riscv: support GNU indirect function

Enable riscv glibc to support GNU indirect function
This commit is contained in:
Vincent Chen 2020-12-15 17:16:39 +08:00 committed by DJ Delorie
parent 2cd361b511
commit c31b1f5231
3 changed files with 79 additions and 0 deletions

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@ -48,3 +48,4 @@ IFUNC sparc64-*-linux*
IFUNC sparc-*-linux* IFUNC sparc-*-linux*
# Absolute (SHN_ABS) symbols working correctly. # Absolute (SHN_ABS) symbols working correctly.
ABSOLUTE ABSOLUTE
IFUNC riscv*-linux*

56
sysdeps/riscv/dl-irel.h Normal file
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@ -0,0 +1,56 @@
/* Machine-dependent ELF indirect relocation inline functions.
RISC-V version.
Copyright (C) 2020 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _DL_IREL_H
#define _DL_IREL_H
#include <stdio.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <sysdep.h>
#define ELF_MACHINE_IRELA 1
static inline ElfW(Addr)
__attribute ((always_inline))
elf_ifunc_invoke (ElfW(Addr) addr)
{
/* The second argument is a void pointer to preserve the extension
fexibility. */
return ((ElfW(Addr) (*) (uint64_t, void *)) (addr))
(GLRO(dl_hwcap), NULL);
}
static inline void
__attribute ((always_inline))
elf_irela (const ElfW(Rela) *reloc)
{
ElfW(Addr) *const reloc_addr = (void *) reloc->r_offset;
const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info);
if (__glibc_likely (r_type == R_RISCV_IRELATIVE))
{
ElfW(Addr) value = elf_ifunc_invoke (reloc->r_addend);
*reloc_addr = value;
}
else
__libc_fatal ("Unexpected reloc type in static binary.\n");
}
#endif

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@ -25,6 +25,7 @@
#include <elf/elf.h> #include <elf/elf.h>
#include <sys/asm.h> #include <sys/asm.h>
#include <dl-tls.h> #include <dl-tls.h>
#include <dl-irel.h>
#ifndef _RTLD_PROLOGUE #ifndef _RTLD_PROLOGUE
# define _RTLD_PROLOGUE(entry) \ # define _RTLD_PROLOGUE(entry) \
@ -176,6 +177,13 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
if (sym_map != NULL) if (sym_map != NULL)
value = SYMBOL_ADDRESS (sym_map, sym, true) + reloc->r_addend; value = SYMBOL_ADDRESS (sym_map, sym, true) + reloc->r_addend;
if (sym != NULL
&& __glibc_unlikely (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC)
&& __glibc_likely (sym->st_shndx != SHN_UNDEF)
&& __glibc_likely (!skip_ifunc))
value = elf_ifunc_invoke (value);
switch (r_type) switch (r_type)
{ {
#ifndef RTLD_BOOTSTRAP #ifndef RTLD_BOOTSTRAP
@ -251,6 +259,13 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
} }
#endif #endif
case R_RISCV_IRELATIVE:
value = map->l_addr + reloc->r_addend;
if (__glibc_likely (!skip_ifunc))
value = elf_ifunc_invoke (value);
*addr_field = value;
break;
case R_RISCV_JUMP_SLOT: case R_RISCV_JUMP_SLOT:
case __WORDSIZE == 64 ? R_RISCV_64 : R_RISCV_32: case __WORDSIZE == 64 ? R_RISCV_64 : R_RISCV_32:
*addr_field = value; *addr_field = value;
@ -292,6 +307,13 @@ elf_machine_lazy_rel (struct link_map *map, ElfW(Addr) l_addr,
else else
*reloc_addr = map->l_mach.plt; *reloc_addr = map->l_mach.plt;
} }
else if (__glibc_unlikely (r_type == R_RISCV_IRELATIVE))
{
ElfW(Addr) value = map->l_addr + reloc->r_addend;
if (__glibc_likely (!skip_ifunc))
value = elf_ifunc_invoke (value);
*reloc_addr = value;
}
else else
_dl_reloc_bad_type (map, r_type, 1); _dl_reloc_bad_type (map, r_type, 1);
} }