diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux')
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86/cpu-features.c | 49 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86/dl-cet.h | 27 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/dl-cet.h | 47 |
3 files changed, 72 insertions, 51 deletions
diff --git a/sysdeps/unix/sysv/linux/x86/cpu-features.c b/sysdeps/unix/sysv/linux/x86/cpu-features.c deleted file mode 100644 index 0e6e2bf855..0000000000 --- a/sysdeps/unix/sysv/linux/x86/cpu-features.c +++ /dev/null @@ -1,49 +0,0 @@ -/* Initialize CPU feature data for Linux/x86. - This file is part of the GNU C Library. - Copyright (C) 2018-2023 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/>. */ - -#if CET_ENABLED -# include <sys/prctl.h> -# include <asm/prctl.h> - -static inline int __attribute__ ((always_inline)) -get_cet_status (void) -{ - unsigned long long kernel_feature; - unsigned int status = 0; - if (INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_STATUS, - &kernel_feature) == 0) - { - if ((kernel_feature & ARCH_SHSTK_SHSTK) != 0) - status = GNU_PROPERTY_X86_FEATURE_1_SHSTK; - } - return status; -} - -# ifndef SHARED -static inline void -x86_setup_tls (void) -{ - __libc_setup_tls (); - THREAD_SETMEM (THREAD_SELF, header.feature_1, GL(dl_x86_feature_1)); -} - -# define ARCH_SETUP_TLS() x86_setup_tls () -# endif -#endif - -#include <sysdeps/x86/cpu-features.c> diff --git a/sysdeps/unix/sysv/linux/x86/dl-cet.h b/sysdeps/unix/sysv/linux/x86/dl-cet.h index da220ac627..6ad5e03f69 100644 --- a/sysdeps/unix/sysv/linux/x86/dl-cet.h +++ b/sysdeps/unix/sysv/linux/x86/dl-cet.h @@ -18,7 +18,7 @@ #include <sys/prctl.h> #include <asm/prctl.h> -static inline int __attribute__ ((always_inline)) +static __always_inline int dl_cet_disable_cet (unsigned int cet_feature) { if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK) @@ -28,7 +28,7 @@ dl_cet_disable_cet (unsigned int cet_feature) kernel_feature); } -static inline int __attribute__ ((always_inline)) +static __always_inline int dl_cet_lock_cet (unsigned int cet_feature) { if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK) @@ -38,3 +38,26 @@ dl_cet_lock_cet (unsigned int cet_feature) return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_LOCK, kernel_feature); } + +static __always_inline unsigned int +dl_cet_get_cet_status (void) +{ + unsigned long long kernel_feature; + unsigned int status = 0; + if (INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_STATUS, + &kernel_feature) == 0) + { + if ((kernel_feature & ARCH_SHSTK_SHSTK) != 0) + status = GNU_PROPERTY_X86_FEATURE_1_SHSTK; + } + return status; +} + +/* 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)) \ + { \ + long long int kernel_feature = ARCH_SHSTK_SHSTK; \ + INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_ENABLE, \ + kernel_feature); \ + } diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h new file mode 100644 index 0000000000..e23e05c6b8 --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h @@ -0,0 +1,47 @@ +/* Linux/x86-64 CET initializers function. + Copyright (C) 2023 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 <cpu-features-offsets.h> +#include_next <dl-cet.h> + +#define X86_STRINGIFY_1(x) #x +#define X86_STRINGIFY(x) X86_STRINGIFY_1 (x) + +/* Enable shadow stack before calling _dl_init if it is enabled in + GL(dl_x86_feature_1). Call _dl_setup_x86_features to setup shadow + stack. */ +#define RTLD_START_ENABLE_X86_FEATURES \ +"\ + # Check if shadow stack is enabled in GL(dl_x86_feature_1).\n\ + movl _rtld_local+" X86_STRINGIFY (RTLD_GLOBAL_DL_X86_FEATURE_1_OFFSET) "(%rip), %edx\n\ + testl $" X86_STRINGIFY (X86_FEATURE_1_SHSTK) ", %edx\n\ + jz 1f\n\ + # Enable shadow stack if enabled in GL(dl_x86_feature_1).\n\ + movl $" X86_STRINGIFY (ARCH_SHSTK_SHSTK) ", %esi\n\ + movl $" X86_STRINGIFY (ARCH_SHSTK_ENABLE) ", %edi\n\ + movl $" X86_STRINGIFY (__NR_arch_prctl) ", %eax\n\ + syscall\n\ +1:\n\ + # Pass GL(dl_x86_feature_1) to _dl_cet_setup_features.\n\ + movl %edx, %edi\n\ + # Align stack for the _dl_cet_setup_features call.\n\ + andq $-16, %rsp\n\ + call _dl_cet_setup_features\n\ + # Restore %rax and %rsp from %r12 and %r13.\n\ + movq %r12, %rax\n\ + movq %r13, %rsp\n\ +" |