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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 */
in_init(struct module * me,void * loc)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  
in_core(struct module * me,void * loc)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  
in_local(struct module * me,void * loc)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.  */
sign_unext(int x,int len)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  
low_sign_unext(int x,int len)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  
reassemble_14(int as14)172  static inline int reassemble_14(int as14)
173  {
174  	return (((as14 & 0x1fff) << 1) |
175  		((as14 & 0x2000) >> 13));
176  }
177  
reassemble_16a(int as16)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  
reassemble_17(int as17)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  
reassemble_21(int as21)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  
reassemble_22(int as22)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  
module_alloc(unsigned long size)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
count_gots(const Elf_Rela * rela,unsigned long n)227  static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
228  {
229  	return 0;
230  }
231  
count_fdescs(const Elf_Rela * rela,unsigned long n)232  static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
233  {
234  	return 0;
235  }
236  
count_stubs(const Elf_Rela * rela,unsigned long n)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
count_gots(const Elf_Rela * rela,unsigned long n)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  
count_fdescs(const Elf_Rela * rela,unsigned long n)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  
count_stubs(const Elf_Rela * rela,unsigned long n)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  
module_arch_freeing_init(struct module * mod)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 */
arch_mod_section_prepend(struct module * mod,unsigned int section)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
module_frob_arch_sections(CONST Elf_Ehdr * hdr,CONST Elf_Shdr * sechdrs,CONST char * secstrings,struct module * me)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
get_got(struct module * me,unsigned long value,long addend)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
get_fdesc(struct module * me,unsigned long value)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  
get_stub(struct module * me,unsigned long value,long addend,enum elf_stub_type stub_type,Elf_Addr loc0,unsigned int targetsec)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
apply_relocate_add(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)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
apply_relocate_add(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)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
register_unwind_table(struct module * me,const Elf_Shdr * sechdrs)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
deregister_unwind_table(struct module * me)858  deregister_unwind_table(struct module *me)
859  {
860  	if (me->arch.unwind)
861  		unwind_table_remove(me->arch.unwind);
862  }
863  
module_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * me)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  
module_arch_cleanup(struct module * mod)945  void module_arch_cleanup(struct module *mod)
946  {
947  	deregister_unwind_table(mod);
948  }
949