diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 491e754f72..47b5ce3005 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -4166,37 +4166,23 @@ static int vma_get_mapping_count(const struct mm_struct *mm) */ static abi_ulong vma_dump_size(const struct vm_area_struct *vma) { - /* if we cannot even read the first page, skip it */ - if (!access_ok_untagged(VERIFY_READ, vma->vma_start, TARGET_PAGE_SIZE)) - return (0); + /* The area must be readable. */ + if (!(vma->vma_flags & PROT_READ)) { + return 0; + } /* * Usually we don't dump executable pages as they contain * non-writable code that debugger can read directly from - * target library etc. However, thread stacks are marked - * also executable so we read in first page of given region - * and check whether it contains elf header. If there is - * no elf header, we dump it. + * target library etc. If there is no elf header, we dump it. */ - if (vma->vma_flags & PROT_EXEC) { - char page[TARGET_PAGE_SIZE]; - - if (copy_from_user(page, vma->vma_start, sizeof (page))) { - return 0; - } - if ((page[EI_MAG0] == ELFMAG0) && - (page[EI_MAG1] == ELFMAG1) && - (page[EI_MAG2] == ELFMAG2) && - (page[EI_MAG3] == ELFMAG3)) { - /* - * Mappings are possibly from ELF binary. Don't dump - * them. - */ - return (0); - } + if (!(vma->vma_flags & PROT_WRITE) && + (vma->vma_flags & PROT_EXEC) && + memcmp(g2h_untagged(vma->vma_start), ELFMAG, SELFMAG) == 0) { + return 0; } - return (vma->vma_end - vma->vma_start); + return vma->vma_end - vma->vma_start; } static int vma_walker(void *priv, target_ulong start, target_ulong end,