diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/x86/elf-read-prop.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86/elf-read-prop.h | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86/elf-read-prop.h b/sysdeps/unix/sysv/linux/x86/elf-read-prop.h new file mode 100644 index 0000000000..85affa2864 --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86/elf-read-prop.h @@ -0,0 +1,60 @@ +/* Support for GNU properties in ldconfig. x86 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 _ELF_READ_PROP_H +#define _ELF_READ_PROP_H + +#include <dl-cache.h> + +/* Called for each property in the NT_GNU_PROPERTY_TYPE_0 note of SEGMENT. + Return value: + false: Continue processing the properties. + true : Stop processing the properties. + */ +static inline bool __attribute__ ((always_inline)) +read_gnu_property (unsigned int *isal_level, uint32_t type, + uint32_t datasz, void *data) +{ + /* Property type must be in ascending order. */ + if (type > GNU_PROPERTY_X86_ISA_1_NEEDED) + return true; + + if (type == GNU_PROPERTY_X86_ISA_1_NEEDED) + { + if (datasz == 4) + { + /* The size of GNU_PROPERTY_X86_ISA_1_NEEDED must be 4 bytes. + There is no point to continue if this type is ill-formed. */ + unsigned int isa_1_needed = *(unsigned int *) data; + _Static_assert (((sizeof (isa_1_needed) * 8) + <= (1 << DL_CACHE_HWCAP_ISA_LEVEL_COUNT)), + "DL_CACHE_HWCAP_ISA_LEVEL_COUNT is too small"); + if (isa_1_needed != 0) + { + unsigned int level; + asm ("bsr %1, %0" : "=r" (level) : "g" (isa_1_needed)); + *isal_level = level; + } + } + return true; + } + + return false; +} + +#endif |