/*
 * 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 "../../include/linux/hw_breakpoint.h"

#include <sys/mman.h>

static int vmlinux_matches_kallsyms_filter(struct map *map __used, 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, false, NULL) < 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, false, NULL) < 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, false, NULL) < 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, false);
                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,
                                         size_t *sizep)
{
        cpu_set_t *mask;
        size_t size;
        int i, cpu = -1, nrcpus = 1024;
realloc:
        mask = CPU_ALLOC(nrcpus);
        size = CPU_ALLOC_SIZE(nrcpus);
        CPU_ZERO_S(size, mask);

        if (sched_getaffinity(pid, size, mask) == -1) {
                CPU_FREE(mask);
                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_S(i, size, mask)) {
                        if (cpu == -1) {
                                cpu = i;
                                *maskp = mask;
                                *sizep = size;
                        } else
                                CPU_CLR_S(i, size, mask);
                }
        }

        if (cpu == -1)
                CPU_FREE(mask);

        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 = NULL;
        size_t cpu_mask_size = 0;
        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 = list_entry(evlist->entries.next, struct perf_evsel, node);
        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,
                                            &cpu_mask_size);
        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_free_cpu_mask;
        }

        /*
         * Call sys_perf_event_open on all the fds on all the evsels,
         * grouping them if asked to.
         */
        err = perf_evlist__open(evlist, opts.group);
        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, false);
                                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_free_cpu_mask:
        CPU_FREE(cpu_mask);
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 __used, siginfo_t *info __used, void *uc __used)
{

        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) {
                die("Error: sys_perf_event_open() syscall returned "
                    "with %d (%s)\n", fd, strerror(errno));
        }

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

        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);
        close(fd);

        pr_debug("   ");

        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 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,
        },
        {
                .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 __used)
{
        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);
}