[OpenRISC] [PATCH v4 04/13] or1k: startup and dynamic linking code

Adhemerval Zanella
2022-01-03T18:17:15Z

On 29/12/2021 01:42, Stafford Horne via Libc-alpha wrote:
> Code for C runtime startup and dynamic loading including PLT layout.

Looks good, although I can't really voucher since I don't have direct access
to a or1k system. Just some comments bellow and a possible fix for the inline
asm.

LGTM with the fixed.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

> ---
> sysdeps/or1k/bits/link.h | 54 +++++++
> sysdeps/or1k/dl-machine.h | 300 +++++++++++++++++++++++++++++++++++++
> sysdeps/or1k/dl-start.S | 98 ++++++++++++
> sysdeps/or1k/ldsodefs.h | 40 +++++
> sysdeps/or1k/sotruss-lib.c | 51 +++++++
> sysdeps/or1k/start.S | 99 ++++++++++++
> sysdeps/or1k/tst-audit.h | 24 +++
> 7 files changed, 666 insertions(+)
> create mode 100644 sysdeps/or1k/bits/link.h
> create mode 100644 sysdeps/or1k/dl-machine.h
> create mode 100644 sysdeps/or1k/dl-start.S
> create mode 100644 sysdeps/or1k/ldsodefs.h
> create mode 100644 sysdeps/or1k/sotruss-lib.c
> create mode 100644 sysdeps/or1k/start.S
> create mode 100644 sysdeps/or1k/tst-audit.h
>
> diff --git a/sysdeps/or1k/bits/link.h b/sysdeps/or1k/bits/link.h
> new file mode 100644
> index 0000000000..f291d66269
> --- /dev/null
> +++ b/sysdeps/or1k/bits/link.h
> @@ -0,0 +1,54 @@
> +/* Declarations for dynamic linker interface. OpenRISC version.
> + Copyright (C) 2021 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. */
> +typedef struct La_or1k_regs
> +{
> + uint32_t lr_reg[6]; /* Args passed in r3-r8. */
> + uint32_t lr_sp; /* Register r1. */
> + uint32_t lr_lr; /* Register r9. */
> +} La_or1k_regs;
> +
> +/* Return values for calls from PLT. */
> +typedef struct La_or1k_retval
> +{
> + /* Up to two 32-bit registers used for a return value. */
> + uint32_t lrv_reg[2];
> +} La_or1k_retval;
> +
> +__BEGIN_DECLS
> +
> +extern ElfW(Addr) la_or1k_gnu_pltenter (ElfW(Sym) *__sym, unsigned int __ndx,
> + uintptr_t *__refcook,
> + uintptr_t *__defcook,
> + La_or1k_regs *__regs,
> + unsigned int *__flags,
> + const char *__symname,
> + long int *__framesizep);
> +extern unsigned int la_or1k_gnu_pltexit (ElfW(Sym) *__sym, unsigned int __ndx,
> + uintptr_t *__refcook,
> + uintptr_t *__defcook,
> + const La_or1k_regs *__inregs,
> + La_or1k_retval *__outregs,
> + const char *__symname);
> +
> +__END_DECLS

I think you can use Elf32_Addr and Elf32_Sym directly here, since or1k
does not have a 64-bit neither this file will be used along it.

> diff --git a/sysdeps/or1k/dl-machine.h b/sysdeps/or1k/dl-machine.h
> new file mode 100644
> index 0000000000..ec4db533d2
> --- /dev/null
> +++ b/sysdeps/or1k/dl-machine.h
> @@ -0,0 +1,300 @@
> +/* Machine-dependent ELF dynamic relocation inline functions. OpenRISC version.
> + Copyright (C) 2021 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 "or1k"
> +
> +#include <sys/cdefs.h>
> +#include <sys/param.h>
> +#include <tls.h>
> +#include <dl-irel.h>
> +#include <dl-static-tls.h>
> +#include <dl-machine-rel.h>
> +
> +/* Return nonzero iff ELF header is compatible with the running host. */
> +static inline int __attribute__ ((unused))
> +elf_machine_matches_host (const Elf32_Ehdr *ehdr)
> +{
> + return ehdr->e_machine == EM_OPENRISC;
> +}
> +
> +static inline Elf32_Addr *
> +or1k_get_got (void)
> +{
> + Elf32_Addr *got;
> +
> + asm ("l.jal 0x8\n"
> + " l.movhi %0, gotpchi(_GLOBAL_OFFSET_TABLE_-4)\n"
> + "l.ori %0, %0, gotpclo(_GLOBAL_OFFSET_TABLE_+0)\n"
> + "l.add %0, %0, r9\n"
> + : "=r" (got) : : "r9");

I think this requires a "memory" clobber.

> +
> + return got;
> +}
> +
> +/* Return the link-time address of _DYNAMIC. Conveniently, this is the
> + first element of the GOT. */
> +static inline Elf32_Addr
> +elf_machine_dynamic (void)
> +{
> + Elf32_Addr *got = or1k_get_got ();
> + return *got;
> +}
> +
> +
> +/* Return the run-time load address of the shared object. */
> +static inline Elf32_Addr
> +elf_machine_load_address (void)
> +{
> + /* Compute the difference between the runtime address of _DYNAMIC as seen
> + by a GOTOFF reference, and the link-time address found in the special
> + unrelocated first GOT entry. */
> + Elf32_Addr dyn;
> + Elf32_Addr *got = or1k_get_got ();
> +
> + asm ("l.movhi %0, gotoffhi(_DYNAMIC);"
> + "l.ori %0, %0, gotofflo(_DYNAMIC);"
> + "l.add %0, %0, %1;"
> + : "=&r"(dyn) : "r"(got));

Also here.

> +
> + return dyn - *got;
> +}
> +
> +/* Initial entry point code for the dynamic linker. The function _dl_start
> + is the real entry point; it's return value is the user program's entry
> + point.
> +
> + Code is really located in dl-start.S, just tell the linker that it
> + exists. */
> +#define RTLD_START asm (".globl _dl_start");
> +
> +/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
> + TLS variable, so undefined references 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_OR1K_JMP_SLOT \
> + || (type) == R_OR1K_TLS_DTPMOD \
> + || (type) == R_OR1K_TLS_DTPOFF \
> + || (type) == R_OR1K_TLS_TPOFF) * ELF_RTYPE_CLASS_PLT \
> + | ((type) == R_OR1K_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_OR1K_JMP_SLOT
> +
> +#define ARCH_LA_PLTENTER or1k_gnu_pltenter
> +#define ARCH_LA_PLTEXIT or1k_gnu_pltexit
> +
> +/* Set up the loaded object described by L so its unrelocated PLT
> + entries will jump to the on-demand fixup code in dl-runtime.c. */
> +static inline int __attribute__ ((unused, always_inline))
> +elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
> + int lazy, int profile)
> +{
> + ElfW(Addr) *pltgot;
> + extern void _dl_runtime_resolve (ElfW(Word));
> + extern void _dl_runtime_profile (ElfW(Word));
> +
> + if (l->l_info[DT_JMPREL] && lazy)
> + {
> + pltgot = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
> +
> + /* Fill in initial entrys of the plt */
> +
> + /* Register the link_map address in the plt at pltgot[1].
> + This will also be used in the resolver for accessing the
> + link_map structure. */
> + pltgot[1] = (ElfW(Addr)) l;
> +
> + /* This function will get called to fix up the GOT entry and
> + then jump to the resolved address. */
> + pltgot[2] = (ElfW(Addr)) &_dl_runtime_resolve;
> +
> + }
> +
> + return lazy;
> +}
> +
> +/* Mask identifying addresses reserved for the user program,
> + where the dynamic linker should not map anything. */
> +#define ELF_MACHINE_USER_ADDRESS_MASK 0xf8000000UL
> +
> +/* We define an initialization functions. This is called very early in
> + _dl_sysdep_start. */
> +#define DL_PLATFORM_INIT dl_platform_init ()
> +
> +static inline void __attribute__ ((unused))
> +dl_platform_init (void)
> +{
> + if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
> + /* Avoid an empty string which would disturb us. */
> + GLRO(dl_platform) = NULL;
> +}
> +
> +static inline ElfW(Addr)
> +elf_machine_fixup_plt (struct link_map *map, lookup_t t,
> + const ElfW(Sym) *refsym, const ElfW(Sym) *sym,
> + const ElfW(Rela) *reloc,
> + ElfW(Addr) *reloc_addr, ElfW(Addr) value)
> +{
> + return *reloc_addr = value;
> +}
> +
> +/* Return the final value of a plt relocation. */
> +static inline Elf32_Addr
> +elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
> + Elf32_Addr value)
> +{
> + return value + reloc->r_addend;
> +}
> +
> +
> +#endif /* !dl_machine_h */
> +
> +#ifdef RESOLVE_MAP
> +
> +/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
> + MAP is the object containing the reloc. */
> +
> +static inline void
> +__attribute ((always_inline))
> +elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[],
> + const ElfW(Rela) *reloc, const ElfW(Sym) *sym,
> + const struct r_found_version *version,
> + void *const reloc_addr_arg, int skip_ifunc)
> +{
> + Elf32_Addr *const reloc_addr = reloc_addr_arg;
> + const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
> +
> + if (__glibc_unlikely (r_type == R_OR1K_NONE))
> + return;
> + else
> + {
> +# ifndef RESOLVE_CONFLICT_FIND_MAP
> + const Elf32_Sym *const refsym = sym;
> +# endif
> + struct link_map *sym_map = RESOLVE_MAP (map, scope, &sym, version,
> + r_type);
> + Elf32_Addr value = SYMBOL_ADDRESS (sym_map, sym, true);
> +
> + 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)
> + {
> +# ifndef RESOLVE_CONFLICT_FIND_MAP
> + case R_OR1K_COPY:
> + if (sym == NULL)
> + /* This can happen in trace mode if an object could not be
> + found. */
> + break;
> + if (__glibc_unlikely (sym->st_size > refsym->st_size)
> + || (__glibc_unlikely (sym->st_size < refsym->st_size)
> + && GLRO(dl_verbose)))
> + {
> + const char *strtab;
> +
> + strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]);
> + _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,
> + MIN (sym->st_size, refsym->st_size));
> + break;
> +# endif /* !RESOLVE_CONFLICT_FIND_MAP */
> + case R_OR1K_32:
> + /* Support relocations on mis-aligned offsets. */
> + value += reloc->r_addend;
> + memcpy (reloc_addr_arg, &value, 4);
> + break;
> + case R_OR1K_GLOB_DAT:
> + case R_OR1K_JMP_SLOT:
> + *reloc_addr = value + reloc->r_addend;
> + break;
> + case R_OR1K_TLS_DTPMOD:
> +# ifdef RTLD_BOOTSTRAP
> + /* During startup the dynamic linker is always the module
> + with index 1. */
> + *reloc_addr = 1;
> +# else
> + if (sym_map != NULL)
> + *reloc_addr = sym_map->l_tls_modid;
> +# endif
> + break;
> + case R_OR1K_TLS_DTPOFF:
> +# ifndef RTLD_BOOTSTRAP
> + *reloc_addr = (sym == NULL ? 0 : sym->st_value) + reloc->r_addend;
> +# endif
> + break;
> +
> + case R_OR1K_TLS_TPOFF:
> +# ifdef RTLD_BOOTSTRAP
> + *reloc_addr = sym->st_value + reloc->r_addend +
> + map->l_tls_offset - TLS_TCB_SIZE;
> +# else
> + if (sym_map != NULL)
> + {
> + CHECK_STATIC_TLS (map, sym_map);
> + *reloc_addr = sym->st_value + reloc->r_addend +
> + sym_map->l_tls_offset - TLS_TCB_SIZE;
> + }
> +# endif
> + break;
> + default:
> + _dl_reloc_bad_type (map, r_type, 0);
> + break;
> + }
> + }
> +}
> +
> +static inline void
> +__attribute__ ((always_inline))
> +elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
> + void *const reloc_addr_arg)
> +{
> + Elf32_Addr *const reloc_addr = reloc_addr_arg;
> + *reloc_addr = l_addr + reloc->r_addend;
> +}
> +
> +static inline void
> +__attribute__ ((always_inline))
> +elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
> + ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
> + int skip_ifunc)
> +{
> + Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
> + const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
> +
> + if (__glibc_likely (r_type == R_OR1K_JMP_SLOT))
> + *reloc_addr += l_addr;
> + else if (__glibc_unlikely (r_type == R_OR1K_NONE))
> + return;
> + else
> + _dl_reloc_bad_type (map, r_type, 1);
> +}
> +
> +#endif /* RESOLVE_MAP */
> diff --git a/sysdeps/or1k/dl-start.S b/sysdeps/or1k/dl-start.S
> new file mode 100644
> index 0000000000..ecb1505427
> --- /dev/null
> +++ b/sysdeps/or1k/dl-start.S
> @@ -0,0 +1,98 @@
> +/* Machine-dependent ELF startup code. OpenRISC version.
> + Copyright (C) 2021 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/>. */
> +
> +#include <sysdep.h>
> +
> +/* Initial entry point code for the dynamic linker.
> + The function _dl_start is the real entry point;
> + it's return value is the user program's entry point. */
> +ENTRY (_start)
> + /* Count arguments in r11 */
> + l.ori r3, r1, 0
> + l.movhi r11, 0
> +1:
> + l.addi r3, r3, 4
> + l.lwz r12, 0(r3)
> + l.sfnei r12, 0
> + l.addi r11, r11, 1
> + l.bf 1b
> + l.nop
> + l.addi r11, r11, -1
> + /* store argument counter to stack. */
> + l.sw 0(r1), r11
> +
> + /* Load the PIC register. */
> + l.jal 0x8
> + l.movhi r16, gotpchi(_GLOBAL_OFFSET_TABLE_-4)
> + l.ori r16, r16, gotpclo(_GLOBAL_OFFSET_TABLE_+0)
> + l.add r16, r16, r9
> +
> + l.ori r3, r1, 0
> +
> + l.jal _dl_start
> + l.nop
> + /* Save user entry in a call saved reg. */
> + l.ori r22, r11, 0
> + /* Fall through to _dl_start_user. */
> +
> +_dl_start_user:
> + /* Set up for _dl_init. */
> +
> + /* Load _rtld_local (a.k.a _dl_loaded). */
> + l.lwz r12, got(_rtld_local)(r16)
> + l.lwz r3, 0(r12)
> +
> + /* Load argc */
> + l.lwz r18, got(_dl_argc)(r16)
> + l.lwz r4, 0(r18)
> +
> + /* Load argv */
> + l.lwz r20, got(_dl_argv)(r16)
> + l.lwz r5, 0(r20)
> +
> + /* Load envp = &argv[argc + 1]. */
> + l.slli r6, r4, 2
> + l.addi r6, r6, 4
> + l.add r6, r6, r5
> +
> + l.jal plt(_dl_init)
> + l.nop
> +
> + /* Now set up for user entry.
> + The already defined ABI loads argc and argv from the stack.
> +
> + argc = 0(r1)
> + argv = r1 + 4
> + */
> +
> + /* Load SP as argv - 4. */
> + l.lwz r3, 0(r20)
> + l.addi r1, r3, -4
> +
> + /* Save argc. */
> + l.lwz r3, 0(r18)
> + l.sw 0(r1), r3
> +
> + /* Pass _dl_fini function address to _start.
> + Next start.S will then pass this as rtld_fini to __libc_start_main. */
> + l.lwz r3, got(_dl_fini)(r16)
> +
> + l.jr r22
> + l.nop
> +
> +END (_start)
> diff --git a/sysdeps/or1k/ldsodefs.h b/sysdeps/or1k/ldsodefs.h
> new file mode 100644
> index 0000000000..89713fcc70
> --- /dev/null
> +++ b/sysdeps/or1k/ldsodefs.h
> @@ -0,0 +1,40 @@
> +/* Run-time dynamic linker data structures for loaded ELF shared objects.
> + Copyright (C) 2021 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 _OR1K_LDSODEFS_H
> +#define _OR1K_LDSODEFS_H 1
> +
> +#include <elf.h>
> +
> +struct La_or1k_regs;
> +struct La_or1k_retval;
> +
> +#define ARCH_PLTENTER_MEMBERS \
> + uintptr_t (*or1k_gnu_pltenter) (Elf32_Sym *, unsigned int, uintptr_t *, \
> + uintptr_t *, struct La_or1k_regs *, \
> + unsigned int *, const char *name, \
> + long int *framesizep)
> +
> +#define ARCH_PLTEXIT_MEMBERS \
> + unsigned int (*or1k_gnu_pltexit) (Elf32_Sym *, unsigned int, uintptr_t *, \
> + uintptr_t *, const struct La_or1k_regs *, \
> + struct La_or1k_retval *, const char *)
> +
> +#include_next <ldsodefs.h>
> +
> +#endif
> diff --git a/sysdeps/or1k/sotruss-lib.c b/sysdeps/or1k/sotruss-lib.c
> new file mode 100644
> index 0000000000..3755b7afd5
> --- /dev/null
> +++ b/sysdeps/or1k/sotruss-lib.c
> @@ -0,0 +1,51 @@
> +/* Override generic sotruss-lib.c to define actual functions for OpenRISC.
> + Copyright (C) 2021 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_or1k_gnu_pltenter (ElfW(Sym) *sym __attribute__ ((unused)),

As before, I think you can use Elf32_Addr and Elf32_Sym directly.

> + unsigned int ndx __attribute__ ((unused)),
> + uintptr_t *refcook, uintptr_t *defcook,
> + La_or1k_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_or1k_gnu_pltexit (ElfW(Sym) *sym, unsigned int ndx, uintptr_t *refcook,
> + uintptr_t *defcook,
> + const struct La_or1k_regs *inregs,
> + struct La_or1k_retval *outregs,
> + const char *symname)
> +{
> + print_exit (refcook, defcook, symname, outregs->lrv_reg[0]);
> +
> + return 0;
> +}
> diff --git a/sysdeps/or1k/start.S b/sysdeps/or1k/start.S
> new file mode 100644
> index 0000000000..0424355f36
> --- /dev/null
> +++ b/sysdeps/or1k/start.S
> @@ -0,0 +1,99 @@
> +/* start, OpenRISC version.
> + Copyright (C) 2021 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, write to the Free
> + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
> + 02111-1307 USA. */
> +
> +/* This is the canonical entry point, usually the first thing in the text
> + segment.
> +
> + sp The stack contains the arguments and environment:
> + 0(sp) argc
> + 4(sp) argv[0]
> + ...
> + (4*argc)(sp) NULL
> + (4*(argc+1))(sp) envp[0]
> + ...
> + NULL
> + */
> +
> +#define __ASSEMBLY__
> +#include <sysdep.h>
> +#include <entry.h>
> +
> +ENTRY (ENTRY_POINT)
> +
> + /* Setup Arguments to the __libc_start_main function. */
> +
> + /* Take values for argc and argv off the stack.
> + These will be passed as arguments two and three to main
> + and thus go in registers r4 and r5, respectively. */
> + l.lwz r4, 0(r1)
> + l.addi r5, r1, 4
> +
> + /* Pass in rtld_fini from dl-start.S. */
> + l.or r8, r3, r3
> +
> +#ifdef PIC
> + /* Obtain a pointer to .got in r16 */
> + l.jal 0x8
> + l.movhi r16, gotpchi(_GLOBAL_OFFSET_TABLE_-4)
> + l.ori r16, r16, gotpclo(_GLOBAL_OFFSET_TABLE_+0)
> + l.add r16, r16, r9
> +
> + /* Pass in the the main symbol. */
> + l.lwz r3, got(main)(r16)
> +#else
> + /* Pass in the the main symbol. */
> + l.movhi r3, hi(main)
> + l.ori r3, r3, lo(main)
> +#endif
> + /* Used to be init and fini. */
> + l.movhi r6, 0x0
> + l.movhi r7, 0x0
> +
> + /* Push stack limit onto the stack.
> + This provides the highest stack address to user code (as stack grows
> + downwards.
> + This is the seventh argument to __libc_start_main and thus needs to
> + be passed on the stack. */
> + l.sw -4(r1), r1
> +
> + /* Adjust stack to account for a total of 7 args (i.e. the last one is
> + on the stack. */
> + l.addi r1, r1, -4
> +
> + /* Clear the frame pointer and link register since this is the
> + outermost frame. */
> + l.movhi r2, 0x0
> + l.movhi r9, 0x0
> +
> + /* Let the libc call main and exit with its return code. */
> +#ifdef PIC
> + l.j plt(__libc_start_main)
> +#else
> + l.j __libc_start_main
> +#endif
> + l.nop
> +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
> diff --git a/sysdeps/or1k/tst-audit.h b/sysdeps/or1k/tst-audit.h
> new file mode 100644
> index 0000000000..66cb2ee48c
> --- /dev/null
> +++ b/sysdeps/or1k/tst-audit.h
> @@ -0,0 +1,24 @@
> +/* Definitions for testing PLT entry/exit auditing. OpenRISC version.
> + Copyright (C) 2021 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_or1k_gnu_pltenter
> +#define pltexit la_or1k_gnu_pltexit
> +#define La_regs La_or1k_regs
> +#define La_retval La_or1k_retval
> +#define int_retval lrv_reg[0]