cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

syscall.c (4134B)

      1/*
      2 * Copyright (C) 2020, Matthias Weckbecker <matthias@weckbecker.name>
      3 *
      4 * License: GNU GPL, version 2 or later.
      5 *   See the COPYING file in the top-level directory.
      6 */
      7#include <inttypes.h>
      8#include <assert.h>
      9#include <stdlib.h>
     10#include <string.h>
     11#include <unistd.h>
     12#include <stdio.h>
     13#include <glib.h>
     14
     15#include <qemu-plugin.h>
     16
     17QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
     18
     19typedef struct {
     20    int64_t num;
     21    int64_t calls;
     22    int64_t errors;
     23} SyscallStats;
     24
     25static GMutex lock;
     26static GHashTable *statistics;
     27
     28static SyscallStats *get_or_create_entry(int64_t num)
     29{
     30    SyscallStats *entry =
     31        (SyscallStats *) g_hash_table_lookup(statistics, GINT_TO_POINTER(num));
     32
     33    if (!entry) {
     34        entry = g_new0(SyscallStats, 1);
     35        entry->num = num;
     36        g_hash_table_insert(statistics, GINT_TO_POINTER(num), (gpointer) entry);
     37    }
     38
     39    return entry;
     40}
     41
     42static void vcpu_syscall(qemu_plugin_id_t id, unsigned int vcpu_index,
     43                         int64_t num, uint64_t a1, uint64_t a2,
     44                         uint64_t a3, uint64_t a4, uint64_t a5,
     45                         uint64_t a6, uint64_t a7, uint64_t a8)
     46{
     47    if (statistics) {
     48        SyscallStats *entry;
     49        g_mutex_lock(&lock);
     50        entry = get_or_create_entry(num);
     51        entry->calls++;
     52        g_mutex_unlock(&lock);
     53    } else {
     54        g_autofree gchar *out = g_strdup_printf("syscall #%" PRIi64 "\n", num);
     55        qemu_plugin_outs(out);
     56    }
     57}
     58
     59static void vcpu_syscall_ret(qemu_plugin_id_t id, unsigned int vcpu_idx,
     60                             int64_t num, int64_t ret)
     61{
     62    if (statistics) {
     63        SyscallStats *entry;
     64
     65        g_mutex_lock(&lock);
     66        /* Should always return an existent entry. */
     67        entry = get_or_create_entry(num);
     68        if (ret < 0) {
     69            entry->errors++;
     70        }
     71        g_mutex_unlock(&lock);
     72    } else {
     73        g_autofree gchar *out;
     74        out = g_strdup_printf("syscall #%" PRIi64 " returned -> %" PRIi64 "\n",
     75                num, ret);
     76        qemu_plugin_outs(out);
     77    }
     78}
     79
     80static void print_entry(gpointer val, gpointer user_data)
     81{
     82    g_autofree gchar *out;
     83    SyscallStats *entry = (SyscallStats *) val;
     84    int64_t syscall_num = entry->num;
     85    out = g_strdup_printf(
     86        "%-13" PRIi64 "%-6" PRIi64 " %" PRIi64 "\n",
     87        syscall_num, entry->calls, entry->errors);
     88    qemu_plugin_outs(out);
     89}
     90
     91static gint comp_func(gconstpointer ea, gconstpointer eb)
     92{
     93    SyscallStats *ent_a = (SyscallStats *) ea;
     94    SyscallStats *ent_b = (SyscallStats *) eb;
     95
     96    return ent_a->calls > ent_b->calls ? -1 : 1;
     97}
     98
     99/* ************************************************************************* */
    100static void plugin_exit(qemu_plugin_id_t id, void *p)
    101{
    102    if (!statistics) {
    103        return;
    104    }
    105
    106    g_mutex_lock(&lock);
    107    GList *entries = g_hash_table_get_values(statistics);
    108    entries = g_list_sort(entries, comp_func);
    109    qemu_plugin_outs("syscall no.  calls  errors\n");
    110
    111    g_list_foreach(entries, print_entry, NULL);
    112
    113    g_list_free(entries);
    114    g_hash_table_destroy(statistics);
    115    g_mutex_unlock(&lock);
    116}
    117
    118QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
    119                                           const qemu_info_t *info,
    120                                           int argc, char **argv)
    121{
    122    bool do_print = false;
    123
    124    for (int i = 0; i < argc; i++) {
    125        char *opt = argv[i];
    126        g_autofree char **tokens = g_strsplit(opt, "=", 2);
    127
    128        if (g_strcmp0(tokens[0], "print") == 0) {
    129            if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &do_print)) {
    130                fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
    131            }
    132        } else {
    133            fprintf(stderr, "unsupported argument: %s\n", argv[i]);
    134            return -1;
    135        }
    136    }
    137
    138    if (!do_print) {
    139        statistics = g_hash_table_new_full(NULL, g_direct_equal, NULL, g_free);
    140    }
    141
    142    qemu_plugin_register_vcpu_syscall_cb(id, vcpu_syscall);
    143    qemu_plugin_register_vcpu_syscall_ret_cb(id, vcpu_syscall_ret);
    144    qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
    145    return 0;
    146}