1 /*
2 * Copyright (C) 2024, Simon Hamelin <simon.hamelin@grenoble-inp.org>
3 *
4 * Stop execution once a given address is reached or if the
5 * count of executed instructions reached a specified limit
6 *
7 * License: GNU GPL, version 2 or later.
8 * See the COPYING file in the top-level directory.
9 */
10
11 #include <assert.h>
12 #include <glib.h>
13 #include <inttypes.h>
14 #include <stdio.h>
15 #include <stdlib.h>
16
17 #include <qemu-plugin.h>
18
19 QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
20
21 /* Scoreboard to track executed instructions count */
22 typedef struct {
23 uint64_t insn_count;
24 } InstructionsCount;
25 static struct qemu_plugin_scoreboard *insn_count_sb;
26 static qemu_plugin_u64 insn_count;
27
28 static uint64_t icount;
29 static int icount_exit_code;
30
31 static bool exit_on_icount;
32 static bool exit_on_address;
33
34 /* Map trigger addresses to exit code */
35 static GHashTable *addrs_ht;
36
exit_emulation(int return_code,char * message)37 static void exit_emulation(int return_code, char *message)
38 {
39 qemu_plugin_outs(message);
40 g_free(message);
41 exit(return_code);
42 }
43
exit_icount_reached(unsigned int cpu_index,void * udata)44 static void exit_icount_reached(unsigned int cpu_index, void *udata)
45 {
46 uint64_t insn_vaddr = GPOINTER_TO_UINT(udata);
47 char *msg = g_strdup_printf("icount reached at 0x%" PRIx64 ", exiting\n",
48 insn_vaddr);
49
50 exit_emulation(icount_exit_code, msg);
51 }
52
exit_address_reached(unsigned int cpu_index,void * udata)53 static void exit_address_reached(unsigned int cpu_index, void *udata)
54 {
55 uint64_t insn_vaddr = GPOINTER_TO_UINT(udata);
56 char *msg = g_strdup_printf("0x%" PRIx64 " reached, exiting\n", insn_vaddr);
57 int exit_code;
58
59 exit_code = GPOINTER_TO_INT(
60 g_hash_table_lookup(addrs_ht, GUINT_TO_POINTER(insn_vaddr)));
61
62 exit_emulation(exit_code, msg);
63 }
64
vcpu_tb_trans(qemu_plugin_id_t id,struct qemu_plugin_tb * tb)65 static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
66 {
67 size_t tb_n = qemu_plugin_tb_n_insns(tb);
68 for (size_t i = 0; i < tb_n; i++) {
69 struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
70 gpointer insn_vaddr = GUINT_TO_POINTER(qemu_plugin_insn_vaddr(insn));
71
72 if (exit_on_icount) {
73 /* Increment and check scoreboard for each instruction */
74 qemu_plugin_register_vcpu_insn_exec_inline_per_vcpu(
75 insn, QEMU_PLUGIN_INLINE_ADD_U64, insn_count, 1);
76 qemu_plugin_register_vcpu_insn_exec_cond_cb(
77 insn, exit_icount_reached, QEMU_PLUGIN_CB_NO_REGS,
78 QEMU_PLUGIN_COND_EQ, insn_count, icount + 1, insn_vaddr);
79 }
80
81 if (exit_on_address) {
82 if (g_hash_table_contains(addrs_ht, insn_vaddr)) {
83 /* Exit triggered by address */
84 qemu_plugin_register_vcpu_insn_exec_cb(
85 insn, exit_address_reached, QEMU_PLUGIN_CB_NO_REGS,
86 insn_vaddr);
87 }
88 }
89 }
90 }
91
plugin_exit(qemu_plugin_id_t id,void * p)92 static void plugin_exit(qemu_plugin_id_t id, void *p)
93 {
94 g_hash_table_destroy(addrs_ht);
95 qemu_plugin_scoreboard_free(insn_count_sb);
96 }
97
qemu_plugin_install(qemu_plugin_id_t id,const qemu_info_t * info,int argc,char ** argv)98 QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
99 const qemu_info_t *info, int argc,
100 char **argv)
101 {
102 addrs_ht = g_hash_table_new(NULL, g_direct_equal);
103
104 insn_count_sb = qemu_plugin_scoreboard_new(sizeof(InstructionsCount));
105 insn_count = qemu_plugin_scoreboard_u64_in_struct(
106 insn_count_sb, InstructionsCount, insn_count);
107
108 for (int i = 0; i < argc; i++) {
109 char *opt = argv[i];
110 g_auto(GStrv) tokens = g_strsplit(opt, "=", 2);
111 if (g_strcmp0(tokens[0], "icount") == 0) {
112 g_auto(GStrv) icount_tokens = g_strsplit(tokens[1], ":", 2);
113 icount = g_ascii_strtoull(icount_tokens[0], NULL, 0);
114 if (icount < 1 || g_strrstr(icount_tokens[0], "-") != NULL) {
115 fprintf(stderr,
116 "icount parsing failed: '%s' must be a positive "
117 "integer\n",
118 icount_tokens[0]);
119 return -1;
120 }
121 if (icount_tokens[1]) {
122 icount_exit_code = g_ascii_strtoull(icount_tokens[1], NULL, 0);
123 }
124 exit_on_icount = true;
125 } else if (g_strcmp0(tokens[0], "addr") == 0) {
126 g_auto(GStrv) addr_tokens = g_strsplit(tokens[1], ":", 2);
127 uint64_t exit_addr = g_ascii_strtoull(addr_tokens[0], NULL, 0);
128 int exit_code = 0;
129 if (addr_tokens[1]) {
130 exit_code = g_ascii_strtoull(addr_tokens[1], NULL, 0);
131 }
132 g_hash_table_insert(addrs_ht, GUINT_TO_POINTER(exit_addr),
133 GINT_TO_POINTER(exit_code));
134 exit_on_address = true;
135 } else {
136 fprintf(stderr, "option parsing failed: %s\n", opt);
137 return -1;
138 }
139 }
140
141 if (!exit_on_icount && !exit_on_address) {
142 fprintf(stderr, "'icount' or 'addr' argument missing\n");
143 return -1;
144 }
145
146 /* Register translation block and exit callbacks */
147 qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
148 qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
149
150 return 0;
151 }
152