granicus.if.org Git - strace/blob - tests/read-write.c

   1 /*
   2  * Check decoding and dumping of read and write syscalls.
   3  *
   4  * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
   5  * Copyright (c) 2016-2018 The strace developers.
   6  * All rights reserved.
   7  *
   8  * SPDX-License-Identifier: GPL-2.0-or-later
   9  */
  10
  11 #include "tests.h"
  12
  13 #include <fcntl.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17 #include <asm/unistd.h>
  18
  19 static void
  20 dump_str(const char *str, const unsigned int len)
  21 {
  22         static const char chars[256] =
  23                 "................................"
  24                 " !\"#$%&'()*+,-./0123456789:;<=>?"
  25                 "@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_"
  26                 "`abcdefghijklmnopqrstuvwxyz{|}~."
  27                 "................................"
  28                 "................................"
  29                 "................................"
  30                 "................................";
  31         unsigned int i;
  32
  33         for (i = 0; i < len; i += 16) {
  34                 unsigned int n = len - i > 16 ? 16 : len - i;
  35                 const char *dump = hexdump_memdup(str + i, n);
  36
  37                 tprintf(" | %05x %-49s  %-16.*s |\n",
  38                         i, dump, n, chars + i);
  39
  40                 free((void *) dump);
  41         }
  42 }
  43
  44 static void
  45 print_hex(const char *str, const unsigned int len)
  46 {
  47         const unsigned char *ustr = (const unsigned char *) str;
  48         unsigned int i;
  49
  50         tprintf("\"");
  51
  52         for (i = 0; i < len; ++i) {
  53                 unsigned int c = ustr[i];
  54
  55                 if (i >= DEFAULT_STRLEN) {
  56                         tprintf("\"...");
  57                         return;
  58                 }
  59
  60                 switch (c) {
  61                 case '\t':
  62                         tprintf("\\t"); break;
  63                 case '\n':
  64                         tprintf("\\n"); break;
  65                 case '\v':
  66                         tprintf("\\v"); break;
  67                 case '\f':
  68                         tprintf("\\f"); break;
  69                 case '\r':
  70                         tprintf("\\r"); break;
  71                 default:
  72                         tprintf("\\%o", ustr[i]);
  73                 }
  74         }
  75
  76         tprintf("\"");
  77 }
  78
  79 static long
  80 k_read(unsigned int fd, void *buf, size_t count)
  81 {
  82         kernel_ulong_t kfd = (kernel_ulong_t) 0xfacefeed00000000ULL | fd;
  83         return syscall(__NR_read, kfd, buf, count);
  84 }
  85
  86 static long
  87 k_write(unsigned int fd, const void *buf, size_t count)
  88 {
  89         kernel_ulong_t kfd = (kernel_ulong_t) 0xfacefeed00000000ULL | fd;
  90         return syscall(__NR_write, kfd, buf, count);
  91 }
  92
  93 static void
  94 test_dump(const unsigned int len, bool err_desc)
  95 {
  96         static char *buf;
  97         const char *rc_str;
  98         int in_fd = err_desc ? 5 : 0;
  99         int out_fd = err_desc ? 4 : 1;
 100
 101         if (buf) {
 102                 size_t ps1 = get_page_size() - 1;
 103                 buf = (void *) (((size_t) buf + ps1) & ~ps1) - len;
 104         } else {
 105                 buf = tail_alloc(len);
 106         }
 107
 108         long rc = k_read(in_fd, buf, len);
 109         rc_str = sprintrc(rc);
 110         if (err_desc ^ (rc != (int) len))
 111                 perror_msg_and_fail("read: expected %d, returned %ld",
 112                                     err_desc ? -1 : (int) len, rc);
 113
 114         tprintf("%s(%d, ", "read", in_fd);
 115         if (!err_desc)
 116                 print_hex(buf, len);
 117         else
 118                 tprintf("%p", buf);
 119         tprintf(", %d) = %s\n", len, rc_str);
 120         if (!err_desc)
 121                 dump_str(buf, len);
 122
 123         unsigned int i;
 124         for (i = 0; i < len; ++i)
 125                 buf[i] = i;
 126
 127         rc = k_write(out_fd, buf, len);
 128         rc_str = sprintrc(rc);
 129         if (err_desc ^ (rc != (int) len))
 130                 perror_msg_and_fail("write: expected %d, returned %ld",
 131                                     err_desc ? -1 : (int) len, rc);
 132
 133         tprintf("%s(%d, ", "write", out_fd);
 134         print_hex(buf, len);
 135         tprintf(", %d) = %s\n", len, rc_str);
 136         dump_str(buf, len);
 137
 138         if (!len)
 139                 buf = 0;
 140 }
 141
 142 int
 143 main(void)
 144 {
 145         tprintf("%s", "");
 146
 147         skip_if_unavailable("/proc/self/fd/");
 148
 149         static const char tmp[] = "read-write-tmpfile";
 150         if (open(tmp, O_CREAT|O_RDONLY|O_TRUNC, 0600) != 0)
 151                 perror_msg_and_fail("creat: %s", tmp);
 152         if (open(tmp, O_WRONLY) != 1)
 153                 perror_msg_and_fail("open: %s", tmp);
 154
 155         static const char w_c[] = "0123456789abcde";
 156         const unsigned int w_len = LENGTH_OF(w_c);
 157         const char *w_d = hexdump_strdup(w_c);
 158         const void *w = tail_memdup(w_c, w_len);
 159
 160         static const char r0_c[] = "01234567";
 161         const char *r0_d = hexdump_strdup(r0_c);
 162         const unsigned int r0_len = (w_len + 1) / 2;
 163         void *r0 = tail_alloc(r0_len);
 164
 165         static const char r1_c[] = "89abcde";
 166         const char *r1_d = hexdump_strdup(r1_c);
 167         const unsigned int r1_len = w_len - r0_len;
 168         void *r1 = tail_alloc(w_len);
 169
 170         void *efault = r1 - get_page_size();
 171
 172         long rc;
 173
 174         rc = k_write(1, w, 0);
 175         if (rc)
 176                 perror_msg_and_fail("write: expected 0, returned %ld", rc);
 177         tprintf("write(1, \"\", 0) = 0\n");
 178
 179         rc = k_write(1, efault, 1);
 180         if (rc != -1)
 181                 perror_msg_and_fail("write: expected -1 EFAULT"
 182                                     ", returned %ld", rc);
 183         tprintf("write(1, %p, 1) = -1 EFAULT (%m)\n", efault);
 184
 185         rc = k_write(1, w, w_len);
 186         if (rc != (int) w_len)
 187                 perror_msg_and_fail("write: expected %u, returned %ld",
 188                                     w_len, rc);
 189         tprintf("write(1, \"%s\", %u) = %ld\n"
 190                 " | 00000 %-49s  %-16s |\n",
 191                 w_c, w_len, rc, w_d, w_c);
 192         close(1);
 193
 194         rc = k_read(0, r0, 0);
 195         if (rc)
 196                 perror_msg_and_fail("read: expected 0, returned %ld", rc);
 197         tprintf("read(0, \"\", 0) = 0\n");
 198
 199         rc = k_read(0, efault, 1);
 200         if (rc != -1)
 201                 perror_msg_and_fail("read: expected -1, returned %ld", rc);
 202         tprintf("read(0, %p, 1) = -1 EFAULT (%m)\n", efault);
 203
 204         rc = k_read(0, r0, r0_len);
 205         if (rc != (int) r0_len)
 206                 perror_msg_and_fail("read: expected %u, returned %ld",
 207                                     r0_len, rc);
 208         tprintf("read(0, \"%s\", %u) = %ld\n"
 209                 " | 00000 %-49s  %-16s |\n",
 210                 r0_c, r0_len, rc, r0_d, r0_c);
 211
 212         rc = k_read(0, r1, w_len);
 213         if (rc != (int) r1_len)
 214                 perror_msg_and_fail("read: expected %u, returned %ld",
 215                                     r1_len, rc);
 216         tprintf("read(0, \"%s\", %u) = %ld\n"
 217                 " | 00000 %-49s  %-16s |\n",
 218                 r1_c, w_len, rc, r1_d, r1_c);
 219         close(0);
 220
 221         if (open("/dev/zero", O_RDONLY))
 222                 perror_msg_and_fail("open");
 223
 224         if (open("/dev/null", O_WRONLY) != 1)
 225                 perror_msg_and_fail("open");
 226
 227         if (open("/dev/zero", O_RDONLY) != 4)
 228                 perror_msg_and_fail("open");
 229
 230         if (open("/dev/null", O_WRONLY) != 5)
 231                 perror_msg_and_fail("open");
 232
 233         unsigned int i;
 234         for (i = 0; i <= DEFAULT_STRLEN; ++i)
 235                 test_dump(i, false);
 236
 237         test_dump(256, true);
 238
 239         tprintf("+++ exited with 0 +++\n");
 240         return 0;
 241 }