Merge remote-tracking branch 'lsk/v3.10/topic/gator' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / kernel / vdso.c

diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index a7149cae16153bbacec32c420e1661b38b8aabd6..84cafbc3eb5452ca621190c3cde0305852b2f315 100644 (file)
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -106,49 +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);
 
@@ -156,11 +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);
@@ -170,35 +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;