sample-parsing.c

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// SPDX-License-Identifier: GPL-2.0
#include <stdbool.h>
#include <inttypes.h>
#include <linux/kernel.h>
#include <linux/types.h>

#include "util.h"
#include "event.h"
#include "evsel.h"
#include "debug.h"

#include "tests.h"

#define COMP(m) do {                    \
    if (s1->m != s2->m) {               \
        pr_debug("Samples differ at '"#m"'\n"); \
        return false;               \
    }                       \
} while (0)

#define MCOMP(m) do {                   \
    if (memcmp(&s1->m, &s2->m, sizeof(s1->m))) {    \
        pr_debug("Samples differ at '"#m"'\n"); \
        return false;               \
    }                       \
} while (0)

static bool samples_same(const struct perf_sample *s1,
             const struct perf_sample *s2,
             u64 type, u64 read_format)
{
    size_t i;

    if (type & PERF_SAMPLE_IDENTIFIER)
        COMP(id);

    if (type & PERF_SAMPLE_IP)
        COMP(ip);

    if (type & PERF_SAMPLE_TID) {
        COMP(pid);
        COMP(tid);
    }

    if (type & PERF_SAMPLE_TIME)
        COMP(time);

    if (type & PERF_SAMPLE_ADDR)
        COMP(addr);

    if (type & PERF_SAMPLE_ID)
        COMP(id);

    if (type & PERF_SAMPLE_STREAM_ID)
        COMP(stream_id);

    if (type & PERF_SAMPLE_CPU)
        COMP(cpu);

    if (type & PERF_SAMPLE_PERIOD)
        COMP(period);

    if (type & PERF_SAMPLE_READ) {
        if (read_format & PERF_FORMAT_GROUP)
            COMP(read.group.nr);
        else
            COMP(read.one.value);
        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
            COMP(read.time_enabled);
        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
            COMP(read.time_running);
        /* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
        if (read_format & PERF_FORMAT_GROUP) {
            for (i = 0; i < s1->read.group.nr; i++)
                MCOMP(read.group.values[i]);
        } else {
            COMP(read.one.id);
        }
    }

    if (type & PERF_SAMPLE_CALLCHAIN) {
        COMP(callchain->nr);
        for (i = 0; i < s1->callchain->nr; i++)
            COMP(callchain->ips[i]);
    }

    if (type & PERF_SAMPLE_RAW) {
        COMP(raw_size);
        if (memcmp(s1->raw_data, s2->raw_data, s1->raw_size)) {
            pr_debug("Samples differ at 'raw_data'\n");
            return false;
        }
    }

    if (type & PERF_SAMPLE_BRANCH_STACK) {
        COMP(branch_stack->nr);
        for (i = 0; i < s1->branch_stack->nr; i++)
            MCOMP(branch_stack->entries[i]);
    }

    if (type & PERF_SAMPLE_REGS_USER) {
        size_t sz = hweight_long(s1->user_regs.mask) * sizeof(u64);

        COMP(user_regs.mask);
        COMP(user_regs.abi);
        if (s1->user_regs.abi &&
            (!s1->user_regs.regs || !s2->user_regs.regs ||
             memcmp(s1->user_regs.regs, s2->user_regs.regs, sz))) {
            pr_debug("Samples differ at 'user_regs'\n");
            return false;
        }
    }

    if (type & PERF_SAMPLE_STACK_USER) {
        COMP(user_stack.size);
        if (memcmp(s1->user_stack.data, s2->user_stack.data,
               s1->user_stack.size)) {
            pr_debug("Samples differ at 'user_stack'\n");
            return false;
        }
    }

    if (type & PERF_SAMPLE_WEIGHT)
        COMP(weight);

    if (type & PERF_SAMPLE_DATA_SRC)
        COMP(data_src);

    if (type & PERF_SAMPLE_TRANSACTION)
        COMP(transaction);

    if (type & PERF_SAMPLE_REGS_INTR) {
        size_t sz = hweight_long(s1->intr_regs.mask) * sizeof(u64);

        COMP(intr_regs.mask);
        COMP(intr_regs.abi);
        if (s1->intr_regs.abi &&
            (!s1->intr_regs.regs || !s2->intr_regs.regs ||
             memcmp(s1->intr_regs.regs, s2->intr_regs.regs, sz))) {
            pr_debug("Samples differ at 'intr_regs'\n");
            return false;
        }
    }

    if (type & PERF_SAMPLE_PHYS_ADDR)
        COMP(phys_addr);

    return true;
}

static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
{
    struct perf_evsel evsel = {
        .needs_swap = false,
        .attr = {
            .sample_type = sample_type,
            .read_format = read_format,
        },
    };
    union perf_event *event;
    union {
        struct ip_callchain callchain;
        u64 data[64];
    } callchain = {
        /* 3 ips */
        .data = {3, 201, 202, 203},
    };
    union {
        struct branch_stack branch_stack;
        u64 data[64];
    } branch_stack = {
        /* 1 branch_entry */
        .data = {1, 211, 212, 213},
    };
    u64 regs[64];
    const u64 raw_data[] = {0x123456780a0b0c0dULL, 0x1102030405060708ULL};
    const u64 data[] = {0x2211443366558877ULL, 0, 0xaabbccddeeff4321ULL};
    struct perf_sample sample = {
        .ip     = 101,
        .pid        = 102,
        .tid        = 103,
        .time       = 104,
        .addr       = 105,
        .id     = 106,
        .stream_id  = 107,
        .period     = 108,
        .weight     = 109,
        .cpu        = 110,
        .raw_size   = sizeof(raw_data),
        .data_src   = 111,
        .transaction    = 112,
        .raw_data   = (void *)raw_data,
        .callchain  = &callchain.callchain,
        .branch_stack   = &branch_stack.branch_stack,
        .user_regs  = {
            .abi    = PERF_SAMPLE_REGS_ABI_64,
            .mask   = sample_regs,
            .regs   = regs,
        },
        .user_stack = {
            .size   = sizeof(data),
            .data   = (void *)data,
        },
        .read       = {
            .time_enabled = 0x030a59d664fca7deULL,
            .time_running = 0x011b6ae553eb98edULL,
        },
        .intr_regs  = {
            .abi    = PERF_SAMPLE_REGS_ABI_64,
            .mask   = sample_regs,
            .regs   = regs,
        },
        .phys_addr  = 113,
    };
    struct sample_read_value values[] = {{1, 5}, {9, 3}, {2, 7}, {6, 4},};
    struct perf_sample sample_out;
    size_t i, sz, bufsz;
    int err, ret = -1;

    if (sample_type & PERF_SAMPLE_REGS_USER)
        evsel.attr.sample_regs_user = sample_regs;

    if (sample_type & PERF_SAMPLE_REGS_INTR)
        evsel.attr.sample_regs_intr = sample_regs;

    for (i = 0; i < sizeof(regs); i++)
        *(i + (u8 *)regs) = i & 0xfe;

    if (read_format & PERF_FORMAT_GROUP) {
        sample.read.group.nr     = 4;
        sample.read.group.values = values;
    } else {
        sample.read.one.value = 0x08789faeb786aa87ULL;
        sample.read.one.id    = 99;
    }

    sz = perf_event__sample_event_size(&sample, sample_type, read_format);
    bufsz = sz + 4096; /* Add a bit for overrun checking */
    event = malloc(bufsz);
    if (!event) {
        pr_debug("malloc failed\n");
        return -1;
    }

    memset(event, 0xff, bufsz);
    event->header.type = PERF_RECORD_SAMPLE;
    event->header.misc = 0;
    event->header.size = sz;

    err = perf_event__synthesize_sample(event, sample_type, read_format,
                        &sample);
    if (err) {
        pr_debug("%s failed for sample_type %#"PRIx64", error %d\n",
             "perf_event__synthesize_sample", sample_type, err);
        goto out_free;
    }

    /* The data does not contain 0xff so we use that to check the size */
    for (i = bufsz; i > 0; i--) {
        if (*(i - 1 + (u8 *)event) != 0xff)
            break;
    }
    if (i != sz) {
        pr_debug("Event size mismatch: actual %zu vs expected %zu\n",
             i, sz);
        goto out_free;
    }

    evsel.sample_size = __perf_evsel__sample_size(sample_type);

    err = perf_evsel__parse_sample(&evsel, event, &sample_out);
    if (err) {
        pr_debug("%s failed for sample_type %#"PRIx64", error %d\n",
             "perf_evsel__parse_sample", sample_type, err);
        goto out_free;
    }

    if (!samples_same(&sample, &sample_out, sample_type, read_format)) {
        pr_debug("parsing failed for sample_type %#"PRIx64"\n",
             sample_type);
        goto out_free;
    }

    ret = 0;
out_free:
    free(event);
    if (ret && read_format)
        pr_debug("read_format %#"PRIx64"\n", read_format);
    return ret;
}

int test__sample_parsing(struct test *test __maybe_unused, int subtest __maybe_unused)
{
    const u64 rf[] = {4, 5, 6, 7, 12, 13, 14, 15};
    u64 sample_type;
    u64 sample_regs;
    size_t i;
    int err;

    /*
     * Fail the test if it has not been updated when new sample format bits
     * were added.  Please actually update the test rather than just change
     * the condition below.
     */
    if (PERF_SAMPLE_MAX > PERF_SAMPLE_PHYS_ADDR << 1) {
        pr_debug("sample format has changed, some new PERF_SAMPLE_ bit was introduced - test needs updating\n");
        return -1;
    }

    /* Test each sample format bit separately */
    for (sample_type = 1; sample_type != PERF_SAMPLE_MAX;
         sample_type <<= 1) {
        /* Test read_format variations */
        if (sample_type == PERF_SAMPLE_READ) {
            for (i = 0; i < ARRAY_SIZE(rf); i++) {
                err = do_test(sample_type, 0, rf[i]);
                if (err)
                    return err;
            }
            continue;
        }
        sample_regs = 0;

        if (sample_type == PERF_SAMPLE_REGS_USER)
            sample_regs = 0x3fff;

        if (sample_type == PERF_SAMPLE_REGS_INTR)
            sample_regs = 0xff0fff;

        err = do_test(sample_type, sample_regs, 0);
        if (err)
            return err;
    }

    /* Test all sample format bits together */
    sample_type = PERF_SAMPLE_MAX - 1;
    sample_regs = 0x3fff; /* shared yb intr and user regs */
    for (i = 0; i < ARRAY_SIZE(rf); i++) {
        err = do_test(sample_type, sample_regs, rf[i]);
        if (err)
            return err;
    }

    return 0;
}