1 /*
2 * Copyright IBM Corp.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2.1 of the GNU Lesser General Public License
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11 *
12 */
13
14 #include <assert.h>
15 #include <errno.h>
16 #include <fcntl.h>
17 #include <signal.h>
18 #include <stdarg.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <sys/mman.h>
23 #include <sys/ptrace.h>
24 #include <sys/syscall.h>
25 #include <ucontext.h>
26 #include <unistd.h>
27
28 #include "utils.h"
29
30 char *file_name;
31
32 int in_test;
33 volatile int faulted;
34 volatile void *dar;
35 int errors;
36
segv(int signum,siginfo_t * info,void * ctxt_v)37 static void segv(int signum, siginfo_t *info, void *ctxt_v)
38 {
39 ucontext_t *ctxt = (ucontext_t *)ctxt_v;
40 struct pt_regs *regs = ctxt->uc_mcontext.regs;
41
42 if (!in_test) {
43 fprintf(stderr, "Segfault outside of test !\n");
44 exit(1);
45 }
46
47 faulted = 1;
48 dar = (void *)regs->dar;
49 regs->nip += 4;
50 }
51
do_read(const volatile void * addr)52 static inline void do_read(const volatile void *addr)
53 {
54 int ret;
55
56 asm volatile("lwz %0,0(%1); twi 0,%0,0; isync;\n"
57 : "=r" (ret) : "r" (addr) : "memory");
58 }
59
do_write(const volatile void * addr)60 static inline void do_write(const volatile void *addr)
61 {
62 int val = 0x1234567;
63
64 asm volatile("stw %0,0(%1); sync; \n"
65 : : "r" (val), "r" (addr) : "memory");
66 }
67
check_faulted(void * addr,long page,long subpage,int write)68 static inline void check_faulted(void *addr, long page, long subpage, int write)
69 {
70 int want_fault = (subpage == ((page + 3) % 16));
71
72 if (write)
73 want_fault |= (subpage == ((page + 1) % 16));
74
75 if (faulted != want_fault) {
76 printf("Failed at %p (p=%ld,sp=%ld,w=%d), want=%s, got=%s !\n",
77 addr, page, subpage, write,
78 want_fault ? "fault" : "pass",
79 faulted ? "fault" : "pass");
80 ++errors;
81 }
82
83 if (faulted) {
84 if (dar != addr) {
85 printf("Fault expected at %p and happened at %p !\n",
86 addr, dar);
87 }
88 faulted = 0;
89 asm volatile("sync" : : : "memory");
90 }
91 }
92
run_test(void * addr,unsigned long size)93 static int run_test(void *addr, unsigned long size)
94 {
95 unsigned int *map;
96 long i, j, pages, err;
97
98 pages = size / 0x10000;
99 map = malloc(pages * 4);
100 assert(map);
101
102 /*
103 * for each page, mark subpage i % 16 read only and subpage
104 * (i + 3) % 16 inaccessible
105 */
106 for (i = 0; i < pages; i++) {
107 map[i] = (0x40000000 >> (((i + 1) * 2) % 32)) |
108 (0xc0000000 >> (((i + 3) * 2) % 32));
109 }
110
111 err = syscall(__NR_subpage_prot, addr, size, map);
112 if (err) {
113 perror("subpage_perm");
114 return 1;
115 }
116 free(map);
117
118 in_test = 1;
119 errors = 0;
120 for (i = 0; i < pages; i++) {
121 for (j = 0; j < 16; j++, addr += 0x1000) {
122 do_read(addr);
123 check_faulted(addr, i, j, 0);
124 do_write(addr);
125 check_faulted(addr, i, j, 1);
126 }
127 }
128
129 in_test = 0;
130 if (errors) {
131 printf("%d errors detected\n", errors);
132 return 1;
133 }
134
135 return 0;
136 }
137
test_anon(void)138 int test_anon(void)
139 {
140 unsigned long align;
141 struct sigaction act = {
142 .sa_sigaction = segv,
143 .sa_flags = SA_SIGINFO
144 };
145 void *mallocblock;
146 unsigned long mallocsize;
147
148 if (getpagesize() != 0x10000) {
149 fprintf(stderr, "Kernel page size must be 64K!\n");
150 return 1;
151 }
152
153 sigaction(SIGSEGV, &act, NULL);
154
155 mallocsize = 4 * 16 * 1024 * 1024;
156
157 FAIL_IF(posix_memalign(&mallocblock, 64 * 1024, mallocsize));
158
159 align = (unsigned long)mallocblock;
160 if (align & 0xffff)
161 align = (align | 0xffff) + 1;
162
163 mallocblock = (void *)align;
164
165 printf("allocated malloc block of 0x%lx bytes at %p\n",
166 mallocsize, mallocblock);
167
168 printf("testing malloc block...\n");
169
170 return run_test(mallocblock, mallocsize);
171 }
172
test_file(void)173 int test_file(void)
174 {
175 struct sigaction act = {
176 .sa_sigaction = segv,
177 .sa_flags = SA_SIGINFO
178 };
179 void *fileblock;
180 off_t filesize;
181 int fd;
182
183 fd = open(file_name, O_RDWR);
184 if (fd == -1) {
185 perror("failed to open file");
186 return 1;
187 }
188 sigaction(SIGSEGV, &act, NULL);
189
190 filesize = lseek(fd, 0, SEEK_END);
191 if (filesize & 0xffff)
192 filesize &= ~0xfffful;
193
194 fileblock = mmap(NULL, filesize, PROT_READ | PROT_WRITE,
195 MAP_SHARED, fd, 0);
196 if (fileblock == MAP_FAILED) {
197 perror("failed to map file");
198 return 1;
199 }
200 printf("allocated %s for 0x%lx bytes at %p\n",
201 file_name, filesize, fileblock);
202
203 printf("testing file map...\n");
204
205 return run_test(fileblock, filesize);
206 }
207
main(int argc,char * argv[])208 int main(int argc, char *argv[])
209 {
210 int rc;
211
212 rc = test_harness(test_anon, "subpage_prot_anon");
213 if (rc)
214 return rc;
215
216 if (argc > 1)
217 file_name = argv[1];
218 else
219 file_name = "tempfile";
220
221 return test_harness(test_file, "subpage_prot_file");
222 }
223