diff options
Diffstat (limited to 'sysdeps/aarch64/dl-bti.c')
-rw-r--r-- | sysdeps/aarch64/dl-bti.c | 54 |
1 files changed, 54 insertions, 0 deletions
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); +} |