diff options
| -rw-r--r-- | sysdeps/aarch64/Makefile | 4 | ||||
| -rw-r--r-- | sysdeps/aarch64/dl-bti.c | 54 | ||||
| -rw-r--r-- | sysdeps/aarch64/dl-prop.h | 63 | ||||
| -rw-r--r-- | sysdeps/aarch64/linkmap.h | 3 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h | 1 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/bits/mman.h | 31 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/cpu-features.c | 3 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/cpu-features.h | 2 |
8 files changed, 161 insertions, 0 deletions
diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile index 9cb141004d..5ae8b082b0 100644 --- a/sysdeps/aarch64/Makefile +++ b/sysdeps/aarch64/Makefile @@ -1,6 +1,10 @@ long-double-fcts = yes ifeq ($(subdir),elf) +sysdep-dl-routines += dl-bti +endif + +ifeq ($(subdir),elf) sysdep-dl-routines += tlsdesc dl-tlsdesc gen-as-const-headers += dl-link.sym diff --git a/sysdeps/aarch64/dl-bti.c b/sysdeps/aarch64/dl-bti.c new file mode 100644 index 0000000000..965ddcc732 --- /dev/null +++ b/sysdeps/aarch64/dl-bti.c @@ -0,0 +1,54 @@ +/* AArch64 BTI functions. + Copyright (C) 2020 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 <unistd.h> +#include <errno.h> +#include <libintl.h> +#include <ldsodefs.h> + +static int +enable_bti (struct link_map *map, const char *program) +{ + const ElfW(Phdr) *phdr; + unsigned prot = PROT_READ | PROT_EXEC | PROT_BTI; + + for (phdr = map->l_phdr; phdr < &map->l_phdr[map->l_phnum]; ++phdr) + if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X)) + { + void *start = (void *) (phdr->p_vaddr + map->l_addr); + size_t len = phdr->p_memsz; + if (__mprotect (start, len, prot) < 0) + { + if (program) + _dl_fatal_printf ("%s: mprotect failed to turn on BTI\n", + map->l_name); + else + _dl_signal_error (errno, map->l_name, "dlopen", + N_("mprotect failed to turn on BTI")); + } + } + return 0; +} + +/* Enable BTI for L if required. */ + +void +_dl_bti_check (struct link_map *l, const char *program) +{ + if (GLRO(dl_aarch64_cpu_features).bti && l->l_mach.bti) + enable_bti (l, program); +} diff --git a/sysdeps/aarch64/dl-prop.h b/sysdeps/aarch64/dl-prop.h new file mode 100644 index 0000000000..b0785bda83 --- /dev/null +++ b/sysdeps/aarch64/dl-prop.h @@ -0,0 +1,63 @@ +/* Support for GNU properties. AArch64 version. + Copyright (C) 2018-2020 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/>. */ + +#ifndef _DL_PROP_H +#define _DL_PROP_H + +extern void _dl_bti_check (struct link_map *, const char *) + attribute_hidden; + +static inline void __attribute__ ((always_inline)) +_rtld_main_check (struct link_map *m, const char *program) +{ + _dl_bti_check (m, program); +} + +static inline void __attribute__ ((always_inline)) +_dl_open_check (struct link_map *m) +{ + _dl_bti_check (m, NULL); +} + +static inline void __attribute__ ((always_inline)) +_dl_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph) +{ +} + +static inline int +_dl_process_gnu_property (struct link_map *l, uint32_t type, uint32_t datasz, + void *data) +{ + if (type == GNU_PROPERTY_AARCH64_FEATURE_1_AND) + { + /* Stop if the property note is ill-formed. */ + if (datasz != 4) + return 0; + + unsigned int feature_1 = *(unsigned int *) data; + if (feature_1 & GNU_PROPERTY_AARCH64_FEATURE_1_BTI) + l->l_mach.bti = true; + + /* Stop if we processed the property note. */ + return 0; + } + /* Continue. */ + return 1; +} + +#endif /* _DL_PROP_H */ diff --git a/sysdeps/aarch64/linkmap.h b/sysdeps/aarch64/linkmap.h index 943a9ee9e4..847a03ace2 100644 --- a/sysdeps/aarch64/linkmap.h +++ b/sysdeps/aarch64/linkmap.h @@ -16,8 +16,11 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ +#include <stdbool.h> + struct link_map_machine { ElfW(Addr) plt; /* Address of .plt */ void *tlsdesc_table; /* Address of TLS descriptor hash table. */ + bool bti; /* Branch Target Identification is enabled. */ }; diff --git a/sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h b/sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h index 4ee14b4208..af90d8a626 100644 --- a/sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h +++ b/sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h @@ -72,3 +72,4 @@ #define HWCAP2_BF16 (1 << 14) #define HWCAP2_DGH (1 << 15) #define HWCAP2_RNG (1 << 16) +#define HWCAP2_BTI (1 << 17) diff --git a/sysdeps/unix/sysv/linux/aarch64/bits/mman.h b/sysdeps/unix/sysv/linux/aarch64/bits/mman.h new file mode 100644 index 0000000000..ecae046344 --- /dev/null +++ b/sysdeps/unix/sysv/linux/aarch64/bits/mman.h @@ -0,0 +1,31 @@ +/* Definitions for POSIX memory map interface. Linux/AArch64 version. + Copyright (C) 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/>. */ + +#ifndef _SYS_MMAN_H +# error "Never use <bits/mman.h> directly; include <sys/mman.h> instead." +#endif + +/* AArch64 specific definitions, should be in sync with + arch/arm64/include/uapi/asm/mman.h. */ + +#define PROT_BTI 0x10 + +#include <bits/mman-map-flags-generic.h> + +/* Include generic Linux declarations. */ +#include <bits/mman-linux.h> diff --git a/sysdeps/unix/sysv/linux/aarch64/cpu-features.c b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c index 896c588fee..b9ab827aca 100644 --- a/sysdeps/unix/sysv/linux/aarch64/cpu-features.c +++ b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c @@ -83,4 +83,7 @@ init_cpu_features (struct cpu_features *cpu_features) if ((dczid & DCZID_DZP_MASK) == 0) cpu_features->zva_size = 4 << (dczid & DCZID_BS_MASK); + + /* Check if BTI is supported. */ + cpu_features->bti = GLRO (dl_hwcap2) & HWCAP2_BTI; } diff --git a/sysdeps/unix/sysv/linux/aarch64/cpu-features.h b/sysdeps/unix/sysv/linux/aarch64/cpu-features.h index 1389cea1b3..a81f186ec2 100644 --- a/sysdeps/unix/sysv/linux/aarch64/cpu-features.h +++ b/sysdeps/unix/sysv/linux/aarch64/cpu-features.h @@ -20,6 +20,7 @@ #define _CPU_FEATURES_AARCH64_H #include <stdint.h> +#include <stdbool.h> #define MIDR_PARTNUM_SHIFT 4 #define MIDR_PARTNUM_MASK (0xfff << MIDR_PARTNUM_SHIFT) @@ -64,6 +65,7 @@ struct cpu_features { uint64_t midr_el1; unsigned zva_size; + bool bti; }; #endif /* _CPU_FEATURES_AARCH64_H */ |