Commit 16fb1a9b authored by Nathan Lynch's avatar Nathan Lynch Committed by Catalin Marinas
Browse files

arm64: vdso: clean up vdso_pagelist initialization 



Remove some unnecessary bits that were apparently carried over from
another architecture's implementation:

- No need to get_page() the vdso text/data - these are part of the
  kernel image.
- No need for ClearPageReserved on the vdso text.
- No need to vmap the first text page to check the ELF header - this
  can be done through &vdso_start.

Also some minor cleanup:
- Use kcalloc for vdso_pagelist array allocation.
- Don't print on allocation failure, slab/slub will do that for us.

Signed-off-by: default avatarNathan Lynch <nathan_lynch@mentor.com>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent bb10eb7b

arch/arm64/kernel/vdso.c

+12 −30
Original line number Diff line number Diff line
@@ -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);

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