1 #include <stdlib.h>
2 #include <string.h>
3 #include <stdio.h>
4 #include <signal.h>
5 #include <unistd.h>
6 #include <sys/mman.h>
7 
8 #include "utils.h"
9 
10 extern char __start___ex_table[];
11 extern char __stop___ex_table[];
12 
13 #if defined(__powerpc64__)
14 #define UCONTEXT_NIA(UC)	(UC)->uc_mcontext.gp_regs[PT_NIP]
15 #elif defined(__powerpc__)
16 #define UCONTEXT_NIA(UC)	(UC)->uc_mcontext.uc_regs->gregs[PT_NIP]
17 #else
18 #error implement UCONTEXT_NIA
19 #endif
20 
21 static void segv_handler(int signr, siginfo_t *info, void *ptr)
22 {
23 	ucontext_t *uc = (ucontext_t *)ptr;
24 	unsigned long addr = (unsigned long)info->si_addr;
25 	unsigned long *ip = &UCONTEXT_NIA(uc);
26 	unsigned long *ex_p = (unsigned long *)__start___ex_table;
27 
28 	while (ex_p < (unsigned long *)__stop___ex_table) {
29 		unsigned long insn, fixup;
30 
31 		insn = *ex_p++;
32 		fixup = *ex_p++;
33 
34 		if (insn == *ip) {
35 			*ip = fixup;
36 			return;
37 		}
38 	}
39 
40 	printf("No exception table match for NIA %lx ADDR %lx\n", *ip, addr);
41 	abort();
42 }
43 
44 static void setup_segv_handler(void)
45 {
46 	struct sigaction action;
47 
48 	memset(&action, 0, sizeof(action));
49 	action.sa_sigaction = segv_handler;
50 	action.sa_flags = SA_SIGINFO;
51 	sigaction(SIGSEGV, &action, NULL);
52 }
53 
54 unsigned long COPY_LOOP(void *to, const void *from, unsigned long size);
55 unsigned long test_copy_tofrom_user_reference(void *to, const void *from, unsigned long size);
56 
57 static int total_passed;
58 static int total_failed;
59 
60 static void do_one_test(char *dstp, char *srcp, unsigned long len)
61 {
62 	unsigned long got, expected;
63 
64 	got = COPY_LOOP(dstp, srcp, len);
65 	expected = test_copy_tofrom_user_reference(dstp, srcp, len);
66 
67 	if (got != expected) {
68 		total_failed++;
69 		printf("FAIL from=%p to=%p len=%ld returned %ld, expected %ld\n",
70 		       srcp, dstp, len, got, expected);
71 		//abort();
72 	} else
73 		total_passed++;
74 }
75 
76 //#define MAX_LEN 512
77 #define MAX_LEN 16
78 
79 int test_copy_exception(void)
80 {
81 	int page_size;
82 	static char *p, *q;
83 	unsigned long src, dst, len;
84 
85 	page_size = getpagesize();
86 	p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,
87 		MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
88 
89 	if (p == MAP_FAILED) {
90 		perror("mmap");
91 		exit(1);
92 	}
93 
94 	memset(p, 0, page_size);
95 
96 	setup_segv_handler();
97 
98 	if (mprotect(p + page_size, page_size, PROT_NONE)) {
99 		perror("mprotect");
100 		exit(1);
101 	}
102 
103 	q = p + page_size - MAX_LEN;
104 
105 	for (src = 0; src < MAX_LEN; src++) {
106 		for (dst = 0; dst < MAX_LEN; dst++) {
107 			for (len = 0; len < MAX_LEN+1; len++) {
108 				// printf("from=%p to=%p len=%ld\n", q+dst, q+src, len);
109 				do_one_test(q+dst, q+src, len);
110 			}
111 		}
112 	}
113 
114 	printf("Totals:\n");
115 	printf("  Pass: %d\n", total_passed);
116 	printf("  Fail: %d\n", total_failed);
117 
118 	return 0;
119 }
120 
121 int main(void)
122 {
123 	return test_harness(test_copy_exception, str(COPY_LOOP));
124 }
125