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Arm/ELF definitions.
This commit is contained in:
Ulrich Drepper
parent
0bee7da30d
commit
046378657f
478
sysdeps/arm/dl-machine.h
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478
sysdeps/arm/dl-machine.h
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@ -0,0 +1,478 @@
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/* Machine-dependent ELF dynamic relocation inline functions. ARM version.
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Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#ifndef dl_machine_h
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#define dl_machine_h
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#define ELF_MACHINE_NAME "ARM"
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#include <sys/param.h>
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#include <assert.h>
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/* Return nonzero iff E_MACHINE is compatible with the running host. */
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static inline int __attribute__ ((unused))
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elf_machine_matches_host (Elf32_Half e_machine)
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{
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switch (e_machine)
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{
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case EM_ARM:
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return 1;
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default:
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return 0;
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}
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}
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/* Return the link-time address of _DYNAMIC. Conveniently, this is the
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first element of the GOT. This must be inlined in a function which
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uses global data. */
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static inline Elf32_Addr __attribute__ ((unused))
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elf_machine_dynamic (void)
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{
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register Elf32_Addr *got asm ("r10");
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return *got;
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}
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/* Return the run-time load address of the shared object. */
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// patb
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static inline Elf32_Addr __attribute__ ((unused))
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elf_machine_load_address (void)
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{
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Elf32_Addr addr;
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asm (" ldr ip,.L1
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ldr r3,.L3
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add r3, r3, sl
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ldr ip,[sl, ip]
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sub ip, r3, ip
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b .L2
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.L1: .word _dl_start(GOT)
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.L3: .word _dl_start(GOTOFF)
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.L2: mov %0, ip"
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: "=r" (addr) : : "ip", "r3");
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return addr;
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}
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/* Set up the loaded object described by L so its unrelocated PLT
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entries will jump to the on-demand fixup code in dl-runtime.c. */
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static inline int __attribute__ ((unused))
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elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
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{
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Elf32_Addr *got;
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extern void _dl_runtime_resolve (Elf32_Word);
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extern void _dl_runtime_profile (Elf32_Word);
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if (l->l_info[DT_JMPREL] && lazy)
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{
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/* patb: this is different than i386 */
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/* The GOT entries for functions in the PLT have not yet been filled
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in. Their initial contents will arrange when called to push an
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index into the .got section, load ip with &_GLOBAL_OFFSET_TABLE_[3],
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and then jump to _GLOBAL_OFFSET_TABLE[2]. */
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got = (Elf32_Addr *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr);
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got[1] = (Elf32_Addr) l; /* Identify this shared object. */
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/* The got[2] entry contains the address of a function which gets
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called to get the address of a so far unresolved function and
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jump to it. The profiling extension of the dynamic linker allows
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to intercept the calls to collect information. In this case we
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don't store the address in the GOT so that all future calls also
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end in this function. */
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if (profile)
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{
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got[2] = (Elf32_Addr) &_dl_runtime_profile;
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/* Say that we really want profiling and the timers are started. */
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_dl_profile_map = l;
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}
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else
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/* This function will get called to fix up the GOT entry indicated by
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the offset on the stack, and then jump to the resolved address. */
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got[2] = (Elf32_Addr) &_dl_runtime_resolve;
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}
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return lazy;
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}
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/* This code is used in dl-runtime.c to call the `fixup' function
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and then redirect to the address it returns. */
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// macro for handling PIC situation....
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#ifdef PIC
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#define CALL_ROUTINE(x) " ldr sl,0f
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add sl, pc, sl
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1: ldr r2, 2f
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mov lr, pc
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add pc, sl, r2
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b 3f
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0: .word _GLOBAL_OFFSET_TABLE_ - 1b - 4
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2: .word " #x "(GOTOFF)
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3: "
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#else
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#define CALL_ROUTINE(x) " bl " #x
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#endif
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#ifndef PROF
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# define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\
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.text
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.globl _dl_runtime_resolve
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.type _dl_runtime_resolve, #function
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.align 2
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_dl_runtime_resolve:
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@ we get called with
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@ stack[0] contains the return address from this call
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@ ip contains &GOT[n+3] (pointer to function)
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@ lr points to &GOT[2]
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@ save almost everything; lr is already on the stack
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stmdb sp!,{r0-r3,sl,fp}
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@ prepare to call fixup()
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@ change &GOT[n+3] into 8*n NOTE: reloc are 8 bytes each
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sub r1, ip, lr
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sub r1, r1, #4
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add r1, r1, r1
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@ get pointer to linker struct
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ldr r0, [lr, #-4]
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" CALL_ROUTINE(fixup) "
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@ save the return
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mov ip, r0
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@ restore the stack
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ldmia sp!,{r0-r3,sl,fp,lr}
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@ jump to the newly found address
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mov pc, ip
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.size _dl_runtime_resolve, .-_dl_runtime_resolve
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.globl _dl_runtime_profile
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.type _dl_runtime_profile, #function
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.align 2
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_dl_runtime_profile:
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@ we get caled with
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@ stack[0] contains the return address from this call
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@ ip contains &GOT[n+3] (pointer to function)
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@ lr points to &GOT[2]
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@ save almost everything; return add is already on the stack
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stmdb sp!,{r0-r3,fp}
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@ prepare to call fixup()
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@ change &GOT[n+3] into 8*n NOTE: reloc are 8 bytes each
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sub r1, ip, lr
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sub r1, r1, #4
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add r1, r1, r1
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@ get pointer to linker struct
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ldr r0, [lr, #-4]
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" CALL_ROUTINE(profile_fixup) "
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@ save the return
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mov ip, r0
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@ restore the stack
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ldmia sp!,{r0-r3,fp,lr}
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@ jump to the newly found address
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mov pc, ip
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.size _dl_runtime_profile, .-_dl_runtime_profile
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.previous
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");
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#else // PROF
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# define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\
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.text
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.globl _dl_runtime_resolve
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.globl _dl_runtime_profile
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.type _dl_runtime_resolve, #function
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.type _dl_runtime_profile, #function
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.align 2
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_dl_runtime_resolve:
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_dl_runtime_profile:
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stmdb sp!,{r0-r3,fp}
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ldr r1,[sp,#0x34]
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sub r1, ip, lr
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sub r1, r1, #4
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add r1, r1, r1
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ldr r0, [lr, #-4]
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" CALL_ROUTINE(fixup) "
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mov ip, r0
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ldmia sp!,{r0-r3,fp,lr}
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mov pc, ip
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.size _dl_runtime_profile, .-_dl_runtime_profile
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.previous
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");
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#endif //PROF
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/* Mask identifying addresses reserved for the user program,
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where the dynamic linker should not map anything. */
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#define ELF_MACHINE_USER_ADDRESS_MASK 0xf8000000UL
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/* Initial entry point code for the dynamic linker.
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The C function `_dl_start' is the real entry point;
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its return value is the user program's entry point. */
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#define RTLD_START asm ("\
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.text
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.globl _start
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.globl _dl_start_user
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_start:
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@ at start time, all the args are on the stack
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mov r0, sp
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bl _dl_start
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@ returns user entry point in r0
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_dl_start_user:
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mov r6, r0
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@ we are PIC code, so get global offset table
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ldr sl, .L_GET_GOT
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add sl, pc, sl
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.L_GOT_GOT:
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@ See if we were run as a command with the executable file
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@ name as an extra leading argument.
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ldr r1, .L_SKIP_ARGS
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ldr r1, [sl, r1]
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@ get the original arg count
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ldr r0, [sp]
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@ subtract _dl_skip_args from it
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sub r0, r0, r1
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@ adjust the stack pointer to skip them
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add sp, sp, r1, lsl #2
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@ store the new argc in the new stack location
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str r0, [sp]
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@ now we enter a _dl_init_next loop
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ldr r2, .L_DEF_SCOPE
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ldr r2, [sl, r2]
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ldr r4, [r2, #8]
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@ call _dl_init_next to get the address of an initalizer
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0: mov r0, r4
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bl _dl_init_next(PLT)
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cmp r0, #0
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beq 1f
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@ call the shared-object initializer
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@ during this call, the stack may get moved around
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mov lr, pc
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mov pc, r0
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@ go back and look for another initializer
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b 0b
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1: @ clear the startup flag
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ldr r2, .L_STARTUP_FLAG
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ldr r1, [sl, r2]
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@ we know r0==0 at this point
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str r0, [r1]
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@ load the finalizer function
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ldr r0, .L_FINI_PROC
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ldr r0, [sl, r0]
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@ jump to the user_s entry point
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mov pc, r6
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.L_GET_GOT:
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.word _GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4 \n\
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.L_SKIP_ARGS: \n\
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.word _dl_skip_args(GOTOFF) \n\
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.L_DEF_SCOPE: \n\
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.word _dl_default_scope(GOT) \n\
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.L_STARTUP_FLAG:
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.word _dl_starting_up(GOT)
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.L_FINI_PROC:
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.word _dl_fini(GOT)
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.previous\n\
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");
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/* Nonzero iff TYPE should not be allowed to resolve to one of
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the main executable's symbols, as for a COPY reloc. */
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#define elf_machine_lookup_noexec_p(type) ((type) == R_ARM_COPY)
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/* Nonzero iff TYPE describes relocation of a PLT entry, so
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PLT entries should not be allowed to define the value. */
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#define elf_machine_lookup_noplt_p(type) ((type) == R_ARM_JMP_SLOT)
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/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
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#define ELF_MACHINE_JMP_SLOT R_ARM_JMP_SLOT
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/* The i386 never uses Elf32_Rela relocations. */
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#define ELF_MACHINE_NO_RELA 1
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/* We define an initialization functions. This is called very early in
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_dl_sysdep_start. */
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#define DL_PLATFORM_INIT dl_platform_init ()
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extern const char *_dl_platform;
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static inline void __attribute__ ((unused))
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dl_platform_init (void)
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{
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if (_dl_platform == NULL)
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/* We default to ARM
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This is where processors could be distinguished arm2, arm6, sa110, etc */
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_dl_platform = "ARM";
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}
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static inline void
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elf_machine_fixup_plt (struct link_map *map, const Elf32_Rel *reloc,
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Elf32_Addr *reloc_addr, Elf32_Addr value)
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{
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*reloc_addr = value;
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}
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/* Return the final value of a plt relocation. */
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static inline Elf32_Addr
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elf_machine_plt_value (struct link_map *map, const Elf32_Rel *reloc,
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Elf32_Addr value)
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{
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return value;
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}
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#endif /* !dl_machine_h */
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#ifdef RESOLVE
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extern char **_dl_argv;
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/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
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MAP is the object containing the reloc. */
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static inline void
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elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
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const Elf32_Sym *sym, const struct r_found_version *version,
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Elf32_Addr *const reloc_addr)
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{
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if (ELF32_R_TYPE (reloc->r_info) == R_ARM_RELATIVE)
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{
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#ifndef RTLD_BOOTSTRAP
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if (map != &_dl_rtld_map) /* Already done in rtld itself. */
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#endif
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*reloc_addr += map->l_addr;
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}
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else if (ELF32_R_TYPE (reloc->r_info) != R_ARM_NONE)
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{
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const Elf32_Sym *const refsym = sym;
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Elf32_Addr value = RESOLVE (&sym, version, ELF32_R_TYPE (reloc->r_info));
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if (sym)
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value += sym->st_value;
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switch (ELF32_R_TYPE (reloc->r_info))
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{
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case R_ARM_COPY:
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if (sym == NULL)
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/* This can happen in trace mode if an object could not be
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found. */
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break;
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if (sym->st_size > refsym->st_size
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|| (_dl_verbose && sym->st_size < refsym->st_size))
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{
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const char *strtab;
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strtab = ((const char *) map->l_addr
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+ map->l_info[DT_STRTAB]->d_un.d_ptr);
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_dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>",
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": Symbol `", strtab + refsym->st_name,
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"' has different size in shared object, "
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"consider re-linking\n", NULL);
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}
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memcpy (reloc_addr, (void *) value, MIN (sym->st_size,
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refsym->st_size));
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break;
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case R_ARM_GLOB_DAT:
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case R_ARM_JMP_SLOT:
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#if 0
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#define _HEX(i) for (j=28; j>=0; j-=4) b[7-j/4]="0123456789abcdef"[((int)i>>j)&15];
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{
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char b[10];
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int j;
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_HEX(map->l_addr);
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__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
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: : "r"(b) : "r0", "r1", "r2" );
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_HEX(sym->st_size);
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__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
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: : "r"(b) : "r0", "r1", "r2" );
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_HEX(&sym->st_value);
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__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
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: : "r"(b) : "r0", "r1", "r2" );
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_HEX(sym->st_value);
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__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
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: : "r"(b) : "r0", "r1", "r2" );
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_HEX(sym);
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__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
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: : "r"(b) : "r0", "r1", "r2" );
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_HEX(reloc_addr);
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__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
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: : "r"(b) : "r0", "r1", "r2" );
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b[0]=' '; b[1]='\n';
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__asm__ (" mov r0, #2; mov r1, %0; mov r2, #2; swi 0x00900004; "
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: : "r"(b) : "r0", "r1", "r2" );
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}
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#endif
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*reloc_addr = value;
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break;
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case R_ARM_32:
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{
|
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#ifndef RTLD_BOOTSTRAP
|
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/* This is defined in rtld.c, but nowhere in the static
|
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libc.a; make the reference weak so static programs can
|
||||
still link. This declaration cannot be done when
|
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compiling rtld.c (i.e. #ifdef RTLD_BOOTSTRAP) because
|
||||
rtld.c contains the common defn for _dl_rtld_map, which
|
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is incompatible with a weak decl in the same file. */
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weak_extern (_dl_rtld_map);
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if (map == &_dl_rtld_map)
|
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/* Undo the relocation done here during bootstrapping.
|
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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. */
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value -= map->l_addr + refsym->st_value;
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#endif
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*reloc_addr += value;
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||||
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 */
|
||||
Loading…
Reference in New Issue
Block a user