diff options
Diffstat (limited to 'sysdeps/unix/sysv')
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86/bits/platform/features.h | 48 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/dl-cet.h | 8 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/get-cpuid-feature-leaf.c | 24 |
3 files changed, 80 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86/bits/platform/features.h b/sysdeps/unix/sysv/linux/x86/bits/platform/features.h new file mode 100644 index 0000000000..7704febe92 --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86/bits/platform/features.h @@ -0,0 +1,48 @@ +/* Inline functions for x86 CPU features. + This file is part of the GNU C Library. + Copyright (C) 2024 Free Software Foundation, Inc. + + 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_PLATFORM_X86_H +# error "Never include <bits/platform/features.h> directly; use <sys/platform/x86.h> instead." +#endif + +/* Bits in the feature_1 field in TCB. */ + +enum +{ + x86_feature_1_ibt = 1U << 0, + x86_feature_1_shstk = 1U << 1 +}; + +static __inline__ _Bool +x86_cpu_cet_active (unsigned int __index) +{ +#ifdef __x86_64__ + unsigned int __feature_1; +# ifdef __LP64__ + __asm__ ("mov %%fs:72, %0" : "=r" (__feature_1)); +# else + __asm__ ("mov %%fs:40, %0" : "=r" (__feature_1)); +# endif + if (__index == x86_cpu_IBT) + return __feature_1 & x86_feature_1_ibt; + else + return __feature_1 & x86_feature_1_shstk; +#else + return false; +#endif +} diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h index a00c7ee662..1fe3133406 100644 --- a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h +++ b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h @@ -54,6 +54,14 @@ dl_cet_get_cet_status (void) return status; } +static __always_inline bool +dl_cet_ibt_enabled (void) +{ + unsigned int feature_1 = THREAD_GETMEM (THREAD_SELF, + header.feature_1); + return (feature_1 & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0; +} + /* Enable shadow stack with a macro to avoid shadow stack underflow. */ #define ENABLE_X86_CET(cet_feature) \ if ((cet_feature & GNU_PROPERTY_X86_FEATURE_1_SHSTK)) \ diff --git a/sysdeps/unix/sysv/linux/x86_64/get-cpuid-feature-leaf.c b/sysdeps/unix/sysv/linux/x86_64/get-cpuid-feature-leaf.c new file mode 100644 index 0000000000..39b342463c --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86_64/get-cpuid-feature-leaf.c @@ -0,0 +1,24 @@ +/* Get CPUID feature leaf. Linux/x86-64 version. + Copyright (C) 2024 Free Software Foundation, Inc. + + 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 <sysdeps/x86/get-cpuid-feature-leaf.c> + +#ifdef __LP64__ +_Static_assert (FEATURE_1_OFFSET == 72, "FEATURE_1_OFFSET != 72"); +#else +_Static_assert (FEATURE_1_OFFSET == 40, "FEATURE_1_OFFSET != 40"); +#endif |