efi/x86: Free efi_pgd with free_pages() (c2fe61d8) · Commits · 戴 / test

Commit ("x86/mm/pti: Allocate a separate user PGD") changed the PGD allocation to allocate PGD_ALLOCATION_ORDER pages, so in the error path it should be freed using free_pages() rather than free_page(). Commit ("x86/efi: Free efi_pgd with free_pages()") fixed one instance of this, but missed another. Move the freeing out-of-line to avoid code duplication and fix this bug. Fixes: ("x86/mm/pti: Allocate a separate user PGD") Link: https://lore.kernel.org/r/20201110163919.1134431-1-nivedita@alum.mit.edu Signed-off-by:

Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by:

Ard Biesheuvel <ardb@kernel.org>

arch/x86/platform/efi/efi_64.c

+13 −11

Original line number	Diff line number	Diff line
		@@ -78,28 +78,30 @@ int __init efi_alloc_page_tables(void)
		gfp_mask = GFP_KERNEL \| __GFP_ZERO;
		efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
		if (!efi_pgd)
		return -ENOMEM;
		goto fail;

		pgd = efi_pgd + pgd_index(EFI_VA_END);
		p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
		if (!p4d) {
		free_page((unsigned long)efi_pgd);
		return -ENOMEM;
		}
		if (!p4d)
		goto free_pgd;

		pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
		if (!pud) {
		if (pgtable_l5_enabled())
		free_page((unsigned long) pgd_page_vaddr(*pgd));
		free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
		return -ENOMEM;
		}
		if (!pud)
		goto free_p4d;

		efi_mm.pgd = efi_pgd;
		mm_init_cpumask(&efi_mm);
		init_new_context(NULL, &efi_mm);

		return 0;

		free_p4d:
		if (pgtable_l5_enabled())
		free_page((unsigned long)pgd_page_vaddr(*pgd));
		free_pgd:
		free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
		fail:
		return -ENOMEM;
		}

		/*

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