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Diffstat (limited to 'sysdeps/arm/dl-machine.h')
| -rw-r--r-- | sysdeps/arm/dl-machine.h | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/sysdeps/arm/dl-machine.h b/sysdeps/arm/dl-machine.h new file mode 100644 index 0000000000..66b69d02db --- /dev/null +++ b/sysdeps/arm/dl-machine.h @@ -0,0 +1,478 @@ +/* Machine-dependent ELF dynamic relocation inline functions. ARM version. + Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#ifndef dl_machine_h +#define dl_machine_h + +#define ELF_MACHINE_NAME "ARM" + +#include <sys/param.h> + +#include <assert.h> + +/* Return nonzero iff E_MACHINE is compatible with the running host. */ +static inline int __attribute__ ((unused)) +elf_machine_matches_host (Elf32_Half e_machine) +{ + switch (e_machine) + { + case EM_ARM: + return 1; + default: + return 0; + } +} + + +/* Return the link-time address of _DYNAMIC. Conveniently, this is the + first element of the GOT. This must be inlined in a function which + uses global data. */ +static inline Elf32_Addr __attribute__ ((unused)) +elf_machine_dynamic (void) +{ + register Elf32_Addr *got asm ("r10"); + return *got; +} + + +/* Return the run-time load address of the shared object. */ +// patb +static inline Elf32_Addr __attribute__ ((unused)) +elf_machine_load_address (void) +{ + Elf32_Addr addr; + asm (" ldr ip,.L1 + ldr r3,.L3 + add r3, r3, sl + ldr ip,[sl, ip] + sub ip, r3, ip + b .L2 + .L1: .word _dl_start(GOT) + .L3: .word _dl_start(GOTOFF) + .L2: mov %0, ip" + : "=r" (addr) : : "ip", "r3"); + return addr; +} + + +/* Set up the loaded object described by L so its unrelocated PLT + entries will jump to the on-demand fixup code in dl-runtime.c. */ + +static inline int __attribute__ ((unused)) +elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) +{ + Elf32_Addr *got; + extern void _dl_runtime_resolve (Elf32_Word); + extern void _dl_runtime_profile (Elf32_Word); + + if (l->l_info[DT_JMPREL] && lazy) + { + /* patb: this is different than i386 */ + /* The GOT entries for functions in the PLT have not yet been filled + in. Their initial contents will arrange when called to push an + index into the .got section, load ip with &_GLOBAL_OFFSET_TABLE_[3], + and then jump to _GLOBAL_OFFSET_TABLE[2]. */ + got = (Elf32_Addr *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr); + got[1] = (Elf32_Addr) l; /* Identify this shared object. */ + + /* The got[2] entry contains the address of a function which gets + called to get the address of a so far unresolved function and + jump to it. The profiling extension of the dynamic linker allows + to intercept the calls to collect information. In this case we + don't store the address in the GOT so that all future calls also + end in this function. */ + if (profile) + { + got[2] = (Elf32_Addr) &_dl_runtime_profile; + /* Say that we really want profiling and the timers are started. */ + _dl_profile_map = l; + } + else + /* This function will get called to fix up the GOT entry indicated by + the offset on the stack, and then jump to the resolved address. */ + got[2] = (Elf32_Addr) &_dl_runtime_resolve; + } + return lazy; +} + +/* This code is used in dl-runtime.c to call the `fixup' function + and then redirect to the address it returns. */ + // macro for handling PIC situation.... +#ifdef PIC +#define CALL_ROUTINE(x) " ldr sl,0f + add sl, pc, sl +1: ldr r2, 2f + mov lr, pc + add pc, sl, r2 + b 3f +0: .word _GLOBAL_OFFSET_TABLE_ - 1b - 4 +2: .word " #x "(GOTOFF) +3: " +#else +#define CALL_ROUTINE(x) " bl " #x +#endif + +#ifndef PROF +# define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\ + .text + .globl _dl_runtime_resolve + .type _dl_runtime_resolve, #function + .align 2 +_dl_runtime_resolve: + @ we get called with + @ stack[0] contains the return address from this call + @ ip contains &GOT[n+3] (pointer to function) + @ lr points to &GOT[2] + + @ save almost everything; lr is already on the stack + stmdb sp!,{r0-r3,sl,fp} + + @ prepare to call fixup() + + @ change &GOT[n+3] into 8*n NOTE: reloc are 8 bytes each + sub r1, ip, lr + sub r1, r1, #4 + add r1, r1, r1 + + @ get pointer to linker struct + ldr r0, [lr, #-4] + + " CALL_ROUTINE(fixup) " + + @ save the return + mov ip, r0 + + @ restore the stack + ldmia sp!,{r0-r3,sl,fp,lr} + + @ jump to the newly found address + mov pc, ip + + .size _dl_runtime_resolve, .-_dl_runtime_resolve + + .globl _dl_runtime_profile + .type _dl_runtime_profile, #function + .align 2 +_dl_runtime_profile: + @ we get caled with + @ stack[0] contains the return address from this call + @ ip contains &GOT[n+3] (pointer to function) + @ lr points to &GOT[2] + + @ save almost everything; return add is already on the stack + stmdb sp!,{r0-r3,fp} + + @ prepare to call fixup() + + @ change &GOT[n+3] into 8*n NOTE: reloc are 8 bytes each + sub r1, ip, lr + sub r1, r1, #4 + add r1, r1, r1 + + @ get pointer to linker struct + ldr r0, [lr, #-4] + + " CALL_ROUTINE(profile_fixup) " + + @ save the return + mov ip, r0 + + @ restore the stack + ldmia sp!,{r0-r3,fp,lr} + + @ jump to the newly found address + mov pc, ip + + .size _dl_runtime_profile, .-_dl_runtime_profile + .previous +"); +#else // PROF +# define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\ + .text + .globl _dl_runtime_resolve + .globl _dl_runtime_profile + .type _dl_runtime_resolve, #function + .type _dl_runtime_profile, #function + .align 2 +_dl_runtime_resolve: +_dl_runtime_profile: + stmdb sp!,{r0-r3,fp} + ldr r1,[sp,#0x34] + sub r1, ip, lr + sub r1, r1, #4 + add r1, r1, r1 + ldr r0, [lr, #-4] + " CALL_ROUTINE(fixup) " + mov ip, r0 + ldmia sp!,{r0-r3,fp,lr} + mov pc, ip + + .size _dl_runtime_profile, .-_dl_runtime_profile + .previous +"); +#endif //PROF + +/* Mask identifying addresses reserved for the user program, + where the dynamic linker should not map anything. */ +#define ELF_MACHINE_USER_ADDRESS_MASK 0xf8000000UL + +/* Initial entry point code for the dynamic linker. + The C function `_dl_start' is the real entry point; + its return value is the user program's entry point. */ + +#define RTLD_START asm ("\ +.text +.globl _start +.globl _dl_start_user +_start: + @ at start time, all the args are on the stack + mov r0, sp + bl _dl_start + @ returns user entry point in r0 +_dl_start_user: + mov r6, r0 + @ we are PIC code, so get global offset table + ldr sl, .L_GET_GOT + add sl, pc, sl +.L_GOT_GOT: + @ See if we were run as a command with the executable file + @ name as an extra leading argument. + ldr r1, .L_SKIP_ARGS + ldr r1, [sl, r1] + @ get the original arg count + ldr r0, [sp] + @ subtract _dl_skip_args from it + sub r0, r0, r1 + @ adjust the stack pointer to skip them + add sp, sp, r1, lsl #2 + @ store the new argc in the new stack location + str r0, [sp] + + @ now we enter a _dl_init_next loop + ldr r2, .L_DEF_SCOPE + ldr r2, [sl, r2] + ldr r4, [r2, #8] + @ call _dl_init_next to get the address of an initalizer +0: mov r0, r4 + bl _dl_init_next(PLT) + cmp r0, #0 + beq 1f + @ call the shared-object initializer + @ during this call, the stack may get moved around + mov lr, pc + mov pc, r0 + @ go back and look for another initializer + b 0b +1: @ clear the startup flag + ldr r2, .L_STARTUP_FLAG + ldr r1, [sl, r2] + @ we know r0==0 at this point + str r0, [r1] + @ load the finalizer function + ldr r0, .L_FINI_PROC + ldr r0, [sl, r0] + @ jump to the user_s entry point + mov pc, r6 +.L_GET_GOT: + .word _GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4 \n\ +.L_SKIP_ARGS: \n\ + .word _dl_skip_args(GOTOFF) \n\ +.L_DEF_SCOPE: \n\ + .word _dl_default_scope(GOT) \n\ +.L_STARTUP_FLAG: + .word _dl_starting_up(GOT) +.L_FINI_PROC: + .word _dl_fini(GOT) +.previous\n\ +"); + +/* Nonzero iff TYPE should not be allowed to resolve to one of + the main executable's symbols, as for a COPY reloc. */ +#define elf_machine_lookup_noexec_p(type) ((type) == R_ARM_COPY) + +/* Nonzero iff TYPE describes relocation of a PLT entry, so + PLT entries should not be allowed to define the value. */ +#define elf_machine_lookup_noplt_p(type) ((type) == R_ARM_JMP_SLOT) + +/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ +#define ELF_MACHINE_JMP_SLOT R_ARM_JMP_SLOT + +/* The i386 never uses Elf32_Rela relocations. */ +#define ELF_MACHINE_NO_RELA 1 + +/* We define an initialization functions. This is called very early in + _dl_sysdep_start. */ +#define DL_PLATFORM_INIT dl_platform_init () + +extern const char *_dl_platform; + +static inline void __attribute__ ((unused)) +dl_platform_init (void) +{ + if (_dl_platform == NULL) + /* We default to ARM + This is where processors could be distinguished arm2, arm6, sa110, etc */ + _dl_platform = "ARM"; +} + +static inline void +elf_machine_fixup_plt (struct link_map *map, const Elf32_Rel *reloc, + Elf32_Addr *reloc_addr, Elf32_Addr value) +{ + *reloc_addr = value; +} + +/* Return the final value of a plt relocation. */ +static inline Elf32_Addr +elf_machine_plt_value (struct link_map *map, const Elf32_Rel *reloc, + Elf32_Addr value) +{ + return value; +} + +#endif /* !dl_machine_h */ + +#ifdef RESOLVE + +extern char **_dl_argv; + +/* Perform the relocation specified by RELOC and SYM (which is fully resolved). + MAP is the object containing the reloc. */ + +static inline void +elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc, + const Elf32_Sym *sym, const struct r_found_version *version, + Elf32_Addr *const reloc_addr) +{ + if (ELF32_R_TYPE (reloc->r_info) == R_ARM_RELATIVE) + { +#ifndef RTLD_BOOTSTRAP + if (map != &_dl_rtld_map) /* Already done in rtld itself. */ +#endif + *reloc_addr += map->l_addr; + } + else if (ELF32_R_TYPE (reloc->r_info) != R_ARM_NONE) + { + const Elf32_Sym *const refsym = sym; + Elf32_Addr value = RESOLVE (&sym, version, ELF32_R_TYPE (reloc->r_info)); + if (sym) + value += sym->st_value; + + switch (ELF32_R_TYPE (reloc->r_info)) + { + case R_ARM_COPY: + if (sym == NULL) + /* This can happen in trace mode if an object could not be + found. */ + break; + if (sym->st_size > refsym->st_size + || (_dl_verbose && sym->st_size < refsym->st_size)) + { + const char *strtab; + + strtab = ((const char *) map->l_addr + + map->l_info[DT_STRTAB]->d_un.d_ptr); + _dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>", + ": Symbol `", strtab + refsym->st_name, + "' has different size in shared object, " + "consider re-linking\n", NULL); + } + memcpy (reloc_addr, (void *) value, MIN (sym->st_size, + refsym->st_size)); + break; + case R_ARM_GLOB_DAT: + case R_ARM_JMP_SLOT: + +#if 0 +#define _HEX(i) for (j=28; j>=0; j-=4) b[7-j/4]="0123456789abcdef"[((int)i>>j)&15]; +{ +char b[10]; +int j; +_HEX(map->l_addr); +__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; " + : : "r"(b) : "r0", "r1", "r2" ); +_HEX(sym->st_size); +__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; " + : : "r"(b) : "r0", "r1", "r2" ); +_HEX(&sym->st_value); +__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; " + : : "r"(b) : "r0", "r1", "r2" ); +_HEX(sym->st_value); +__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; " + : : "r"(b) : "r0", "r1", "r2" ); +_HEX(sym); +__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; " + : : "r"(b) : "r0", "r1", "r2" ); +_HEX(reloc_addr); +__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; " + : : "r"(b) : "r0", "r1", "r2" ); +b[0]=' '; b[1]='\n'; +__asm__ (" mov r0, #2; mov r1, %0; mov r2, #2; swi 0x00900004; " + : : "r"(b) : "r0", "r1", "r2" ); +} +#endif + *reloc_addr = value; + break; + case R_ARM_32: + { +#ifndef RTLD_BOOTSTRAP + /* This is defined in rtld.c, but nowhere in the static + libc.a; make the reference weak so static programs can + still link. This declaration cannot be done when + compiling rtld.c (i.e. #ifdef RTLD_BOOTSTRAP) because + rtld.c contains the common defn for _dl_rtld_map, which + is incompatible with a weak decl in the same file. */ + weak_extern (_dl_rtld_map); + if (map == &_dl_rtld_map) + /* Undo the relocation done here during bootstrapping. + Now we will relocate it anew, possibly using a + binding found in the user program or a loaded library + rather than the dynamic linker's built-in definitions + used while loading those libraries. */ + value -= map->l_addr + refsym->st_value; +#endif + *reloc_addr += value; + break; + } + case R_ARM_PC26: + *reloc_addr += (value - (Elf32_Addr) reloc_addr); + break; + default: + assert (! "unexpected dynamic reloc type"); + break; + } + } +} + +static inline void +elf_machine_lazy_rel (struct link_map *map, const Elf32_Rel *reloc) +{ + Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset); + switch (ELF32_R_TYPE (reloc->r_info)) + { + case R_ARM_JMP_SLOT: + *reloc_addr += map->l_addr; + break; + default: + assert (! "unexpected PLT reloc type"); + break; + } +} + +#endif /* RESOLVE */ |