2 Copyright © 1995-2007, The AROS Development Team. All rights reserved.
5 Desc: Code to dynamically load ELF executables
8 1997/12/13: Changed filename to internalloadseg_elf.c
9 Original file was created by digulla.
14 #include <exec/memory.h>
15 #include <proto/exec.h>
16 #include <dos/dosasl.h>
17 #include <proto/dos.h>
18 #include <proto/arossupport.h>
19 #include <aros/asmcall.h>
20 #include "internalloadseg.h"
21 #include "dos_intern.h"
23 #include <aros/debug.h>
27 #include <aros/macros.h>
29 #define SHT_PROGBITS 1
35 #define SHT_SYMTAB_SHNDX 18
43 #define EM_X86_64 62 /* AMD x86-64 */
49 /* AMD x86-64 relocations. */
50 #define R_X86_64_NONE 0 /* No reloc */
51 #define R_X86_64_64 1 /* Direct 64 bit */
52 #define R_X86_64_PC32 2 /* PC relative 32 bit signed */
59 #define R_PPC_ADDR32 1
60 #define R_PPC_ADDR16_LO 4
61 #define R_PPC_ADDR16_HA 6
62 #define R_PPC_REL24 10
63 #define R_PPC_REL32 26
73 #define SHN_LORESERVE 0xff00
74 #define SHN_ABS 0xfff1
75 #define SHN_COMMON 0xfff2
76 #define SHN_XINDEX 0xffff
77 #define SHN_HIRESERVE 0xffff
79 #define SHF_ALLOC (1 << 1)
80 #define SHF_EXECINSTR (1 << 2)
82 #define ELF32_ST_TYPE(i) ((i) & 0x0F)
93 #define ELFCLASS64 2 /* 64-bit objects */
95 #define ELF32_R_SYM(val) ((val) >> 8)
96 #define ELF32_R_TYPE(val) ((val) & 0xff)
97 #define ELF32_R_INFO(sym, type) (((sym) << 8) + ((type) & 0xff))
117 /* these are internal, and not part of the header proper. they are wider
118 * versions of shnum and shstrndx for when they don't fit in the header
119 * and we need to get them from the first section header. see
120 * load_header() for details
142 ULONG name
; /* Offset of the name string in the string table */
143 ULONG value
; /* Varies; eg. the offset of the symbol in its hunk */
144 ULONG size
; /* How much memory does the symbol occupy */
145 UBYTE info
; /* What kind of symbol is this ? (global, variable, etc) */
146 UBYTE other
; /* undefined */
147 UWORD shindex
; /* In which section is the symbol defined ? */
152 ULONG offset
; /* Address of the relocation relative to the section it refers to */
153 ULONG info
; /* Type of the relocation */
154 #if defined(__mc68000__) || defined (__x86_64__) || defined (__ppc__) || defined (__powerpc__) || defined(__arm__)
155 LONG addend
; /* Constant addend used to compute value */
164 } __attribute__((packed
));
166 #define BPTR2HUNK(bptr) ((struct hunk *)((char *)BADDR(bptr) - offsetof(struct hunk, next)))
167 #define HUNK2BPTR(hunk) MKBADDR(&hunk->next)
169 /* convert section header number to array index */
171 ((n) < SHN_LORESERVE ? (n) : ((n) <= SHN_HIRESERVE ? 0 : (n) - (SHN_HIRESERVE + 1 - SHN_LORESERVE)))
173 /* convert section header array index to section number */
175 ((i) < SHN_LORESERVE ? (i) : (i) + (SHN_HIRESERVE + 1 - SHN_LORESERVE))
182 #define MyRead(file, buf, size) \
185 LONG, funcarray[0], \
186 AROS_LCA(BPTR, file, D1), \
187 AROS_LCA(void *, buf, D2), \
188 AROS_LCA(LONG, size, D3), \
189 struct DosLibrary *, DOSBase \
193 #define MyAlloc(size, flags) \
196 void *, funcarray[1], \
197 AROS_LCA(ULONG, size, D0), \
198 AROS_LCA(ULONG, flags, D1), \
199 struct ExecBase *, SysBase \
203 #define MyFree(addr, size) \
206 void, funcarray[2], \
207 AROS_LCA(void *, addr, A1), \
208 AROS_LCA(ULONG, size, D0), \
209 struct ExecBase *, SysBase \
212 static int read_block
219 struct DosLibrary
*DOSBase
222 UBYTE
*buf
= (UBYTE
*)buffer
;
225 if (Seek(file
, offset
, OFFSET_BEGINNING
) < 0)
230 subsize
= MyRead(file
, buf
, size
);
235 SetIoErr(ERROR_BAD_HUNK
);
247 static void * load_block
253 struct DosLibrary
*DOSBase
256 D(bug("[ELF Loader] Load Block\n"));
257 D(bug("[ELF Loader] (size=%d)\n",size
));
258 D(bug("[ELF Loader] (funcarray=0x%x)\n",funcarray
));
259 D(bug("[ELF Loader] (funcarray[1]=0x%x)\n",funcarray
[1]));
260 void *block
= MyAlloc(size
, MEMF_ANY
);
263 if (read_block(file
, offset
, block
, size
, funcarray
, DOSBase
))
269 SetIoErr(ERROR_NO_FREE_STORE
);
274 static int load_header(BPTR file
, struct elfheader
*eh
, SIPTR
*funcarray
, struct DosLibrary
*DOSBase
) {
275 if (!read_block(file
, 0, eh
, offsetof(struct elfheader
, int_shnum
), funcarray
, DOSBase
))
278 if (eh
->ident
[0] != 0x7f || eh
->ident
[1] != 'E' ||
279 eh
->ident
[2] != 'L' || eh
->ident
[3] != 'F') {
280 D(bug("[ELF Loader] Not an ELF object\n"));
281 SetIoErr(ERROR_NOT_EXECUTABLE
);
284 D(bug("[ELF Loader] ELF object\n"));
286 eh
->int_shnum
= eh
->shnum
;
287 eh
->int_shstrndx
= eh
->shstrndx
;
289 /* the ELF header only uses 16 bits to store the count of section headers,
290 * so it can't handle more than 65535 headers. if the count is 0, and an
291 * offset is defined, then the real count can be found in the first
292 * section header (which always exists).
294 * similarly, if the string table index is SHN_XINDEX, then the actual
295 * index is found in the first section header also.
297 * see the System V ABI 2001-04-24 draft for more details.
299 if (eh
->int_shnum
== 0 || eh
->int_shstrndx
== SHN_XINDEX
) {
300 if (eh
->shoff
== 0) {
301 SetIoErr(ERROR_NOT_EXECUTABLE
);
306 if (!read_block(file
, eh
->shoff
, &sh
, sizeof(sh
), funcarray
, DOSBase
))
309 /* wider section header count is in the size field */
310 if (eh
->int_shnum
== 0)
311 eh
->int_shnum
= sh
.size
;
313 /* wider string table index is in the link field */
314 if (eh
->int_shstrndx
== SHN_XINDEX
)
315 eh
->int_shstrndx
= sh
.link
;
317 /* sanity, if they're still invalid then this isn't elf */
318 if (eh
->int_shnum
== 0 || eh
->int_shstrndx
== SHN_XINDEX
) {
319 SetIoErr(ERROR_NOT_EXECUTABLE
);
326 eh
->ident
[EI_CLASS
] != ELFCLASS32
||
327 eh
->ident
[EI_VERSION
] != EV_CURRENT
||
328 eh
->type
!= ET_REL
||
330 #if defined(__i386__)
331 eh
->ident
[EI_DATA
] != ELFDATA2LSB
||
332 eh
->machine
!= EM_386
334 #elif defined(__x86_64__)
335 eh
->ident
[EI_DATA
] != ELFDATA2LSB
||
336 eh
->machine
!= EM_X86_64
338 #elif defined(__mc68000__)
339 eh
->ident
[EI_DATA
] != ELFDATA2MSB
||
340 eh
->machine
!= EM_68K
342 #elif defined(__ppc__) || defined(__powerpc__)
343 eh
->ident
[EI_DATA
] != ELFDATA2MSB
||
344 eh
->machine
!= EM_PPC
346 #elif defined(__arm__)
347 eh
->ident
[EI_DATA
] != ELFDATA2LSB
||
348 eh
->machine
!= EM_ARM
349 #warning ARM has not been tested, yet!
352 # error Your architecture is not supported
356 D(bug("[ELF Loader] Object is of wrong type\n"));
357 #if defined(__x86_64__)
358 D(bug("[ELF Loader] EI_CLASS is %d - should be %d\n", eh
->ident
[EI_CLASS
], ELFCLASS64
));
360 D(bug("[ELF Loader] EI_CLASS is %d - should be %d\n", eh
->ident
[EI_CLASS
], ELFCLASS32
));
362 D(bug("[ELF Loader] EI_VERSION is %d - should be %d\n", eh
->ident
[EI_VERSION
], EV_CURRENT
));
363 D(bug("[ELF Loader] type is %d - should be %d\n", eh
->type
, ET_REL
));
364 #if defined (__i386__)
365 D(bug("[ELF Loader] EI_DATA is %d - should be %d\n", eh
->ident
[EI_DATA
],ELFDATA2LSB
));
366 #elif defined (__mc68000__)
367 D(bug("[ELF Loader] EI_DATA is %d - should be %d\n", eh
->ident
[EI_DATA
],ELFDATA2MSB
));
368 #elif defined(__ppc__) || defined(__powerpc__)
369 D(bug("[ELF Loader] EI_DATA is %d - should be %d\n", eh
->ident
[EI_DATA
],ELFDATA2MSB
));
370 #elif defined (__arm__)
371 D(bug("[ELF Loader] EI_DATA is %d - should be %d\n", eh
->ident
[EI_DATA
],ELFDATA2MSB
));
374 #if defined (__i386__)
375 D(bug("[ELF Loader] machine is %d - should be %d\n", eh
->machine
, EM_386
));
376 #elif defined(__mc68000__)
377 D(bug("[ELF Loader] machine is %d - should be %d\n", eh
->machine
, EM_68K
));
378 #elif defined(__ppc__) || defined(__powerpc__)
379 D(bug("[ELF Loader] machine is %d - should be %d\n", eh
->machine
, EM_PPC
));
380 #elif defined(__arm__)
381 D(bug("[ELF Loader] machine is %d - should be %d\n", eh
->machine
, EM_ARM
));
384 SetIoErr(ERROR_NOT_EXECUTABLE
);
394 BPTR
**next_hunk_ptr
,
398 struct DosLibrary
*DOSBase
407 /* The size of the hunk is the size of the section, plus
408 the size of the hunk structure, plus the size of the alignment (if necessary)*/
409 hunk_size
= sh
->size
+ sizeof(struct hunk
);
413 hunk_size
+= sh
->addralign
;
415 /* Also create space for a trampoline, if necessary */
416 if (sh
->flags
& SHF_EXECINSTR
)
417 hunk_size
+= sizeof(struct FullJumpVec
);
420 hunk
= MyAlloc(hunk_size
, MEMF_ANY
| (sh
->type
== SHT_NOBITS
) ? MEMF_CLEAR
: 0);
424 hunk
->size
= hunk_size
;
426 /* In case we are required to honour alignment, and If this section contains
427 executable code, create a trampoline to its beginning, so that even if the
428 alignment requirements make the actual code go much after the end of the
429 hunk structure, the code can still be reached in the usual way. */
432 if (sh
->flags
& SHF_EXECINSTR
)
434 sh
->addr
= (char *)AROS_ROUNDUP2
436 (ULONG
)hunk
->data
+ sizeof(struct FullJumpVec
), sh
->addralign
438 __AROS_SET_FULLJMP((struct FullJumpVec
*)hunk
->data
, sh
->addr
);
441 sh
->addr
= (char *)AROS_ROUNDUP2((ULONG
)hunk
->data
, sh
->addralign
);
444 sh
->addr
= hunk
->data
;
446 /* Link the previous one with the new one */
447 BPTR2HUNK(*next_hunk_ptr
)->next
= HUNK2BPTR(hunk
);
449 /* Update the pointer to the previous one, which is now the current one */
450 *next_hunk_ptr
= HUNK2BPTR(hunk
);
452 if (sh
->type
!= SHT_NOBITS
)
453 return read_block(file
, sh
->offset
, sh
->addr
, sh
->size
, funcarray
, DOSBase
);
459 SetIoErr(ERROR_NO_FREE_STORE
);
466 struct elfheader
*eh
,
469 struct sheader
*symtab_shndx
,
470 struct DosLibrary
*DOSBase
473 struct sheader
*shrel
= &sh
[shrel_idx
];
474 struct sheader
*shsymtab
= &sh
[SHINDEX(shrel
->link
)];
475 struct sheader
*toreloc
= &sh
[SHINDEX(shrel
->info
)];
477 struct symbol
*symtab
= (struct symbol
*)shsymtab
->addr
;
478 struct relo
*rel
= (struct relo
*)shrel
->addr
;
479 char *section
= toreloc
->addr
;
481 /* this happens if the target section has no allocation. that can happen
482 * eg. with a .debug PROGBITS and a .rel.debug section */
486 ULONG numrel
= shrel
->size
/ shrel
->entsize
;
489 struct symbol
*SysBase_sym
= NULL
;
491 for (i
=0; i
<numrel
; i
++, rel
++)
493 struct symbol
*sym
= &symtab
[ELF32_R_SYM(rel
->info
)];
494 ULONG
*p
= (ULONG
*)§ion
[rel
->offset
];
498 if (sym
->shindex
!= SHN_XINDEX
)
499 shindex
= sym
->shindex
;
502 if (symtab_shndx
== NULL
) {
503 D(bug("[ELF Loader] got symbol with shndx 0xfff, but there's no symtab shndx table\n"));
504 SetIoErr(ERROR_BAD_HUNK
);
507 shindex
= ((ULONG
*)symtab_shndx
->addr
)[ELF32_R_SYM(rel
->info
)];
514 D(bug("[ELF Loader] Undefined symbol '%s' while relocating the section '%s'\n",
515 (STRPTR
)sh
[SHINDEX(shsymtab
->link
)].addr
+ sym
->name
,
516 (STRPTR
)sh
[SHINDEX(eh
->int_shstrndx
)].addr
+ toreloc
->name
));
517 SetIoErr(ERROR_BAD_HUNK
);
521 D(bug("[ELF Loader] COMMON symbol '%s' while relocating the section '%s'\n",
522 (STRPTR
)sh
[SHINDEX(shsymtab
->link
)].addr
+ sym
->name
,
523 (STRPTR
)sh
[SHINDEX(eh
->int_shstrndx
)].addr
+ toreloc
->name
));
524 SetIoErr(ERROR_BAD_HUNK
);
529 if (SysBase_sym
== NULL
)
531 if (strncmp((STRPTR
)sh
[SHINDEX(shsymtab
->link
)].addr
+ sym
->name
, "SysBase", 8) == 0)
540 if (SysBase_sym
== sym
)
542 SysBase_yes
: s
= (ULONG
)&SysBase
;
545 SysBase_no
: s
= sym
->value
;
549 s
= (ULONG
)sh
[SHINDEX(shindex
)].addr
+ sym
->value
;
552 switch (ELF32_R_TYPE(rel
->info
))
554 #if defined(__i386__)
556 case R_386_32
: /* 32bit absolute */
560 case R_386_PC32
: /* 32bit PC relative */
567 #elif defined(__x86_64__)
568 /* These weren't tested */
569 case R_X86_64_64
: /* 64bit direct/absolute */
570 *p
= s
+ rel
->addend
;
573 case R_X86_64_PC32
: /* PC relative 32 bit signed */
574 *p
= s
+ rel
->addend
- (ULONG
)p
;
577 case R_X86_64_NONE
: /* No reloc */
580 #elif defined(__mc68000__)
583 *p
= s
+ rel
->addend
;
587 *p
= s
+ rel
->addend
- (ULONG
)p
;
593 #elif defined(__ppc__) || defined(__powerpc__)
596 *p
= s
+ rel
->addend
;
599 case R_PPC_ADDR16_LO
:
601 unsigned short *c
= (unsigned short *) p
;
602 *c
= (s
+ rel
->addend
) & 0xffff;
606 case R_PPC_ADDR16_HA
:
608 unsigned short *c
= (unsigned short *) p
;
609 ULONG temp
= s
+ rel
->addend
;
611 if ((temp
& 0x8000) != 0)
618 *p
|= (s
+ rel
->addend
- (ULONG
) p
) & 0x3fffffc;
622 *p
= s
+ rel
->addend
- (ULONG
) p
;
628 #elif defined(__arm__)
631 * This has not been tested. Taken from ARMELF.pdf
632 * from arm.com page 33ff.
635 *p
= s
+ rel
->addend
- (ULONG
)p
;
639 *p
= s
+ rel
->addend
;
646 # error Your architecture is not supported
650 D(bug("[ELF Loader] Unrecognized relocation type %d %d\n", i
, ELF32_R_TYPE(rel
->info
)));
651 SetIoErr(ERROR_BAD_HUNK
);
659 BPTR InternalLoadSeg_ELF
664 SIPTR
*stack __unused
,
665 struct MinList
*seginfos
,
666 struct DosLibrary
*DOSBase
671 struct sheader
*symtab_shndx
= NULL
;
673 BPTR
*next_hunk_ptr
= MKBADDR(&hunks
);
675 BOOL exec_hunk_seen
= FALSE
;
677 /* load and validate ELF header */
678 if (!load_header(file
, &eh
, funcarray
, DOSBase
))
681 /* load section headers */
682 if (!(sh
= load_block(file
, eh
.shoff
, eh
.int_shnum
* eh
.shentsize
, funcarray
, DOSBase
)))
685 /* load the string table */
687 struct sheader
*shstr
= sh
+ SHINDEX(eh
.int_shstrndx
);
688 if (shstr
->size
!= 0)
690 st
= MyAlloc(shstr
->size
, MEMF_ANY
| MEMF_CLEAR
);
691 read_block(file
, shstr
->offset
, st
, shstr
->size
, funcarray
, DOSBase
);
694 /* Iterate over the section headers in order to do some stuff... */
695 for (i
= 0; i
< eh
.int_shnum
; i
++)
698 Load the symbol and string table(s).
700 NOTICE: the ELF standard, at the moment (Nov 2002) explicitely states
701 that only one symbol table per file is allowed. However, it
702 also states that this may change in future... we already handle it.
704 if (sh
[i
].type
== SHT_SYMTAB
|| sh
[i
].type
== SHT_STRTAB
|| sh
[i
].type
== SHT_SYMTAB_SHNDX
)
706 sh
[i
].addr
= load_block(file
, sh
[i
].offset
, sh
[i
].size
, funcarray
, DOSBase
);
710 if (sh
[i
].type
== SHT_SYMTAB_SHNDX
) {
711 if (symtab_shndx
== NULL
)
712 symtab_shndx
= &sh
[i
];
714 D(bug("[ELF Loader] file contains multiple symtab shndx tables. only using the first one\n"));
718 /* Load the section in memory if needed, and make an hunk out of it */
719 if (sh
[i
].flags
& SHF_ALLOC
)
723 /* Only allow alignment if this is an executable hunk
724 or if an executable hunk has been loaded already,
725 so to avoid the situation in which a data hunk has its
726 content displaced from the hunk's header in case it's the
727 first hunk (this happens with Keymaps, for instance). */
728 if (sh
[i
].flags
& SHF_EXECINSTR
)
729 exec_hunk_seen
= TRUE
;
731 if (!load_hunk(file
, &next_hunk_ptr
, &sh
[i
], funcarray
, exec_hunk_seen
, DOSBase
))
736 STRPTR name
= st
+ sh
[i
].name
;
737 ULONG size
= sizeof(struct seginfo
);
738 struct seginfo
*si
= MyAlloc(size
, MEMF_ANY
);
740 D(bug("[ELF Loader] seg %s at 0x%x\n", name
, sh
[i
].addr
));
742 si
->addr
= sh
[i
].addr
;
743 size
= sizeof(si
->name
) - 1;
744 strncpy(si
->name
, name
, size
);
745 si
->name
[size
] = '\0';
747 ADDTAIL(seginfos
, &si
->node
);
754 /* Relocate the sections */
755 for (i
= 0; i
< eh
.int_shnum
; i
++)
759 #if defined(__i386__)
761 sh
[i
].type
== SHT_REL
&&
763 #elif defined(__x86_64__)
765 sh
[i
].type
== SHT_RELA
&&
767 #elif defined(__mc68000__)
769 sh
[i
].type
== SHT_RELA
&&
771 #elif defined(__ppc__) || defined(__powerpc__)
773 sh
[i
].type
== SHT_RELA
&&
775 #elif defined(__arm__)
776 #warning Missing code for ARM
780 # error Your architecture is not supported
783 /* Does this relocation section refer to a hunk? If so, addr must be != 0 */
784 sh
[SHINDEX(sh
[i
].info
)].addr
787 sh
[i
].addr
= load_block(file
, sh
[i
].offset
, sh
[i
].size
, funcarray
, DOSBase
);
788 if (!sh
[i
].addr
|| !relocate(&eh
, sh
, i
, symtab_shndx
, DOSBase
))
791 MyFree(sh
[i
].addr
, sh
[i
].size
);
801 /* There were some errors, deallocate The hunks */
803 InternalUnLoadSeg(hunks
, (VOID_FUNC
)funcarray
[2]);
808 /* Clear the caches to let the CPU see the new data and instructions */
813 struct hunk
*hunk
= BPTR2HUNK(curr
);
815 CacheClearE(hunk
->data
, hunk
->size
, CACRF_ClearD
| CACRF_ClearI
);
821 /* deallocate the symbol tables */
822 for (i
= 0; i
< eh
.int_shnum
; i
++)
824 if (((sh
[i
].type
== SHT_SYMTAB
) || (sh
[i
].type
== SHT_STRTAB
)) && (sh
[i
].addr
!= NULL
))
825 MyFree(sh
[i
].addr
, sh
[i
].size
);
828 /* Free the string table */
829 MyFree(st
, shstr
->size
);
831 /* Free the section headers */
832 MyFree(sh
, eh
.int_shnum
* eh
.shentsize
);