/*
 * 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/parse-options.h"
#include "util/session.h"
#include "util/symbol.h"
#include "util/thread.h"

static long page_size;

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;
        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 *event_name)
{
        char *filename;
        int err = -1, fd;

        if (asprintf(&filename,
                     "/sys/kernel/debug/tracing/events/syscalls/%s/id",
                     event_name) < 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());
        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__open_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());
        if (threads == NULL) {
                pr_debug("thread_map__new\n");
                return -1;
        }

        cpus = cpu_map__new(NULL);
        if (threads == NULL) {
                pr_debug("thread_map__new\n");
                return -1;
        }


        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;
        }

        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__open_read_on_cpu\n");
                        goto out_close_fd;
                }

                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);
                        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;
}

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,
        },
        {
                .func = NULL,
        },
};

static int __cmd_test(void)
{
        int i = 0;

        page_size = sysconf(_SC_PAGE_SIZE);

        while (tests[i].func) {
                int err;
                pr_info("%2d: %s:", i + 1, tests[i].desc);
                pr_debug("\n--- start ---\n");
                err = tests[i].func();
                pr_debug("---- end ----\n%s:", tests[i].desc);
                pr_info(" %s\n", err ? "FAILED!\n" : "Ok");
                ++i;
        }

        return 0;
}

static const char * const test_usage[] = {
        "perf test [<options>]",
        NULL,
};

static const struct option test_options[] = {
        OPT_INTEGER('v', "verbose", &verbose,
                    "be more verbose (show symbol address, etc)"),
        OPT_END()
};

int cmd_test(int argc, const char **argv, const char *prefix __used)
{
        argc = parse_options(argc, argv, test_options, test_usage, 0);
        if (argc)
                usage_with_options(test_usage, test_options);

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

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

        setup_pager();

        return __cmd_test();
}