diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 428dcaa152..bf8c1bd253 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -1522,6 +1522,28 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, #include "elf.h" +/* We must delay the following stanzas until after "elf.h". */ +#if defined(TARGET_AARCH64) + +static bool arch_parse_elf_property(uint32_t pr_type, uint32_t pr_datasz, + const uint32_t *data, + struct image_info *info, + Error **errp) +{ + if (pr_type == GNU_PROPERTY_AARCH64_FEATURE_1_AND) { + if (pr_datasz != sizeof(uint32_t)) { + error_setg(errp, "Ill-formed GNU_PROPERTY_AARCH64_FEATURE_1_AND"); + return false; + } + /* We will extract GNU_PROPERTY_AARCH64_FEATURE_1_BTI later. */ + info->note_flags = *data; + } + return true; +} +#define ARCH_USE_GNU_PROPERTY 1 + +#else + static bool arch_parse_elf_property(uint32_t pr_type, uint32_t pr_datasz, const uint32_t *data, struct image_info *info, @@ -1531,6 +1553,8 @@ static bool arch_parse_elf_property(uint32_t pr_type, uint32_t pr_datasz, } #define ARCH_USE_GNU_PROPERTY 0 +#endif + struct exec { unsigned int a_info; /* Use macros N_MAGIC, etc for access */ @@ -2545,7 +2569,7 @@ static void load_elf_image(const char *image_name, int image_fd, struct elfhdr *ehdr = (struct elfhdr *)bprm_buf; struct elf_phdr *phdr; abi_ulong load_addr, load_bias, loaddr, hiaddr, error; - int i, retval; + int i, retval, prot_exec; Error *err = NULL; /* First of all, some simple consistency checks */ @@ -2712,6 +2736,26 @@ static void load_elf_image(const char *image_name, int image_fd, info->brk = 0; info->elf_flags = ehdr->e_flags; + prot_exec = PROT_EXEC; +#ifdef TARGET_AARCH64 + /* + * If the BTI feature is present, this indicates that the executable + * pages of the startup binary should be mapped with PROT_BTI, so that + * branch targets are enforced. + * + * The startup binary is either the interpreter or the static executable. + * The interpreter is responsible for all pages of a dynamic executable. + * + * Elf notes are backward compatible to older cpus. + * Do not enable BTI unless it is supported. + */ + if ((info->note_flags & GNU_PROPERTY_AARCH64_FEATURE_1_BTI) + && (pinterp_name == NULL || *pinterp_name == 0) + && cpu_isar_feature(aa64_bti, ARM_CPU(thread_cpu))) { + prot_exec |= TARGET_PROT_BTI; + } +#endif + for (i = 0; i < ehdr->e_phnum; i++) { struct elf_phdr *eppnt = phdr + i; if (eppnt->p_type == PT_LOAD) { @@ -2725,7 +2769,7 @@ static void load_elf_image(const char *image_name, int image_fd, elf_prot |= PROT_WRITE; } if (eppnt->p_flags & PF_X) { - elf_prot |= PROT_EXEC; + elf_prot |= prot_exec; } vaddr = load_bias + eppnt->p_vaddr;