glibc/sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h
Sudakshina Das 605338745b aarch64: enable BTI at runtime
Binaries can opt-in to using BTI via an ELF object file marking.
The dynamic linker has to then mprotect the executable segments
with PROT_BTI. In case of static linked executables or in case
of the dynamic linker itself, PROT_BTI protection is done by the
operating system.

On AArch64 glibc uses PT_GNU_PROPERTY instead of PT_NOTE to check
the properties of a binary because PT_NOTE can be unreliable with
old linkers (old linkers just append the notes of input objects
together and add them to the output without checking them for
consistency which means multiple incompatible GNU property notes
can be present in PT_NOTE).

BTI property is handled in the loader even if glibc is not built
with BTI support, so in theory user code can be BTI protected
independently of glibc. In practice though user binaries are not
marked with the BTI property if glibc has no support because the
static linked libc objects (crt files, libc_nonshared.a) are
unmarked.

This patch relies on Linux userspace API that is not yet in a
linux release but in v5.8-rc1 so scheduled to be in Linux 5.8.

Co-authored-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-07-08 15:02:37 +01:00

76 lines
2.6 KiB
C

/* Defines for bits in AT_HWCAP. AArch64 Linux version.
Copyright (C) 2016-2020 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/>. */
#if !defined (_SYS_AUXV_H)
# error "Never include <bits/hwcap.h> directly; use <sys/auxv.h> instead."
#endif
/* The following must match the kernel's <asm/hwcap.h> and update the
list together with sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c. */
#define HWCAP_FP (1 << 0)
#define HWCAP_ASIMD (1 << 1)
#define HWCAP_EVTSTRM (1 << 2)
#define HWCAP_AES (1 << 3)
#define HWCAP_PMULL (1 << 4)
#define HWCAP_SHA1 (1 << 5)
#define HWCAP_SHA2 (1 << 6)
#define HWCAP_CRC32 (1 << 7)
#define HWCAP_ATOMICS (1 << 8)
#define HWCAP_FPHP (1 << 9)
#define HWCAP_ASIMDHP (1 << 10)
#define HWCAP_CPUID (1 << 11)
#define HWCAP_ASIMDRDM (1 << 12)
#define HWCAP_JSCVT (1 << 13)
#define HWCAP_FCMA (1 << 14)
#define HWCAP_LRCPC (1 << 15)
#define HWCAP_DCPOP (1 << 16)
#define HWCAP_SHA3 (1 << 17)
#define HWCAP_SM3 (1 << 18)
#define HWCAP_SM4 (1 << 19)
#define HWCAP_ASIMDDP (1 << 20)
#define HWCAP_SHA512 (1 << 21)
#define HWCAP_SVE (1 << 22)
#define HWCAP_ASIMDFHM (1 << 23)
#define HWCAP_DIT (1 << 24)
#define HWCAP_USCAT (1 << 25)
#define HWCAP_ILRCPC (1 << 26)
#define HWCAP_FLAGM (1 << 27)
#define HWCAP_SSBS (1 << 28)
#define HWCAP_SB (1 << 29)
#define HWCAP_PACA (1 << 30)
#define HWCAP_PACG (1UL << 31)
#define HWCAP2_DCPODP (1 << 0)
#define HWCAP2_SVE2 (1 << 1)
#define HWCAP2_SVEAES (1 << 2)
#define HWCAP2_SVEPMULL (1 << 3)
#define HWCAP2_SVEBITPERM (1 << 4)
#define HWCAP2_SVESHA3 (1 << 5)
#define HWCAP2_SVESM4 (1 << 6)
#define HWCAP2_FLAGM2 (1 << 7)
#define HWCAP2_FRINT (1 << 8)
#define HWCAP2_SVEI8MM (1 << 9)
#define HWCAP2_SVEF32MM (1 << 10)
#define HWCAP2_SVEF64MM (1 << 11)
#define HWCAP2_SVEBF16 (1 << 12)
#define HWCAP2_I8MM (1 << 13)
#define HWCAP2_BF16 (1 << 14)
#define HWCAP2_DGH (1 << 15)
#define HWCAP2_RNG (1 << 16)
#define HWCAP2_BTI (1 << 17)