| 1 | /* Auxiliary vector support for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 2004 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 20 | Boston, MA 02110-1301, USA. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "target.h" |
| 24 | #include "gdbtypes.h" |
| 25 | #include "command.h" |
| 26 | #include "inferior.h" |
| 27 | #include "valprint.h" |
| 28 | #include "gdb_assert.h" |
| 29 | |
| 30 | #include "auxv.h" |
| 31 | #include "elf/common.h" |
| 32 | |
| 33 | #include <unistd.h> |
| 34 | #include <fcntl.h> |
| 35 | |
| 36 | |
| 37 | /* This function is called like a to_xfer_partial hook, |
| 38 | but must be called with TARGET_OBJECT_AUXV. |
| 39 | It handles access via /proc/PID/auxv, which is the common method. |
| 40 | This function is appropriate for doing: |
| 41 | #define NATIVE_XFER_AUXV procfs_xfer_auxv |
| 42 | for a native target that uses inftarg.c's child_xfer_partial hook. */ |
| 43 | |
| 44 | LONGEST |
| 45 | procfs_xfer_auxv (struct target_ops *ops, |
| 46 | int /* enum target_object */ object, |
| 47 | const char *annex, |
| 48 | gdb_byte *readbuf, |
| 49 | const gdb_byte *writebuf, |
| 50 | ULONGEST offset, |
| 51 | LONGEST len) |
| 52 | { |
| 53 | char *pathname; |
| 54 | int fd; |
| 55 | LONGEST n; |
| 56 | |
| 57 | gdb_assert (object == TARGET_OBJECT_AUXV); |
| 58 | gdb_assert (readbuf || writebuf); |
| 59 | |
| 60 | pathname = xstrprintf ("/proc/%d/auxv", PIDGET (inferior_ptid)); |
| 61 | fd = open (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY); |
| 62 | xfree (pathname); |
| 63 | if (fd < 0) |
| 64 | return -1; |
| 65 | |
| 66 | if (offset != (ULONGEST) 0 |
| 67 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) |
| 68 | n = -1; |
| 69 | else if (readbuf != NULL) |
| 70 | n = read (fd, readbuf, len); |
| 71 | else |
| 72 | n = write (fd, writebuf, len); |
| 73 | |
| 74 | (void) close (fd); |
| 75 | |
| 76 | return n; |
| 77 | } |
| 78 | |
| 79 | /* Read all the auxv data into a contiguous xmalloc'd buffer, |
| 80 | stored in *DATA. Return the size in bytes of this data. |
| 81 | If zero, there is no data and *DATA is null. |
| 82 | if < 0, there was an error and *DATA is null. */ |
| 83 | LONGEST |
| 84 | target_auxv_read (struct target_ops *ops, gdb_byte **data) |
| 85 | { |
| 86 | size_t auxv_alloc = 512, auxv_pos = 0; |
| 87 | gdb_byte *auxv = xmalloc (auxv_alloc); |
| 88 | int n; |
| 89 | |
| 90 | while (1) |
| 91 | { |
| 92 | n = target_read_partial (ops, TARGET_OBJECT_AUXV, |
| 93 | NULL, &auxv[auxv_pos], 0, |
| 94 | auxv_alloc - auxv_pos); |
| 95 | if (n <= 0) |
| 96 | break; |
| 97 | auxv_pos += n; |
| 98 | if (auxv_pos < auxv_alloc) /* Read all there was. */ |
| 99 | break; |
| 100 | gdb_assert (auxv_pos == auxv_alloc); |
| 101 | auxv_alloc *= 2; |
| 102 | auxv = xrealloc (auxv, auxv_alloc); |
| 103 | } |
| 104 | |
| 105 | if (auxv_pos == 0) |
| 106 | { |
| 107 | xfree (auxv); |
| 108 | *data = NULL; |
| 109 | return n; |
| 110 | } |
| 111 | |
| 112 | *data = auxv; |
| 113 | return auxv_pos; |
| 114 | } |
| 115 | |
| 116 | /* Read one auxv entry from *READPTR, not reading locations >= ENDPTR. |
| 117 | Return 0 if *READPTR is already at the end of the buffer. |
| 118 | Return -1 if there is insufficient buffer for a whole entry. |
| 119 | Return 1 if an entry was read into *TYPEP and *VALP. */ |
| 120 | int |
| 121 | target_auxv_parse (struct target_ops *ops, gdb_byte **readptr, |
| 122 | gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp) |
| 123 | { |
| 124 | const int sizeof_auxv_field = TYPE_LENGTH (builtin_type_void_data_ptr); |
| 125 | gdb_byte *ptr = *readptr; |
| 126 | |
| 127 | if (endptr == ptr) |
| 128 | return 0; |
| 129 | |
| 130 | if (endptr - ptr < sizeof_auxv_field * 2) |
| 131 | return -1; |
| 132 | |
| 133 | *typep = extract_unsigned_integer (ptr, sizeof_auxv_field); |
| 134 | ptr += sizeof_auxv_field; |
| 135 | *valp = extract_unsigned_integer (ptr, sizeof_auxv_field); |
| 136 | ptr += sizeof_auxv_field; |
| 137 | |
| 138 | *readptr = ptr; |
| 139 | return 1; |
| 140 | } |
| 141 | |
| 142 | /* Extract the auxiliary vector entry with a_type matching MATCH. |
| 143 | Return zero if no such entry was found, or -1 if there was |
| 144 | an error getting the information. On success, return 1 after |
| 145 | storing the entry's value field in *VALP. */ |
| 146 | int |
| 147 | target_auxv_search (struct target_ops *ops, CORE_ADDR match, CORE_ADDR *valp) |
| 148 | { |
| 149 | CORE_ADDR type, val; |
| 150 | gdb_byte *data; |
| 151 | int n = target_auxv_read (ops, &data); |
| 152 | gdb_byte *ptr = data; |
| 153 | int ents = 0; |
| 154 | |
| 155 | if (n <= 0) |
| 156 | return n; |
| 157 | |
| 158 | while (1) |
| 159 | switch (target_auxv_parse (ops, &ptr, data + n, &type, &val)) |
| 160 | { |
| 161 | case 1: /* Here's an entry, check it. */ |
| 162 | if (type == match) |
| 163 | { |
| 164 | xfree (data); |
| 165 | *valp = val; |
| 166 | return 1; |
| 167 | } |
| 168 | break; |
| 169 | case 0: /* End of the vector. */ |
| 170 | xfree (data); |
| 171 | return 0; |
| 172 | default: /* Bogosity. */ |
| 173 | xfree (data); |
| 174 | return -1; |
| 175 | } |
| 176 | |
| 177 | /*NOTREACHED*/ |
| 178 | } |
| 179 | |
| 180 | |
| 181 | /* Print the contents of the target's AUXV on the specified file. */ |
| 182 | int |
| 183 | fprint_target_auxv (struct ui_file *file, struct target_ops *ops) |
| 184 | { |
| 185 | CORE_ADDR type, val; |
| 186 | gdb_byte *data; |
| 187 | int len = target_auxv_read (ops, &data); |
| 188 | gdb_byte *ptr = data; |
| 189 | int ents = 0; |
| 190 | |
| 191 | if (len <= 0) |
| 192 | return len; |
| 193 | |
| 194 | while (target_auxv_parse (ops, &ptr, data + len, &type, &val) > 0) |
| 195 | { |
| 196 | extern int addressprint; |
| 197 | const char *name = "???"; |
| 198 | const char *description = ""; |
| 199 | enum { dec, hex, str } flavor = hex; |
| 200 | |
| 201 | switch (type) |
| 202 | { |
| 203 | #define TAG(tag, text, kind) \ |
| 204 | case tag: name = #tag; description = text; flavor = kind; break |
| 205 | TAG (AT_NULL, _("End of vector"), hex); |
| 206 | TAG (AT_IGNORE, _("Entry should be ignored"), hex); |
| 207 | TAG (AT_EXECFD, _("File descriptor of program"), dec); |
| 208 | TAG (AT_PHDR, _("Program headers for program"), hex); |
| 209 | TAG (AT_PHENT, _("Size of program header entry"), dec); |
| 210 | TAG (AT_PHNUM, _("Number of program headers"), dec); |
| 211 | TAG (AT_PAGESZ, _("System page size"), dec); |
| 212 | TAG (AT_BASE, _("Base address of interpreter"), hex); |
| 213 | TAG (AT_FLAGS, _("Flags"), hex); |
| 214 | TAG (AT_ENTRY, _("Entry point of program"), hex); |
| 215 | TAG (AT_NOTELF, _("Program is not ELF"), dec); |
| 216 | TAG (AT_UID, _("Real user ID"), dec); |
| 217 | TAG (AT_EUID, _("Effective user ID"), dec); |
| 218 | TAG (AT_GID, _("Real group ID"), dec); |
| 219 | TAG (AT_EGID, _("Effective group ID"), dec); |
| 220 | TAG (AT_CLKTCK, _("Frequency of times()"), dec); |
| 221 | TAG (AT_PLATFORM, _("String identifying platform"), str); |
| 222 | TAG (AT_HWCAP, _("Machine-dependent CPU capability hints"), hex); |
| 223 | TAG (AT_FPUCW, _("Used FPU control word"), dec); |
| 224 | TAG (AT_DCACHEBSIZE, _("Data cache block size"), dec); |
| 225 | TAG (AT_ICACHEBSIZE, _("Instruction cache block size"), dec); |
| 226 | TAG (AT_UCACHEBSIZE, _("Unified cache block size"), dec); |
| 227 | TAG (AT_IGNOREPPC, _("Entry should be ignored"), dec); |
| 228 | TAG (AT_SYSINFO, _("Special system info/entry points"), hex); |
| 229 | TAG (AT_SYSINFO_EHDR, _("System-supplied DSO's ELF header"), hex); |
| 230 | TAG (AT_SECURE, _("Boolean, was exec setuid-like?"), dec); |
| 231 | TAG (AT_SUN_UID, _("Effective user ID"), dec); |
| 232 | TAG (AT_SUN_RUID, _("Real user ID"), dec); |
| 233 | TAG (AT_SUN_GID, _("Effective group ID"), dec); |
| 234 | TAG (AT_SUN_RGID, _("Real group ID"), dec); |
| 235 | TAG (AT_SUN_LDELF, _("Dynamic linker's ELF header"), hex); |
| 236 | TAG (AT_SUN_LDSHDR, _("Dynamic linker's section headers"), hex); |
| 237 | TAG (AT_SUN_LDNAME, _("String giving name of dynamic linker"), str); |
| 238 | TAG (AT_SUN_LPAGESZ, _("Large pagesize"), dec); |
| 239 | TAG (AT_SUN_PLATFORM, _("Platform name string"), str); |
| 240 | TAG (AT_SUN_HWCAP, _("Machine-dependent CPU capability hints"), hex); |
| 241 | TAG (AT_SUN_IFLUSH, _("Should flush icache?"), dec); |
| 242 | TAG (AT_SUN_CPU, _("CPU name string"), str); |
| 243 | TAG (AT_SUN_EMUL_ENTRY, _("COFF entry point address"), hex); |
| 244 | TAG (AT_SUN_EMUL_EXECFD, _("COFF executable file descriptor"), dec); |
| 245 | TAG (AT_SUN_EXECNAME, |
| 246 | _("Canonicalized file name given to execve"), str); |
| 247 | TAG (AT_SUN_MMU, _("String for name of MMU module"), str); |
| 248 | TAG (AT_SUN_LDDATA, _("Dynamic linker's data segment address"), hex); |
| 249 | } |
| 250 | |
| 251 | fprintf_filtered (file, "%-4s %-20s %-30s ", |
| 252 | paddr_d (type), name, description); |
| 253 | switch (flavor) |
| 254 | { |
| 255 | case dec: |
| 256 | fprintf_filtered (file, "%s\n", paddr_d (val)); |
| 257 | break; |
| 258 | case hex: |
| 259 | fprintf_filtered (file, "0x%s\n", paddr_nz (val)); |
| 260 | break; |
| 261 | case str: |
| 262 | if (addressprint) |
| 263 | fprintf_filtered (file, "0x%s", paddr_nz (val)); |
| 264 | val_print_string (val, -1, 1, file); |
| 265 | fprintf_filtered (file, "\n"); |
| 266 | break; |
| 267 | } |
| 268 | ++ents; |
| 269 | } |
| 270 | |
| 271 | xfree (data); |
| 272 | |
| 273 | return ents; |
| 274 | } |
| 275 | |
| 276 | static void |
| 277 | info_auxv_command (char *cmd, int from_tty) |
| 278 | { |
| 279 | if (! target_has_stack) |
| 280 | error (_("The program has no auxiliary information now.")); |
| 281 | else |
| 282 | { |
| 283 | int ents = fprint_target_auxv (gdb_stdout, ¤t_target); |
| 284 | if (ents < 0) |
| 285 | error (_("No auxiliary vector found, or failed reading it.")); |
| 286 | else if (ents == 0) |
| 287 | error (_("Auxiliary vector is empty.")); |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | |
| 292 | extern initialize_file_ftype _initialize_auxv; /* -Wmissing-prototypes; */ |
| 293 | |
| 294 | void |
| 295 | _initialize_auxv (void) |
| 296 | { |
| 297 | add_info ("auxv", info_auxv_command, |
| 298 | _("Display the inferior's auxiliary vector.\n\ |
| 299 | This is information provided by the operating system at program startup.")); |
| 300 | } |