[v7,02/13] ARC: startup and dynamic linking code
Commit Message
Code for C runtime startup and dynamic loading including PLT layout.
---
sysdeps/arc/bits/link.h | 52 ++++++
sysdeps/arc/dl-machine.h | 341 ++++++++++++++++++++++++++++++++++++++
sysdeps/arc/entry.h | 5 +
sysdeps/arc/ldsodefs.h | 43 +++++
sysdeps/arc/sotruss-lib.c | 50 ++++++
sysdeps/arc/start.S | 74 +++++++++
sysdeps/arc/tst-audit.h | 23 +++
7 files changed, 588 insertions(+)
create mode 100644 sysdeps/arc/bits/link.h
create mode 100644 sysdeps/arc/dl-machine.h
create mode 100644 sysdeps/arc/entry.h
create mode 100644 sysdeps/arc/ldsodefs.h
create mode 100644 sysdeps/arc/sotruss-lib.c
create mode 100644 sysdeps/arc/start.S
create mode 100644 sysdeps/arc/tst-audit.h
Comments
On 15/06/2020 17:14, Vineet Gupta via Libc-alpha wrote:
> Code for C runtime startup and dynamic loading including PLT layout.
LGTM, just a couple of indentations nits below.
Revewied-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> sysdeps/arc/bits/link.h | 52 ++++++
> sysdeps/arc/dl-machine.h | 341 ++++++++++++++++++++++++++++++++++++++
> sysdeps/arc/entry.h | 5 +
> sysdeps/arc/ldsodefs.h | 43 +++++
> sysdeps/arc/sotruss-lib.c | 50 ++++++
> sysdeps/arc/start.S | 74 +++++++++
> sysdeps/arc/tst-audit.h | 23 +++
> 7 files changed, 588 insertions(+)
> create mode 100644 sysdeps/arc/bits/link.h
> create mode 100644 sysdeps/arc/dl-machine.h
> create mode 100644 sysdeps/arc/entry.h
> create mode 100644 sysdeps/arc/ldsodefs.h
> create mode 100644 sysdeps/arc/sotruss-lib.c
> create mode 100644 sysdeps/arc/start.S
> create mode 100644 sysdeps/arc/tst-audit.h
>
> diff --git a/sysdeps/arc/bits/link.h b/sysdeps/arc/bits/link.h
> new file mode 100644
> index 000000000000..b687250a7a07
> --- /dev/null
> +++ b/sysdeps/arc/bits/link.h
> @@ -0,0 +1,52 @@
> +/* Machine-specific declarations for dynamic linker interface, ARC 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 _LINK_H
> +# error "Never include <bits/link.h> directly; use <link.h> instead."
> +#endif
> +
> +/* Registers for entry into PLT on ARC. */
> +typedef struct La_arc_regs
> +{
> + uint32_t lr_reg[8]; /* r0 through r7 (upto 8 args). */
> +} La_arc_regs;
> +
> +/* Return values for calls from PLT on ARC. */
> +typedef struct La_arc_retval
> +{
> + /* For ARCv2, a 64-bit integer return value can use 2 regs. */
> + uint32_t lrv_reg[2];
> +} La_arc_retval;
> +
> +__BEGIN_DECLS
> +
> +extern ElfW(Addr) la_arc_gnu_pltenter (ElfW(Sym) *__sym, unsigned int __ndx,
> + uintptr_t *__refcook,
> + uintptr_t *__defcook,
> + La_arc_regs *__regs,
> + unsigned int *__flags,
> + const char *__symname,
> + long int *__framesizep);
> +extern unsigned int la_arc_gnu_pltexit (ElfW(Sym) *__sym, unsigned int __ndx,
> + uintptr_t *__refcook,
> + uintptr_t *__defcook,
> + const La_arc_regs *__inregs,
> + La_arc_retval *__outregs,
> + const char *symname);
> +
> +__END_DECLS
Ok.
> diff --git a/sysdeps/arc/dl-machine.h b/sysdeps/arc/dl-machine.h
> new file mode 100644
> index 000000000000..82940d8a701e
> --- /dev/null
> +++ b/sysdeps/arc/dl-machine.h
> @@ -0,0 +1,341 @@
> +/* Machine-dependent ELF dynamic relocation inline functions. ARC 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_machine_h
> +#define dl_machine_h
> +
> +#define ELF_MACHINE_NAME "arc"
> +
> +#include <entry.h>
> +
> +#ifndef ENTRY_POINT
> +# error ENTRY_POINT needs to be defined for ARC
> +#endif
> +
> +#include <string.h>
> +#include <link.h>
> +#include <dl-tls.h>
> +
> +/* Dynamic Linking ABI for ARCv2 ISA.
> +
> + PLT
> + -------------------------------- <---- DT_PLTGOT
> + | ld r11, [pcl, off-to-GOT[1] | 0
> + | | 4
> + plt0 | ld r10, [pcl, off-to-GOT[2] | 8
> + | | 12
> + | j [r10] | 16
> + --------------------------------
> + | Base address of GOT | 20
> + --------------------------------
> + | ld r12, [pcl, off-to-GOT[3] | 24
> + plt1 | |
> + | j.d [r12] | 32
> + | mov r12, pcl | 36
> + --------------------------------
> + | | 40
> + ~ ~
> + ~ ~
> + | |
> + --------------------------------
> +
> + .got
> + --------------
> + | [0] |
> + | ... | Runtime address for data symbols
> + | [n] |
> + --------------
> +
> + .got.plt
> + --------------
> + | [0] | Build address of .dynamic
> + --------------
> + | [1] | Module info - setup by ld.so
> + --------------
> + | [2] | resolver entry point
> + --------------
> + | [3] |
> + | ... | Runtime address for function symbols
> + | [f] |
> + --------------
> +
> + For ARCompact, the PLT is 12 bytes due to short instructions
> +
> + --------------------------------
> + | ld r12, [pcl, off-to-GOT[3] | 24 (12 bytes each)
> + plt1 | |
> + | j_s.d [r12] | 32
> + | mov_s r12, pcl | 34
> + --------------------------------
> + | | 36 */
> +
> +/* Return nonzero iff ELF header is compatible with the running host. */
Nice description.
> +static inline int
> +elf_machine_matches_host (const Elf32_Ehdr *ehdr)
> +{
> + return (ehdr->e_machine == EM_ARCV2 /* ARC HS. */
> + || ehdr->e_machine == EM_ARC_COMPACT); /* ARC 700. */
> +}
> +
> +/* Get build time address of .dynamic as setup in GOT[0]
> + This is called very early in _dl_start so it has not been relocated to
> + runtime value. */
> +static inline ElfW(Addr)
> +elf_machine_dynamic (void)
> +{
> + extern const ElfW(Addr) _GLOBAL_OFFSET_TABLE_[] attribute_hidden;
> + return _GLOBAL_OFFSET_TABLE_[0];
> +}
> +
> +
> +/* Return the run-time load address of the shared object. */
> +static inline ElfW(Addr)
> +elf_machine_load_address (void)
> +{
> + ElfW(Addr) build_addr, run_addr;
> +
> + /* For build address, below generates
> + ld r0, [pcl, _GLOBAL_OFFSET_TABLE_@pcl]. */
> + build_addr = elf_machine_dynamic ();
> + __asm__ ("add %0, pcl, _DYNAMIC@pcl \n" : "=r" (run_addr));
> +
> + return run_addr - build_addr;
> +}
Ok.
> +
> +/* 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__ ((always_inline))
> +elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
> +{
> + extern void _dl_runtime_resolve (Elf32_Word);
> +
> + if (l->l_info[DT_JMPREL] && lazy)
> + {
> + /* On ARC DT_PLTGOT point to .plt whose 5th word (after the PLT header)
> + contains the address of .got. */
> + ElfW(Addr) *plt_base = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
> + ElfW(Addr) *got = (ElfW(Addr) *) (plt_base[5] + l->l_addr);
> +
> + got[1] = (ElfW(Addr)) l; /* Identify this shared object. */
> +
> + /* 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] = (ElfW(Addr)) &_dl_runtime_resolve;
> + }
> +
> + return lazy;
> +}
> +
> +/* What this code does:
> + -ldso starts execution here when kernel returns from execve
> + -calls into generic ldso entry point _dl_start
> + -optionally adjusts argc for executable if exec passed as cmd
> + -calls into app main with address of finaliser. */
> +
> +#define RTLD_START asm ("\
> +.text \n\
> +.globl __start \n\
> +.type __start, @function \n\
> +__start: \n\
> + /* (1). bootstrap ld.so. */ \n\
> + bl.d _dl_start \n\
> + mov_s r0, sp /* pass ptr to aux vector tbl. */ \n\
> + mov r13, r0 /* safekeep app elf entry point. */ \n\
> + \n\
> + /* (2). If ldso ran with executable as arg. */ \n\
> + /* skip the extra args calc by dl_start. */ \n\
> + ld_s r1, [sp] /* orig argc. */ \n\
> + ld r12, [pcl, _dl_skip_args@pcl] \n\
> + breq r12, 0, 1f \n\
> + \n\
> + add2 sp, sp, r12 /* discard argv entries from stack. */ \n\
> + sub_s r1, r1, r12 /* adjusted argc on stack. */ \n\
> + st_s r1, [sp] \n\
> + add r2, sp, 4 \n\
> + /* intermediate LD for ST emcoding limitations. */ \n\
> + ld r3, [pcl, _dl_argv@gotpc] \n\
> + st r2, [r3] \n\
> +1: \n\
> + /* (3). call preinit stuff. */ \n\
> + ld r0, [pcl, _rtld_local@pcl] \n\
> + add r2, sp, 4 ; argv \n\
> + add2 r3, r2, r1 \n\
> + add r3, r3, 4 ; env \n\
> + bl _dl_init@plt \n\
> + \n\
> + /* (4) call app elf entry point. */ \n\
> + add r0, pcl, _dl_fini@pcl \n\
> + j [r13] \n\
> + \n\
> + .size __start,.-__start \n\
> + .previous \n\
> +");
> +
Ok.
> +/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
> + PLT entries should not be allowed to define the value.
> + ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
> + of the main executable's symbols, as for a COPY reloc. */
> +#define elf_machine_type_class(type) \
> + ((((type) == R_ARC_JUMP_SLOT \
> + || (type) == R_ARC_TLS_DTPMOD \
> + || (type) == R_ARC_TLS_DTPOFF \
> + || (type) == R_ARC_TLS_TPOFF) * ELF_RTYPE_CLASS_PLT) \
> + | (((type) == R_ARC_COPY) * ELF_RTYPE_CLASS_COPY))
> +
> +/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
> +#define ELF_MACHINE_JMP_SLOT R_ARC_JUMP_SLOT
> +
> +/* ARC uses Elf32_Rela relocations. */
> +#define ELF_MACHINE_NO_REL 1
> +#define ELF_MACHINE_NO_RELA 0
> +
> +/* Fixup a PLT entry to bounce directly to the function at VALUE. */
> +
> +static inline ElfW(Addr)
> +elf_machine_fixup_plt (struct link_map *map, lookup_t t,
> + const ElfW(Sym) *refsym, const ElfW(Sym) *sym,
> + const Elf32_Rela *reloc,
> + ElfW(Addr) *reloc_addr, ElfW(Addr) value)
> +{
> + return *reloc_addr = value;
> +}
> +
> +/* Return the final value of a plt relocation. */
> +static inline ElfW(Addr)
> +elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
> + ElfW(Addr) value)
> +{
> + return value;
> +}
Ok.
> +
> +/* Names of the architecture-specific auditing callback functions. */
> +#define ARCH_LA_PLTENTER arc_gnu_pltenter
> +#define ARCH_LA_PLTEXIT arc_gnu_pltexit
> +
> +#endif /* dl_machine_h */
> +
> +#ifdef RESOLVE_MAP
> +
> +inline void
> +__attribute__ ((always_inline))
> +elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
> + const ElfW(Sym) *sym, const struct r_found_version *version,
> + void *const reloc_addr_arg, int skip_ifunc)
> +{
> + ElfW(Addr) *const reloc_addr = reloc_addr_arg;
> + const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
> +
> + if (__glibc_unlikely (r_type == R_ARC_RELATIVE))
> + *reloc_addr += map->l_addr;
> + else if (__glibc_unlikely (r_type == R_ARC_NONE))
> + return;
> + else
> + {
> + const ElfW(Sym) *const refsym = sym;
> + struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
> + ElfW(Addr) value = SYMBOL_ADDRESS (sym_map, sym, true);
> +
> + switch (r_type)
> + {
> + case R_ARC_COPY:
> + if (__glibc_unlikely (sym == NULL))
> + /* This can happen in trace mode if an object could not be
> + found. */
> + break;
> +
> + size_t size = sym->st_size;
> + if (__glibc_unlikely (size != refsym->st_size))
> + {
> + const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
> + if (sym->st_size > refsym->st_size)
> + size = refsym->st_size;
> + if (sym->st_size > refsym->st_size || GLRO(dl_verbose))
> + _dl_error_printf ("\
> + %s: Symbol `%s' has different size in shared object, consider re-linking\n",
> + rtld_progname ?: "<program name unknown>",
> + strtab + refsym->st_name);
> + }
> +
> + memcpy (reloc_addr_arg, (void *) value, size);
> + break;
> + case R_ARC_GLOB_DAT:
> + case R_ARC_JUMP_SLOT:
> + *reloc_addr = value;
> + break;
> + case R_ARC_TLS_DTPMOD:
Indentation seems off here.
> + if (sym_map != NULL)
> + /* Get the information from the link map returned by the
> + resolv function. */
> + *reloc_addr = sym_map->l_tls_modid;
> + break;
> +
> + case R_ARC_TLS_DTPOFF:
> + if (sym != NULL)
> + /* Offset set by the linker in the GOT entry would be overwritten
> + by dynamic loader instead of added to the symbol location.
> + Other target have the same approach on DTPOFF relocs. */
> + *reloc_addr += sym->st_value;
> + break;
> +
> + case R_ARC_TLS_TPOFF:
> + if (sym != NULL)
> + {
> + CHECK_STATIC_TLS (map, sym_map);
> + *reloc_addr = sym_map->l_tls_offset + sym->st_value + reloc->r_addend;
> + }
> + break;
> + case R_ARC_32:
> + *reloc_addr += value + reloc->r_addend;
> + break;
> +
> + case R_ARC_PC32:
> + *reloc_addr += value + reloc->r_addend - (unsigned long int) reloc_addr;
> + break;
> +
> + default:
> + _dl_reloc_bad_type (map, r_type, 0);
> + break;
> + }
> + }
> +}
> +
Ok.
> +inline void
> +__attribute__ ((always_inline))
> +elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
> + void *const reloc_addr_arg)
> +{
> + ElfW(Addr) *const reloc_addr = reloc_addr_arg;
> + *reloc_addr += l_addr;
> +}
> +
> +inline void
> +__attribute__ ((always_inline))
> +elf_machine_lazy_rel (struct link_map *map,
> + ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
> + int skip_ifunc)
> +{
> + ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
> + if (ELF32_R_TYPE (reloc->r_info) == R_ARC_JUMP_SLOT)
> + *reloc_addr += l_addr;
> + else
> + _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1);
> +}
> +
> +#endif /* RESOLVE_MAP */
OK.
> diff --git a/sysdeps/arc/entry.h b/sysdeps/arc/entry.h
> new file mode 100644
> index 000000000000..adb01d981afd
> --- /dev/null
> +++ b/sysdeps/arc/entry.h
> @@ -0,0 +1,5 @@
> +#ifndef __ASSEMBLY__
> +extern void __start (void) attribute_hidden;
> +#endif
> +
> +#define ENTRY_POINT __start
Ok.
> diff --git a/sysdeps/arc/ldsodefs.h b/sysdeps/arc/ldsodefs.h
> new file mode 100644
> index 000000000000..cf1df36f6ccd
> --- /dev/null
> +++ b/sysdeps/arc/ldsodefs.h
> @@ -0,0 +1,43 @@
> +/* Run-time dynamic linker data structures for loaded ELF shared objects.
> + 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 _ARC_LDSODEFS_H
> +#define _ARC_LDSODEFS_H 1
> +
> +#include <elf.h>
> +
> +struct La_arc_regs;
> +struct La_arc_retval;
> +
> +#define ARCH_PLTENTER_MEMBERS \
> + ElfW(Addr) (*arc_gnu_pltenter) (ElfW(Sym) *, unsigned int, \
> + uintptr_t *, uintptr_t *, \
> + const struct La_arc_regs *, \
> + unsigned int *, const char *, \
> + long int *);
> +
> +#define ARCH_PLTEXIT_MEMBERS \
> + unsigned int (*arc_gnu_pltexit) (ElfW(Sym) *, unsigned int, \
> + uintptr_t *, uintptr_t *, \
> + const struct La_arc_regs *, \
> + struct La_arc_retval *, \
> + const char *);
> +
> +#include_next <ldsodefs.h>
> +
> +#endif
Ok.
> diff --git a/sysdeps/arc/sotruss-lib.c b/sysdeps/arc/sotruss-lib.c
> new file mode 100644
> index 000000000000..dfb0f0ee8d12
> --- /dev/null
> +++ b/sysdeps/arc/sotruss-lib.c
> @@ -0,0 +1,50 @@
> +/* Override generic sotruss-lib.c to define actual functions for ARC.
> + 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/>. */
> +
> +#define HAVE_ARCH_PLTENTER
> +#define HAVE_ARCH_PLTEXIT
> +
> +#include <elf/sotruss-lib.c>
> +
> +ElfW(Addr)
> +la_arc_gnu_pltenter (ElfW(Sym) *sym __attribute__ ((unused)),
> + unsigned int ndx __attribute__ ((unused)),
> + uintptr_t *refcook, uintptr_t *defcook,
> + La_arc_regs *regs, unsigned int *flags,
> + const char *symname, long int *framesizep)
> +{
> + print_enter (refcook, defcook, symname,
> + regs->lr_reg[0], regs->lr_reg[1], regs->lr_reg[2],
> + *flags);
> +
> + /* No need to copy anything, we will not need the parameters in any case. */
> + *framesizep = 0;
> +
> + return sym->st_value;
> +}
> +
> +unsigned int
> +la_arc_gnu_pltexit (ElfW(Sym) *sym, unsigned int ndx, uintptr_t *refcook,
> + uintptr_t *defcook,
> + const struct La_arc_regs *inregs,
> + struct La_arc_retval *outregs, const char *symname)
> +{
> + print_exit (refcook, defcook, symname, outregs->lrv_reg[0]);
> +
> + return 0;
> +}
Ok.
> diff --git a/sysdeps/arc/start.S b/sysdeps/arc/start.S
> new file mode 100644
> index 000000000000..83dd5308bd5e
> --- /dev/null
> +++ b/sysdeps/arc/start.S
> @@ -0,0 +1,74 @@
> +/* Startup code for ARC.
> + 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/>. */
> +
> +#define __ASSEMBLY__ 1
> +#include <entry.h>
> +#include <sysdep.h>
> +
> +#ifndef ENTRY_POINT
> +# error ENTRY_POINT needs to be defined for ARC
> +#endif
> +
> +/* When we enter this piece of code, the program stack looks like this:
> + argc argument counter (integer)
> + argv[0] program name (pointer)
> + argv[1...N] program args (pointers)
> + argv[argc-1] end of args (integer)
> + NULL
Indentation seems off here.
> + env[0...N] environment variables (pointers)
> + NULL. */
> +
> +ENTRY (ENTRY_POINT)
> +
> + /* Needed to make gdb backtraces stop here. */
> + .cfi_label .Ldummy
> + cfi_undefined (blink)
> +
> + mov fp, 0
> + ld_s r1, [sp] /* argc. */
> +
> + mov_s r5, r0 /* rltd_fini. */
> + add_s r2, sp, 4 /* argv. */
> + and sp, sp, -8
> + mov r6, sp
> +
> + /* __libc_start_main (main, argc, argv, init, fini, rtld_fini, stack_end). */
> +
> +#ifdef SHARED
> + ld r0, [pcl, @main@gotpc]
> + ld r3, [pcl, @__libc_csu_init@gotpc]
> + ld r4, [pcl, @__libc_csu_fini@gotpc]
> + bl __libc_start_main@plt
> +#else
> + mov_s r0, main
> + mov_s r3, __libc_csu_init
> + mov r4, __libc_csu_fini
> + bl __libc_start_main
> +#endif
> +
> + /* Should never get here. */
> + flag 1
> +END (ENTRY_POINT)
> +
> +/* Define a symbol for the first piece of initialized data. */
> + .data
> + .globl __data_start
> +__data_start:
> + .long 0
> + .weak data_start
> + data_start = __data_start
Ok.
> diff --git a/sysdeps/arc/tst-audit.h b/sysdeps/arc/tst-audit.h
> new file mode 100644
> index 000000000000..0b8f0b9c2f3f
> --- /dev/null
> +++ b/sysdeps/arc/tst-audit.h
> @@ -0,0 +1,23 @@
> +/* Definitions for testing PLT entry/exit auditing. ARC 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/>. */
> +
> +#define pltenter la_arc_gnu_pltenter
> +#define pltexit la_arc_gnu_pltexit
> +#define La_regs La_arc_regs
> +#define La_retval La_arc_retval
> +#define int_retval lrv_reg[0]
>
Ok.
On 7/2/20 4:12 AM, Adhemerval Zanella via Libc-alpha wrote:
>
>
> On 15/06/2020 17:14, Vineet Gupta via Libc-alpha wrote:
>> Code for C runtime startup and dynamic loading including PLT layout.
>
> LGTM, just a couple of indentations nits below.
>
> Revewied-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
>> + case R_ARC_GLOB_DAT:
>> + case R_ARC_JUMP_SLOT:
>> + *reloc_addr = value;
>> + break;
>> + case R_ARC_TLS_DTPMOD:
>
> Indentation seems off here.
Fixed.
>> +/* When we enter this piece of code, the program stack looks like this:
>> + argc argument counter (integer)
>> + argv[0] program name (pointer)
>> + argv[1...N] program args (pointers)
>> + argv[argc-1] end of args (integer)
>> + NULL
>
> Indentation seems off here.
Fixed.
Thx,
-Vineet
new file mode 100644
@@ -0,0 +1,52 @@
+/* Machine-specific declarations for dynamic linker interface, ARC 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 _LINK_H
+# error "Never include <bits/link.h> directly; use <link.h> instead."
+#endif
+
+/* Registers for entry into PLT on ARC. */
+typedef struct La_arc_regs
+{
+ uint32_t lr_reg[8]; /* r0 through r7 (upto 8 args). */
+} La_arc_regs;
+
+/* Return values for calls from PLT on ARC. */
+typedef struct La_arc_retval
+{
+ /* For ARCv2, a 64-bit integer return value can use 2 regs. */
+ uint32_t lrv_reg[2];
+} La_arc_retval;
+
+__BEGIN_DECLS
+
+extern ElfW(Addr) la_arc_gnu_pltenter (ElfW(Sym) *__sym, unsigned int __ndx,
+ uintptr_t *__refcook,
+ uintptr_t *__defcook,
+ La_arc_regs *__regs,
+ unsigned int *__flags,
+ const char *__symname,
+ long int *__framesizep);
+extern unsigned int la_arc_gnu_pltexit (ElfW(Sym) *__sym, unsigned int __ndx,
+ uintptr_t *__refcook,
+ uintptr_t *__defcook,
+ const La_arc_regs *__inregs,
+ La_arc_retval *__outregs,
+ const char *symname);
+
+__END_DECLS
new file mode 100644
@@ -0,0 +1,341 @@
+/* Machine-dependent ELF dynamic relocation inline functions. ARC 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_machine_h
+#define dl_machine_h
+
+#define ELF_MACHINE_NAME "arc"
+
+#include <entry.h>
+
+#ifndef ENTRY_POINT
+# error ENTRY_POINT needs to be defined for ARC
+#endif
+
+#include <string.h>
+#include <link.h>
+#include <dl-tls.h>
+
+/* Dynamic Linking ABI for ARCv2 ISA.
+
+ PLT
+ -------------------------------- <---- DT_PLTGOT
+ | ld r11, [pcl, off-to-GOT[1] | 0
+ | | 4
+ plt0 | ld r10, [pcl, off-to-GOT[2] | 8
+ | | 12
+ | j [r10] | 16
+ --------------------------------
+ | Base address of GOT | 20
+ --------------------------------
+ | ld r12, [pcl, off-to-GOT[3] | 24
+ plt1 | |
+ | j.d [r12] | 32
+ | mov r12, pcl | 36
+ --------------------------------
+ | | 40
+ ~ ~
+ ~ ~
+ | |
+ --------------------------------
+
+ .got
+ --------------
+ | [0] |
+ | ... | Runtime address for data symbols
+ | [n] |
+ --------------
+
+ .got.plt
+ --------------
+ | [0] | Build address of .dynamic
+ --------------
+ | [1] | Module info - setup by ld.so
+ --------------
+ | [2] | resolver entry point
+ --------------
+ | [3] |
+ | ... | Runtime address for function symbols
+ | [f] |
+ --------------
+
+ For ARCompact, the PLT is 12 bytes due to short instructions
+
+ --------------------------------
+ | ld r12, [pcl, off-to-GOT[3] | 24 (12 bytes each)
+ plt1 | |
+ | j_s.d [r12] | 32
+ | mov_s r12, pcl | 34
+ --------------------------------
+ | | 36 */
+
+/* Return nonzero iff ELF header is compatible with the running host. */
+static inline int
+elf_machine_matches_host (const Elf32_Ehdr *ehdr)
+{
+ return (ehdr->e_machine == EM_ARCV2 /* ARC HS. */
+ || ehdr->e_machine == EM_ARC_COMPACT); /* ARC 700. */
+}
+
+/* Get build time address of .dynamic as setup in GOT[0]
+ This is called very early in _dl_start so it has not been relocated to
+ runtime value. */
+static inline ElfW(Addr)
+elf_machine_dynamic (void)
+{
+ extern const ElfW(Addr) _GLOBAL_OFFSET_TABLE_[] attribute_hidden;
+ return _GLOBAL_OFFSET_TABLE_[0];
+}
+
+
+/* Return the run-time load address of the shared object. */
+static inline ElfW(Addr)
+elf_machine_load_address (void)
+{
+ ElfW(Addr) build_addr, run_addr;
+
+ /* For build address, below generates
+ ld r0, [pcl, _GLOBAL_OFFSET_TABLE_@pcl]. */
+ build_addr = elf_machine_dynamic ();
+ __asm__ ("add %0, pcl, _DYNAMIC@pcl \n" : "=r" (run_addr));
+
+ return run_addr - build_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__ ((always_inline))
+elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
+{
+ extern void _dl_runtime_resolve (Elf32_Word);
+
+ if (l->l_info[DT_JMPREL] && lazy)
+ {
+ /* On ARC DT_PLTGOT point to .plt whose 5th word (after the PLT header)
+ contains the address of .got. */
+ ElfW(Addr) *plt_base = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
+ ElfW(Addr) *got = (ElfW(Addr) *) (plt_base[5] + l->l_addr);
+
+ got[1] = (ElfW(Addr)) l; /* Identify this shared object. */
+
+ /* 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] = (ElfW(Addr)) &_dl_runtime_resolve;
+ }
+
+ return lazy;
+}
+
+/* What this code does:
+ -ldso starts execution here when kernel returns from execve
+ -calls into generic ldso entry point _dl_start
+ -optionally adjusts argc for executable if exec passed as cmd
+ -calls into app main with address of finaliser. */
+
+#define RTLD_START asm ("\
+.text \n\
+.globl __start \n\
+.type __start, @function \n\
+__start: \n\
+ /* (1). bootstrap ld.so. */ \n\
+ bl.d _dl_start \n\
+ mov_s r0, sp /* pass ptr to aux vector tbl. */ \n\
+ mov r13, r0 /* safekeep app elf entry point. */ \n\
+ \n\
+ /* (2). If ldso ran with executable as arg. */ \n\
+ /* skip the extra args calc by dl_start. */ \n\
+ ld_s r1, [sp] /* orig argc. */ \n\
+ ld r12, [pcl, _dl_skip_args@pcl] \n\
+ breq r12, 0, 1f \n\
+ \n\
+ add2 sp, sp, r12 /* discard argv entries from stack. */ \n\
+ sub_s r1, r1, r12 /* adjusted argc on stack. */ \n\
+ st_s r1, [sp] \n\
+ add r2, sp, 4 \n\
+ /* intermediate LD for ST emcoding limitations. */ \n\
+ ld r3, [pcl, _dl_argv@gotpc] \n\
+ st r2, [r3] \n\
+1: \n\
+ /* (3). call preinit stuff. */ \n\
+ ld r0, [pcl, _rtld_local@pcl] \n\
+ add r2, sp, 4 ; argv \n\
+ add2 r3, r2, r1 \n\
+ add r3, r3, 4 ; env \n\
+ bl _dl_init@plt \n\
+ \n\
+ /* (4) call app elf entry point. */ \n\
+ add r0, pcl, _dl_fini@pcl \n\
+ j [r13] \n\
+ \n\
+ .size __start,.-__start \n\
+ .previous \n\
+");
+
+/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
+ PLT entries should not be allowed to define the value.
+ ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
+ of the main executable's symbols, as for a COPY reloc. */
+#define elf_machine_type_class(type) \
+ ((((type) == R_ARC_JUMP_SLOT \
+ || (type) == R_ARC_TLS_DTPMOD \
+ || (type) == R_ARC_TLS_DTPOFF \
+ || (type) == R_ARC_TLS_TPOFF) * ELF_RTYPE_CLASS_PLT) \
+ | (((type) == R_ARC_COPY) * ELF_RTYPE_CLASS_COPY))
+
+/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
+#define ELF_MACHINE_JMP_SLOT R_ARC_JUMP_SLOT
+
+/* ARC uses Elf32_Rela relocations. */
+#define ELF_MACHINE_NO_REL 1
+#define ELF_MACHINE_NO_RELA 0
+
+/* Fixup a PLT entry to bounce directly to the function at VALUE. */
+
+static inline ElfW(Addr)
+elf_machine_fixup_plt (struct link_map *map, lookup_t t,
+ const ElfW(Sym) *refsym, const ElfW(Sym) *sym,
+ const Elf32_Rela *reloc,
+ ElfW(Addr) *reloc_addr, ElfW(Addr) value)
+{
+ return *reloc_addr = value;
+}
+
+/* Return the final value of a plt relocation. */
+static inline ElfW(Addr)
+elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
+ ElfW(Addr) value)
+{
+ return value;
+}
+
+/* Names of the architecture-specific auditing callback functions. */
+#define ARCH_LA_PLTENTER arc_gnu_pltenter
+#define ARCH_LA_PLTEXIT arc_gnu_pltexit
+
+#endif /* dl_machine_h */
+
+#ifdef RESOLVE_MAP
+
+inline void
+__attribute__ ((always_inline))
+elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
+ const ElfW(Sym) *sym, const struct r_found_version *version,
+ void *const reloc_addr_arg, int skip_ifunc)
+{
+ ElfW(Addr) *const reloc_addr = reloc_addr_arg;
+ const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
+
+ if (__glibc_unlikely (r_type == R_ARC_RELATIVE))
+ *reloc_addr += map->l_addr;
+ else if (__glibc_unlikely (r_type == R_ARC_NONE))
+ return;
+ else
+ {
+ const ElfW(Sym) *const refsym = sym;
+ struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
+ ElfW(Addr) value = SYMBOL_ADDRESS (sym_map, sym, true);
+
+ switch (r_type)
+ {
+ case R_ARC_COPY:
+ if (__glibc_unlikely (sym == NULL))
+ /* This can happen in trace mode if an object could not be
+ found. */
+ break;
+
+ size_t size = sym->st_size;
+ if (__glibc_unlikely (size != refsym->st_size))
+ {
+ const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
+ if (sym->st_size > refsym->st_size)
+ size = refsym->st_size;
+ if (sym->st_size > refsym->st_size || GLRO(dl_verbose))
+ _dl_error_printf ("\
+ %s: Symbol `%s' has different size in shared object, consider re-linking\n",
+ rtld_progname ?: "<program name unknown>",
+ strtab + refsym->st_name);
+ }
+
+ memcpy (reloc_addr_arg, (void *) value, size);
+ break;
+ case R_ARC_GLOB_DAT:
+ case R_ARC_JUMP_SLOT:
+ *reloc_addr = value;
+ break;
+ case R_ARC_TLS_DTPMOD:
+ if (sym_map != NULL)
+ /* Get the information from the link map returned by the
+ resolv function. */
+ *reloc_addr = sym_map->l_tls_modid;
+ break;
+
+ case R_ARC_TLS_DTPOFF:
+ if (sym != NULL)
+ /* Offset set by the linker in the GOT entry would be overwritten
+ by dynamic loader instead of added to the symbol location.
+ Other target have the same approach on DTPOFF relocs. */
+ *reloc_addr += sym->st_value;
+ break;
+
+ case R_ARC_TLS_TPOFF:
+ if (sym != NULL)
+ {
+ CHECK_STATIC_TLS (map, sym_map);
+ *reloc_addr = sym_map->l_tls_offset + sym->st_value + reloc->r_addend;
+ }
+ break;
+ case R_ARC_32:
+ *reloc_addr += value + reloc->r_addend;
+ break;
+
+ case R_ARC_PC32:
+ *reloc_addr += value + reloc->r_addend - (unsigned long int) reloc_addr;
+ break;
+
+ default:
+ _dl_reloc_bad_type (map, r_type, 0);
+ break;
+ }
+ }
+}
+
+inline void
+__attribute__ ((always_inline))
+elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
+ void *const reloc_addr_arg)
+{
+ ElfW(Addr) *const reloc_addr = reloc_addr_arg;
+ *reloc_addr += l_addr;
+}
+
+inline void
+__attribute__ ((always_inline))
+elf_machine_lazy_rel (struct link_map *map,
+ ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
+ int skip_ifunc)
+{
+ ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
+ if (ELF32_R_TYPE (reloc->r_info) == R_ARC_JUMP_SLOT)
+ *reloc_addr += l_addr;
+ else
+ _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1);
+}
+
+#endif /* RESOLVE_MAP */
new file mode 100644
@@ -0,0 +1,5 @@
+#ifndef __ASSEMBLY__
+extern void __start (void) attribute_hidden;
+#endif
+
+#define ENTRY_POINT __start
new file mode 100644
@@ -0,0 +1,43 @@
+/* Run-time dynamic linker data structures for loaded ELF shared objects.
+ 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 _ARC_LDSODEFS_H
+#define _ARC_LDSODEFS_H 1
+
+#include <elf.h>
+
+struct La_arc_regs;
+struct La_arc_retval;
+
+#define ARCH_PLTENTER_MEMBERS \
+ ElfW(Addr) (*arc_gnu_pltenter) (ElfW(Sym) *, unsigned int, \
+ uintptr_t *, uintptr_t *, \
+ const struct La_arc_regs *, \
+ unsigned int *, const char *, \
+ long int *);
+
+#define ARCH_PLTEXIT_MEMBERS \
+ unsigned int (*arc_gnu_pltexit) (ElfW(Sym) *, unsigned int, \
+ uintptr_t *, uintptr_t *, \
+ const struct La_arc_regs *, \
+ struct La_arc_retval *, \
+ const char *);
+
+#include_next <ldsodefs.h>
+
+#endif
new file mode 100644
@@ -0,0 +1,50 @@
+/* Override generic sotruss-lib.c to define actual functions for ARC.
+ 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/>. */
+
+#define HAVE_ARCH_PLTENTER
+#define HAVE_ARCH_PLTEXIT
+
+#include <elf/sotruss-lib.c>
+
+ElfW(Addr)
+la_arc_gnu_pltenter (ElfW(Sym) *sym __attribute__ ((unused)),
+ unsigned int ndx __attribute__ ((unused)),
+ uintptr_t *refcook, uintptr_t *defcook,
+ La_arc_regs *regs, unsigned int *flags,
+ const char *symname, long int *framesizep)
+{
+ print_enter (refcook, defcook, symname,
+ regs->lr_reg[0], regs->lr_reg[1], regs->lr_reg[2],
+ *flags);
+
+ /* No need to copy anything, we will not need the parameters in any case. */
+ *framesizep = 0;
+
+ return sym->st_value;
+}
+
+unsigned int
+la_arc_gnu_pltexit (ElfW(Sym) *sym, unsigned int ndx, uintptr_t *refcook,
+ uintptr_t *defcook,
+ const struct La_arc_regs *inregs,
+ struct La_arc_retval *outregs, const char *symname)
+{
+ print_exit (refcook, defcook, symname, outregs->lrv_reg[0]);
+
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,74 @@
+/* Startup code for ARC.
+ 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/>. */
+
+#define __ASSEMBLY__ 1
+#include <entry.h>
+#include <sysdep.h>
+
+#ifndef ENTRY_POINT
+# error ENTRY_POINT needs to be defined for ARC
+#endif
+
+/* When we enter this piece of code, the program stack looks like this:
+ argc argument counter (integer)
+ argv[0] program name (pointer)
+ argv[1...N] program args (pointers)
+ argv[argc-1] end of args (integer)
+ NULL
+ env[0...N] environment variables (pointers)
+ NULL. */
+
+ENTRY (ENTRY_POINT)
+
+ /* Needed to make gdb backtraces stop here. */
+ .cfi_label .Ldummy
+ cfi_undefined (blink)
+
+ mov fp, 0
+ ld_s r1, [sp] /* argc. */
+
+ mov_s r5, r0 /* rltd_fini. */
+ add_s r2, sp, 4 /* argv. */
+ and sp, sp, -8
+ mov r6, sp
+
+ /* __libc_start_main (main, argc, argv, init, fini, rtld_fini, stack_end). */
+
+#ifdef SHARED
+ ld r0, [pcl, @main@gotpc]
+ ld r3, [pcl, @__libc_csu_init@gotpc]
+ ld r4, [pcl, @__libc_csu_fini@gotpc]
+ bl __libc_start_main@plt
+#else
+ mov_s r0, main
+ mov_s r3, __libc_csu_init
+ mov r4, __libc_csu_fini
+ bl __libc_start_main
+#endif
+
+ /* Should never get here. */
+ flag 1
+END (ENTRY_POINT)
+
+/* Define a symbol for the first piece of initialized data. */
+ .data
+ .globl __data_start
+__data_start:
+ .long 0
+ .weak data_start
+ data_start = __data_start
new file mode 100644
@@ -0,0 +1,23 @@
+/* Definitions for testing PLT entry/exit auditing. ARC 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/>. */
+
+#define pltenter la_arc_gnu_pltenter
+#define pltexit la_arc_gnu_pltexit
+#define La_regs La_arc_regs
+#define La_retval La_arc_retval
+#define int_retval lrv_reg[0]