1 /*******************************************************************************
2  *
3  * Module Name: nsnames - Name manipulation and search
4  *
5  ******************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2018, Intel Corp.
12  * All rights reserved.
13  *
14  * 2. License
15  *
16  * 2.1. This is your license from Intel Corp. under its intellectual property
17  * rights. You may have additional license terms from the party that provided
18  * you this software, covering your right to use that party's intellectual
19  * property rights.
20  *
21  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
22  * copy of the source code appearing in this file ("Covered Code") an
23  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
24  * base code distributed originally by Intel ("Original Intel Code") to copy,
25  * make derivatives, distribute, use and display any portion of the Covered
26  * Code in any form, with the right to sublicense such rights; and
27  *
28  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
29  * license (with the right to sublicense), under only those claims of Intel
30  * patents that are infringed by the Original Intel Code, to make, use, sell,
31  * offer to sell, and import the Covered Code and derivative works thereof
32  * solely to the minimum extent necessary to exercise the above copyright
33  * license, and in no event shall the patent license extend to any additions
34  * to or modifications of the Original Intel Code. No other license or right
35  * is granted directly or by implication, estoppel or otherwise;
36  *
37  * The above copyright and patent license is granted only if the following
38  * conditions are met:
39  *
40  * 3. Conditions
41  *
42  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
43  * Redistribution of source code of any substantial portion of the Covered
44  * Code or modification with rights to further distribute source must include
45  * the above Copyright Notice, the above License, this list of Conditions,
46  * and the following Disclaimer and Export Compliance provision. In addition,
47  * Licensee must cause all Covered Code to which Licensee contributes to
48  * contain a file documenting the changes Licensee made to create that Covered
49  * Code and the date of any change. Licensee must include in that file the
50  * documentation of any changes made by any predecessor Licensee. Licensee
51  * must include a prominent statement that the modification is derived,
52  * directly or indirectly, from Original Intel Code.
53  *
54  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
55  * Redistribution of source code of any substantial portion of the Covered
56  * Code or modification without rights to further distribute source must
57  * include the following Disclaimer and Export Compliance provision in the
58  * documentation and/or other materials provided with distribution. In
59  * addition, Licensee may not authorize further sublicense of source of any
60  * portion of the Covered Code, and must include terms to the effect that the
61  * license from Licensee to its licensee is limited to the intellectual
62  * property embodied in the software Licensee provides to its licensee, and
63  * not to intellectual property embodied in modifications its licensee may
64  * make.
65  *
66  * 3.3. Redistribution of Executable. Redistribution in executable form of any
67  * substantial portion of the Covered Code or modification must reproduce the
68  * above Copyright Notice, and the following Disclaimer and Export Compliance
69  * provision in the documentation and/or other materials provided with the
70  * distribution.
71  *
72  * 3.4. Intel retains all right, title, and interest in and to the Original
73  * Intel Code.
74  *
75  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
76  * Intel shall be used in advertising or otherwise to promote the sale, use or
77  * other dealings in products derived from or relating to the Covered Code
78  * without prior written authorization from Intel.
79  *
80  * 4. Disclaimer and Export Compliance
81  *
82  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
83  * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
84  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
85  * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
86  * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
87  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
88  * PARTICULAR PURPOSE.
89  *
90  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
91  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
92  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
93  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
94  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
95  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
96  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
97  * LIMITED REMEDY.
98  *
99  * 4.3. Licensee shall not export, either directly or indirectly, any of this
100  * software or system incorporating such software without first obtaining any
101  * required license or other approval from the U. S. Department of Commerce or
102  * any other agency or department of the United States Government. In the
103  * event Licensee exports any such software from the United States or
104  * re-exports any such software from a foreign destination, Licensee shall
105  * ensure that the distribution and export/re-export of the software is in
106  * compliance with all laws, regulations, orders, or other restrictions of the
107  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
108  * any of its subsidiaries will export/re-export any technical data, process,
109  * software, or service, directly or indirectly, to any country for which the
110  * United States government or any agency thereof requires an export license,
111  * other governmental approval, or letter of assurance, without first obtaining
112  * such license, approval or letter.
113  *
114  *****************************************************************************
115  *
116  * Alternatively, you may choose to be licensed under the terms of the
117  * following license:
118  *
119  * Redistribution and use in source and binary forms, with or without
120  * modification, are permitted provided that the following conditions
121  * are met:
122  * 1. Redistributions of source code must retain the above copyright
123  *    notice, this list of conditions, and the following disclaimer,
124  *    without modification.
125  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
126  *    substantially similar to the "NO WARRANTY" disclaimer below
127  *    ("Disclaimer") and any redistribution must be conditioned upon
128  *    including a substantially similar Disclaimer requirement for further
129  *    binary redistribution.
130  * 3. Neither the names of the above-listed copyright holders nor the names
131  *    of any contributors may be used to endorse or promote products derived
132  *    from this software without specific prior written permission.
133  *
134  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
135  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
136  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
137  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
138  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
139  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
140  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
141  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
142  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
143  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
144  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
145  *
146  * Alternatively, you may choose to be licensed under the terms of the
147  * GNU General Public License ("GPL") version 2 as published by the Free
148  * Software Foundation.
149  *
150  *****************************************************************************/
151 
152 #include "acpi.h"
153 #include "accommon.h"
154 #include "amlcode.h"
155 #include "acnamesp.h"
156 
157 
158 #define _COMPONENT          ACPI_NAMESPACE
159         ACPI_MODULE_NAME    ("nsnames")
160 
161 /* Local Prototypes */
162 
163 static void
164 AcpiNsNormalizePathname (
165     char                    *OriginalPath);
166 
167 
168 /*******************************************************************************
169  *
170  * FUNCTION:    AcpiNsGetExternalPathname
171  *
172  * PARAMETERS:  Node            - Namespace node whose pathname is needed
173  *
174  * RETURN:      Pointer to storage containing the fully qualified name of
175  *              the node, In external format (name segments separated by path
176  *              separators.)
177  *
178  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
179  *              for error and debug statements.
180  *
181  ******************************************************************************/
182 
183 char *
AcpiNsGetExternalPathname(ACPI_NAMESPACE_NODE * Node)184 AcpiNsGetExternalPathname (
185     ACPI_NAMESPACE_NODE     *Node)
186 {
187     char                    *NameBuffer;
188 
189 
190     ACPI_FUNCTION_TRACE_PTR (NsGetExternalPathname, Node);
191 
192 
193     NameBuffer = AcpiNsGetNormalizedPathname (Node, FALSE);
194     return_PTR (NameBuffer);
195 }
196 
197 
198 /*******************************************************************************
199  *
200  * FUNCTION:    AcpiNsGetPathnameLength
201  *
202  * PARAMETERS:  Node        - Namespace node
203  *
204  * RETURN:      Length of path, including prefix
205  *
206  * DESCRIPTION: Get the length of the pathname string for this node
207  *
208  ******************************************************************************/
209 
210 ACPI_SIZE
AcpiNsGetPathnameLength(ACPI_NAMESPACE_NODE * Node)211 AcpiNsGetPathnameLength (
212     ACPI_NAMESPACE_NODE     *Node)
213 {
214     ACPI_SIZE               Size;
215 
216 
217     /* Validate the Node */
218 
219     if (ACPI_GET_DESCRIPTOR_TYPE (Node) != ACPI_DESC_TYPE_NAMED)
220     {
221         ACPI_ERROR ((AE_INFO,
222             "Invalid/cached reference target node: %p, descriptor type %d",
223             Node, ACPI_GET_DESCRIPTOR_TYPE (Node)));
224         return (0);
225     }
226 
227     Size = AcpiNsBuildNormalizedPath (Node, NULL, 0, FALSE);
228     return (Size);
229 }
230 
231 
232 /*******************************************************************************
233  *
234  * FUNCTION:    AcpiNsHandleToName
235  *
236  * PARAMETERS:  TargetHandle            - Handle of named object whose name is
237  *                                        to be found
238  *              Buffer                  - Where the name is returned
239  *
240  * RETURN:      Status, Buffer is filled with name if status is AE_OK
241  *
242  * DESCRIPTION: Build and return a full namespace name
243  *
244  ******************************************************************************/
245 
246 ACPI_STATUS
AcpiNsHandleToName(ACPI_HANDLE TargetHandle,ACPI_BUFFER * Buffer)247 AcpiNsHandleToName (
248     ACPI_HANDLE             TargetHandle,
249     ACPI_BUFFER             *Buffer)
250 {
251     ACPI_STATUS             Status;
252     ACPI_NAMESPACE_NODE     *Node;
253     const char              *NodeName;
254 
255 
256     ACPI_FUNCTION_TRACE_PTR (NsHandleToName, TargetHandle);
257 
258 
259     Node = AcpiNsValidateHandle (TargetHandle);
260     if (!Node)
261     {
262         return_ACPI_STATUS (AE_BAD_PARAMETER);
263     }
264 
265     /* Validate/Allocate/Clear caller buffer */
266 
267     Status = AcpiUtInitializeBuffer (Buffer, ACPI_PATH_SEGMENT_LENGTH);
268     if (ACPI_FAILURE (Status))
269     {
270         return_ACPI_STATUS (Status);
271     }
272 
273     /* Just copy the ACPI name from the Node and zero terminate it */
274 
275     NodeName = AcpiUtGetNodeName (Node);
276     ACPI_MOVE_NAME (Buffer->Pointer, NodeName);
277     ((char *) Buffer->Pointer) [ACPI_NAME_SIZE] = 0;
278 
279     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "%4.4s\n", (char *) Buffer->Pointer));
280     return_ACPI_STATUS (AE_OK);
281 }
282 
283 
284 /*******************************************************************************
285  *
286  * FUNCTION:    AcpiNsHandleToPathname
287  *
288  * PARAMETERS:  TargetHandle            - Handle of named object whose name is
289  *                                        to be found
290  *              Buffer                  - Where the pathname is returned
291  *              NoTrailing              - Remove trailing '_' for each name
292  *                                        segment
293  *
294  * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
295  *
296  * DESCRIPTION: Build and return a full namespace pathname
297  *
298  ******************************************************************************/
299 
300 ACPI_STATUS
AcpiNsHandleToPathname(ACPI_HANDLE TargetHandle,ACPI_BUFFER * Buffer,BOOLEAN NoTrailing)301 AcpiNsHandleToPathname (
302     ACPI_HANDLE             TargetHandle,
303     ACPI_BUFFER             *Buffer,
304     BOOLEAN                 NoTrailing)
305 {
306     ACPI_STATUS             Status;
307     ACPI_NAMESPACE_NODE     *Node;
308     ACPI_SIZE               RequiredSize;
309 
310 
311     ACPI_FUNCTION_TRACE_PTR (NsHandleToPathname, TargetHandle);
312 
313 
314     Node = AcpiNsValidateHandle (TargetHandle);
315     if (!Node)
316     {
317         return_ACPI_STATUS (AE_BAD_PARAMETER);
318     }
319 
320     /* Determine size required for the caller buffer */
321 
322     RequiredSize = AcpiNsBuildNormalizedPath (Node, NULL, 0, NoTrailing);
323     if (!RequiredSize)
324     {
325         return_ACPI_STATUS (AE_BAD_PARAMETER);
326     }
327 
328     /* Validate/Allocate/Clear caller buffer */
329 
330     Status = AcpiUtInitializeBuffer (Buffer, RequiredSize);
331     if (ACPI_FAILURE (Status))
332     {
333         return_ACPI_STATUS (Status);
334     }
335 
336     /* Build the path in the caller buffer */
337 
338     (void) AcpiNsBuildNormalizedPath (Node, Buffer->Pointer,
339         RequiredSize, NoTrailing);
340 
341     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "%s [%X]\n",
342         (char *) Buffer->Pointer, (UINT32) RequiredSize));
343     return_ACPI_STATUS (AE_OK);
344 }
345 
346 
347 /*******************************************************************************
348  *
349  * FUNCTION:    AcpiNsBuildNormalizedPath
350  *
351  * PARAMETERS:  Node        - Namespace node
352  *              FullPath    - Where the path name is returned
353  *              PathSize    - Size of returned path name buffer
354  *              NoTrailing  - Remove trailing '_' from each name segment
355  *
356  * RETURN:      Return 1 if the AML path is empty, otherwise returning (length
357  *              of pathname + 1) which means the 'FullPath' contains a trailing
358  *              null.
359  *
360  * DESCRIPTION: Build and return a full namespace pathname.
361  *              Note that if the size of 'FullPath' isn't large enough to
362  *              contain the namespace node's path name, the actual required
363  *              buffer length is returned, and it should be greater than
364  *              'PathSize'. So callers are able to check the returning value
365  *              to determine the buffer size of 'FullPath'.
366  *
367  ******************************************************************************/
368 
369 UINT32
AcpiNsBuildNormalizedPath(ACPI_NAMESPACE_NODE * Node,char * FullPath,UINT32 PathSize,BOOLEAN NoTrailing)370 AcpiNsBuildNormalizedPath (
371     ACPI_NAMESPACE_NODE     *Node,
372     char                    *FullPath,
373     UINT32                  PathSize,
374     BOOLEAN                 NoTrailing)
375 {
376     UINT32                  Length = 0, i;
377     char                    Name[ACPI_NAME_SIZE];
378     BOOLEAN                 DoNoTrailing;
379     char                    c, *Left, *Right;
380     ACPI_NAMESPACE_NODE     *NextNode;
381 
382 
383     ACPI_FUNCTION_TRACE_PTR (NsBuildNormalizedPath, Node);
384 
385 
386 #define ACPI_PATH_PUT8(Path, Size, Byte, Length)    \
387     do {                                            \
388         if ((Length) < (Size))                      \
389         {                                           \
390             (Path)[(Length)] = (Byte);              \
391         }                                           \
392         (Length)++;                                 \
393     } while (0)
394 
395     /*
396      * Make sure the PathSize is correct, so that we don't need to
397      * validate both FullPath and PathSize.
398      */
399     if (!FullPath)
400     {
401         PathSize = 0;
402     }
403 
404     if (!Node)
405     {
406         goto BuildTrailingNull;
407     }
408 
409     NextNode = Node;
410     while (NextNode && NextNode != AcpiGbl_RootNode)
411     {
412         if (NextNode != Node)
413         {
414             ACPI_PATH_PUT8(FullPath, PathSize, AML_DUAL_NAME_PREFIX, Length);
415         }
416 
417         ACPI_MOVE_32_TO_32 (Name, &NextNode->Name);
418         DoNoTrailing = NoTrailing;
419         for (i = 0; i < 4; i++)
420         {
421             c = Name[4-i-1];
422             if (DoNoTrailing && c != '_')
423             {
424                 DoNoTrailing = FALSE;
425             }
426             if (!DoNoTrailing)
427             {
428                 ACPI_PATH_PUT8(FullPath, PathSize, c, Length);
429             }
430         }
431 
432         NextNode = NextNode->Parent;
433     }
434 
435     ACPI_PATH_PUT8(FullPath, PathSize, AML_ROOT_PREFIX, Length);
436 
437     /* Reverse the path string */
438 
439     if (Length <= PathSize)
440     {
441         Left = FullPath;
442         Right = FullPath+Length - 1;
443 
444         while (Left < Right)
445         {
446             c = *Left;
447             *Left++ = *Right;
448             *Right-- = c;
449         }
450     }
451 
452     /* Append the trailing null */
453 
454 BuildTrailingNull:
455     ACPI_PATH_PUT8 (FullPath, PathSize, '\0', Length);
456 
457 #undef ACPI_PATH_PUT8
458 
459     return_UINT32 (Length);
460 }
461 
462 
463 /*******************************************************************************
464  *
465  * FUNCTION:    AcpiNsGetNormalizedPathname
466  *
467  * PARAMETERS:  Node            - Namespace node whose pathname is needed
468  *              NoTrailing      - Remove trailing '_' from each name segment
469  *
470  * RETURN:      Pointer to storage containing the fully qualified name of
471  *              the node, In external format (name segments separated by path
472  *              separators.)
473  *
474  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
475  *              for error and debug statements. All trailing '_' will be
476  *              removed from the full pathname if 'NoTrailing' is specified..
477  *
478  ******************************************************************************/
479 
480 char *
AcpiNsGetNormalizedPathname(ACPI_NAMESPACE_NODE * Node,BOOLEAN NoTrailing)481 AcpiNsGetNormalizedPathname (
482     ACPI_NAMESPACE_NODE     *Node,
483     BOOLEAN                 NoTrailing)
484 {
485     char                    *NameBuffer;
486     ACPI_SIZE               Size;
487 
488 
489     ACPI_FUNCTION_TRACE_PTR (NsGetNormalizedPathname, Node);
490 
491 
492     /* Calculate required buffer size based on depth below root */
493 
494     Size = AcpiNsBuildNormalizedPath (Node, NULL, 0, NoTrailing);
495     if (!Size)
496     {
497         return_PTR (NULL);
498     }
499 
500     /* Allocate a buffer to be returned to caller */
501 
502     NameBuffer = ACPI_ALLOCATE_ZEROED (Size);
503     if (!NameBuffer)
504     {
505         ACPI_ERROR ((AE_INFO,
506             "Could not allocate %u bytes", (UINT32) Size));
507         return_PTR (NULL);
508     }
509 
510     /* Build the path in the allocated buffer */
511 
512     (void) AcpiNsBuildNormalizedPath (Node, NameBuffer, Size, NoTrailing);
513 
514     ACPI_DEBUG_PRINT_RAW ((ACPI_DB_NAMES, "%s: Path \"%s\"\n",
515         ACPI_GET_FUNCTION_NAME, NameBuffer));
516 
517     return_PTR (NameBuffer);
518 }
519 
520 
521 /*******************************************************************************
522  *
523  * FUNCTION:    AcpiNsBuildPrefixedPathname
524  *
525  * PARAMETERS:  PrefixScope         - Scope/Path that prefixes the internal path
526  *              InternalPath        - Name or path of the namespace node
527  *
528  * RETURN:      None
529  *
530  * DESCRIPTION: Construct a fully qualified pathname from a concatenation of:
531  *              1) Path associated with the PrefixScope namespace node
532  *              2) External path representation of the Internal path
533  *
534  ******************************************************************************/
535 
536 char *
AcpiNsBuildPrefixedPathname(ACPI_GENERIC_STATE * PrefixScope,const char * InternalPath)537 AcpiNsBuildPrefixedPathname (
538     ACPI_GENERIC_STATE      *PrefixScope,
539     const char              *InternalPath)
540 {
541     ACPI_STATUS             Status;
542     char                    *FullPath = NULL;
543     char                    *ExternalPath = NULL;
544     char                    *PrefixPath = NULL;
545     UINT32                  PrefixPathLength = 0;
546 
547 
548     /* If there is a prefix, get the pathname to it */
549 
550     if (PrefixScope && PrefixScope->Scope.Node)
551     {
552         PrefixPath = AcpiNsGetNormalizedPathname (PrefixScope->Scope.Node, TRUE);
553         if (PrefixPath)
554         {
555             PrefixPathLength = strlen (PrefixPath);
556         }
557     }
558 
559     Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, InternalPath,
560         NULL, &ExternalPath);
561     if (ACPI_FAILURE (Status))
562     {
563         goto Cleanup;
564     }
565 
566     /* Merge the prefix path and the path. 2 is for one dot and trailing null */
567 
568     FullPath = ACPI_ALLOCATE_ZEROED (
569         PrefixPathLength + strlen (ExternalPath) + 2);
570     if (!FullPath)
571     {
572         goto Cleanup;
573     }
574 
575     /* Don't merge if the External path is already fully qualified */
576 
577     if (PrefixPath &&
578         (*ExternalPath != '\\') &&
579         (*ExternalPath != '^'))
580     {
581         strcat (FullPath, PrefixPath);
582         if (PrefixPath[1])
583         {
584             strcat (FullPath, ".");
585         }
586     }
587 
588     AcpiNsNormalizePathname (ExternalPath);
589     strcat (FullPath, ExternalPath);
590 
591 Cleanup:
592     if (PrefixPath)
593     {
594         ACPI_FREE (PrefixPath);
595     }
596     if (ExternalPath)
597     {
598         ACPI_FREE (ExternalPath);
599     }
600 
601     return (FullPath);
602 }
603 
604 
605 /*******************************************************************************
606  *
607  * FUNCTION:    AcpiNsNormalizePathname
608  *
609  * PARAMETERS:  OriginalPath        - Path to be normalized, in External format
610  *
611  * RETURN:      The original path is processed in-place
612  *
613  * DESCRIPTION: Remove trailing underscores from each element of a path.
614  *
615  *              For example:  \A___.B___.C___ becomes \A.B.C
616  *
617  ******************************************************************************/
618 
619 static void
AcpiNsNormalizePathname(char * OriginalPath)620 AcpiNsNormalizePathname (
621     char                    *OriginalPath)
622 {
623     char                    *InputPath = OriginalPath;
624     char                    *NewPathBuffer;
625     char                    *NewPath;
626     UINT32                  i;
627 
628 
629     /* Allocate a temp buffer in which to construct the new path */
630 
631     NewPathBuffer = ACPI_ALLOCATE_ZEROED (strlen (InputPath) + 1);
632     NewPath = NewPathBuffer;
633     if (!NewPathBuffer)
634     {
635         return;
636     }
637 
638     /* Special characters may appear at the beginning of the path */
639 
640     if (*InputPath == '\\')
641     {
642         *NewPath = *InputPath;
643         NewPath++;
644         InputPath++;
645     }
646 
647     while (*InputPath == '^')
648     {
649         *NewPath = *InputPath;
650         NewPath++;
651         InputPath++;
652     }
653 
654     /* Remainder of the path */
655 
656     while (*InputPath)
657     {
658         /* Do one nameseg at a time */
659 
660         for (i = 0; (i < ACPI_NAME_SIZE) && *InputPath; i++)
661         {
662             if ((i == 0) || (*InputPath != '_')) /* First char is allowed to be underscore */
663             {
664                 *NewPath = *InputPath;
665                 NewPath++;
666             }
667 
668             InputPath++;
669         }
670 
671         /* Dot means that there are more namesegs to come */
672 
673         if (*InputPath == '.')
674         {
675             *NewPath = *InputPath;
676             NewPath++;
677             InputPath++;
678         }
679     }
680 
681     *NewPath = 0;
682     strcpy (OriginalPath, NewPathBuffer);
683     ACPI_FREE (NewPathBuffer);
684 }
685