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Linux/arch/parisc/kernel/module.c

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  1 /*    Kernel dynamically loadable module help for PARISC.
  2  *
  3  *    The best reference for this stuff is probably the Processor-
  4  *    Specific ELF Supplement for PA-RISC:
  5  *        http://ftp.parisc-linux.org/docs/arch/elf-pa-hp.pdf
  6  *
  7  *    Linux/PA-RISC Project (http://www.parisc-linux.org/)
  8  *    Copyright (C) 2003 Randolph Chung <tausq at debian . org>
  9  *    Copyright (C) 2008 Helge Deller <deller@gmx.de>
 10  *
 11  *
 12  *    This program is free software; you can redistribute it and/or modify
 13  *    it under the terms of the GNU General Public License as published by
 14  *    the Free Software Foundation; either version 2 of the License, or
 15  *    (at your option) any later version.
 16  *
 17  *    This program is distributed in the hope that it will be useful,
 18  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 19  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 20  *    GNU General Public License for more details.
 21  *
 22  *    You should have received a copy of the GNU General Public License
 23  *    along with this program; if not, write to the Free Software
 24  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 25  *
 26  *
 27  *    Notes:
 28  *    - PLT stub handling
 29  *      On 32bit (and sometimes 64bit) and with big kernel modules like xfs or
 30  *      ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may
 31  *      fail to reach their PLT stub if we only create one big stub array for
 32  *      all sections at the beginning of the core or init section.
 33  *      Instead we now insert individual PLT stub entries directly in front of
 34  *      of the code sections where the stubs are actually called.
 35  *      This reduces the distance between the PCREL location and the stub entry
 36  *      so that the relocations can be fulfilled.
 37  *      While calculating the final layout of the kernel module in memory, the
 38  *      kernel module loader calls arch_mod_section_prepend() to request the
 39  *      to be reserved amount of memory in front of each individual section.
 40  *
 41  *    - SEGREL32 handling
 42  *      We are not doing SEGREL32 handling correctly. According to the ABI, we
 43  *      should do a value offset, like this:
 44  *                      if (in_init(me, (void *)val))
 45  *                              val -= (uint32_t)me->init_layout.base;
 46  *                      else
 47  *                              val -= (uint32_t)me->core_layout.base;
 48  *      However, SEGREL32 is used only for PARISC unwind entries, and we want
 49  *      those entries to have an absolute address, and not just an offset.
 50  *
 51  *      The unwind table mechanism has the ability to specify an offset for 
 52  *      the unwind table; however, because we split off the init functions into
 53  *      a different piece of memory, it is not possible to do this using a 
 54  *      single offset. Instead, we use the above hack for now.
 55  */
 56 
 57 #include <linux/moduleloader.h>
 58 #include <linux/elf.h>
 59 #include <linux/vmalloc.h>
 60 #include <linux/fs.h>
 61 #include <linux/string.h>
 62 #include <linux/kernel.h>
 63 #include <linux/bug.h>
 64 #include <linux/mm.h>
 65 #include <linux/slab.h>
 66 
 67 #include <asm/pgtable.h>
 68 #include <asm/unwind.h>
 69 
 70 #if 0
 71 #define DEBUGP printk
 72 #else
 73 #define DEBUGP(fmt...)
 74 #endif
 75 
 76 #define RELOC_REACHABLE(val, bits) \
 77         (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 )  ||   \
 78              ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \
 79         0 : 1)
 80 
 81 #define CHECK_RELOC(val, bits) \
 82         if (!RELOC_REACHABLE(val, bits)) { \
 83                 printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \
 84                 me->name, strtab + sym->st_name, (unsigned long)val, bits); \
 85                 return -ENOEXEC;                        \
 86         }
 87 
 88 /* Maximum number of GOT entries. We use a long displacement ldd from
 89  * the bottom of the table, which has a maximum signed displacement of
 90  * 0x3fff; however, since we're only going forward, this becomes
 91  * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have
 92  * at most 1023 entries.
 93  * To overcome this 14bit displacement with some kernel modules, we'll
 94  * use instead the unusal 16bit displacement method (see reassemble_16a)
 95  * which gives us a maximum positive displacement of 0x7fff, and as such
 96  * allows us to allocate up to 4095 GOT entries. */
 97 #define MAX_GOTS        4095
 98 
 99 /* three functions to determine where in the module core
100  * or init pieces the location is */
101 static inline int in_init(struct module *me, void *loc)
102 {
103         return (loc >= me->init_layout.base &&
104                 loc <= (me->init_layout.base + me->init_layout.size));
105 }
106 
107 static inline int in_core(struct module *me, void *loc)
108 {
109         return (loc >= me->core_layout.base &&
110                 loc <= (me->core_layout.base + me->core_layout.size));
111 }
112 
113 static inline int in_local(struct module *me, void *loc)
114 {
115         return in_init(me, loc) || in_core(me, loc);
116 }
117 
118 #ifndef CONFIG_64BIT
119 struct got_entry {
120         Elf32_Addr addr;
121 };
122 
123 struct stub_entry {
124         Elf32_Word insns[2]; /* each stub entry has two insns */
125 };
126 #else
127 struct got_entry {
128         Elf64_Addr addr;
129 };
130 
131 struct stub_entry {
132         Elf64_Word insns[4]; /* each stub entry has four insns */
133 };
134 #endif
135 
136 /* Field selection types defined by hppa */
137 #define rnd(x)                  (((x)+0x1000)&~0x1fff)
138 /* fsel: full 32 bits */
139 #define fsel(v,a)               ((v)+(a))
140 /* lsel: select left 21 bits */
141 #define lsel(v,a)               (((v)+(a))>>11)
142 /* rsel: select right 11 bits */
143 #define rsel(v,a)               (((v)+(a))&0x7ff)
144 /* lrsel with rounding of addend to nearest 8k */
145 #define lrsel(v,a)              (((v)+rnd(a))>>11)
146 /* rrsel with rounding of addend to nearest 8k */
147 #define rrsel(v,a)              ((((v)+rnd(a))&0x7ff)+((a)-rnd(a)))
148 
149 #define mask(x,sz)              ((x) & ~((1<<(sz))-1))
150 
151 
152 /* The reassemble_* functions prepare an immediate value for
153    insertion into an opcode. pa-risc uses all sorts of weird bitfields
154    in the instruction to hold the value.  */
155 static inline int sign_unext(int x, int len)
156 {
157         int len_ones;
158 
159         len_ones = (1 << len) - 1;
160         return x & len_ones;
161 }
162 
163 static inline int low_sign_unext(int x, int len)
164 {
165         int sign, temp;
166 
167         sign = (x >> (len-1)) & 1;
168         temp = sign_unext(x, len-1);
169         return (temp << 1) | sign;
170 }
171 
172 static inline int reassemble_14(int as14)
173 {
174         return (((as14 & 0x1fff) << 1) |
175                 ((as14 & 0x2000) >> 13));
176 }
177 
178 static inline int reassemble_16a(int as16)
179 {
180         int s, t;
181 
182         /* Unusual 16-bit encoding, for wide mode only.  */
183         t = (as16 << 1) & 0xffff;
184         s = (as16 & 0x8000);
185         return (t ^ s ^ (s >> 1)) | (s >> 15);
186 }
187 
188 
189 static inline int reassemble_17(int as17)
190 {
191         return (((as17 & 0x10000) >> 16) |
192                 ((as17 & 0x0f800) << 5) |
193                 ((as17 & 0x00400) >> 8) |
194                 ((as17 & 0x003ff) << 3));
195 }
196 
197 static inline int reassemble_21(int as21)
198 {
199         return (((as21 & 0x100000) >> 20) |
200                 ((as21 & 0x0ffe00) >> 8) |
201                 ((as21 & 0x000180) << 7) |
202                 ((as21 & 0x00007c) << 14) |
203                 ((as21 & 0x000003) << 12));
204 }
205 
206 static inline int reassemble_22(int as22)
207 {
208         return (((as22 & 0x200000) >> 21) |
209                 ((as22 & 0x1f0000) << 5) |
210                 ((as22 & 0x00f800) << 5) |
211                 ((as22 & 0x000400) >> 8) |
212                 ((as22 & 0x0003ff) << 3));
213 }
214 
215 void *module_alloc(unsigned long size)
216 {
217         /* using RWX means less protection for modules, but it's
218          * easier than trying to map the text, data, init_text and
219          * init_data correctly */
220         return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
221                                     GFP_KERNEL | __GFP_HIGHMEM,
222                                     PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
223                                     __builtin_return_address(0));
224 }
225 
226 #ifndef CONFIG_64BIT
227 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
228 {
229         return 0;
230 }
231 
232 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
233 {
234         return 0;
235 }
236 
237 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
238 {
239         unsigned long cnt = 0;
240 
241         for (; n > 0; n--, rela++)
242         {
243                 switch (ELF32_R_TYPE(rela->r_info)) {
244                         case R_PARISC_PCREL17F:
245                         case R_PARISC_PCREL22F:
246                                 cnt++;
247                 }
248         }
249 
250         return cnt;
251 }
252 #else
253 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
254 {
255         unsigned long cnt = 0;
256 
257         for (; n > 0; n--, rela++)
258         {
259                 switch (ELF64_R_TYPE(rela->r_info)) {
260                         case R_PARISC_LTOFF21L:
261                         case R_PARISC_LTOFF14R:
262                         case R_PARISC_PCREL22F:
263                                 cnt++;
264                 }
265         }
266 
267         return cnt;
268 }
269 
270 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
271 {
272         unsigned long cnt = 0;
273 
274         for (; n > 0; n--, rela++)
275         {
276                 switch (ELF64_R_TYPE(rela->r_info)) {
277                         case R_PARISC_FPTR64:
278                                 cnt++;
279                 }
280         }
281 
282         return cnt;
283 }
284 
285 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
286 {
287         unsigned long cnt = 0;
288 
289         for (; n > 0; n--, rela++)
290         {
291                 switch (ELF64_R_TYPE(rela->r_info)) {
292                         case R_PARISC_PCREL22F:
293                                 cnt++;
294                 }
295         }
296 
297         return cnt;
298 }
299 #endif
300 
301 void module_arch_freeing_init(struct module *mod)
302 {
303         kfree(mod->arch.section);
304         mod->arch.section = NULL;
305 }
306 
307 /* Additional bytes needed in front of individual sections */
308 unsigned int arch_mod_section_prepend(struct module *mod,
309                                       unsigned int section)
310 {
311         /* size needed for all stubs of this section (including
312          * one additional for correct alignment of the stubs) */
313         return (mod->arch.section[section].stub_entries + 1)
314                 * sizeof(struct stub_entry);
315 }
316 
317 #define CONST 
318 int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
319                               CONST Elf_Shdr *sechdrs,
320                               CONST char *secstrings,
321                               struct module *me)
322 {
323         unsigned long gots = 0, fdescs = 0, len;
324         unsigned int i;
325 
326         len = hdr->e_shnum * sizeof(me->arch.section[0]);
327         me->arch.section = kzalloc(len, GFP_KERNEL);
328         if (!me->arch.section)
329                 return -ENOMEM;
330 
331         for (i = 1; i < hdr->e_shnum; i++) {
332                 const Elf_Rela *rels = (void *)sechdrs[i].sh_addr;
333                 unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels);
334                 unsigned int count, s;
335 
336                 if (strncmp(secstrings + sechdrs[i].sh_name,
337                             ".PARISC.unwind", 14) == 0)
338                         me->arch.unwind_section = i;
339 
340                 if (sechdrs[i].sh_type != SHT_RELA)
341                         continue;
342 
343                 /* some of these are not relevant for 32-bit/64-bit
344                  * we leave them here to make the code common. the
345                  * compiler will do its thing and optimize out the
346                  * stuff we don't need
347                  */
348                 gots += count_gots(rels, nrels);
349                 fdescs += count_fdescs(rels, nrels);
350 
351                 /* XXX: By sorting the relocs and finding duplicate entries
352                  *  we could reduce the number of necessary stubs and save
353                  *  some memory. */
354                 count = count_stubs(rels, nrels);
355                 if (!count)
356                         continue;
357 
358                 /* so we need relocation stubs. reserve necessary memory. */
359                 /* sh_info gives the section for which we need to add stubs. */
360                 s = sechdrs[i].sh_info;
361 
362                 /* each code section should only have one relocation section */
363                 WARN_ON(me->arch.section[s].stub_entries);
364 
365                 /* store number of stubs we need for this section */
366                 me->arch.section[s].stub_entries += count;
367         }
368 
369         /* align things a bit */
370         me->core_layout.size = ALIGN(me->core_layout.size, 16);
371         me->arch.got_offset = me->core_layout.size;
372         me->core_layout.size += gots * sizeof(struct got_entry);
373 
374         me->core_layout.size = ALIGN(me->core_layout.size, 16);
375         me->arch.fdesc_offset = me->core_layout.size;
376         me->core_layout.size += fdescs * sizeof(Elf_Fdesc);
377 
378         me->arch.got_max = gots;
379         me->arch.fdesc_max = fdescs;
380 
381         return 0;
382 }
383 
384 #ifdef CONFIG_64BIT
385 static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
386 {
387         unsigned int i;
388         struct got_entry *got;
389 
390         value += addend;
391 
392         BUG_ON(value == 0);
393 
394         got = me->core_layout.base + me->arch.got_offset;
395         for (i = 0; got[i].addr; i++)
396                 if (got[i].addr == value)
397                         goto out;
398 
399         BUG_ON(++me->arch.got_count > me->arch.got_max);
400 
401         got[i].addr = value;
402  out:
403         DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry),
404                value);
405         return i * sizeof(struct got_entry);
406 }
407 #endif /* CONFIG_64BIT */
408 
409 #ifdef CONFIG_64BIT
410 static Elf_Addr get_fdesc(struct module *me, unsigned long value)
411 {
412         Elf_Fdesc *fdesc = me->core_layout.base + me->arch.fdesc_offset;
413 
414         if (!value) {
415                 printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
416                 return 0;
417         }
418 
419         /* Look for existing fdesc entry. */
420         while (fdesc->addr) {
421                 if (fdesc->addr == value)
422                         return (Elf_Addr)fdesc;
423                 fdesc++;
424         }
425 
426         BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max);
427 
428         /* Create new one */
429         fdesc->addr = value;
430         fdesc->gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
431         return (Elf_Addr)fdesc;
432 }
433 #endif /* CONFIG_64BIT */
434 
435 enum elf_stub_type {
436         ELF_STUB_GOT,
437         ELF_STUB_MILLI,
438         ELF_STUB_DIRECT,
439 };
440 
441 static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
442         enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
443 {
444         struct stub_entry *stub;
445         int __maybe_unused d;
446 
447         /* initialize stub_offset to point in front of the section */
448         if (!me->arch.section[targetsec].stub_offset) {
449                 loc0 -= (me->arch.section[targetsec].stub_entries + 1) *
450                                 sizeof(struct stub_entry);
451                 /* get correct alignment for the stubs */
452                 loc0 = ALIGN(loc0, sizeof(struct stub_entry));
453                 me->arch.section[targetsec].stub_offset = loc0;
454         }
455 
456         /* get address of stub entry */
457         stub = (void *) me->arch.section[targetsec].stub_offset;
458         me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry);
459 
460         /* do not write outside available stub area */
461         BUG_ON(0 == me->arch.section[targetsec].stub_entries--);
462 
463 
464 #ifndef CONFIG_64BIT
465 /* for 32-bit the stub looks like this:
466  *      ldil L'XXX,%r1
467  *      be,n R'XXX(%sr4,%r1)
468  */
469         //value = *(unsigned long *)((value + addend) & ~3); /* why? */
470 
471         stub->insns[0] = 0x20200000;    /* ldil L'XXX,%r1       */
472         stub->insns[1] = 0xe0202002;    /* be,n R'XXX(%sr4,%r1) */
473 
474         stub->insns[0] |= reassemble_21(lrsel(value, addend));
475         stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4);
476 
477 #else
478 /* for 64-bit we have three kinds of stubs:
479  * for normal function calls:
480  *      ldd 0(%dp),%dp
481  *      ldd 10(%dp), %r1
482  *      bve (%r1)
483  *      ldd 18(%dp), %dp
484  *
485  * for millicode:
486  *      ldil 0, %r1
487  *      ldo 0(%r1), %r1
488  *      ldd 10(%r1), %r1
489  *      bve,n (%r1)
490  *
491  * for direct branches (jumps between different section of the
492  * same module):
493  *      ldil 0, %r1
494  *      ldo 0(%r1), %r1
495  *      bve,n (%r1)
496  */
497         switch (stub_type) {
498         case ELF_STUB_GOT:
499                 d = get_got(me, value, addend);
500                 if (d <= 15) {
501                         /* Format 5 */
502                         stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp  */
503                         stub->insns[0] |= low_sign_unext(d, 5) << 16;
504                 } else {
505                         /* Format 3 */
506                         stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp  */
507                         stub->insns[0] |= reassemble_16a(d);
508                 }
509                 stub->insns[1] = 0x53610020;    /* ldd 10(%dp),%r1      */
510                 stub->insns[2] = 0xe820d000;    /* bve (%r1)            */
511                 stub->insns[3] = 0x537b0030;    /* ldd 18(%dp),%dp      */
512                 break;
513         case ELF_STUB_MILLI:
514                 stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */
515                 stub->insns[1] = 0x34210000;    /* ldo 0(%r1), %r1      */
516                 stub->insns[2] = 0x50210020;    /* ldd 10(%r1),%r1      */
517                 stub->insns[3] = 0xe820d002;    /* bve,n (%r1)          */
518 
519                 stub->insns[0] |= reassemble_21(lrsel(value, addend));
520                 stub->insns[1] |= reassemble_14(rrsel(value, addend));
521                 break;
522         case ELF_STUB_DIRECT:
523                 stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */
524                 stub->insns[1] = 0x34210000;    /* ldo 0(%r1), %r1      */
525                 stub->insns[2] = 0xe820d002;    /* bve,n (%r1)          */
526 
527                 stub->insns[0] |= reassemble_21(lrsel(value, addend));
528                 stub->insns[1] |= reassemble_14(rrsel(value, addend));
529                 break;
530         }
531 
532 #endif
533 
534         return (Elf_Addr)stub;
535 }
536 
537 #ifndef CONFIG_64BIT
538 int apply_relocate_add(Elf_Shdr *sechdrs,
539                        const char *strtab,
540                        unsigned int symindex,
541                        unsigned int relsec,
542                        struct module *me)
543 {
544         int i;
545         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
546         Elf32_Sym *sym;
547         Elf32_Word *loc;
548         Elf32_Addr val;
549         Elf32_Sword addend;
550         Elf32_Addr dot;
551         Elf_Addr loc0;
552         unsigned int targetsec = sechdrs[relsec].sh_info;
553         //unsigned long dp = (unsigned long)$global$;
554         register unsigned long dp asm ("r27");
555 
556         DEBUGP("Applying relocate section %u to %u\n", relsec,
557                targetsec);
558         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
559                 /* This is where to make the change */
560                 loc = (void *)sechdrs[targetsec].sh_addr
561                       + rel[i].r_offset;
562                 /* This is the start of the target section */
563                 loc0 = sechdrs[targetsec].sh_addr;
564                 /* This is the symbol it is referring to */
565                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
566                         + ELF32_R_SYM(rel[i].r_info);
567                 if (!sym->st_value) {
568                         printk(KERN_WARNING "%s: Unknown symbol %s\n",
569                                me->name, strtab + sym->st_name);
570                         return -ENOENT;
571                 }
572                 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
573                 dot =  (Elf32_Addr)loc & ~0x03;
574 
575                 val = sym->st_value;
576                 addend = rel[i].r_addend;
577 
578 #if 0
579 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
580                 DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
581                         strtab + sym->st_name,
582                         (uint32_t)loc, val, addend,
583                         r(R_PARISC_PLABEL32)
584                         r(R_PARISC_DIR32)
585                         r(R_PARISC_DIR21L)
586                         r(R_PARISC_DIR14R)
587                         r(R_PARISC_SEGREL32)
588                         r(R_PARISC_DPREL21L)
589                         r(R_PARISC_DPREL14R)
590                         r(R_PARISC_PCREL17F)
591                         r(R_PARISC_PCREL22F)
592                         "UNKNOWN");
593 #undef r
594 #endif
595 
596                 switch (ELF32_R_TYPE(rel[i].r_info)) {
597                 case R_PARISC_PLABEL32:
598                         /* 32-bit function address */
599                         /* no function descriptors... */
600                         *loc = fsel(val, addend);
601                         break;
602                 case R_PARISC_DIR32:
603                         /* direct 32-bit ref */
604                         *loc = fsel(val, addend);
605                         break;
606                 case R_PARISC_DIR21L:
607                         /* left 21 bits of effective address */
608                         val = lrsel(val, addend);
609                         *loc = mask(*loc, 21) | reassemble_21(val);
610                         break;
611                 case R_PARISC_DIR14R:
612                         /* right 14 bits of effective address */
613                         val = rrsel(val, addend);
614                         *loc = mask(*loc, 14) | reassemble_14(val);
615                         break;
616                 case R_PARISC_SEGREL32:
617                         /* 32-bit segment relative address */
618                         /* See note about special handling of SEGREL32 at
619                          * the beginning of this file.
620                          */
621                         *loc = fsel(val, addend); 
622                         break;
623                 case R_PARISC_DPREL21L:
624                         /* left 21 bit of relative address */
625                         val = lrsel(val - dp, addend);
626                         *loc = mask(*loc, 21) | reassemble_21(val);
627                         break;
628                 case R_PARISC_DPREL14R:
629                         /* right 14 bit of relative address */
630                         val = rrsel(val - dp, addend);
631                         *loc = mask(*loc, 14) | reassemble_14(val);
632                         break;
633                 case R_PARISC_PCREL17F:
634                         /* 17-bit PC relative address */
635                         /* calculate direct call offset */
636                         val += addend;
637                         val = (val - dot - 8)/4;
638                         if (!RELOC_REACHABLE(val, 17)) {
639                                 /* direct distance too far, create
640                                  * stub entry instead */
641                                 val = get_stub(me, sym->st_value, addend,
642                                         ELF_STUB_DIRECT, loc0, targetsec);
643                                 val = (val - dot - 8)/4;
644                                 CHECK_RELOC(val, 17);
645                         }
646                         *loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
647                         break;
648                 case R_PARISC_PCREL22F:
649                         /* 22-bit PC relative address; only defined for pa20 */
650                         /* calculate direct call offset */
651                         val += addend;
652                         val = (val - dot - 8)/4;
653                         if (!RELOC_REACHABLE(val, 22)) {
654                                 /* direct distance too far, create
655                                  * stub entry instead */
656                                 val = get_stub(me, sym->st_value, addend,
657                                         ELF_STUB_DIRECT, loc0, targetsec);
658                                 val = (val - dot - 8)/4;
659                                 CHECK_RELOC(val, 22);
660                         }
661                         *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
662                         break;
663                 case R_PARISC_PCREL32:
664                         /* 32-bit PC relative address */
665                         *loc = val - dot - 8 + addend;
666                         break;
667 
668                 default:
669                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
670                                me->name, ELF32_R_TYPE(rel[i].r_info));
671                         return -ENOEXEC;
672                 }
673         }
674 
675         return 0;
676 }
677 
678 #else
679 int apply_relocate_add(Elf_Shdr *sechdrs,
680                        const char *strtab,
681                        unsigned int symindex,
682                        unsigned int relsec,
683                        struct module *me)
684 {
685         int i;
686         Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
687         Elf64_Sym *sym;
688         Elf64_Word *loc;
689         Elf64_Xword *loc64;
690         Elf64_Addr val;
691         Elf64_Sxword addend;
692         Elf64_Addr dot;
693         Elf_Addr loc0;
694         unsigned int targetsec = sechdrs[relsec].sh_info;
695 
696         DEBUGP("Applying relocate section %u to %u\n", relsec,
697                targetsec);
698         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
699                 /* This is where to make the change */
700                 loc = (void *)sechdrs[targetsec].sh_addr
701                       + rel[i].r_offset;
702                 /* This is the start of the target section */
703                 loc0 = sechdrs[targetsec].sh_addr;
704                 /* This is the symbol it is referring to */
705                 sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
706                         + ELF64_R_SYM(rel[i].r_info);
707                 if (!sym->st_value) {
708                         printk(KERN_WARNING "%s: Unknown symbol %s\n",
709                                me->name, strtab + sym->st_name);
710                         return -ENOENT;
711                 }
712                 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
713                 dot = (Elf64_Addr)loc & ~0x03;
714                 loc64 = (Elf64_Xword *)loc;
715 
716                 val = sym->st_value;
717                 addend = rel[i].r_addend;
718 
719 #if 0
720 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t :
721                 printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n",
722                         strtab + sym->st_name,
723                         loc, val, addend,
724                         r(R_PARISC_LTOFF14R)
725                         r(R_PARISC_LTOFF21L)
726                         r(R_PARISC_PCREL22F)
727                         r(R_PARISC_DIR64)
728                         r(R_PARISC_SEGREL32)
729                         r(R_PARISC_FPTR64)
730                         "UNKNOWN");
731 #undef r
732 #endif
733 
734                 switch (ELF64_R_TYPE(rel[i].r_info)) {
735                 case R_PARISC_LTOFF21L:
736                         /* LT-relative; left 21 bits */
737                         val = get_got(me, val, addend);
738                         DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n",
739                                strtab + sym->st_name,
740                                loc, val);
741                         val = lrsel(val, 0);
742                         *loc = mask(*loc, 21) | reassemble_21(val);
743                         break;
744                 case R_PARISC_LTOFF14R:
745                         /* L(ltoff(val+addend)) */
746                         /* LT-relative; right 14 bits */
747                         val = get_got(me, val, addend);
748                         val = rrsel(val, 0);
749                         DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n",
750                                strtab + sym->st_name,
751                                loc, val);
752                         *loc = mask(*loc, 14) | reassemble_14(val);
753                         break;
754                 case R_PARISC_PCREL22F:
755                         /* PC-relative; 22 bits */
756                         DEBUGP("PCREL22F Symbol %s loc %p val %lx\n",
757                                strtab + sym->st_name,
758                                loc, val);
759                         val += addend;
760                         /* can we reach it locally? */
761                         if (in_local(me, (void *)val)) {
762                                 /* this is the case where the symbol is local
763                                  * to the module, but in a different section,
764                                  * so stub the jump in case it's more than 22
765                                  * bits away */
766                                 val = (val - dot - 8)/4;
767                                 if (!RELOC_REACHABLE(val, 22)) {
768                                         /* direct distance too far, create
769                                          * stub entry instead */
770                                         val = get_stub(me, sym->st_value,
771                                                 addend, ELF_STUB_DIRECT,
772                                                 loc0, targetsec);
773                                 } else {
774                                         /* Ok, we can reach it directly. */
775                                         val = sym->st_value;
776                                         val += addend;
777                                 }
778                         } else {
779                                 val = sym->st_value;
780                                 if (strncmp(strtab + sym->st_name, "$$", 2)
781                                     == 0)
782                                         val = get_stub(me, val, addend, ELF_STUB_MILLI,
783                                                        loc0, targetsec);
784                                 else
785                                         val = get_stub(me, val, addend, ELF_STUB_GOT,
786                                                        loc0, targetsec);
787                         }
788                         DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n", 
789                                strtab + sym->st_name, loc, sym->st_value,
790                                addend, val);
791                         val = (val - dot - 8)/4;
792                         CHECK_RELOC(val, 22);
793                         *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
794                         break;
795                 case R_PARISC_PCREL32:
796                         /* 32-bit PC relative address */
797                         *loc = val - dot - 8 + addend;
798                         break;
799                 case R_PARISC_DIR64:
800                         /* 64-bit effective address */
801                         *loc64 = val + addend;
802                         break;
803                 case R_PARISC_SEGREL32:
804                         /* 32-bit segment relative address */
805                         /* See note about special handling of SEGREL32 at
806                          * the beginning of this file.
807                          */
808                         *loc = fsel(val, addend); 
809                         break;
810                 case R_PARISC_FPTR64:
811                         /* 64-bit function address */
812                         if(in_local(me, (void *)(val + addend))) {
813                                 *loc64 = get_fdesc(me, val+addend);
814                                 DEBUGP("FDESC for %s at %p points to %lx\n",
815                                        strtab + sym->st_name, *loc64,
816                                        ((Elf_Fdesc *)*loc64)->addr);
817                         } else {
818                                 /* if the symbol is not local to this
819                                  * module then val+addend is a pointer
820                                  * to the function descriptor */
821                                 DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n",
822                                        strtab + sym->st_name,
823                                        loc, val);
824                                 *loc64 = val + addend;
825                         }
826                         break;
827 
828                 default:
829                         printk(KERN_ERR "module %s: Unknown relocation: %Lu\n",
830                                me->name, ELF64_R_TYPE(rel[i].r_info));
831                         return -ENOEXEC;
832                 }
833         }
834         return 0;
835 }
836 #endif
837 
838 static void
839 register_unwind_table(struct module *me,
840                       const Elf_Shdr *sechdrs)
841 {
842         unsigned char *table, *end;
843         unsigned long gp;
844 
845         if (!me->arch.unwind_section)
846                 return;
847 
848         table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
849         end = table + sechdrs[me->arch.unwind_section].sh_size;
850         gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
851 
852         DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
853                me->arch.unwind_section, table, end, gp);
854         me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
855 }
856 
857 static void
858 deregister_unwind_table(struct module *me)
859 {
860         if (me->arch.unwind)
861                 unwind_table_remove(me->arch.unwind);
862 }
863 
864 int module_finalize(const Elf_Ehdr *hdr,
865                     const Elf_Shdr *sechdrs,
866                     struct module *me)
867 {
868         int i;
869         unsigned long nsyms;
870         const char *strtab = NULL;
871         Elf_Sym *newptr, *oldptr;
872         Elf_Shdr *symhdr = NULL;
873 #ifdef DEBUG
874         Elf_Fdesc *entry;
875         u32 *addr;
876 
877         entry = (Elf_Fdesc *)me->init;
878         printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry,
879                entry->gp, entry->addr);
880         addr = (u32 *)entry->addr;
881         printk("INSNS: %x %x %x %x\n",
882                addr[0], addr[1], addr[2], addr[3]);
883         printk("got entries used %ld, gots max %ld\n"
884                "fdescs used %ld, fdescs max %ld\n",
885                me->arch.got_count, me->arch.got_max,
886                me->arch.fdesc_count, me->arch.fdesc_max);
887 #endif
888 
889         register_unwind_table(me, sechdrs);
890 
891         /* haven't filled in me->symtab yet, so have to find it
892          * ourselves */
893         for (i = 1; i < hdr->e_shnum; i++) {
894                 if(sechdrs[i].sh_type == SHT_SYMTAB
895                    && (sechdrs[i].sh_flags & SHF_ALLOC)) {
896                         int strindex = sechdrs[i].sh_link;
897                         /* FIXME: AWFUL HACK
898                          * The cast is to drop the const from
899                          * the sechdrs pointer */
900                         symhdr = (Elf_Shdr *)&sechdrs[i];
901                         strtab = (char *)sechdrs[strindex].sh_addr;
902                         break;
903                 }
904         }
905 
906         DEBUGP("module %s: strtab %p, symhdr %p\n",
907                me->name, strtab, symhdr);
908 
909         if(me->arch.got_count > MAX_GOTS) {
910                 printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n",
911                                 me->name, me->arch.got_count, MAX_GOTS);
912                 return -EINVAL;
913         }
914 
915         kfree(me->arch.section);
916         me->arch.section = NULL;
917 
918         /* no symbol table */
919         if(symhdr == NULL)
920                 return 0;
921 
922         oldptr = (void *)symhdr->sh_addr;
923         newptr = oldptr + 1;    /* we start counting at 1 */
924         nsyms = symhdr->sh_size / sizeof(Elf_Sym);
925         DEBUGP("OLD num_symtab %lu\n", nsyms);
926 
927         for (i = 1; i < nsyms; i++) {
928                 oldptr++;       /* note, count starts at 1 so preincrement */
929                 if(strncmp(strtab + oldptr->st_name,
930                               ".L", 2) == 0)
931                         continue;
932 
933                 if(newptr != oldptr)
934                         *newptr++ = *oldptr;
935                 else
936                         newptr++;
937 
938         }
939         nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
940         DEBUGP("NEW num_symtab %lu\n", nsyms);
941         symhdr->sh_size = nsyms * sizeof(Elf_Sym);
942         return 0;
943 }
944 
945 void module_arch_cleanup(struct module *mod)
946 {
947         deregister_unwind_table(mod);
948 }
949 

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