xref: /titanic_41/usr/src/uts/intel/amd64/krtld/doreloc.c (revision 726fad2a65f16c200a03969c29cb5c86c2d427db)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 #if	defined(_KERNEL)
27 #include	<sys/types.h>
28 #include	"reloc.h"
29 #else
30 #define	ELF_TARGET_AMD64
31 #if defined(DO_RELOC_LIBLD)
32 #undef DO_RELOC_LIBLD
33 #define	DO_RELOC_LIBLD_X86
34 #endif
35 #include	<stdio.h>
36 #include	"sgs.h"
37 #include	"machdep.h"
38 #include	"libld.h"
39 #include	"reloc.h"
40 #include	"conv.h"
41 #include	"msg.h"
42 #endif
43 
44 /*
45  * We need to build this code differently when it is used for
46  * cross linking:
47  *	- Data alignment requirements can differ from those
48  *		of the running system, so we can't access data
49  *		in units larger than a byte
50  *	- We have to include code to do byte swapping when the
51  *		target and linker host use different byte ordering,
52  *		but such code is a waste when running natively.
53  */
54 #if !defined(DO_RELOC_LIBLD) || defined(__i386) || defined(__amd64)
55 #define	DORELOC_NATIVE
56 #endif
57 
58 /*
59  * This table represents the current relocations that do_reloc() is able to
60  * process.  The relocations below that are marked SPECIAL are relocations that
61  * take special processing and shouldn't actually ever be passed to do_reloc().
62  */
63 const Rel_entry	reloc_table[R_AMD64_NUM] = {
64 /* R_AMD64_NONE */	{0, FLG_RE_NOTREL, 0, 0, 0},
65 /* R_AMD64_64 */	{0, FLG_RE_NOTREL, 8, 0, 0},
66 /* R_AMD64_PC32 */	{0, FLG_RE_PCREL, 4, 0, 0},
67 /* R_AMD64_GOT32 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
68 /* R_AMD64_PLT32 */	{0, FLG_RE_PCREL | FLG_RE_PLTREL |
69 			    FLG_RE_VERIFY | FLG_RE_SIGN, 4, 0, 0},
70 /* R_AMD64_COPY */	{0, FLG_RE_NOTSUP, 0, 0, 0},	/* SPECIAL */
71 /* R_AMD64_GLOB_DAT */	{0, FLG_RE_NOTREL, 8, 0, 0},
72 /* R_AMD64_JUMP_SLOT */	{0, FLG_RE_NOTSUP, 0, 0, 0},	/* SPECIAL */
73 /* R_AMD64_RELATIVE */	{0, FLG_RE_NOTREL, 8, 0, 0},
74 /* R_AMD64_GOTPCREL */	{0, FLG_RE_GOTPC | FLG_RE_GOTADD, 4, 0, 0},
75 /* R_AMD64_32 */	{0, FLG_RE_NOTREL, 4, 0, 0},
76 /* R_AMD64_32S */	{0, FLG_RE_NOTREL, 4, 0, 0},
77 /* R_AMD64_16 */	{0, FLG_RE_NOTREL, 2, 0, 0},
78 /* R_AMD64_PC16 */	{0, FLG_RE_PCREL, 2, 0, 0},
79 /* R_AMD64_8 */		{0, FLG_RE_NOTREL, 1, 0, 0},
80 /* R_AMD64_PC8 */	{0, FLG_RE_PCREL, 1, 0, 0},
81 /* R_AMD64_DTPMOD64 */	{0, FLG_RE_NOTREL, 8, 0, 0},
82 /* R_AMD64_DTPOFF64 */	{0, FLG_RE_NOTREL, 8, 0, 0},
83 /* R_AMD64_TPOFF64 */	{0, FLG_RE_NOTREL, 8, 0, 0},
84 /* R_AMD64_TLSGD */	{0, FLG_RE_GOTPC | FLG_RE_GOTADD | FLG_RE_TLSGD,
85 			    4, 0, 0},
86 /* R_AMD64_TLSLD */	{0, FLG_RE_GOTPC | FLG_RE_GOTADD | FLG_RE_TLSLD,
87 			    4, 0, 0},
88 /* R_AMD64_DTPOFF32 */	{0, FLG_RE_TLSLD, 4},
89 /* R_AMD64_GOTTPOFF */	{0, FLG_RE_GOTPC | FLG_RE_GOTADD | FLG_RE_TLSIE,
90 			    4, 0, 0},
91 /* R_AMD64_TPOFF32 */	{0, FLG_RE_TLSLE, 4, 0, 0},
92 /* R_AMD64_PC64 */	{0, FLG_RE_PCREL, 8, 0, 0},
93 /* R_AMD64_GOTOFF64 */	{0, FLG_RE_GOTREL, 8, 0, 0},
94 /* R_AMD64_GOTPC32 */	{0, FLG_RE_PCREL | FLG_RE_GOTPC | FLG_RE_LOCLBND,
95 			    4, 0, 0},
96 /* R_AMD64_GOT64 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
97 /* R_AMD64_GOTPCREL64 */	{FLG_RE_NOTSUP, 0, 0, 0},
98 /* R_AMD64_GOTPC6 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
99 /* R_AMD64_GOTPLT64 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
100 /* R_AMD64_PLTOFF64 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
101 /* R_AMD64_SIZE32 */	{0, FLG_RE_SIZE, 4, 0, 0},
102 /* R_AMD64_SIZE64 */	{0, FLG_RE_SIZE, 8, 0, 0}
103 };
104 #if	(R_AMD64_NUM != (R_AMD64_SIZE64 + 1))
105 #error	"R_AMD64_NUM has grown"
106 #endif
107 
108 /*
109  * Write a single relocated value to its reference location.
110  * We assume we wish to add the relocation amount, value, to the
111  * value of the address already present at the offset.
112  *
113  * NAME			VALUE	FIELD		CALCULATION
114  *
115  * R_AMD64_NONE		 0	none		none
116  * R_AMD64_64		 1	word64		S + A
117  * R_AMD64_PC32		 2	word64		S + A
118  * R_AMD64_GOT32	 3	word32		G + A
119  * R_AMD64_PLT32	 4	word32		L + A - P
120  * R_AMD64_COPY		 5	none		none
121  * R_AMD64_GLOB_DAT	 6	word64		S
122  * R_AMD64_JUMP_SLOT	 7	word64		S
123  * R_AMD64_RELATIVE	 8	word64		B + A
124  * R_AMD64_GOTPCREL	 9	word32		G + GOT + A - P
125  * R_AMD64_32		10	word32		S + A
126  * R_AMD64_32S		11	word32		S + A
127  * R_AMD64_16		12	word16		S + A
128  * R_AMD64_PC16		13	word16		S + A - P
129  * R_AMD64_8		14	word8		S + A
130  * R_AMD64_PC8		15	word8		S + A - P
131  * R_AMD64_DTPMOD64	16	word64
132  * R_AMD64_DTPOFF64	17	word64
133  * R_AMD64_TPOFF64	18	word64
134  * R_AMD64_TLSGD	19	word32
135  * R_AMD64_TLSLD	20	word32
136  * R_AMD64_DTPOFF32	21	word32
137  * R_AMD64_GOTTPOFF	22	word32
138  * R_AMD64_TPOFF32	23	word32
139  * R_AMD64_PC64		24	word32		S + A - P
140  * R_AMD64_GOTOFF64	25	word32		S + A - GOT
141  * R_AMD64_GOTPC32	26	word32		GOT + A - P
142  * R_AMD64_GOT64	27			reserved for future expansion
143  * R_AMD64_GOTPCREL64	28			reserved for future expansion
144  * R_AMD64_GOTPC64	29			reserved for future expansion
145  * R_AMD64_GOTPLT64	30			reserved for future expansion
146  * R_AMD64_PLTOFF64	31			reserved for future expansion
147  * R_AMD64_SIZE32	32	word32		Z + A
148  * R_AMD64_SIZE64	33	word64		Z + A
149  *
150  * Relocation calculations:
151  *	A	Represents the addend used to compute the value of the
152  *		relocatable field.
153  *
154  *	B	Represents the base address at which a shared objects has
155  *		been loaded into memory during executaion.  Generally, a
156  *		shared objects is built with a 0 base virtual address,
157  *		but the execution address will be different.
158  *
159  *	G	Represents the offset into the global offset table
160  *		at which the relocation entry's symbol will reside
161  *		during execution.
162  *
163  *	GOT	Rrepresents the address of the global offset table.
164  *
165  *	L	Represents the place (section offset or address) of
166  *		the Procedure Linkage Table entry for a symbol.
167  *
168  *	P	Represents the place (section offset or address) of the
169  *		storage unit being relocated (computed using r_offset).
170  *
171  *	S	Represents the value of the symbol whose index resides
172  *		in the relocation entry.
173  *
174  *	Z	the size of the symbol whose index resides in the relocation
175  *		entry
176  */
177 
178 #define	HIBITS	0xffffffff80000000ULL
179 
180 #if defined(_KERNEL)
181 #define	lml	0		/* Needed by arglist of REL_ERR_* macros */
182 int
183 do_reloc_krtld(uchar_t rtype, uchar_t *off, Xword *value, const char *sym,
184     const char *file)
185 #elif defined(DO_RELOC_LIBLD)
186 /*ARGSUSED5*/
187 int
188 do_reloc_ld(Rel_desc *rdesc, uchar_t *off, Xword *value,
189     rel_desc_sname_func_t rel_desc_sname_func,
190     const char *file, int bswap, void *lml)
191 #else
192 int
193 do_reloc_rtld(uchar_t rtype, uchar_t *off, Xword *value, const char *sym,
194     const char *file, void *lml)
195 #endif
196 {
197 #ifdef DO_RELOC_LIBLD
198 #define	sym (* rel_desc_sname_func)(rdesc)
199 	uchar_t	rtype = rdesc->rel_rtype;
200 #endif
201 	const Rel_entry	*rep;
202 
203 	rep = &reloc_table[rtype];
204 
205 	switch (rep->re_fsize) {
206 	case 1:
207 		/* LINTED */
208 		*((uchar_t *)off) = (uchar_t)(*value);
209 		break;
210 
211 	case 2:
212 #if defined(DORELOC_NATIVE)
213 		/* LINTED */
214 		*((Half *)off) = (Half)(*value);
215 #else
216 		{
217 			Half	v = (Half)(*value);
218 			uchar_t	*v_bytes = (uchar_t *)&v;
219 
220 			if (bswap) {
221 				UL_ASSIGN_BSWAP_HALF(off, v_bytes);
222 			} else {
223 				UL_ASSIGN_HALF(off, v_bytes);
224 			}
225 		}
226 #endif
227 		break;
228 
229 	case 4:
230 		/*
231 		 * The amd64 psABI requires that we perform the following
232 		 * verifications:
233 		 *
234 		 *    The R_AMD64_32 and R_AMD64_32S relocations truncate the
235 		 *    computed value to 32bits.  Verify that the generated value
236 		 *    for the R_AMD64_32/32S relocation zero-extends (sign
237 		 *    extends) to the original 64-bit value.
238 		 *
239 		 * Also, the following relocations are all 32 bit PC relative
240 		 * references.  Validate that the value being written will fit
241 		 * in the field provided.
242 		 *
243 		 *    R_AMD64_PC32, R_AMD64_GOTPC32, R_AMD64_GOTPCREL
244 		 */
245 		if (rtype == R_AMD64_32) {
246 			/*
247 			 * Verify that this value will 'zero-extend', this
248 			 * requires that the upper 33bits all be 'zero'.
249 			 */
250 			if ((*value & HIBITS) != 0) {
251 				/*
252 				 * To keep chkmsg() happy:
253 				 *  MSG_INTL(MSG_REL_NOFIT)
254 				 */
255 				REL_ERR_NOFIT(lml, file, sym, rtype, *value);
256 				return (0);
257 			}
258 		} else if ((rtype == R_AMD64_32S) || (rtype == R_AMD64_PC32) ||
259 		    (rtype == R_AMD64_GOTPCREL) || (rtype == R_AMD64_GOTPC32)) {
260 			/*
261 			 * Verify that this value will properly sign extend.
262 			 * This is true of the upper 33bits are all either
263 			 * 'zero' or all 'one'.
264 			 */
265 			if (((*value & HIBITS) != HIBITS) &&
266 			    ((*value & HIBITS) != 0)) {
267 				/*
268 				 * To keep chkmsg() happy:
269 				 *  MSG_INTL(MSG_REL_NOFIT)
270 				 */
271 				REL_ERR_NOFIT(lml, file, sym, rtype, *value);
272 				return (0);
273 			}
274 		}
275 
276 #if defined(DORELOC_NATIVE)
277 		/* LINTED */
278 		*((Word *)off) += *value;
279 #else
280 		{
281 			Word	v;
282 			uchar_t	*v_bytes = (uchar_t *)&v;
283 
284 			if (bswap) {
285 				UL_ASSIGN_BSWAP_WORD(v_bytes, off);
286 				v += *value;
287 				UL_ASSIGN_BSWAP_WORD(off, v_bytes);
288 			} else {
289 				UL_ASSIGN_WORD(v_bytes, off);
290 				v += *value;
291 				UL_ASSIGN_WORD(off, v_bytes);
292 			}
293 		}
294 #endif
295 		break;
296 
297 	case 8:
298 #if defined(DORELOC_NATIVE)
299 		/* LINTED */
300 		*((Xword *)off) += *value;
301 #else
302 		{
303 			Xword	v;
304 			uchar_t	*v_bytes = (uchar_t *)&v;
305 
306 			if (bswap) {
307 				UL_ASSIGN_BSWAP_XWORD(v_bytes, off);
308 				v += *value;
309 				UL_ASSIGN_BSWAP_XWORD(off, v_bytes);
310 			} else {
311 				UL_ASSIGN_XWORD(v_bytes, off);
312 				v += *value;
313 				UL_ASSIGN_XWORD(off, v_bytes);
314 			}
315 		}
316 #endif
317 		break;
318 	default:
319 		/*
320 		 * To keep chkmsg() happy: MSG_INTL(MSG_REL_UNSUPSZ)
321 		 */
322 		REL_ERR_UNSUPSZ(lml, file, sym, rtype, rep->re_fsize);
323 		return (0);
324 	}
325 	return (1);
326 
327 #ifdef DO_RELOC_LIBLD
328 #undef sym
329 #endif
330 }
331