drivers/bus/acpi/acpica/executer/exnames.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exnames - interpreter/scanner name load/execute
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2018, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include "acpi.h"
  45 #include "accommon.h"
  46 #include "acinterp.h"
  47 #include "amlcode.h"
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50         ACPI_MODULE_NAME    ("exnames")
  51
  52 /* Local prototypes */
  53
  54 static char *
  55 AcpiExAllocateNameString (
  56     UINT32                  PrefixCount,
  57     UINT32                  NumNameSegs);
  58
  59 static ACPI_STATUS
  60 AcpiExNameSegment (
  61     UINT8                   **InAmlAddress,
  62     char                    *NameString);
  63
  64
  65 /*******************************************************************************
  66  *
  67  * FUNCTION:    AcpiExAllocateNameString
  68  *
  69  * PARAMETERS:  PrefixCount         - Count of parent levels. Special cases:
  70  *                                    (-1)==root,  0==none
  71  *              NumNameSegs         - count of 4-character name segments
  72  *
  73  * RETURN:      A pointer to the allocated string segment. This segment must
  74  *              be deleted by the caller.
  75  *
  76  * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
  77  *              string is long enough, and set up prefix if any.
  78  *
  79  ******************************************************************************/
  80
  81 static char *
  82 AcpiExAllocateNameString (
  83     UINT32                  PrefixCount,
  84     UINT32                  NumNameSegs)
  85 {
  86     char                    *TempPtr;
  87     char                    *NameString;
  88     UINT32                   SizeNeeded;
  89
  90     ACPI_FUNCTION_TRACE (ExAllocateNameString);
  91
  92
  93     /*
  94      * Allow room for all \ and ^ prefixes, all segments and a MultiNamePrefix.
  95      * Also, one byte for the null terminator.
  96      * This may actually be somewhat longer than needed.
  97      */
  98     if (PrefixCount == ACPI_UINT32_MAX)
  99     {
 100         /* Special case for root */
 101
 102         SizeNeeded = 1 + (ACPI_NAME_SIZE * NumNameSegs) + 2 + 1;
 103     }
 104     else
 105     {
 106         SizeNeeded = PrefixCount + (ACPI_NAME_SIZE * NumNameSegs) + 2 + 1;
 107     }
 108
 109     /*
 110      * Allocate a buffer for the name.
 111      * This buffer must be deleted by the caller!
 112      */
 113     NameString = ACPI_ALLOCATE (SizeNeeded);
 114     if (!NameString)
 115     {
 116         ACPI_ERROR ((AE_INFO,
 117             "Could not allocate size %u", SizeNeeded));
 118         return_PTR (NULL);
 119     }
 120
 121     TempPtr = NameString;
 122
 123     /* Set up Root or Parent prefixes if needed */
 124
 125     if (PrefixCount == ACPI_UINT32_MAX)
 126     {
 127         *TempPtr++ = AML_ROOT_PREFIX;
 128     }
 129     else
 130     {
 131         while (PrefixCount--)
 132         {
 133             *TempPtr++ = AML_PARENT_PREFIX;
 134         }
 135     }
 136
 137
 138     /* Set up Dual or Multi prefixes if needed */
 139
 140     if (NumNameSegs > 2)
 141     {
 142         /* Set up multi prefixes   */
 143
 144         *TempPtr++ = AML_MULTI_NAME_PREFIX;
 145         *TempPtr++ = (char) NumNameSegs;
 146     }
 147     else if (2 == NumNameSegs)
 148     {
 149         /* Set up dual prefixes */
 150
 151         *TempPtr++ = AML_DUAL_NAME_PREFIX;
 152     }
 153
 154     /*
 155      * Terminate string following prefixes. AcpiExNameSegment() will
 156      * append the segment(s)
 157      */
 158     *TempPtr = 0;
 159
 160     return_PTR (NameString);
 161 }
 162
 163
 164 /*******************************************************************************
 165  *
 166  * FUNCTION:    AcpiExNameSegment
 167  *
 168  * PARAMETERS:  InAmlAddress    - Pointer to the name in the AML code
 169  *              NameString      - Where to return the name. The name is appended
 170  *                                to any existing string to form a namepath
 171  *
 172  * RETURN:      Status
 173  *
 174  * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
 175  *
 176  ******************************************************************************/
 177
 178 static ACPI_STATUS
 179 AcpiExNameSegment (
 180     UINT8                   **InAmlAddress,
 181     char                    *NameString)
 182 {
 183     char                    *AmlAddress = (void *) *InAmlAddress;
 184     ACPI_STATUS             Status = AE_OK;
 185     UINT32                  Index;
 186     char                    CharBuf[5];
 187
 188
 189     ACPI_FUNCTION_TRACE (ExNameSegment);
 190
 191
 192     /*
 193      * If first character is a digit, then we know that we aren't looking
 194      * at a valid name segment
 195      */
 196     CharBuf[0] = *AmlAddress;
 197
 198     if ('0' <= CharBuf[0] && CharBuf[0] <= '9')
 199     {
 200         ACPI_ERROR ((AE_INFO, "Invalid leading digit: %c", CharBuf[0]));
 201         return_ACPI_STATUS (AE_CTRL_PENDING);
 202     }
 203
 204     ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "Bytes from stream:\n"));
 205
 206     for (Index = 0;
 207         (Index < ACPI_NAME_SIZE) && (AcpiUtValidNameChar (*AmlAddress, 0));
 208         Index++)
 209     {
 210         CharBuf[Index] = *AmlAddress++;
 211         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "%c\n", CharBuf[Index]));
 212     }
 213
 214
 215     /* Valid name segment  */
 216
 217     if (Index == 4)
 218     {
 219         /* Found 4 valid characters */
 220
 221         CharBuf[4] = '\0';
 222
 223         if (NameString)
 224         {
 225             strcat (NameString, CharBuf);
 226             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 227                 "Appended to - %s\n", NameString));
 228         }
 229         else
 230         {
 231             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 232                 "No Name string - %s\n", CharBuf));
 233         }
 234     }
 235     else if (Index == 0)
 236     {
 237         /*
 238          * First character was not a valid name character,
 239          * so we are looking at something other than a name.
 240          */
 241         ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 242             "Leading character is not alpha: %02Xh (not a name)\n",
 243             CharBuf[0]));
 244         Status = AE_CTRL_PENDING;
 245     }
 246     else
 247     {
 248         /*
 249          * Segment started with one or more valid characters, but fewer than
 250          * the required 4
 251          */
 252         Status = AE_AML_BAD_NAME;
 253         ACPI_ERROR ((AE_INFO,
 254             "Bad character 0x%02x in name, at %p",
 255             *AmlAddress, AmlAddress));
 256     }
 257
 258     *InAmlAddress = ACPI_CAST_PTR (UINT8, AmlAddress);
 259     return_ACPI_STATUS (Status);
 260 }
 261
 262
 263 /*******************************************************************************
 264  *
 265  * FUNCTION:    AcpiExGetNameString
 266  *
 267  * PARAMETERS:  DataType            - Object type to be associated with this
 268  *                                    name
 269  *              InAmlAddress        - Pointer to the namestring in the AML code
 270  *              OutNameString       - Where the namestring is returned
 271  *              OutNameLength       - Length of the returned string
 272  *
 273  * RETURN:      Status, namestring and length
 274  *
 275  * DESCRIPTION: Extract a full namepath from the AML byte stream,
 276  *              including any prefixes.
 277  *
 278  ******************************************************************************/
 279
 280 ACPI_STATUS
 281 AcpiExGetNameString (
 282     ACPI_OBJECT_TYPE        DataType,
 283     UINT8                   *InAmlAddress,
 284     char                    **OutNameString,
 285     UINT32                  *OutNameLength)
 286 {
 287     ACPI_STATUS             Status = AE_OK;
 288     UINT8                   *AmlAddress = InAmlAddress;
 289     char                    *NameString = NULL;
 290     UINT32                  NumSegments;
 291     UINT32                  PrefixCount = 0;
 292     BOOLEAN                 HasPrefix = FALSE;
 293
 294
 295     ACPI_FUNCTION_TRACE_PTR (ExGetNameString, AmlAddress);
 296
 297
 298     if (ACPI_TYPE_LOCAL_REGION_FIELD == DataType   ||
 299         ACPI_TYPE_LOCAL_BANK_FIELD == DataType     ||
 300         ACPI_TYPE_LOCAL_INDEX_FIELD == DataType)
 301     {
 302         /* Disallow prefixes for types associated with FieldUnit names */
 303
 304         NameString = AcpiExAllocateNameString (0, 1);
 305         if (!NameString)
 306         {
 307             Status = AE_NO_MEMORY;
 308         }
 309         else
 310         {
 311             Status = AcpiExNameSegment (&AmlAddress, NameString);
 312         }
 313     }
 314     else
 315     {
 316         /*
 317          * DataType is not a field name.
 318          * Examine first character of name for root or parent prefix operators
 319          */
 320         switch (*AmlAddress)
 321         {
 322         case AML_ROOT_PREFIX:
 323
 324             ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "RootPrefix(\\) at %p\n",
 325                 AmlAddress));
 326
 327             /*
 328              * Remember that we have a RootPrefix --
 329              * see comment in AcpiExAllocateNameString()
 330              */
 331             AmlAddress++;
 332             PrefixCount = ACPI_UINT32_MAX;
 333             HasPrefix = TRUE;
 334             break;
 335
 336         case AML_PARENT_PREFIX:
 337
 338             /* Increment past possibly multiple parent prefixes */
 339
 340             do
 341             {
 342                 ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "ParentPrefix (^) at %p\n",
 343                     AmlAddress));
 344
 345                 AmlAddress++;
 346                 PrefixCount++;
 347
 348             } while (*AmlAddress == AML_PARENT_PREFIX);
 349
 350             HasPrefix = TRUE;
 351             break;
 352
 353         default:
 354
 355             /* Not a prefix character */
 356
 357             break;
 358         }
 359
 360         /* Examine first character of name for name segment prefix operator */
 361
 362         switch (*AmlAddress)
 363         {
 364         case AML_DUAL_NAME_PREFIX:
 365
 366             ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "DualNamePrefix at %p\n",
 367                 AmlAddress));
 368
 369             AmlAddress++;
 370             NameString = AcpiExAllocateNameString (PrefixCount, 2);
 371             if (!NameString)
 372             {
 373                 Status = AE_NO_MEMORY;
 374                 break;
 375             }
 376
 377             /* Indicate that we processed a prefix */
 378
 379             HasPrefix = TRUE;
 380
 381             Status = AcpiExNameSegment (&AmlAddress, NameString);
 382             if (ACPI_SUCCESS (Status))
 383             {
 384                 Status = AcpiExNameSegment (&AmlAddress, NameString);
 385             }
 386             break;
 387
 388         case AML_MULTI_NAME_PREFIX:
 389
 390             ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "MultiNamePrefix at %p\n",
 391                 AmlAddress));
 392
 393             /* Fetch count of segments remaining in name path */
 394
 395             AmlAddress++;
 396             NumSegments = *AmlAddress;
 397
 398             NameString = AcpiExAllocateNameString (
 399                 PrefixCount, NumSegments);
 400             if (!NameString)
 401             {
 402                 Status = AE_NO_MEMORY;
 403                 break;
 404             }
 405
 406             /* Indicate that we processed a prefix */
 407
 408             AmlAddress++;
 409             HasPrefix = TRUE;
 410
 411             while (NumSegments &&
 412                     (Status = AcpiExNameSegment (&AmlAddress, NameString)) ==
 413                         AE_OK)
 414             {
 415                 NumSegments--;
 416             }
 417
 418             break;
 419
 420         case 0:
 421
 422             /* NullName valid as of 8-12-98 ASL/AML Grammar Update */
 423
 424             if (PrefixCount == ACPI_UINT32_MAX)
 425             {
 426                 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
 427                     "NameSeg is \"\\\" followed by NULL\n"));
 428             }
 429
 430             /* Consume the NULL byte */
 431
 432             AmlAddress++;
 433             NameString = AcpiExAllocateNameString (PrefixCount, 0);
 434             if (!NameString)
 435             {
 436                 Status = AE_NO_MEMORY;
 437                 break;
 438             }
 439
 440             break;
 441
 442         default:
 443
 444             /* Name segment string */
 445
 446             NameString = AcpiExAllocateNameString (PrefixCount, 1);
 447             if (!NameString)
 448             {
 449                 Status = AE_NO_MEMORY;
 450                 break;
 451             }
 452
 453             Status = AcpiExNameSegment (&AmlAddress, NameString);
 454             break;
 455         }
 456     }
 457
 458     if (AE_CTRL_PENDING == Status && HasPrefix)
 459     {
 460         /* Ran out of segments after processing a prefix */
 461
 462         ACPI_ERROR ((AE_INFO,
 463             "Malformed Name at %p", NameString));
 464         Status = AE_AML_BAD_NAME;
 465     }
 466
 467     if (ACPI_FAILURE (Status))
 468     {
 469         if (NameString)
 470         {
 471             ACPI_FREE (NameString);
 472         }
 473         return_ACPI_STATUS (Status);
 474     }
 475
 476     *OutNameString = NameString;
 477     *OutNameLength = (UINT32) (AmlAddress - InAmlAddress);
 478
 479     return_ACPI_STATUS (Status);
 480 }