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ee7f4c54e1
This patch adds a new feature for powerpc. In order to get faster
access to the HWCAP3/HWCAP4 masks, similar to HWCAP/HWCAP2 (i.e. for
implementing __builtin_cpu_supports() in GCC) without the overhead of
reading them from the auxiliary vector, we now reserve space for them
in the TCB.
Suggested-by: Peter Bergner <bergner@linux.ibm.com>
Reviewed-by: Peter Bergner <bergner@linux.ibm.com>
(cherry picked from commit 3ab9b88e2a)
64 lines
2.3 KiB
C
64 lines
2.3 KiB
C
/* Parse the Linux auxiliary vector.
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Copyright (C) 1995-2024 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <elf.h>
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#include <entry.h>
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#include <fpu_control.h>
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#include <ldsodefs.h>
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#include <link.h>
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typedef ElfW(Addr) dl_parse_auxv_t[AT_MINSIGSTKSZ + 1];
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/* Copy the auxiliary vector into AUXV_VALUES and set up GLRO
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variables. */
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static inline
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void _dl_parse_auxv (ElfW(auxv_t) *av, dl_parse_auxv_t auxv_values)
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{
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auxv_values[AT_ENTRY] = (ElfW(Addr)) ENTRY_POINT;
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auxv_values[AT_PAGESZ] = EXEC_PAGESIZE;
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auxv_values[AT_FPUCW] = _FPU_DEFAULT;
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/* NB: Default to a constant CONSTANT_MINSIGSTKSZ. */
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_Static_assert (__builtin_constant_p (CONSTANT_MINSIGSTKSZ),
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"CONSTANT_MINSIGSTKSZ is constant");
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auxv_values[AT_MINSIGSTKSZ] = CONSTANT_MINSIGSTKSZ;
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for (; av->a_type != AT_NULL; av++)
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if (av->a_type <= AT_MINSIGSTKSZ)
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auxv_values[av->a_type] = av->a_un.a_val;
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GLRO(dl_pagesize) = auxv_values[AT_PAGESZ];
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__libc_enable_secure = auxv_values[AT_SECURE];
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GLRO(dl_platform) = (void *) auxv_values[AT_PLATFORM];
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GLRO(dl_hwcap) = auxv_values[AT_HWCAP];
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GLRO(dl_hwcap2) = auxv_values[AT_HWCAP2];
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GLRO(dl_hwcap3) = auxv_values[AT_HWCAP3];
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GLRO(dl_hwcap4) = auxv_values[AT_HWCAP4];
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GLRO(dl_clktck) = auxv_values[AT_CLKTCK];
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GLRO(dl_fpu_control) = auxv_values[AT_FPUCW];
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_dl_random = (void *) auxv_values[AT_RANDOM];
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GLRO(dl_minsigstacksize) = auxv_values[AT_MINSIGSTKSZ];
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GLRO(dl_sysinfo_dso) = (void *) auxv_values[AT_SYSINFO_EHDR];
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#ifdef NEED_DL_SYSINFO
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if (GLRO(dl_sysinfo_dso) != NULL)
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GLRO(dl_sysinfo) = auxv_values[AT_SYSINFO];
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#endif
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DL_PLATFORM_AUXV
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}
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