Re: [PATCH v4 04/13] LoongArch: ABI Implementation

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 08/05/2022 23:30, caiyinyu wrote:
> ---
>  sysdeps/loongarch/__longjmp.S                |  52 +++
>  sysdeps/loongarch/bits/endianness.h          |  11 +
>  sysdeps/loongarch/bits/link.h                |  58 +++
>  sysdeps/loongarch/bits/setjmp.h              |  42 +++
>  sysdeps/loongarch/bsd-_setjmp.c              |   1 +
>  sysdeps/loongarch/bsd-setjmp.c               |   1 +
>  sysdeps/loongarch/dl-machine.h               | 362 +++++++++++++++++++
>  sysdeps/loongarch/dl-trampoline.S            |  91 +++++
>  sysdeps/loongarch/jmpbuf-offsets.h           |  22 ++
>  sysdeps/loongarch/jmpbuf-unwind.h            |  45 +++
>  sysdeps/loongarch/ldsodefs.h                 |  41 +++
>  sysdeps/loongarch/linkmap.h                  |  22 ++
>  sysdeps/loongarch/machine-gmon.h             |  37 ++
>  sysdeps/loongarch/setjmp.S                   |  66 ++++
>  sysdeps/loongarch/sotruss-lib.c              |  50 +++
>  sysdeps/loongarch/start.S                    |  67 ++++
>  sysdeps/loongarch/sys/asm.h                  |  59 +++
>  sysdeps/loongarch/tst-audit.h                |  23 ++
>  sysdeps/unix/sysv/linux/loongarch/ldconfig.h |  26 ++
>  19 files changed, 1076 insertions(+)
>  create mode 100644 sysdeps/loongarch/__longjmp.S
>  create mode 100644 sysdeps/loongarch/bits/endianness.h
>  create mode 100644 sysdeps/loongarch/bits/link.h
>  create mode 100644 sysdeps/loongarch/bits/setjmp.h
>  create mode 100644 sysdeps/loongarch/bsd-_setjmp.c
>  create mode 100644 sysdeps/loongarch/bsd-setjmp.c
>  create mode 100644 sysdeps/loongarch/dl-machine.h
>  create mode 100644 sysdeps/loongarch/dl-trampoline.S
>  create mode 100644 sysdeps/loongarch/jmpbuf-offsets.h
>  create mode 100644 sysdeps/loongarch/jmpbuf-unwind.h
>  create mode 100644 sysdeps/loongarch/ldsodefs.h
>  create mode 100644 sysdeps/loongarch/linkmap.h
>  create mode 100644 sysdeps/loongarch/machine-gmon.h
>  create mode 100644 sysdeps/loongarch/setjmp.S
>  create mode 100644 sysdeps/loongarch/sotruss-lib.c
>  create mode 100644 sysdeps/loongarch/start.S
>  create mode 100644 sysdeps/loongarch/sys/asm.h
>  create mode 100644 sysdeps/loongarch/tst-audit.h
>  create mode 100644 sysdeps/unix/sysv/linux/loongarch/ldconfig.h
> 
> diff --git a/sysdeps/loongarch/__longjmp.S b/sysdeps/loongarch/__longjmp.S
> new file mode 100644
> index 0000000000..b7690dd94f
> --- /dev/null
> +++ b/sysdeps/loongarch/__longjmp.S
> @@ -0,0 +1,52 @@
> +/* longjmp.
> +   Copyright (C) 2022 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>
> +#include <sys/asm.h>
> +
> +ENTRY (__longjmp)
> +	REG_L ra, a0, 0*SZREG
> +	REG_L sp, a0, 1*SZREG
> +	REG_L x,  a0, 2*SZREG
> +	REG_L fp, a0, 3*SZREG
> +	REG_L s0, a0, 4*SZREG
> +	REG_L s1, a0, 5*SZREG
> +	REG_L s2, a0, 6*SZREG
> +	REG_L s3, a0, 7*SZREG
> +	REG_L s4, a0, 8*SZREG
> +	REG_L s5, a0, 9*SZREG
> +	REG_L s6, a0, 10*SZREG
> +	REG_L s7, a0, 11*SZREG
> +	REG_L s8, a0, 12*SZREG
> +
> +#ifndef __loongarch_soft_float
> +	FREG_L $f24, a0, 13*SZREG + 0*SZFREG
> +	FREG_L $f25, a0, 13*SZREG + 1*SZFREG
> +	FREG_L $f26, a0, 13*SZREG + 2*SZFREG
> +	FREG_L $f27, a0, 13*SZREG + 3*SZFREG
> +	FREG_L $f28, a0, 13*SZREG + 4*SZFREG
> +	FREG_L $f29, a0, 13*SZREG + 5*SZFREG
> +	FREG_L $f30, a0, 13*SZREG + 6*SZFREG
> +	FREG_L $f31, a0, 13*SZREG + 7*SZFREG
> +#endif
> +
> +	sltui	a0,a1,1
> +	ADD	a0, a0, a1	 # a0 = (a1 == 0) ? 1 : a1
> +	jirl	zero,ra,0
> +
> +END (__longjmp)
> diff --git a/sysdeps/loongarch/bits/endianness.h b/sysdeps/loongarch/bits/endianness.h
> new file mode 100644
> index 0000000000..7290be7b18
> --- /dev/null
> +++ b/sysdeps/loongarch/bits/endianness.h
> @@ -0,0 +1,11 @@
> +#ifndef _BITS_ENDIANNESS_H
> +#define _BITS_ENDIANNESS_H 1
> +
> +#ifndef _BITS_ENDIAN_H
> +#error "Never use <bits/endianness.h> directly; include <endian.h> instead."
> +#endif
> +
> +/* LoongArch is little-endian.  */
> +#define __BYTE_ORDER __LITTLE_ENDIAN
> +
> +#endif /* bits/endianness.h */
> diff --git a/sysdeps/loongarch/bits/link.h b/sysdeps/loongarch/bits/link.h
> new file mode 100644
> index 0000000000..4df09989cb
> --- /dev/null
> +++ b/sysdeps/loongarch/bits/link.h
> @@ -0,0 +1,58 @@
> +/* Machine-specific declarations for dynamic linker interface.
> +   Copyright (C) 2022 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
> +
> +typedef struct La_loongarch_regs
> +{
> +  unsigned long int lr_reg[8]; /* a0 - a7 */
> +  double lr_fpreg[8];	       /* fa0 - fa7 */
> +  unsigned long int lr_ra;
> +  unsigned long int lr_sp;
> +} La_loongarch_regs;
> +
> +/* Return values for calls from PLT on LoongArch.  */
> +typedef struct La_loongarch_retval
> +{
> +  unsigned long int lrv_a0;
> +  unsigned long int lrv_a1;
> +  double lrv_fa0;
> +  double lrv_fa1;
> +} La_loongarch_retval;
> +
> +__BEGIN_DECLS
> +
> +extern ElfW (Addr) la_loongarch_gnu_pltenter (ElfW (Sym) * __sym,
> +					      unsigned int __ndx,
> +					      uintptr_t *__refcook,
> +					      uintptr_t *__defcook,
> +					      La_loongarch_regs *__regs,
> +					      unsigned int *__flags,
> +					      const char *__symname,
> +					      long int *__framesizep);
> +extern unsigned int la_loongarch_gnu_pltexit (ElfW (Sym) * __sym,
> +					      unsigned int __ndx,
> +					      uintptr_t *__refcook,
> +					      uintptr_t *__defcook,
> +					      const La_loongarch_regs *__inregs,
> +					      La_loongarch_retval *__outregs,
> +					      const char *__symname);
> +
> +__END_DECLS
> diff --git a/sysdeps/loongarch/bits/setjmp.h b/sysdeps/loongarch/bits/setjmp.h
> new file mode 100644
> index 0000000000..8b323ad2b6
> --- /dev/null
> +++ b/sysdeps/loongarch/bits/setjmp.h
> @@ -0,0 +1,42 @@
> +/* Define the machine-dependent type `jmp_buf'.
> +   Copyright (C) 2022 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 _LOONGARCH_BITS_SETJMP_H
> +#define _LOONGARCH_BITS_SETJMP_H
> +
> +typedef struct __jmp_buf_internal_tag
> +{
> +  /* Program counter.  */
> +  long int __pc;
> +  /* Stack pointer.  */
> +  long int __sp;
> +  /* Reserved */
> +  long int __x;
> +  /* Frame pointer.  */
> +  long int __fp;
> +  /* Callee-saved registers.  */
> +  long int __regs[9];
> +
> +#ifndef __loongarch_soft_float
> +  /* Callee-saved floating point registers.  */
> +  double __fpregs[8];
> +#endif
> +
> +} __jmp_buf[1];
> +
> +#endif /* _LOONGARCH_BITS_SETJMP_H */
> diff --git a/sysdeps/loongarch/bsd-_setjmp.c b/sysdeps/loongarch/bsd-_setjmp.c
> new file mode 100644
> index 0000000000..32f49441c3
> --- /dev/null
> +++ b/sysdeps/loongarch/bsd-_setjmp.c
> @@ -0,0 +1 @@
> +/* _setjmp is implemented in setjmp.S.  */
> diff --git a/sysdeps/loongarch/bsd-setjmp.c b/sysdeps/loongarch/bsd-setjmp.c
> new file mode 100644
> index 0000000000..45fd802aac
> --- /dev/null
> +++ b/sysdeps/loongarch/bsd-setjmp.c
> @@ -0,0 +1 @@
> +/* setjmp is implemented in setjmp.S.  */
> diff --git a/sysdeps/loongarch/dl-machine.h b/sysdeps/loongarch/dl-machine.h
> new file mode 100644
> index 0000000000..68b68e677d
> --- /dev/null
> +++ b/sysdeps/loongarch/dl-machine.h
> @@ -0,0 +1,362 @@
> +/* Machine-dependent ELF dynamic relocation inline functions.
> +   Copyright (C) 2022 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 "LoongArch"
> +
> +#include <entry.h>
> +#include <elf/elf.h>
> +#include <sys/asm.h>
> +#include <dl-tls.h>
> +#include <dl-static-tls.h>
> +#include <dl-machine-rel.h>
> +
> +#ifndef _RTLD_PROLOGUE
> +# define _RTLD_PROLOGUE(entry)					\
> +	".globl\t" __STRING (entry) "\n\t"			\
> +	".type\t" __STRING (entry) ", @function\n\t"		\
> +	CFI_STARTPROC "\n"					\
> +	__STRING (entry) ":\n"
> +#endif
> +
> +#ifndef _RTLD_EPILOGUE
> +# define _RTLD_EPILOGUE(entry)					\
> +	CFI_ENDPROC "\n\t"					\
> +	".size\t" __STRING (entry) ", . - " __STRING (entry) "\n"
> +#endif
> +
> +#define ELF_MACHINE_JMP_SLOT R_LARCH_JUMP_SLOT
> +#define ELF_MACHINE_IRELATIVE R_LARCH_IRELATIVE
> +
> +#define elf_machine_type_class(type)				\
> +  ((ELF_RTYPE_CLASS_PLT * ((type) == ELF_MACHINE_JMP_SLOT	\
> +     || (__WORDSIZE == 32 && (type) == R_LARCH_TLS_DTPREL32)	\
> +     || (__WORDSIZE == 32 && (type) == R_LARCH_TLS_DTPMOD32)	\
> +     || (__WORDSIZE == 32 && (type) == R_LARCH_TLS_TPREL32)	\
> +     || (__WORDSIZE == 64 && (type) == R_LARCH_TLS_DTPREL64)	\
> +     || (__WORDSIZE == 64 && (type) == R_LARCH_TLS_DTPMOD64)	\
> +     || (__WORDSIZE == 64 && (type) == R_LARCH_TLS_TPREL64)))	\
> +   | (ELF_RTYPE_CLASS_COPY * ((type) == R_LARCH_COPY)))
> +
> +#define ELF_MACHINE_NO_REL 1
> +#define ELF_MACHINE_NO_RELA 0
> +
> +/* Return nonzero iff ELF header is compatible with the running host.  */
> +static inline int __attribute_used__

I am almost sure that with GNU C11 that we use to build glibc there is no need
to use __attribute_used__.  I take you are copy/paste from other ports, but it
would be goot to see if we can clean this up.

> +elf_machine_matches_host (const ElfW (Ehdr) * ehdr)
> +{
> +  /* We can only run LoongArch binaries.  */
> +  if (ehdr->e_machine != EM_LOONGARCH)
> +    return 0;
> +
> +  return 1;
> +}
> +
> +/* Runtime address of .got */
> +#define _GLOBAL_OFFSET_TABLE_ \
> +  ({ \
> +    ElfW (Addr) * r; \
> +    asm("la.pcrel %0, _GLOBAL_OFFSET_TABLE_" : "=r"(r)); \
> +    r; \
> +  })
> +
> +/* Return the link-time address of _DYNAMIC.  */
> +static inline ElfW (Addr) elf_machine_dynamic (void)
> +{
> +  return _GLOBAL_OFFSET_TABLE_[0];
> +}
> +
> +#define STRINGXP(X) __STRING (X)
> +#define STRINGXV(X) STRINGV_ (X)
> +#define STRINGV_(...) #__VA_ARGS__

These seems not be used on the patch.

> +
> +/* Return the run-time load address of the shared object.  */
> +static inline ElfW (Addr) elf_machine_load_address (void)
> +{
> +  ElfW (Addr) got_linktime_addr;
> +  asm("la.got %0, _GLOBAL_OFFSET_TABLE_"
> +      /* Link-time address in GOT entry before runtime relocation */
> +      : "=r"(got_linktime_addr));
> +  return (ElfW (Addr)) _GLOBAL_OFFSET_TABLE_ - got_linktime_addr;
> +}
> +
> +/* Initial entry point code for the dynamic linker.
> +   The C function `_dl_start' is the real entry point;
> +   its return value is the user program's entry point.  */
> +
> +#define RTLD_START \
> +  asm(".text\n\
> +      " _RTLD_PROLOGUE (ENTRY_POINT) "\
> +      .cfi_label .Ldummy   \n\
> +      " CFI_UNDEFINED (1) "   \n\
> +      or	$a0, $sp, $zero   \n\
> +      bl	_dl_start   \n\
> +      # Stash user entry point in s0.   \n\
> +      or	$s0, $v0, $zero   \n\
> +      # See if we were run as a command with the executable file   \n\
> +      # name as an extra leading argument.   \n\
> +      la	$a0, _dl_skip_args   \n\
> +      ld.w	$a0, $a0, 0   \n\
> +      # Load the original argument count.   \n\
> +      ld.d	$a1, $sp, 0   \n\
> +      # Subtract _dl_skip_args from it.   \n\
> +      sub.d	$a1, $a1, $a0   \n\
> +      # Adjust the stack pointer to skip _dl_skip_args words.   \n\
> +      slli.d	$a0, $a0, 3   \n\
> +      add.d	$sp, $sp, $a0   \n\
> +      # Save back the modified argument count.   \n\
> +      st.d	$a1, $sp, 0   \n\
> +      # Call _dl_init (struct link_map *main_map, int argc, char **argv, \
> +		       char **env)    \n\
> +      la	$a0, _rtld_local   \n\
> +      ld.d	$a0, $a0, 0   \n\
> +      addi.d	$a2, $sp, 8   \n\
> +      slli.d	$a3, $a1, 3   \n\
> +      add.d	$a3, $a3, $a2   \n\
> +      addi.d	$a3, $a3, 8   \n\
> +      # Adjust $sp for 16-aligned   \n\
> +      srli.d  $t0, $sp, 4   \n\
> +      slli.d  $t0, $t0, 4   \n\
> +      ori	$t1, $sp, 0   \n\
> +      addi.d  $sp, $t0, -32   \n\
> +      st.d	$t1, $sp, 24   \n\
> +      # Call the function to run the initializers.   \n\
> +      bl	_dl_init   \n\
> +      # Pass our finalizer function to _start.   \n\
> +      ld.d    $sp, $sp, 24   \n\
> +      la	$a0, _dl_fini   \n\
> +      # Jump to the user entry point.   \n\
> +      jirl	$zero, $s0, 0   \n\
> +      " _RTLD_EPILOGUE (ENTRY_POINT) "\
> +      .previous");
> +
> +/* Names of the architecture-specific auditing callback functions.  */
> +#define ARCH_LA_PLTENTER loongarch_gnu_pltenter
> +#define ARCH_LA_PLTEXIT loongarch_gnu_pltexit
> +
> +/* Bias .got.plt entry by the offset requested by the PLT header.  */
> +#define elf_machine_plt_value(map, reloc, value) (value)
> +
> +static inline ElfW (Addr)
> +  elf_machine_fixup_plt (struct link_map *map, lookup_t t,

Indentation seeems off here.

> +			 const ElfW (Sym) * refsym, const ElfW (Sym) * sym,
> +			 const ElfW (Rela) * reloc, ElfW (Addr) * reloc_addr,
> +			 ElfW (Addr) value)
> +{
> +  return *reloc_addr = value;
> +}
> +
> +#endif /* !dl_machine_h */
> +
> +#ifdef RESOLVE_MAP
> +
> +/* Perform a relocation described by R_INFO at the location pointed to
> +   by RELOC_ADDR.  SYM is the relocation symbol specified by R_INFO and
> +   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, int skip_ifunc)
> +{
> +  ElfW (Addr) r_info = reloc->r_info;
> +  const unsigned long int r_type = ELFW (R_TYPE) (r_info);
> +  ElfW (Addr) *addr_field = (ElfW (Addr) *) reloc_addr;
> +  const ElfW (Sym) *const __attribute__ ((unused)) refsym = sym;
> +  struct link_map *sym_map = RESOLVE_MAP (map, scope, &sym, version, r_type);
> +  ElfW (Addr) value = 0;
> +  if (sym_map != NULL)
> +    value = SYMBOL_ADDRESS (sym_map, sym, true) + reloc->r_addend;
> +
> +  if (sym != NULL
> +      && __builtin_expect (ELFW (ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
> +      && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
> +      && __builtin_expect (!skip_ifunc, 1))

I think we should use __glibc_likely on newer code, as you are already doing
below.

> +    value = ((ElfW (Addr) (*) (int)) value) (GLRO (dl_hwcap));
> +
> +  switch (r_type)
> +    {
> +#ifndef RTLD_BOOTSTRAP
> +    case __WORDSIZE == 64 ? R_LARCH_TLS_DTPMOD64:
> +    R_LARCH_TLS_DTPMOD32:
> +      if (sym_map)
> +	*addr_field = sym_map->l_tls_modid;
> +      break;
> +
> +    case __WORDSIZE == 64 ? R_LARCH_TLS_DTPREL64:
> +    R_LARCH_TLS_DTPREL32:
> +      if (sym != NULL)
> +	*addr_field = TLS_DTPREL_VALUE (sym) + reloc->r_addend;
> +      break;
> +
> +    case __WORDSIZE == 64 ? R_LARCH_TLS_TPREL64:
> +    R_LARCH_TLS_TPREL32:
> +      if (sym != NULL)
> +	{
> +	  CHECK_STATIC_TLS (map, sym_map);
> +	  *addr_field = TLS_TPREL_VALUE (sym_map, sym) + reloc->r_addend;
> +	}
> +      break;
> +
> +    case R_LARCH_COPY:
> +      {
> +	if (__glibc_unlikely (sym == NULL))
> +	  /* This can happen in trace mode if an object could not be
> +	     found.  */
> +	  break;
> +
> +	/* Handle TLS copy relocations.  */
> +	if (__glibc_unlikely (ELFW (ST_TYPE) (sym->st_info) == STT_TLS))
> +	  {
> +	    /* There's nothing to do if the symbol is in .tbss.  */
> +	    if (__glibc_likely (sym->st_value
> +				>= sym_map->l_tls_initimage_size))
> +	      break;
> +	    value += (ElfW (Addr)) sym_map->l_tls_initimage - sym_map->l_addr;
> +	  }
> +
> +	size_t size = sym->st_size;
> +	if (__glibc_unlikely (sym->st_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, (void *) value, size);
> +	break;
> +      }
> +#endif
> +
> +#if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
> +    case R_LARCH_RELATIVE:
> +      {
> +#if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
> +	/* This is defined in rtld.c, but nowhere in the static libc.a;
> +	   make the reference weak so static programs can still link.
> +	   This declaration cannot be done when compiling rtld.c
> +	   (i.e. #ifdef RTLD_BOOTSTRAP) because rtld.c contains the
> +	   common defn for _dl_rtld_map, which is incompatible with a
> +	   weak decl in the same file.  */
> +#ifndef SHARED
> +	weak_extern (GL (dl_rtld_map));
> +#endif
> +	if (map != &GL (dl_rtld_map)) /* Already done in rtld itself.  */
> +#endif
> +	  *addr_field = map->l_addr + reloc->r_addend;
> +	break;
> +      }
> +#endif
> +
> +    case R_LARCH_JUMP_SLOT:
> +    case __WORDSIZE == 64 ? R_LARCH_64:
> +    R_LARCH_32:
> +      *addr_field = value;
> +      break;
> +
> +    case R_LARCH_IRELATIVE:
> +      value = map->l_addr + reloc->r_addend;
> +      if (__glibc_likely (!skip_ifunc))
> +	value = ((ElfW (Addr) (*) (void)) value) ();
> +      *addr_field = value;
> +      break;
> +
> +    case R_LARCH_NONE:
> +      break;
> +
> +    default:
> +      _dl_reloc_bad_type (map, r_type, 0);
> +      break;
> +    }
> +}
> +
> +static inline void __attribute__ ((always_inline))
> +elf_machine_rela_relative (ElfW (Addr) l_addr, const ElfW (Rela) * reloc,
> +			   void *const reloc_addr)
> +{
> +  *(ElfW (Addr) *) 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)
> +{
> +  ElfW (Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
> +  const unsigned int r_type = ELFW (R_TYPE) (reloc->r_info);
> +
> +  /* Check for unexpected PLT reloc type.  */
> +  if (__glibc_likely (r_type == R_LARCH_JUMP_SLOT))
> +    {
> +      if (__glibc_unlikely (map->l_mach.plt == 0))
> +	{
> +	  if (l_addr)
> +	    *reloc_addr += l_addr;
> +	}
> +      else
> +	*reloc_addr = map->l_mach.plt;
> +    }
> +  else if (__glibc_unlikely (r_type == R_LARCH_IRELATIVE))
> +    {
> +      ElfW (Addr) *value = (void *) (l_addr + reloc->r_addend);
> +      if (__glibc_likely (!skip_ifunc))
> +	value = (ElfW (Addr) *) ((ElfW (Addr) (*) (void)) value) ();
> +      *reloc_addr = (ElfW (Addr)) value;
> +    }
> +  else
> +    _dl_reloc_bad_type (map, r_type, 1);
> +}
> +
> +/* Set up the loaded object described by L so its stub function
> +   will jump to the on-demand fixup code __dl_runtime_resolve.  */
> +
> +static inline int __attribute__ ((always_inline))
> +elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
> +			   int lazy, int profile)
> +{
> +#ifndef RTLD_BOOTSTRAP
> +  /* If using PLTs, fill in the first two entries of .got.plt.  */
> +  if (l->l_info[DT_JMPREL])
> +    {
> +      extern void _dl_runtime_resolve (void)
> +	__attribute__ ((visibility ("hidden")));
> +      ElfW (Addr) *gotplt = (ElfW (Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
> +      /* If a library is prelinked but we have to relocate anyway,
> +	 we have to be able to undo the prelinking of .got.plt.
> +	 The prelinker saved the address of .plt for us here.  */
> +      if (gotplt[1])
> +	l->l_mach.plt = gotplt[1] + l->l_addr;
> +      gotplt[0] = (ElfW (Addr)) & _dl_runtime_resolve;
> +      gotplt[1] = (ElfW (Addr)) l;
> +    }
> +#endif
> +
> +  return lazy;
> +}
> +
> +#endif /* RESOLVE_MAP */
> diff --git a/sysdeps/loongarch/dl-trampoline.S b/sysdeps/loongarch/dl-trampoline.S
> new file mode 100644
> index 0000000000..eb610392f6
> --- /dev/null
> +++ b/sysdeps/loongarch/dl-trampoline.S
> @@ -0,0 +1,91 @@
> +/* PLT trampolines.
> +   Copyright (C) 2022 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>
> +#include <sys/asm.h>
> +
> +/* Assembler veneer called from the PLT header code for lazy loading.
> +   The PLT header passes its own args in t0-t2.  */
> +
> +#ifdef __loongarch_soft_float
> +# define FRAME_SIZE (-((-10 * SZREG) & ALMASK))
> +#else
> +# define FRAME_SIZE (-((-10 * SZREG - 8 * SZFREG) & ALMASK))
> +#endif
> +
> +ENTRY (_dl_runtime_resolve)
> +
> +	/* Save arguments to stack. */
> +	ADDI	sp, sp, -FRAME_SIZE
> +
> +	REG_S	ra, sp, 9*SZREG
> +	REG_S	a0, sp, 1*SZREG
> +	REG_S	a1, sp, 2*SZREG
> +	REG_S	a2, sp, 3*SZREG
> +	REG_S	a3, sp, 4*SZREG
> +	REG_S	a4, sp, 5*SZREG
> +	REG_S	a5, sp, 6*SZREG
> +	REG_S	a6, sp, 7*SZREG
> +	REG_S	a7, sp, 8*SZREG
> +
> +#ifndef __loongarch_soft_float
> +	FREG_S	fa0, sp, 10*SZREG + 0*SZFREG
> +	FREG_S	fa1, sp, 10*SZREG + 1*SZFREG
> +	FREG_S	fa2, sp, 10*SZREG + 2*SZFREG
> +	FREG_S	fa3, sp, 10*SZREG + 3*SZFREG
> +	FREG_S	fa4, sp, 10*SZREG + 4*SZFREG
> +	FREG_S	fa5, sp, 10*SZREG + 5*SZFREG
> +	FREG_S	fa6, sp, 10*SZREG + 6*SZFREG
> +	FREG_S	fa7, sp, 10*SZREG + 7*SZFREG
> +#endif
> +
> +	/* Update .got.plt and obtain runtime address of callee */
> +	SLLI	a1, t1, 1
> +	or	a0, t0, zero
> +	ADD	a1, a1, t1
> +	la	a2, _dl_fixup
> +	jirl	ra, a2, 0
> +	or	t1, v0, zero
> +
> +	/* Restore arguments from stack. */
> +	REG_L	ra, sp, 9*SZREG
> +	REG_L	a0, sp, 1*SZREG
> +	REG_L	a1, sp, 2*SZREG
> +	REG_L	a2, sp, 3*SZREG
> +	REG_L	a3, sp, 4*SZREG
> +	REG_L	a4, sp, 5*SZREG
> +	REG_L	a5, sp, 6*SZREG
> +	REG_L	a6, sp, 7*SZREG
> +	REG_L	a7, sp, 8*SZREG
> +
> +#ifndef __loongarch_soft_float
> +	FREG_L	fa0, sp, 10*SZREG + 0*SZFREG
> +	FREG_L	fa1, sp, 10*SZREG + 1*SZFREG
> +	FREG_L	fa2, sp, 10*SZREG + 2*SZFREG
> +	FREG_L	fa3, sp, 10*SZREG + 3*SZFREG
> +	FREG_L	fa4, sp, 10*SZREG + 4*SZFREG
> +	FREG_L	fa5, sp, 10*SZREG + 5*SZFREG
> +	FREG_L	fa6, sp, 10*SZREG + 6*SZFREG
> +	FREG_L	fa7, sp, 10*SZREG + 7*SZFREG
> +#endif
> +
> +	ADDI	sp, sp, FRAME_SIZE
> +
> +	/* Invoke the callee. */
> +	jirl		zero, t1, 0
> +END (_dl_runtime_resolve)
> diff --git a/sysdeps/loongarch/jmpbuf-offsets.h b/sysdeps/loongarch/jmpbuf-offsets.h
> new file mode 100644
> index 0000000000..a4b8ea690e
> --- /dev/null
> +++ b/sysdeps/loongarch/jmpbuf-offsets.h
> @@ -0,0 +1,22 @@
> +/* Private macros for accessing __jmp_buf contents.
> +   Copyright (C) 2022 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 <jmpbuf-unwind.h>
> +
> +/* Helper for generic ____longjmp_chk().  */
> +#define JB_FRAME_ADDRESS(buf) ((void *) _jmpbuf_sp (buf))
> diff --git a/sysdeps/loongarch/jmpbuf-unwind.h b/sysdeps/loongarch/jmpbuf-unwind.h
> new file mode 100644
> index 0000000000..6fa509151d
> --- /dev/null
> +++ b/sysdeps/loongarch/jmpbuf-unwind.h
> @@ -0,0 +1,45 @@
> +/* Examine __jmp_buf for unwinding frames.
> +   Copyright (C) 2022 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 <setjmp.h>
> +#include <stdint.h>
> +#include <unwind.h>
> +#include <sysdep.h>
> +
> +/* Test if longjmp to JMPBUF would unwind the frame
> +   containing a local variable at ADDRESS.  */
> +#define _JMPBUF_UNWINDS(jmpbuf, address, demangle) \
> +  ((void *) (address) < (void *) demangle ((jmpbuf)[0].__sp))
> +
> +#define _JMPBUF_CFA_UNWINDS_ADJ(_jmpbuf, _context, _adj) \
> +  _JMPBUF_UNWINDS_ADJ (_jmpbuf, (void *) _Unwind_GetCFA (_context), _adj)
> +
> +static inline uintptr_t __attribute__ ((unused)) _jmpbuf_sp (__jmp_buf regs)
> +{
> +  uintptr_t sp = regs[0].__sp;
> +#ifdef PTR_DEMANGLE
> +  PTR_DEMANGLE (sp);
> +#endif
> +  return sp;
> +}
> +
> +#define _JMPBUF_UNWINDS_ADJ(_jmpbuf, _address, _adj) \
> +  ((uintptr_t) (_address) - (_adj) < _jmpbuf_sp (_jmpbuf) - (_adj))
> +
> +/* We use the normal longjmp for unwinding.  */
> +#define __libc_unwind_longjmp(buf, val) __libc_longjmp (buf, val)
> diff --git a/sysdeps/loongarch/ldsodefs.h b/sysdeps/loongarch/ldsodefs.h
> new file mode 100644
> index 0000000000..36b1b25b9f
> --- /dev/null
> +++ b/sysdeps/loongarch/ldsodefs.h
> @@ -0,0 +1,41 @@
> +/* Run-time dynamic linker data structures for loaded ELF shared objects.
> +   Copyright (C) 2022 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 _LOONGARCH_LDSODEFS_H
> +#define _LOONGARCH_LDSODEFS_H 1
> +
> +#include <elf.h>
> +
> +struct La_loongarch_regs;
> +struct La_loongarch_retval;
> +
> +#define ARCH_PLTENTER_MEMBERS \
> +  ElfW (Addr) (*loongarch_gnu_pltenter) (ElfW (Sym) *, unsigned int, \
> +					 uintptr_t *, uintptr_t *, \
> +					 const struct La_loongarch_regs *, \
> +					 unsigned int *, const char *name, \
> +					 long int *framesizep);
> +
> +#define ARCH_PLTEXIT_MEMBERS \
> +  unsigned int (*loongarch_gnu_pltexit) (ElfW (Sym) *, unsigned int, \
> +		uintptr_t *, uintptr_t *, const struct La_loongarch_regs *, \
> +		struct La_loongarch_retval *, const char *);
> +
> +#include_next <ldsodefs.h>
> +
> +#endif
> diff --git a/sysdeps/loongarch/linkmap.h b/sysdeps/loongarch/linkmap.h
> new file mode 100644
> index 0000000000..bbba73ed70
> --- /dev/null
> +++ b/sysdeps/loongarch/linkmap.h
> @@ -0,0 +1,22 @@
> +/* Definition of link_map_machine.
> +   Copyright (C) 2022 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/>.  */
> +
> +struct link_map_machine
> +{
> +  ElfW (Addr) plt; /* Address of .plt.  */
> +};
> diff --git a/sysdeps/loongarch/machine-gmon.h b/sysdeps/loongarch/machine-gmon.h
> new file mode 100644
> index 0000000000..4a3cdd964e
> --- /dev/null
> +++ b/sysdeps/loongarch/machine-gmon.h
> @@ -0,0 +1,37 @@
> +/* LoongArch definitions for profiling support.
> +   Copyright (C) 2022 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/>.  */
> +
> +/* Accept 'frompc' address as argument from the function that calls
> +   _mcount for profiling.  Use  __builtin_return_address (0)
> +   for the 'selfpc' address.  */
> +
> +#include <sysdep.h>
> +
> +static void mcount_internal (unsigned long int frompc,
> +			     unsigned long int selfpc);
> +
> +#define _MCOUNT_DECL(frompc, selfpc) \
> +  static inline void mcount_internal (unsigned long int frompc, \
> +				      unsigned long int selfpc)
> +
> +#define MCOUNT \
> +  void _mcount (void *frompc) \
> +  { \
> +    mcount_internal ((unsigned long int) frompc, \
> +		     (unsigned long int) RETURN_ADDRESS (0)); \
> +  }
> diff --git a/sysdeps/loongarch/setjmp.S b/sysdeps/loongarch/setjmp.S
> new file mode 100644
> index 0000000000..b93ae2f5da
> --- /dev/null
> +++ b/sysdeps/loongarch/setjmp.S
> @@ -0,0 +1,66 @@
> +/* setjmp for LoongArch.
> +   Copyright (C) 2022 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>
> +#include <sys/asm.h>
> +
> +ENTRY (_setjmp)
> +	li.w		a1,0
> +	b		__sigsetjmp
> +END (_setjmp)
> +
> +ENTRY (setjmp)
> +	li.w		a1,1
> +END (setjmp)
> +
> +ENTRY (__sigsetjmp)
> +	REG_S ra, a0, 0*SZREG
> +	REG_S sp, a0, 1*SZREG
> +	REG_S x,  a0, 2*SZREG
> +	REG_S fp, a0, 3*SZREG
> +	REG_S s0, a0, 4*SZREG
> +	REG_S s1, a0, 5*SZREG
> +	REG_S s2, a0, 6*SZREG
> +	REG_S s3, a0, 7*SZREG
> +	REG_S s4, a0, 8*SZREG
> +	REG_S s5, a0, 9*SZREG
> +	REG_S s6, a0, 10*SZREG
> +	REG_S s7, a0, 11*SZREG
> +	REG_S s8, a0, 12*SZREG
> +
> +#ifndef __loongarch_soft_float
> +	FREG_S $f24, a0, 13*SZREG + 0*SZFREG
> +	FREG_S $f25, a0, 13*SZREG + 1*SZFREG
> +	FREG_S $f26, a0, 13*SZREG + 2*SZFREG
> +	FREG_S $f27, a0, 13*SZREG + 3*SZFREG
> +	FREG_S $f28, a0, 13*SZREG + 4*SZFREG
> +	FREG_S $f29, a0, 13*SZREG + 5*SZFREG
> +	FREG_S $f30, a0, 13*SZREG + 6*SZFREG
> +	FREG_S $f31, a0, 13*SZREG + 7*SZFREG
> +#endif
> +
> +#if !IS_IN (libc) && IS_IN(rtld)
> +	li.w		v0, 0
> +	jirl		zero,ra,0
> +#else
> +	b		__sigjmp_save
> +#endif
> +END (__sigsetjmp)
> +
> +hidden_def (__sigsetjmp)
> +weak_alias (_setjmp, __GI__setjmp)
> diff --git a/sysdeps/loongarch/sotruss-lib.c b/sysdeps/loongarch/sotruss-lib.c
> new file mode 100644
> index 0000000000..5b15f4815a
> --- /dev/null
> +++ b/sysdeps/loongarch/sotruss-lib.c
> @@ -0,0 +1,50 @@
> +/* Override generic sotruss-lib.c to define actual functions for LoongArch.
> +   Copyright (C) 2022 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_loongarch_gnu_pltenter (ElfW (Sym) * sym __attribute__ ((unused)),
> +			   unsigned int ndx __attribute__ ((unused)),
> +			   uintptr_t *refcook, uintptr_t *defcook,
> +			   La_loongarch_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_loongarch_gnu_pltexit (ElfW (Sym) * sym, unsigned int ndx,
> +			  uintptr_t *refcook, uintptr_t *defcook,
> +			  const struct La_loongarch_regs *inregs,
> +			  struct La_loongarch_retval *outregs,
> +			  const char *symname)
> +{
> +  print_exit (refcook, defcook, symname, outregs->lrv_a0);
> +
> +  return 0;
> +}
> diff --git a/sysdeps/loongarch/start.S b/sysdeps/loongarch/start.S
> new file mode 100644
> index 0000000000..a9b32aa966
> --- /dev/null
> +++ b/sysdeps/loongarch/start.S
> @@ -0,0 +1,67 @@
> +/* Startup code compliant to the ELF LoongArch ABI.
> +   Copyright (C) 2022 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 <sys/asm.h>
> +
> +/* The entry point's job is to call __libc_start_main.  Per the ABI,
> +   a0 contains the address of a function to be passed to atexit.
> +   __libc_start_main wants this in a5.  */
> +
> +/*
> +int
> +__libc_start_main (int (*main) (int, char **, char **),
> +		   int argc,
> +		   char **argv,
> +		   __typeof (main) init,
> +		   void (*fini) (void),
> +		   void (*rtld_fini) (void),
> +		   void *stack_end);
> + */
> +
> +ENTRY (ENTRY_POINT)
> +
> +/* Terminate call stack by noting ra is undefined.  Use a dummy
> +   .cfi_label to force starting the FDE.  */
> +	.cfi_label .Ldummy
> +	cfi_undefined (1)
> +	or		a5, a0, zero /* rtld_fini */
> +
> +/* We must get symbol main through GOT table, since main may not be local.
> +   For instance: googletest defines main in dynamic library.  */
> +	la.got		a0, t0, main
> +	REG_L		a1, sp, 0
> +	ADDI		a2, sp, SZREG
> +
> +	/* Adjust $sp for 16-aligned */
> +	SRLI		sp, sp, 4
> +	SLLI		sp, sp, 4
> +
> +	move		a3, zero /* used to be init */
> +	move		a4, zero /* used to be fini */
> +	or		a6, sp, zero /* stack_end */
> +
> +	la.got		ra, t0, __libc_start_main
> +	jirl		ra, ra, 0
> +
> +	la.got		ra, t0, abort
> +	jirl		ra, ra, 0
> +END (ENTRY_POINT)
> +
> diff --git a/sysdeps/loongarch/sys/asm.h b/sysdeps/loongarch/sys/asm.h
> new file mode 100644
> index 0000000000..b41ee59694
> --- /dev/null
> +++ b/sysdeps/loongarch/sys/asm.h
> @@ -0,0 +1,59 @@
> +/* Miscellaneous macros.
> +   Copyright (C) 2022 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 _SYS_ASM_H
> +#define _SYS_ASM_H
> +
> +#include <sys/regdef.h>
> +#include <sysdeps/generic/sysdep.h>
> +
> +/* Macros to handle different pointer/register sizes for 32/64-bit code.  */
> +#define SZREG 8
> +#define SZFREG 8
> +#define REG_L ld.d
> +#define REG_S st.d
> +#define SRLI srli.d
> +#define SLLI slli.d
> +#define ADDI addi.d
> +#define ADD  add.d
> +#define BSTRINS  bstrins.d
> +#define LI  li.d
> +#define FREG_L fld.d
> +#define FREG_S fst.d
> +
> +/* Declare leaf routine.  */
> +#define LEAF(symbol) \
> +  .text; \
> +  .globl symbol; \
> +  .align 3; \
> +  cfi_startproc; \
> +  .type symbol, @function; \
> +  symbol:
> +
> +#define ENTRY(symbol) LEAF (symbol)
> +
> +/* Mark end of function.  */
> +#undef END
> +#define END(function) \
> +  cfi_endproc; \
> +  .size function, .- function;
> +
> +/* Stack alignment.  */
> +#define ALMASK ~15
> +
> +#endif /* sys/asm.h */
> diff --git a/sysdeps/loongarch/tst-audit.h b/sysdeps/loongarch/tst-audit.h
> new file mode 100644
> index 0000000000..e71948c86e
> --- /dev/null
> +++ b/sysdeps/loongarch/tst-audit.h
> @@ -0,0 +1,23 @@
> +/* Definitions for testing PLT entry/exit auditing.
> +   Copyright (C) 2022 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_loongarch_gnu_pltenter
> +#define pltexit la_loongarch_gnu_pltexit
> +#define La_regs La_loongarch_regs
> +#define La_retval La_loongarch_retval
> +#define int_retval lrv_a0
> diff --git a/sysdeps/unix/sysv/linux/loongarch/ldconfig.h b/sysdeps/unix/sysv/linux/loongarch/ldconfig.h
> new file mode 100644
> index 0000000000..4887c30ca2
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/loongarch/ldconfig.h
> @@ -0,0 +1,26 @@
> +/* ldconfig default paths and libraries.
> +   Copyright (C) 2022 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
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sysdeps/generic/ldconfig.h>
> +
> +#define SYSDEP_KNOWN_INTERPRETER_NAMES \
> +  { "/lib64/ld-linux-loongarch-lp64d.so.1", FLAG_ELF_LIBC6 },
> +
> +#define SYSDEP_KNOWN_LIBRARY_NAMES	\
> +  { "libc.so.6", FLAG_ELF_LIBC6 },	\
> +  { "libm.so.6", FLAG_ELF_LIBC6 },