479 lines
15 KiB
C
479 lines
15 KiB
C
/* Machine-dependent ELF dynamic relocation inline functions. AM33 version.
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Copyright (C) 1995-2014 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. If not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef dl_machine_h
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#define dl_machine_h
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#define ELF_MACHINE_NAME "mn10300"
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#include <sys/param.h>
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/* Return nonzero iff ELF header is compatible with the running host. */
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static inline int __attribute__ ((unused))
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elf_machine_matches_host (const Elf32_Ehdr *ehdr)
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{
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return ehdr->e_machine == EM_MN10300;
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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 ("a2");
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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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static inline Elf32_Addr __attribute__ ((unused))
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elf_machine_load_address (void)
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{
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register Elf32_Addr gotaddr asm ("a2");
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Elf32_Addr off, gotval;
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asm ("mov _dl_start@GOTOFF,%0" : "=r" (off));
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asm ("mov (_dl_start@GOT,%1),%0" : "=r" (gotval) : "r" (gotaddr));
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return off + gotaddr - gotval;
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}
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#ifndef PROF
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/* We add a declaration of this function here so that in dl-runtime.c
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the ELF_MACHINE_RUNTIME_TRAMPOLINE macro really can pass the parameters
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in registers.
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We cannot use this scheme for profiling because the _mcount call
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destroys the passed register information. */
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static ElfW(Addr) fixup (struct link_map *l, ElfW(Word) reloc_offset)
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__attribute__ ((unused));
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static ElfW(Addr) profile_fixup (struct link_map *l, ElfW(Word) reloc_offset,
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ElfW(Addr) retaddr)
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__attribute__ ((unused));
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#endif
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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) attribute_hidden;
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extern void _dl_runtime_profile (Elf32_Word) attribute_hidden;
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if (l->l_info[DT_JMPREL] && lazy)
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{
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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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offset into the .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1],
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and then jump to _GLOBAL_OFFSET_TABLE[2]. */
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got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
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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 (__builtin_expect (profile, 0))
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{
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got[2] = (Elf32_Addr) &_dl_runtime_profile;
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if (_dl_name_match_p (GLRO(dl_profile), l))
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/* This is the object we are looking for. Say that we really
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want profiling and the timers are started. */
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GL(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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#ifndef PROF
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# define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\
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.text\n\
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.globl _dl_runtime_resolve\n\
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.type _dl_runtime_resolve, @function\n\
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_dl_runtime_resolve:\n\
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add -12,sp # Preserve registers otherwise clobbered.\n\
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mov d1,(20,sp)\n\
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mov d0,(16,sp)\n\
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mov r1,d0\n\
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mov r0,d1\n\
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call fixup,[],0 # Call resolver.\n\
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mov d0,a0\n\
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mov (12,sp),d1 # Copy return address back to mdr,\n\
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mov d1,mdr # in case the callee returns with retf\n\
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mov (16,sp),d0 # Get register content back.\n\
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mov (20,sp),d1\n\
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add 12,sp\n\
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jmp (a0)\n\
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.size _dl_runtime_resolve, .-_dl_runtime_resolve\n\
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\n\
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.globl _dl_runtime_profile\n\
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.type _dl_runtime_profile, @function\n\
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_dl_runtime_profile:\n\
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add -12,sp # Preserve registers otherwise clobbered.\n\
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mov d1,(20,sp)\n\
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mov d0,(16,sp)\n\
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mov r1,d0\n\
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mov r0,d1\n\
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call profile_fixup,[],0 # Call resolver.\n\
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mov d0,a0\n\
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mov (12,sp),d1 # Copy return address back to mdr,\n\
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mov d1,mdr # in case the callee returns with retf\n\
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mov (16,sp),d0 # Get register content back.\n\
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mov (20,sp),d1\n\
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add 12,sp\n\
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jmp (a0)\n\
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.size _dl_runtime_profile, .-_dl_runtime_profile\n\
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.previous\n\
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");
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#else
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# define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\n\
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.text\n\
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.globl _dl_runtime_resolve\n\
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.globl _dl_runtime_profile\n\
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.type _dl_runtime_resolve, @function\n\
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.type _dl_runtime_profile, @function\n\
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_dl_runtime_resolve:\n\
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_dl_runtime_profile:\n\
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add -12,sp # Preserve registers otherwise clobbered.\n\
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mov d1,(20,sp)\n\
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mov d0,(16,sp)\n\
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mov r1,d0\n\
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mov r0,d1\n\
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call profile_fixup,[],0 # Call resolver.\n\
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mov d0,a0\n\
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mov (12,sp),d1 # Copy return address back to mdr,\n\
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mov d1,mdr # in case the callee returns with retf\n\
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mov (16,sp),d0 # Get register content back.\n\
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mov (20,sp),d1\n\
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add 12,sp\n\
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jmp (a0)\n\
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.size _dl_runtime_resolve, .-_dl_runtime_resolve\n\
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.size _dl_runtime_profile, .-_dl_runtime_profile\n\
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.previous\n\
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");
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#endif
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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 ("\n\
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.text\n\
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.globl _start\n\
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.globl _dl_start_user\n\
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_start:\n\
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mov 0,a3 # Mark the top of the stack\n\
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mov sp,a1\n\
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add -20,sp # Prepare for function call\n\
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mov a1,d0\n\
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call _dl_start,[],0\n\
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_dl_start_user:\n\
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# Save the user entry point address in d2.\n\
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mov d0,d2\n\
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# Point a2 at the GOT.\n\
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0: mov pc,a2\n\
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add _GLOBAL_OFFSET_TABLE_ - (0b-.),a2\n\
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# Store the highest stack address\n\
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mov (__libc_stack_end@GOT,a2),a0\n\
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mov a1,(a0)\n\
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# See if we were run as a command with the executable file\n\
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# name as an extra leading argument.\n\
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mov (_dl_skip_args@GOT,a2),a0\n\
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mov (a0),d0\n\
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# Pop the original argument count.\n\
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mov (20,sp),d3\n\
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# Subtract _dl_skip_args from it.\n\
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sub d0,d3\n\
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# Adjust the stack pointer to skip _dl_skip_args words.\n\
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asl2 d0\n\
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mov sp,a0\n\
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add d0,a0\n\
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mov a0,sp\n\
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# Push argc back on the stack.\n\
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mov d3,(20,sp)\n\
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# The special initializer gets called with the stack just\n\
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# as the application's entry point will see it; it can\n\
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# switch stacks if it moves these contents over.\n\
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" RTLD_START_SPECIAL_INIT "\n\
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# Load the parameters again.\n\
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# (d0, d1, (12,sp), (16,sp)) = (_dl_loaded, argc, argv, envp)\n\
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add 24,a0\n\
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mov a0,(12,sp) # a0 is 24+sp\n\
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mov d3,d1 # d3 contained argc\n\
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inc d3\n\
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asl2 d3 # d3 is now (argc+1)*4,\n\
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add d3,a0 # the offset between argv and envp\n\
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mov a0,(16,sp)\n\
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mov (_rtld_local@GOTOFF,a2),d0\n\
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# Call the function to run the initializers.\n\
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call _dl_init@PLT,[],0\n\
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# Pass our finalizer function to the user in d0, as per ELF ABI.\n\
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mov (_dl_fini@GOT,a2),d0\n\
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add 20,sp\n\
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# Jump to the user's entry point.\n\
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mov d2,a1\n\
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jmp (a1)\n\
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.previous\n\
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");
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#ifndef RTLD_START_SPECIAL_INIT
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#define RTLD_START_SPECIAL_INIT /* nothing */
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#endif
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/* ELF_RTYPE_CLASS_PLT 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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ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
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of the main executable's symbols, as for a COPY reloc. */
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#define elf_machine_type_class(type) \
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((((type) == R_MN10300_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
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| (((type) == R_MN10300_COPY) * ELF_RTYPE_CLASS_COPY))
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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_MN10300_JMP_SLOT
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static inline Elf32_Addr
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elf_machine_fixup_plt (struct link_map *map, lookup_t t,
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const Elf32_Rela *reloc,
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Elf32_Addr *reloc_addr, Elf32_Addr value)
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{
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return *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_Rela *reloc,
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Elf32_Addr value)
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{
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return value + reloc->r_addend;
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}
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#endif /* !dl_machine_h */
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#ifdef RESOLVE
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/* The mn10300 never uses Elf32_Rel relocations. */
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#define ELF_MACHINE_NO_REL 1
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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_rela (struct link_map *map, const Elf32_Rela *reloc,
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const Elf32_Sym *sym, const struct r_found_version *version,
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void *const reloc_addr_arg, int skip_ifunc)
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{
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const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
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Elf32_Addr value, *reloc_addr;
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/* Make sure we drop any previous alignment assumptions. */
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asm ("" : "=r" (reloc_addr) : "0" (reloc_addr_arg));
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#define COPY_UNALIGNED_WORD(sw, tw, align) \
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{ \
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unsigned long *__sl = (void*)&(sw), *__tl = (void*)&(tw); \
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unsigned short *__ss = (void*)&(sw), *__ts = (void*)&(tw); \
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unsigned char *__sc = (void*)&(sw), *__tc = (void*)&(tw); \
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switch ((align)) \
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{ \
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case 0: \
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*__tl = *__sl; \
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break; \
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case 2: \
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*__ts++ = *__ss++; \
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*__ts = *__ss; \
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break; \
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default: \
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*__tc++ = *__sc++; \
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*__tc++ = *__sc++; \
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*__tc++ = *__sc++; \
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*__tc = *__sc; \
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break; \
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} \
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}
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#define COPY_UNALIGNED_HALFWORD(sw, tw, align) \
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{ \
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unsigned short *__ss = (void*)&(sw), *__ts = (void*)&(tw); \
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unsigned char *__sc = (void*)&(sw), *__tc = (void*)&(tw); \
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switch ((align)) \
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{ \
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case 0: \
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*__ts = *__ss; \
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break; \
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default: \
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*__tc++ = *__sc++; \
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*__tc = *__sc; \
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break; \
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} \
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}
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#if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
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if (__builtin_expect (r_type == R_MN10300_RELATIVE, 0))
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{
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# if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
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/* This is defined in rtld.c, but nowhere in the static libc.a;
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make the reference weak so static programs can still link.
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This declaration cannot be done when compiling rtld.c (i.e.
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#ifdef RTLD_BOOTSTRAP) because rtld.c contains the common
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defn for _dl_rtld_map, which is incompatible with a weak decl
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in the same file. */
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weak_extern (_dl_rtld_map);
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if (map != &_dl_rtld_map) /* Already done in rtld itself. */
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# endif
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{
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COPY_UNALIGNED_WORD (*reloc_addr, value, (int) reloc_addr & 3);
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value += map->l_addr;
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COPY_UNALIGNED_WORD (value, *reloc_addr, (int) reloc_addr & 3);
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}
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}
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# ifndef RTLD_BOOTSTRAP
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else if (__builtin_expect (r_type == R_MN10300_NONE, 0))
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return;
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# endif
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else
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#endif
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{
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#ifndef RTLD_BOOTSTRAP
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const Elf32_Sym *const refsym = sym;
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#endif
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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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value += reloc->r_addend; /* Assume copy relocs have zero addend. */
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switch (r_type)
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{
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#ifndef RTLD_BOOTSTRAP
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case R_MN10300_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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|| (GLRO(dl_verbose) && sym->st_size < refsym->st_size))
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{
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extern char **_dl_argv;
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const char *strtab;
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strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
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_dl_error_printf ("\
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%s: Symbol `%s' has different size in shared object, consider re-linking\n",
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_dl_argv[0] ?: "<program name unknown>",
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strtab + refsym->st_name);
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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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#endif
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case R_MN10300_GLOB_DAT:
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case R_MN10300_JMP_SLOT:
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/* These addresses are always aligned. */
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*reloc_addr = value;
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break;
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case R_MN10300_32:
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COPY_UNALIGNED_WORD (value, *reloc_addr, (int) reloc_addr & 3);
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break;
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#ifndef RTLD_BOOTSTRAP
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case R_MN10300_16:
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COPY_UNALIGNED_HALFWORD (value, *reloc_addr, (int) reloc_addr & 1);
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break;
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case R_MN10300_8:
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*(char *) reloc_addr = value;
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break;
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case R_MN10300_PCREL32:
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value -= (Elf32_Addr) reloc_addr;
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COPY_UNALIGNED_WORD (value, *reloc_addr, (int) reloc_addr & 3);
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break;
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case R_MN10300_PCREL16:
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value -= (Elf32_Addr) reloc_addr;
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COPY_UNALIGNED_HALFWORD (value, *reloc_addr, (int) reloc_addr & 1);
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break;
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case R_MN10300_PCREL8:
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value -= (Elf32_Addr) reloc_addr;
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*(char *) reloc_addr = (value - (Elf32_Addr) reloc_addr);
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break;
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#endif
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case R_MN10300_NONE: /* Alright, Wilbur. */
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break;
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#if !defined RTLD_BOOTSTRAP || defined _NDEBUG
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default:
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_dl_reloc_bad_type (map, ELFW(R_TYPE) (reloc->r_info), 0);
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break;
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#endif
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}
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}
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}
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static inline void
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elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
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void *const reloc_addr_arg)
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{
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Elf32_Addr value, *reloc_addr;
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asm ("" : "=r" (reloc_addr) : "0" (reloc_addr_arg));
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COPY_UNALIGNED_WORD (*reloc_addr, value, (int)reloc_addr & 3);
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value += l_addr;
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COPY_UNALIGNED_WORD (value, *reloc_addr, (int)reloc_addr & 3);
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}
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static inline void
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elf_machine_lazy_rel (struct link_map *map,
|
|
Elf32_Addr l_addr, const Elf32_Rela *reloc,
|
|
int skip_ifunc)
|
|
{
|
|
unsigned long int const r_type = ELF32_R_TYPE (reloc->r_info);
|
|
|
|
/* Check for unexpected PLT reloc type. */
|
|
if (__builtin_expect (r_type, R_MN10300_JMP_SLOT) == R_MN10300_JMP_SLOT)
|
|
{
|
|
Elf32_Addr* const reloc_addr = (void *)(l_addr + reloc->r_offset);
|
|
Elf32_Addr value;
|
|
|
|
/* Perform a RELATIVE reloc on the .got entry that transfers
|
|
to the .plt. */
|
|
COPY_UNALIGNED_WORD (*reloc_addr, value, (int)reloc_addr & 3);
|
|
value += l_addr;
|
|
COPY_UNALIGNED_WORD (value, *reloc_addr, (int)reloc_addr & 3);
|
|
}
|
|
else if (__builtin_expect (r_type, R_MN10300_NONE) != R_MN10300_NONE)
|
|
_dl_reloc_bad_type (map, ELFW(R_TYPE) (reloc->r_info), 1);
|
|
|
|
}
|
|
|
|
#endif /* RESOLVE */
|