[PATCH v2 10/14] LoongArch: Linux Startup and Dynamic Loading Code

[caiyinyu]

在 2022/1/4 下午10:27, Adhemerval Zanella 写道:
> On 31/12/2021 03:44, caiyinyu wrote:
>> This contains the Linux-specific code for loading programs on LoongArch.
>> ---
>>   sysdeps/unix/sysv/linux/loongarch/dl-static.c | 80 +++++++++++++++++++
>>   sysdeps/unix/sysv/linux/loongarch/ldsodefs.h  | 33 ++++++++
>>   2 files changed, 113 insertions(+)
>>   create mode 100644 sysdeps/unix/sysv/linux/loongarch/dl-static.c
>>   create mode 100644 sysdeps/unix/sysv/linux/loongarch/ldsodefs.h
>>
>> diff --git a/sysdeps/unix/sysv/linux/loongarch/dl-static.c b/sysdeps/unix/sysv/linux/loongarch/dl-static.c
>> new file mode 100644
>> index 0000000000..b9a7b2a61f
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/loongarch/dl-static.c
>> @@ -0,0 +1,80 @@
>> +/* dl_static_init for loongarch.
>> +   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 <ldsodefs.h>
>> +
>> +#ifdef SHARED
>> +
>> +void
>> +_dl_var_init (void *array[])
>> +{
>> +  /* It has to match "variables" below.  */
>> +  enum
>> +  {
>> +    DL_PAGESIZE = 0
>> +  };
>> +
>> +  GLRO (dl_pagesize) = *((size_t *) array[DL_PAGESIZE]);
>> +}
>> +
>> +#else
>> +
>> +static void *variables[] = {&GLRO (dl_pagesize)};
>> +
>> +static void _dl_unprotect_relro (struct link_map *l)
>> +{
>> +  ElfW (Addr) start = ((l->l_addr + l->l_relro_addr)
>> +			& ~(GLRO (dl_pagesize) - 1));
>> +  ElfW (Addr) end = ((l->l_addr + l->l_relro_addr + l->l_relro_size)
>> +		      & ~(GLRO (dl_pagesize) - 1));
>> +
>> +  if (start != end)
>> +    __mprotect ((void *) start, end - start, PROT_READ | PROT_WRITE);
>> +}
>> +
>> +void dl_static_init (struct link_map *l)
>> +{
>> +  struct link_map *rtld_map = l;
>> +  struct r_scope_elem **scope;
>> +  const ElfW (Sym) *ref = NULL;
>> +  lookup_t loadbase;
>> +  void (*f) (void *[]);
>> +  size_t i;
>> +
>> +  loadbase = _dl_lookup_symbol_x ("_dl_var_init", l, &ref, l->l_local_scope,
>> +				  NULL, 0, 1, NULL);
>> +
>> +  for (scope = l->l_local_scope; *scope != NULL; scope++)
>> +    for (i = 0; i < (*scope)->r_nlist; i++)
>> +      if ((*scope)->r_list[i] == loadbase)
>> +	{
>> +	  rtld_map = (*scope)->r_list[i];
>> +	  break;
>> +	}
>> +
>> +  if (ref != NULL)
>> +    {
>> +      f = (void (*) (void *[])) DL_SYMBOL_ADDRESS (loadbase, ref);
>> +      _dl_unprotect_relro (rtld_map);
>> +      f (variables);
>> +      _dl_protect_relro (rtld_map);
>> +    }
>> +}
>> +
>> +#endif
> This file should not be required, Florian has refactored it to avoid this
> boilerplate code (check bdc90abc48f0528588600df37eebdc04ce01b2f0 and
> related commits).
Removed and modified related code.
>
>> diff --git a/sysdeps/unix/sysv/linux/loongarch/ldsodefs.h b/sysdeps/unix/sysv/linux/loongarch/ldsodefs.h
>> new file mode 100644
>> index 0000000000..680baf2edc
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/loongarch/ldsodefs.h
>> @@ -0,0 +1,33 @@
>> +/* 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 _LDSODEFS_H
>> +
>> +/* Get the real definitions.  */
>> +#include_next <ldsodefs.h>
>> +
>> +/* Now define our stuff.  */
>> +
>> +/* We need special support to initialize DSO loaded for statically linked
>> +   binaries.  */
>> +extern void _dl_static_init (struct link_map *map);
>> +#undef DL_STATIC_INIT
>> +#define DL_STATIC_INIT(map) _dl_static_init (map)
>> +
>> +#endif /* ldsodefs.h */
> Same as before.
Removed.