event.c

Go to the documentation of this file.

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

#include "../../util/machine.h"
#include "../../util/tool.h"
#include "../../util/map.h"
#include "../../util/util.h"
#include "../../util/debug.h"

#if defined(__x86_64__)

int perf_event__synthesize_extra_kmaps(struct perf_tool *tool,
                       perf_event__handler_t process,
                       struct machine *machine)
{
    int rc = 0;
    struct map *pos;
    struct map_groups *kmaps = &machine->kmaps;
    struct maps *maps = &kmaps->maps;
    union perf_event *event = zalloc(sizeof(event->mmap) +
                     machine->id_hdr_size);

    if (!event) {
        pr_debug("Not enough memory synthesizing mmap event "
             "for extra kernel maps\n");
        return -1;
    }

    for (pos = maps__first(maps); pos; pos = map__next(pos)) {
        struct kmap *kmap;
        size_t size;

        if (!__map__is_extra_kernel_map(pos))
            continue;

        kmap = map__kmap(pos);

        size = sizeof(event->mmap) - sizeof(event->mmap.filename) +
               PERF_ALIGN(strlen(kmap->name) + 1, sizeof(u64)) +
               machine->id_hdr_size;

        memset(event, 0, size);

        event->mmap.header.type = PERF_RECORD_MMAP;

        /*
         * kernel uses 0 for user space maps, see kernel/perf_event.c
         * __perf_event_mmap
         */
        if (machine__is_host(machine))
            event->header.misc = PERF_RECORD_MISC_KERNEL;
        else
            event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;

        event->mmap.header.size = size;

        event->mmap.start = pos->start;
        event->mmap.len   = pos->end - pos->start;
        event->mmap.pgoff = pos->pgoff;
        event->mmap.pid   = machine->pid;

        strlcpy(event->mmap.filename, kmap->name, PATH_MAX);

        if (perf_tool__process_synth_event(tool, event, machine,
                           process) != 0) {
            rc = -1;
            break;
        }
    }

    free(event);
    return rc;
}

#endif