diff options
Diffstat (limited to 'arch/arm64/kernel/vdso.c')
-rw-r--r-- | arch/arm64/kernel/vdso.c | 81 |
1 files changed, 42 insertions, 39 deletions
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 0ea7a22bcdf2..84cafbc3eb54 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -58,7 +58,10 @@ static struct page *vectors_page[1]; static int alloc_vectors_page(void) { extern char __kuser_helper_start[], __kuser_helper_end[]; + extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; + int kuser_sz = __kuser_helper_end - __kuser_helper_start; + int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start; unsigned long vpage; vpage = get_zeroed_page(GFP_ATOMIC); @@ -72,7 +75,7 @@ static int alloc_vectors_page(void) /* sigreturn code */ memcpy((void *)vpage + AARCH32_KERN_SIGRET_CODE_OFFSET, - aarch32_sigret_code, sizeof(aarch32_sigret_code)); + __aarch32_sigret_code_start, sigret_sz); flush_icache_range(vpage, vpage + PAGE_SIZE); vectors_page[0] = virt_to_page(vpage); @@ -103,49 +106,31 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp) static int __init vdso_init(void) { - struct page *pg; - char *vbase; - int i, ret = 0; + int i; + + if (memcmp(&vdso_start, "\177ELF", 4)) { + pr_err("vDSO is not a valid ELF object!\n"); + return -EINVAL; + } vdso_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT; pr_info("vdso: %ld pages (%ld code, %ld data) at base %p\n", vdso_pages + 1, vdso_pages, 1L, &vdso_start); /* Allocate the vDSO pagelist, plus a page for the data. */ - vdso_pagelist = kzalloc(sizeof(struct page *) * (vdso_pages + 1), + vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL); - if (vdso_pagelist == NULL) { - pr_err("Failed to allocate vDSO pagelist!\n"); + if (vdso_pagelist == NULL) return -ENOMEM; - } /* Grab the vDSO code pages. */ - for (i = 0; i < vdso_pages; i++) { - pg = virt_to_page(&vdso_start + i*PAGE_SIZE); - ClearPageReserved(pg); - get_page(pg); - vdso_pagelist[i] = pg; - } - - /* Sanity check the shared object header. */ - vbase = vmap(vdso_pagelist, 1, 0, PAGE_KERNEL); - if (vbase == NULL) { - pr_err("Failed to map vDSO pagelist!\n"); - return -ENOMEM; - } else if (memcmp(vbase, "\177ELF", 4)) { - pr_err("vDSO is not a valid ELF object!\n"); - ret = -EINVAL; - goto unmap; - } + for (i = 0; i < vdso_pages; i++) + vdso_pagelist[i] = virt_to_page(&vdso_start + i * PAGE_SIZE); /* Grab the vDSO data page. */ - pg = virt_to_page(vdso_data); - get_page(pg); - vdso_pagelist[i] = pg; + vdso_pagelist[i] = virt_to_page(vdso_data); -unmap: - vunmap(vbase); - return ret; + return 0; } arch_initcall(vdso_init); @@ -153,11 +138,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { struct mm_struct *mm = current->mm; - unsigned long vdso_base, vdso_mapping_len; + unsigned long vdso_base, vdso_text_len, vdso_mapping_len; int ret; + vdso_text_len = vdso_pages << PAGE_SHIFT; /* Be sure to map the data page */ - vdso_mapping_len = (vdso_pages + 1) << PAGE_SHIFT; + vdso_mapping_len = vdso_text_len + PAGE_SIZE; down_write(&mm->mmap_sem); vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); @@ -167,35 +153,52 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, } mm->context.vdso = (void *)vdso_base; - ret = install_special_mapping(mm, vdso_base, vdso_mapping_len, + ret = install_special_mapping(mm, vdso_base, vdso_text_len, VM_READ|VM_EXEC| VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, vdso_pagelist); - if (ret) { - mm->context.vdso = NULL; + if (ret) + goto up_fail; + + vdso_base += vdso_text_len; + ret = install_special_mapping(mm, vdso_base, PAGE_SIZE, + VM_READ|VM_MAYREAD, + vdso_pagelist + vdso_pages); + if (ret) goto up_fail; - } -up_fail: up_write(&mm->mmap_sem); + return 0; +up_fail: + mm->context.vdso = NULL; + up_write(&mm->mmap_sem); return ret; } const char *arch_vma_name(struct vm_area_struct *vma) { + unsigned long vdso_text; + + if (!vma->vm_mm) + return NULL; + + vdso_text = (unsigned long)vma->vm_mm->context.vdso; + /* * We can re-use the vdso pointer in mm_context_t for identifying * the vectors page for compat applications. The vDSO will always * sit above TASK_UNMAPPED_BASE and so we don't need to worry about * it conflicting with the vectors base. */ - if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) { + if (vma->vm_start == vdso_text) { #ifdef CONFIG_COMPAT if (vma->vm_start == AARCH32_VECTORS_BASE) return "[vectors]"; #endif return "[vdso]"; + } else if (vma->vm_start == (vdso_text + (vdso_pages << PAGE_SHIFT))) { + return "[vvar]"; } return NULL; |