xref: /openbmc/qemu/tests/tcg/aarch64/bti-2.c (revision 764a6ee9)
1 /*
2  * Branch target identification, basic notskip cases.
3  */
4 
5 #include <stdio.h>
6 #include <signal.h>
7 #include <string.h>
8 #include <unistd.h>
9 #include <sys/mman.h>
10 
11 #ifndef PROT_BTI
12 #define PROT_BTI  0x10
13 #endif
14 
15 static void skip2_sigill(int sig, siginfo_t *info, void *vuc)
16 {
17     ucontext_t *uc = vuc;
18     uc->uc_mcontext.pc += 8;
19     uc->uc_mcontext.pstate = 1;
20 }
21 
22 #define NOP       "nop"
23 #define BTI_N     "hint #32"
24 #define BTI_C     "hint #34"
25 #define BTI_J     "hint #36"
26 #define BTI_JC    "hint #38"
27 
28 #define BTYPE_1(DEST)    \
29     "mov x1, #1\n\t"     \
30     "adr x16, 1f\n\t"    \
31     "br x16\n"           \
32 "1: " DEST "\n\t"        \
33     "mov x1, #0"
34 
35 #define BTYPE_2(DEST)    \
36     "mov x1, #1\n\t"     \
37     "adr x16, 1f\n\t"    \
38     "blr x16\n"          \
39 "1: " DEST "\n\t"        \
40     "mov x1, #0"
41 
42 #define BTYPE_3(DEST)    \
43     "mov x1, #1\n\t"     \
44     "adr x15, 1f\n\t"    \
45     "br x15\n"           \
46 "1: " DEST "\n\t"        \
47     "mov x1, #0"
48 
49 #define TEST(WHICH, DEST, EXPECT) \
50     WHICH(DEST) "\n"              \
51     ".if " #EXPECT "\n\t"         \
52     "eor x1, x1," #EXPECT "\n"    \
53     ".endif\n\t"                  \
54     "add x0, x0, x1\n\t"
55 
56 asm("\n"
57 "test_begin:\n\t"
58     BTI_C "\n\t"
59     "mov x2, x30\n\t"
60     "mov x0, #0\n\t"
61 
62     TEST(BTYPE_1, NOP, 1)
63     TEST(BTYPE_1, BTI_N, 1)
64     TEST(BTYPE_1, BTI_C, 0)
65     TEST(BTYPE_1, BTI_J, 0)
66     TEST(BTYPE_1, BTI_JC, 0)
67 
68     TEST(BTYPE_2, NOP, 1)
69     TEST(BTYPE_2, BTI_N, 1)
70     TEST(BTYPE_2, BTI_C, 0)
71     TEST(BTYPE_2, BTI_J, 1)
72     TEST(BTYPE_2, BTI_JC, 0)
73 
74     TEST(BTYPE_3, NOP, 1)
75     TEST(BTYPE_3, BTI_N, 1)
76     TEST(BTYPE_3, BTI_C, 1)
77     TEST(BTYPE_3, BTI_J, 0)
78     TEST(BTYPE_3, BTI_JC, 0)
79 
80     "ret x2\n"
81 "test_end:"
82 );
83 
84 int main()
85 {
86     struct sigaction sa;
87     void *tb, *te;
88 
89     void *p = mmap(0, getpagesize(),
90                    PROT_EXEC | PROT_READ | PROT_WRITE | PROT_BTI,
91                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
92     if (p == MAP_FAILED) {
93         perror("mmap");
94         return 1;
95     }
96 
97     memset(&sa, 0, sizeof(sa));
98     sa.sa_sigaction = skip2_sigill;
99     sa.sa_flags = SA_SIGINFO;
100     if (sigaction(SIGILL, &sa, NULL) < 0) {
101         perror("sigaction");
102         return 1;
103     }
104 
105     /*
106      * ??? With "extern char test_begin[]", some compiler versions
107      * will use :got references, and some linker versions will
108      * resolve this reference to a static symbol incorrectly.
109      * Bypass this error by using a pc-relative reference directly.
110      */
111     asm("adr %0, test_begin; adr %1, test_end" : "=r"(tb), "=r"(te));
112 
113     memcpy(p, tb, te - tb);
114 
115     return ((int (*)(void))p)();
116 }
117