xref: /openbmc/qemu/tests/tcg/multiarch/noexec.c.inc (revision bf0c50d4) 
1/*
2 * Common code for arch-specific MMU_INST_FETCH fault testing.
3 */
4
5#define _GNU_SOURCE
6
7#include <assert.h>
8#include <signal.h>
9#include <stdio.h>
10#include <stdlib.h>
11#include <string.h>
12#include <errno.h>
13#include <unistd.h>
14#include <sys/mman.h>
15#include <sys/ucontext.h>
16
17/* Forward declarations. */
18
19static void *arch_mcontext_pc(const mcontext_t *ctx);
20static int arch_mcontext_arg(const mcontext_t *ctx);
21static void arch_flush(void *p, int len);
22
23/* Testing infrastructure. */
24
25struct noexec_test {
26    const char *name;
27    const char *test_code;
28    int test_len;
29    int page_ofs;
30    int entry_ofs;
31    int expected_si_ofs;
32    int expected_pc_ofs;
33    int expected_arg;
34};
35
36static void *page_base;
37static int page_size;
38static const struct noexec_test *current_noexec_test;
39
40static void handle_err(const char *syscall)
41{
42    printf("[  FAILED  ] %s: %s\n", syscall, strerror(errno));
43    exit(EXIT_FAILURE);
44}
45
46static void handle_segv(int sig, siginfo_t *info, void *ucontext)
47{
48    const struct noexec_test *test = current_noexec_test;
49    const mcontext_t *mc = &((ucontext_t *)ucontext)->uc_mcontext;
50    void *expected_si;
51    void *expected_pc;
52    void *pc;
53    int arg;
54
55    if (test == NULL) {
56        printf("[  FAILED  ] unexpected SEGV\n");
57        exit(EXIT_FAILURE);
58    }
59    current_noexec_test = NULL;
60
61    expected_si = page_base + test->expected_si_ofs;
62    if (info->si_addr != expected_si) {
63        printf("[  FAILED  ] wrong si_addr (%p != %p)\n",
64               info->si_addr, expected_si);
65        exit(EXIT_FAILURE);
66    }
67
68    pc = arch_mcontext_pc(mc);
69    expected_pc = page_base + test->expected_pc_ofs;
70    if (pc != expected_pc) {
71        printf("[  FAILED  ] wrong pc (%p != %p)\n", pc, expected_pc);
72        exit(EXIT_FAILURE);
73    }
74
75    arg = arch_mcontext_arg(mc);
76    if (arg != test->expected_arg) {
77        printf("[  FAILED  ] wrong arg (%d != %d)\n", arg, test->expected_arg);
78        exit(EXIT_FAILURE);
79    }
80
81    if (mprotect(page_base, page_size,
82                 PROT_READ | PROT_WRITE | PROT_EXEC) < 0) {
83        handle_err("mprotect");
84    }
85}
86
87static void test_noexec_1(const struct noexec_test *test)
88{
89    void *start = page_base + test->page_ofs;
90    void (*fn)(int arg) = page_base + test->entry_ofs;
91
92    memcpy(start, test->test_code, test->test_len);
93    arch_flush(start, test->test_len);
94
95    /* Trigger TB creation in order to test invalidation. */
96    fn(0);
97
98    if (mprotect(page_base, page_size, PROT_NONE) < 0) {
99        handle_err("mprotect");
100    }
101
102    /* Trigger SEGV and check that handle_segv() ran. */
103    current_noexec_test = test;
104    fn(0);
105    assert(current_noexec_test == NULL);
106}
107
108static int test_noexec(struct noexec_test *tests, size_t n_tests)
109{
110    struct sigaction act;
111    size_t i;
112
113    memset(&act, 0, sizeof(act));
114    act.sa_sigaction = handle_segv;
115    act.sa_flags = SA_SIGINFO;
116    if (sigaction(SIGSEGV, &act, NULL) < 0) {
117        handle_err("sigaction");
118    }
119
120    page_size = getpagesize();
121    page_base = mmap(NULL, 2 * page_size,
122                     PROT_READ | PROT_WRITE | PROT_EXEC,
123                     MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
124    if (page_base == MAP_FAILED) {
125        handle_err("mmap");
126    }
127    page_base += page_size;
128
129    for (i = 0; i < n_tests; i++) {
130        struct noexec_test *test = &tests[i];
131
132        printf("[ RUN      ] %s\n", test->name);
133        test_noexec_1(test);
134        printf("[       OK ]\n");
135    }
136
137    printf("[  PASSED  ]\n");
138    return EXIT_SUCCESS;
139}
140