O_RDONLY);
            close(fd);
        }
        CPU_CLR(cpus->map[cpu], &cpu_set);
    }

    /*
     * Here we need to explicitely preallocate the counts, as if
     * we use the auto allocation it will allocate just for 1 cpu,
     * as we start by cpu 0.
     */
    if (perf_evsel__alloc_counts(evsel, cpus->nr) < 0) {
        pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
        goto out_close_fd;
    }

    err = 0;

    for (cpu = 0; cpu < cpus->nr; ++cpu) {
        unsigned int expected;

        if (cpus->map[cpu] >= CPU_SETSIZE)
            continue;

        if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
            pr_debug("perf_evsel__read_on_cpu\n");
            err = -1;
            break;
        }

        expected = nr_open_calls + cpu;
        if (evsel->counts->cpu[cpu].val != expected) {
            pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
                 expected, cpus->map[cpu], evsel->counts->cpu[cpu].val);
            err = -1;
        }
    }

out_close_fd:
    perf_evsel__close_fd(evsel, 1, threads->nr);
out_evsel_delete:
    perf_evsel__delete(evsel);
out_thread_map_delete:
    thread_map__delete(threads);
    return err;
}

/*
 * This test will generate random numbers of calls to some getpid syscalls,
 * then establish an mmap for a group of events that are created to monitor
 * the syscalls.
 *
 * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
 * sample.id field to map back to its respective perf_evsel instance.
 *
 * Then it checks if the number of syscalls reported as perf events by
 * the kernel corresponds to the number of syscalls made.
 */
static int test__basic_mmap(void)
{
    int err = -1;
    union perf_event *event;
    struct thread_map *threads;
    struct cpu_map *cpus;
    struct perf_evlist *evlist;
    struct perf_event_attr attr = {
        .type       = PERF_TYPE_TRACEPOINT,
        .read_format    = PERF_FORMAT_ID,
        .sample_type    = PERF_SAMPLE_ID,
        .watermark  = 0,
    };
    cpu_set_t cpu_set;
    const char *syscall_names[] = { "getsid", "getppid", "getpgrp",
                    "getpgid", };
    pid_t (*syscalls[])(void) = { (void *)getsid, getppid, getpgrp,
                      (void*)getpgid };
#define nsyscalls ARRAY_SIZE(syscall_names)
    int ids[nsyscalls];
    unsigned int nr_events[nsyscalls],
             expected_nr_events[nsyscalls], i, j;
    struct perf_evsel *evsels[nsyscalls], *evsel;

    for (i = 0; i < nsyscalls; ++i) {
        char name[64];

        snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
        ids[i] = trace_event__id(name);
        if (ids[i] < 0) {
            pr_debug("Is debugfs mounted on /sys/kernel/debug?\n");
            return -1;
        }
        nr_events[i] = 0;
        expected_nr_events[i] = random() % 257;
    }

    threads = thread_map__new(-1, getpid(), UINT_MAX);
    if (threads == NULL) {
        pr_debug("thread_map__new\n");
        return -1;
    }

    cpus = cpu_map__new(NULL);
    if (cpus == NULL) {
        pr_debug("cpu_map__new\n");
        goto out_free_threads;
    }

    CPU_ZERO(&cpu_set);
    CPU_SET(cpus->map[0], &cpu_set);
    sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
    if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
        pr_debug("sched_setaffinity() failed on CPU %d: %s ",
             cpus->map[0], strerror(errno));
        goto out_free_cpus;
    }

    evlist = perf_evlist__new(cpus, threads);
    if (evlist == NULL) {
        pr_debug("perf_evlist__new\n");
        goto out_free_cpus;
    }

    /* anonymous union fields, can't be initialized above */
    attr.wakeup_events = 1;
    attr.sample_period = 1;

    for (i = 0; i < nsyscalls; ++i) {
        attr.config = ids[i];
        evsels[i] = perf_evsel__new(&attr, i);
        if (evsels[i] == NULL) {
            pr_debug("perf_evsel__new\n");
            goto out_free_evlist;
        }

        perf_evlist__add(evlist, evsels[i]);

        if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
            pr_debug("failed to open counter: %s, "
                 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
                 strerror(errno));
            goto out_close_fd;
        }
    }

    if (perf_evlist__mmap(evlist, 128, true) < 0) {
        pr_debug("failed to mmap events: %d (%s)\n", errno,
             strerror(errno));
        goto out_close_fd;
    }

    for (i = 0; i < nsyscalls; ++i)
        for (j = 0; j < expected_nr_events[i]; ++j) {
            int foo = syscalls[i]();
            ++foo;
        }

    while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
        struct perf_sample sample;

        if (event->header.type != PERF_RECORD_SAMPLE) {
            pr_debug("unexpected %s event\n",
                 perf_event__name(event->header.type));
            goto out_munmap;
        }

        err = perf_evlist__parse_sample(evlist, event, &sample);
        if (err) {
            pr_err("Can't parse sample, err = %d\n", err);
            goto out_munmap;
        }

        evsel = perf_evlist__id2evsel(evlist, sample.id);
        if (evsel == NULL) {
            pr_debug("event with id %" PRIu64
                 " doesn't map to an evsel\n", sample.id);
            goto out_munmap;
        }
        nr_events[evsel->idx]++;
    }

    list_for_each_entry(evsel, &evlist->entries, node) {
        if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
            pr_debug("expected %d %s events, got %d\n",
                 expected_nr_events[evsel->idx],
                 perf_evsel__name(evsel), nr_events[evsel->idx]);
            goto out_munmap;
        }
    }

    err = 0;
out_munmap:
    perf_evlist__munmap(evlist);
out_close_fd:
    for (i = 0; i < nsyscalls; ++i)
        perf_evsel__close_fd(evsels[i], 1, threads->nr);
out_free_evlist:
    perf_evlist__delete(evlist);
out_free_cpus:
    cpu_map__delete(cpus);
out_free_threads:
    thread_map__delete(threads);
    return err;
#undef nsyscalls
}

static int sched__get_first_possible_cpu(pid_t pid, cpu_set_t *maskp)
{
    int i, cpu = -1, nrcpus = 1024;
realloc:
    CPU_ZERO(maskp);

    if (sched_getaffinity(pid, sizeof(*maskp), maskp) == -1) {
        if (errno == EINVAL && nrcpus < (1024 << 8)) {
            nrcpus = nrcpus << 2;
            goto realloc;
        }
        perror("sched_getaffinity");
            return -1;
    }

    for (i = 0; i < nrcpus; i++) {
        if (CPU_ISSET(i, maskp)) {
            if (cpu == -1)
                cpu = i;
            else
                CPU_CLR(i, maskp);
        }
    }

    return cpu;
}

static int test__PERF_RECORD(void)
{
    struct perf_record_opts opts = {
        .target = {
            .uid = UINT_MAX,
            .uses_mmap = true,
        },
        .no_delay   = true,
        .freq       = 10,
        .mmap_pages = 256,
    };
    cpu_set_t cpu_mask;
    size_t cpu_mask_size = sizeof(cpu_mask);
    struct perf_evlist *evlist = perf_evlist__new(NULL, NULL);
    struct perf_evsel *evsel;
    struct perf_sample sample;
    const char *cmd = "sleep";
    const char *argv[] = { cmd, "1", NULL, };
    char *bname;
    u64 prev_time = 0;
    bool found_cmd_mmap = false,
         found_libc_mmap = false,
         found_vdso_mmap = false,
         found_ld_mmap = false;
    int err = -1, errs = 0, i, wakeups = 0;
    u32 cpu;
    int total_events = 0, nr_events[PERF_RECORD_MAX] = { 0, };

    if (evlist == NULL || argv == NULL) {
        pr_debug("Not enough memory to create evlist\n");
        goto out;
    }

    /*
     * We need at least one evsel in the evlist, use the default
     * one: "cycles".
     */
    err = perf_evlist__add_default(evlist);
    if (err < 0) {
        pr_debug("Not enough memory to create evsel\n");
        goto out_delete_evlist;
    }

    /*
     * Create maps of threads and cpus to monitor. In this case
     * we start with all threads and cpus (-1, -1) but then in
     * perf_evlist__prepare_workload we'll fill in the only thread
     * we're monitoring, the one forked there.
     */
    err = perf_evlist__create_maps(evlist, &opts.target);
    if (err < 0) {
        pr_debug("Not enough memory to create thread/cpu maps\n");
        goto out_delete_evlist;
    }

    /*
     * Prepare the workload in argv[] to run, it'll fork it, and then wait
     * for perf_evlist__start_workload() to exec it. This is done this way
     * so that we have time to open the evlist (calling sys_perf_event_open
     * on all the fds) and then mmap them.
     */
    err = perf_evlist__prepare_workload(evlist, &opts, argv);
    if (err < 0) {
        pr_debug("Couldn't run the workload!\n");
        goto out_delete_evlist;
    }

    /*
     * Config the evsels, setting attr->comm on the first one, etc.
     */
    evsel = perf_evlist__first(evlist);
    evsel->attr.sample_type |= PERF_SAMPLE_CPU;
    evsel->attr.sample_type |= PERF_SAMPLE_TID;
    evsel->attr.sample_type |= PERF_SAMPLE_TIME;
    perf_evlist__config_attrs(evlist, &opts);

    err = sched__get_first_possible_cpu(evlist->workload.pid, &cpu_mask);
    if (err < 0) {
        pr_debug("sched__get_first_possible_cpu: %s\n", strerror(errno));
        goto out_delete_evlist;
    }

    cpu = err;

    /*
     * So that we can check perf_sample.cpu on all the samples.
     */
    if (sched_setaffinity(evlist->workload.pid, cpu_mask_size, &cpu_mask) < 0) {
        pr_debug("sched_setaffinity: %s\n", strerror(errno));
        goto out_delete_evlist;
    }

    /*
     * Call sys_perf_event_open on all the fds on all the evsels,
     * grouping them if asked to.
     */
    err = perf_evlist__open(evlist);
    if (err < 0) {
        pr_debug("perf_evlist__open: %s\n", strerror(errno));
        goto out_delete_evlist;
    }

    /*
     * mmap the first fd on a given CPU and ask for events for the other
     * fds in the same CPU to be injected in the same mmap ring buffer
     * (using ioctl(PERF_EVENT_IOC_SET_OUTPUT)).
     */
    err = perf_evlist__mmap(evlist, opts.mmap_pages, false);
    if (err < 0) {
        pr_debug("perf_evlist__mmap: %s\n", strerror(errno));
        goto out_delete_evlist;
    }

    /*
     * Now that all is properly set up, enable the events, they will
     * count just on workload.pid, which will start...
     */
    perf_evlist__enable(evlist);

    /*
     * Now!
     */
    perf_evlist__start_workload(evlist);

    while (1) {
        int before = total_events;

        for (i = 0; i < evlist->nr_mmaps; i++) {
            union perf_event *event;

            while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
                const u32 type = event->header.type;
                const char *name = perf_event__name(type);

                ++total_events;
                if (type < PERF_RECORD_MAX)
                    nr_events[type]++;

                err = perf_evlist__parse_sample(evlist, event, &sample);
                if (err < 0) {
                    if (verbose)
                        perf_event__fprintf(event, stderr);
                    pr_debug("Couldn't parse sample\n");
                    goto out_err;
                }

                if (verbose) {
                    pr_info("%" PRIu64" %d ", sample.time, sample.cpu);
                    perf_event__fprintf(event, stderr);
                }

                if (prev_time > sample.time) {
                    pr_debug("%s going backwards in time, prev=%" PRIu64 ", curr=%" PRIu64 "\n",
                         name, prev_time, sample.time);
                    ++errs;
                }

                prev_time = sample.time;

                if (sample.cpu != cpu) {
                    pr_debug("%s with unexpected cpu, expected %d, got %d\n",
                         name, cpu, sample.cpu);
                    ++errs;
                }

                if ((pid_t)sample.pid != evlist->workload.pid) {
                    pr_debug("%s with unexpected pid, expected %d, got %d\n",
                         name, evlist->workload.pid, sample.pid);
                    ++errs;
                }

                if ((pid_t)sample.tid != evlist->workload.pid) {
                    pr_debug("%s with unexpected tid, expected %d, got %d\n",
                         name, evlist->workload.pid, sample.tid);
                    ++errs;
                }

                if ((type == PERF_RECORD_COMM ||
                     type == PERF_RECORD_MMAP ||
                     type == PERF_RECORD_FORK ||
                     type == PERF_RECORD_EXIT) &&
                     (pid_t)event->comm.pid != evlist->workload.pid) {
                    pr_debug("%s with unexpected pid/tid\n", name);
                    ++errs;
                }

                if ((type == PERF_RECORD_COMM ||
                     type == PERF_RECORD_MMAP) &&
                     event->comm.pid != event->comm.tid) {
                    pr_debug("%s with different pid/tid!\n", name);
                    ++errs;
                }

                switch (type) {
                case PERF_RECORD_COMM:
                    if (strcmp(event->comm.comm, cmd)) {
                        pr_debug("%s with unexpected comm!\n", name);
                        ++errs;
                    }
                    break;
                case PERF_RECORD_EXIT:
                    goto found_exit;
                case PERF_RECORD_MMAP:
                    bname = strrchr(event->mmap.filename, '/');
                    if (bname != NULL) {
                        if (!found_cmd_mmap)
                            found_cmd_mmap = !strcmp(bname + 1, cmd);
                        if (!found_libc_mmap)
                            found_libc_mmap = !strncmp(bname + 1, "libc", 4);
                        if (!found_ld_mmap)
                            found_ld_mmap = !strncmp(bname + 1, "ld", 2);
                    } else if (!found_vdso_mmap)
                        found_vdso_mmap = !strcmp(event->mmap.filename, "[vdso]");
                    break;

                case PERF_RECORD_SAMPLE:
                    /* Just ignore samples for now */
                    break;
                default:
                    pr_debug("Unexpected perf_event->header.type %d!\n",
                         type);
                    ++errs;
                }
            }
        }

        /*
         * We don't use poll here because at least at 3.1 times the
         * PERF_RECORD_{!SAMPLE} events don't honour
         * perf_event_attr.wakeup_events, just PERF_EVENT_SAMPLE does.
         */
        if (total_events == before && false)
            poll(evlist->pollfd, evlist->nr_fds, -1);

        sleep(1);
        if (++wakeups > 5) {
            pr_debug("No PERF_RECORD_EXIT event!\n");
            break;
        }
    }

found_exit:
    if (nr_events[PERF_RECORD_COMM] > 1) {
        pr_debug("Excessive number of PERF_RECORD_COMM events!\n");
        ++errs;
    }

    if (nr_events[PERF_RECORD_COMM] == 0) {
        pr_debug("Missing PERF_RECORD_COMM for %s!\n", cmd);
        ++errs;
    }

    if (!found_cmd_mmap) {
        pr_debug("PERF_RECORD_MMAP for %s missing!\n", cmd);
        ++errs;
    }

    if (!found_libc_mmap) {
        pr_debug("PERF_RECORD_MMAP for %s missing!\n", "libc");
        ++errs;
    }

    if (!found_ld_mmap) {
        pr_debug("PERF_RECORD_MMAP for %s missing!\n", "ld");
        ++errs;
    }

    if (!found_vdso_mmap) {
        pr_debug("PERF_RECORD_MMAP for %s missing!\n", "[vdso]");
        ++errs;
    }
out_err:
    perf_evlist__munmap(evlist);
out_delete_evlist:
    perf_evlist__delete(evlist);
out:
    return (err < 0 || errs > 0) ? -1 : 0;
}


#if defined(__x86_64__) || defined(__i386__)

#define barrier() asm volatile("" ::: "memory")

static u64 rdpmc(unsigned int counter)
{
    unsigned int low, high;

    asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter));

    return low | ((u64)high) << 32;
}

static u64 rdtsc(void)
{
    unsigned int low, high;

    asm volatile("rdtsc" : "=a" (low), "=d" (high));

    return low | ((u64)high) << 32;
}

static u64 mmap_read_self(void *addr)
{
    struct perf_event_mmap_page *pc = addr;
    u32 seq, idx, time_mult = 0, time_shift = 0;
    u64 count, cyc = 0, time_offset = 0, enabled, running, delta;

    do {
        seq = pc->lock;
        barrier();

        enabled = pc->time_enabled;
        running = pc->time_running;

        if (enabled != running) {
            cyc = rdtsc();
            time_mult = pc->time_mult;
            time_shift = pc->time_shift;
            time_offset = pc->time_offset;
        }

        idx = pc->index;
        count = pc->offset;
        if (idx)
            count += rdpmc(idx - 1);

        barrier();
    } while (pc->lock != seq);

    if (enabled != running) {
        u64 quot, rem;

        quot = (cyc >> time_shift);
        rem = cyc & ((1 << time_shift) - 1);
        delta = time_offset + quot * time_mult +
            ((rem * time_mult) >> time_shift);

        enabled += delta;
        if (idx)
            running += delta;

        quot = count / running;
        rem = count % running;
        count = quot * enabled + (rem * enabled) / running;
    }

    return count;
}

/*
 * If the RDPMC instruction faults then signal this back to the test parent task:
 */
static void segfault_handler(int sig __maybe_unused,
                 siginfo_t *info __maybe_unused,
                 void *uc __maybe_unused)
{
    exit(-1);
}

static int __test__rdpmc(void)
{
    long page_size = sysconf(_SC_PAGE_SIZE);
    volatile int tmp = 0;
    u64 i, loops = 1000;
    int n;
    int fd;
    void *addr;
    struct perf_event_attr attr = {
        .type = PERF_TYPE_HARDWARE,
        .config = PERF_COUNT_HW_INSTRUCTIONS,
        .exclude_kernel = 1,
    };
    u64 delta_sum = 0;
        struct sigaction sa;

    sigfillset(&sa.sa_mask);
    sa.sa_sigaction = segfault_handler;
    sigaction(SIGSEGV, &sa, NULL);

    fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
    if (fd < 0) {
        pr_err("Error: sys_perf_event_open() syscall returned "
               "with %d (%s)\n", fd, strerror(errno));
        return -1;
    }

    addr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0);
    if (addr == (void *)(-1)) {
        pr_err("Error: mmap() syscall returned with (%s)\n",
               strerror(errno));
        goto out_close;
    }

    for (n = 0; n < 6; n++) {
        u64 stamp, now, delta;

        stamp = mmap_read_self(addr);

        for (i = 0; i < loops; i++)
            tmp++;

        now = mmap_read_self(addr);
        loops *= 10;

        delta = now - stamp;
        pr_debug("%14d: %14Lu\n", n, (long long)delta);

        delta_sum += delta;
    }

    munmap(addr, page_size);
    pr_debug("   ");
out_close:
    close(fd);

    if (!delta_sum)
        return -1;

    return 0;
}

static int test__rdpmc(void)
{
    int status = 0;
    int wret = 0;
    int ret;
    int pid;

    pid = fork();
    if (pid < 0)
        return -1;

    if (!pid) {
        ret = __test__rdpmc();

        exit(ret);
    }

    wret = waitpid(pid, &status, 0);
    if (wret < 0 || status)
        return -1;

    return 0;
}

#endif

static int test__perf_pmu(void)
{
    return perf_pmu__test();
}

static int perf_evsel__roundtrip_cache_name_test(void)
{
    char name[128];
    int type, op, err = 0, ret = 0, i, idx;
    struct perf_evsel *evsel;
        struct perf_evlist *evlist = perf_evlist__new(NULL, NULL);

        if (evlist == NULL)
                return -ENOMEM;

    for (type = 0; type < PERF_COUNT_HW_CACHE_MAX; type++) {
        for (op = 0; op < PERF_COUNT_HW_CACHE_OP_MAX; op++) {
            /* skip invalid cache type */
            if (!perf_evsel__is_cache_op_valid(type, op))
                continue;

            for (i = 0; i < PERF_COUNT_HW_CACHE_RESULT_MAX; i++) {
                __perf_evsel__hw_cache_type_op_res_name(type, op, i,
                                    name, sizeof(name));
                err = parse_events(evlist, name, 0);
                if (err)
                    ret = err;
            }
        }
    }

    idx = 0;
    evsel = perf_evlist__first(evlist);

    for (type = 0; type < PERF_COUNT_HW_CACHE_MAX; type++) {
        for (op = 0; op < PERF_COUNT_HW_CACHE_OP_MAX; op++) {
            /* skip invalid cache type */
            if (!perf_evsel__is_cache_op_valid(type, op))
                continue;

            for (i = 0; i < PERF_COUNT_HW_CACHE_RESULT_MAX; i++) {
                __perf_evsel__hw_cache_type_op_res_name(type, op, i,
                                    name, sizeof(name));
                if (evsel->idx != idx)
                    continue;

                ++idx;

                if (strcmp(perf_evsel__name(evsel), name)) {
                    pr_debug("%s != %s\n", perf_evsel__name(evsel), name);
                    ret = -1;
                }

                evsel = perf_evsel__next(evsel);
            }
        }
    }

    perf_evlist__delete(evlist);
    return ret;
}

static int __perf_evsel__name_array_test(const char *names[], int nr_names)
{
    int i, err;
    struct perf_evsel *evsel;
        struct perf_evlist *evlist = perf_evlist__new(NULL, NULL);

        if (evlist == NULL)
                return -ENOMEM;

    for (i = 0; i < nr_names; ++i) {
        err = parse_events(evlist, names[i], 0);
        if (err) {
            pr_debug("failed to parse event '%s', err %d\n",
                 names[i], err);
            goto out_delete_evlist;
        }
    }

    err = 0;
    list_for_each_entry(evsel, &evlist->entries, node) {
        if (strcmp(perf_evsel__name(evsel), names[evsel->idx])) {
            --err;
            pr_debug("%s != %s\n", perf_evsel__name(evsel), names[evsel->idx]);
        }
    }

out_delete_evlist:
    perf_evlist__delete(evlist);
    return err;
}

#define perf_evsel__name_array_test(names) \
    __perf_evsel__name_array_test(names, ARRAY_SIZE(names))

static int perf_evsel__roundtrip_name_test(void)
{
    int err = 0, ret = 0;

    err = perf_evsel__name_array_test(perf_evsel__hw_names);
    if (err)
        ret = err;

    err = perf_evsel__name_array_test(perf_evsel__sw_names);
    if (err)
        ret = err;

    err = perf_evsel__roundtrip_cache_name_test();
    if (err)
        ret = err;

    return ret;
}

static int perf_evsel__test_field(struct perf_evsel *evsel, const char *name,
                  int size, bool should_be_signed)
{
    struct format_field *field = perf_evsel__field(evsel, name);
    int is_signed;
    int ret = 0;

    if (field == NULL) {
        pr_debug("%s: \"%s\" field not found!\n", evsel->name, name);
        return -1;
    }

    is_signed = !!(field->flags | FIELD_IS_SIGNED);
    if (should_be_signed && !is_signed) {
        pr_debug("%s: \"%s\" signedness(%d) is wrong, should be %d\n",
             evsel->name, name, is_signed, should_be_signed);
        ret = -1;
    }

    if (field->size != size) {
        pr_debug("%s: \"%s\" size (%d) should be %d!\n",
             evsel->name, name, field->size, size);
        ret = -1;
    }

    return ret;
}

static int perf_evsel__tp_sched_test(void)
{
    struct perf_evsel *evsel = perf_evsel__newtp("sched", "sched_switch", 0);
    int ret = 0;

    if (evsel == NULL) {
        pr_debug("perf_evsel__new\n");
        return -1;
    }

    if (perf_evsel__test_field(evsel, "prev_comm", 16, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "prev_pid", 4, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "prev_prio", 4, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "prev_state", 8, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "next_comm", 16, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "next_pid", 4, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "next_prio", 4, true))
        ret = -1;

    perf_evsel__delete(evsel);

    evsel = perf_evsel__newtp("sched", "sched_wakeup", 0);

    if (perf_evsel__test_field(evsel, "comm", 16, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "pid", 4, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "prio", 4, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "success", 4, true))
        ret = -1;

    if (perf_evsel__test_field(evsel, "target_cpu", 4, true))
        ret = -1;

    return ret;
}

static int test__syscall_open_tp_fields(void)
{
    struct perf_record_opts opts = {
        .target = {
            .uid = UINT_MAX,
            .uses_mmap = true,
        },
        .no_delay   = true,
        .freq       = 1,
        .mmap_pages = 256,
        .raw_samples = true,
    };
    const char *filename = "/etc/passwd";
    int flags = O_RDONLY | O_DIRECTORY;
    struct perf_evlist *evlist = perf_evlist__new(NULL, NULL);
    struct perf_evsel *evsel;
    int err = -1, i, nr_events = 0, nr_polls = 0;

    if (evlist == NULL) {
        pr_debug("%s: perf_evlist__new\n", __func__);
        goto out;
    }

    evsel = perf_evsel__newtp("syscalls", "sys_enter_open", 0);
    if (evsel == NULL) {
        pr_debug("%s: perf_evsel__newtp\n", __func__);
        goto out_delete_evlist;
    }

    perf_evlist__add(evlist, evsel);

    err = perf_evlist__create_maps(evlist, &opts.target);
    if (err < 0) {
        pr_debug("%s: perf_evlist__create_maps\n", __func__);
        goto out_delete_evlist;
    }

    perf_evsel__config(evsel, &opts, evsel);

    evlist->threads->map[0] = getpid();

    err = perf_evlist__open(evlist);
    if (err < 0) {
        pr_debug("perf_evlist__open: %s\n", strerror(errno));
        goto out_delete_evlist;
    }

    err = perf_evlist__mmap(evlist, UINT_MAX, false);
    if (err < 0) {
        pr_debug("perf_evlist__mmap: %s\n", strerror(errno));
        goto out_delete_evlist;
    }

    perf_evlist__enable(evlist);

    /*
     * Generate the event:
     */
    open(filename, flags);

    while (1) {
        int before = nr_events;

        for (i = 0; i < evlist->nr_mmaps; i++) {
            union perf_event *event;

            while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
                const u32 type = event->header.type;
                int tp_flags;
                struct perf_sample sample;

                ++nr_events;

                if (type != PERF_RECORD_SAMPLE)
                    continue;

                err = perf_evsel__parse_sample(evsel, event, &sample);
                if (err) {
                    pr_err("Can't parse sample, err = %d\n", err);
                    goto out_munmap;
                }

                tp_flags = perf_evsel__intval(evsel, &sample, "flags");

                if (flags != tp_flags) {
                    pr_debug("%s: Expected flags=%#x, got %#x\n",
                         __func__, flags, tp_flags);
                    goto out_munmap;
                }

                goto out_ok;
            }
        }

        if (nr_events == before)
            poll(evlist->pollfd, evlist->nr_fds, 10);

        if (++nr_polls > 5) {
            pr_debug("%s: no events!\n", __func__);
            goto out_munmap;
        }
    }
out_ok:
    err = 0;
out_munmap:
    perf_evlist__munmap(evlist);
out_delete_evlist:
    perf_evlist__delete(evlist);
out:
    return err;
}

static struct test {
    const char *desc;
    int (*func)(void);
} tests[] = {
    {
        .desc = "vmlinux symtab matches kallsyms",
        .func = test__vmlinux_matches_kallsyms,
    },
    {
        .desc = "detect open syscall event",
        .func = test__open_syscall_event,
    },
    {
        .desc = "detect open syscall event on all cpus",
        .func = test__open_syscall_event_on_all_cpus,
    },
    {
        .desc = "read samples using the mmap interface",
        .func = test__basic_mmap,
    },
    {
        .desc = "parse events tests",
        .func = parse_events__test,
    },
#if defined(__x86_64__) || defined(__i386__)
    {
        .desc = "x86 rdpmc test",
        .func = test__rdpmc,
    },
#endif
    {
        .desc = "Validate PERF_RECORD_* events & perf_sample fields",
        .func = test__PERF_RECORD,
    },
    {
        .desc = "Test perf pmu format parsing",
        .func = test__perf_pmu,
    },
    {
        .desc = "Test dso data interface",
        .func = dso__test_data,
    },
    {
        .desc = "roundtrip evsel->name check",
        .func = perf_evsel__roundtrip_name_test,
    },
    {
        .desc = "Check parsing of sched tracepoints fields",
        .func = perf_evsel__tp_sched_test,
    },
    {
        .desc = "Generate and check syscalls:sys_enter_open event fields",
        .func = test__syscall_open_tp_fields,
    },
    {
        .func = NULL,
    },
};

static bool perf_test__matches(int curr, int argc, const char *argv[])
{
    int i;

    if (argc == 0)
        return true;

    for (i = 0; i < argc; ++i) {
        char *end;
        long nr = strtoul(argv[i], &end, 10);

        if (*end == '\0') {
            if (nr == curr + 1)
                return true;
            continue;
        }

        if (strstr(tests[curr].desc, argv[i]))
            return true;
    }

    return false;
}

static int __cmd_test(int argc, const char *argv[])
{
    int i = 0;

    while (tests[i].func) {
        int curr = i++, err;

        if (!perf_test__matches(curr, argc, argv))
            continue;

        pr_info("%2d: %s:", i, tests[curr].desc);
        pr_debug("\n--- start ---\n");
        err = tests[curr].func();
        pr_debug("---- end ----\n%s:", tests[curr].desc);
        pr_info(" %s\n", err ? "FAILED!\n" : "Ok");
    }

    return 0;
}

static int perf_test__list(int argc, const char **argv)
{
    int i = 0;

    while (tests[i].func) {
        int curr = i++;

        if (argc > 1 && !strstr(tests[curr].desc, argv[1]))
            continue;

        pr_info("%2d: %s\n", i, tests[curr].desc);
    }

    return 0;
}

int cmd_test(int argc, const char **argv, const char *prefix __maybe_unused)
{
    const char * const test_usage[] = {
    "perf test [<options>] [{list <test-name-fragment>|[<test-name-fragments>|<test-numbers>]}]",
    NULL,
    };
    const struct option test_options[] = {
    OPT_INCR('v', "verbose", &verbose,
            "be more verbose (show symbol address, etc)"),
    OPT_END()
    };

    argc = parse_options(argc, argv, test_options, test_usage, 0);
    if (argc >= 1 && !strcmp(argv[0], "list"))
        return perf_test__list(argc, argv);

    symbol_conf.priv_size = sizeof(int);
    symbol_conf.sort_by_name = true;
    symbol_conf.try_vmlinux_path = true;

    if (symbol__init() < 0)
        return -1;

    return __cmd_test(argc, argv);
}