Commit 31d17076 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Andrew Morton
Browse files

mm/debug_vm_pgtable: drop protection_map[] usage 

Patch series "mm: protection_map[] cleanups".


This patch (of 2):

Although protection_map[] contains the platform defined page protection
map for a given vm_flags combination, vm_get_page_prot() is the right
interface to use.  This will also reduce dependency on protection_map[]
which is going to be dropped off completely later on.

Link: https://lkml.kernel.org/r/20220404031840.588321-1-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/20220404031840.588321-2-anshuman.khandual@arm.com


Signed-off-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent b191c9bc

mm/debug_vm_pgtable.c

+19 −12
Original line number Diff line number Diff line
@@ -93,7 +93,7 @@ struct pgtable_debug_args { 


static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx)

{

	pgprot_t prot = protection_map[idx];

	pgprot_t prot = vm_get_page_prot(idx);

	pte_t pte = pfn_pte(args->fixed_pte_pfn, prot);

	unsigned long val = idx, *ptr = &val;
@@ -101,7 +101,7 @@ static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx) 


	/*

	 * This test needs to be executed after the given page table entry

	 * is created with pfn_pte() to make sure that protection_map[idx]

	 * is created with pfn_pte() to make sure that vm_get_page_prot(idx)

	 * does not have the dirty bit enabled from the beginning. This is

	 * important for platforms like arm64 where (!PTE_RDONLY) indicate

	 * dirty bit being set.
@@ -190,7 +190,7 @@ static void __init pte_savedwrite_tests(struct pgtable_debug_args *args) 
#ifdef CONFIG_TRANSPARENT_HUGEPAGE

static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)

{

	pgprot_t prot = protection_map[idx];

	pgprot_t prot = vm_get_page_prot(idx);

	unsigned long val = idx, *ptr = &val;

	pmd_t pmd;
@@ -202,7 +202,7 @@ static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) 


	/*

	 * This test needs to be executed after the given page table entry

	 * is created with pfn_pmd() to make sure that protection_map[idx]

	 * is created with pfn_pmd() to make sure that vm_get_page_prot(idx)

	 * does not have the dirty bit enabled from the beginning. This is

	 * important for platforms like arm64 where (!PTE_RDONLY) indicate

	 * dirty bit being set.
@@ -325,7 +325,7 @@ static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args) 
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD

static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)

{

	pgprot_t prot = protection_map[idx];

	pgprot_t prot = vm_get_page_prot(idx);

	unsigned long val = idx, *ptr = &val;

	pud_t pud;
@@ -337,7 +337,7 @@ static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) 


	/*

	 * This test needs to be executed after the given page table entry

	 * is created with pfn_pud() to make sure that protection_map[idx]

	 * is created with pfn_pud() to make sure that vm_get_page_prot(idx)

	 * does not have the dirty bit enabled from the beginning. This is

	 * important for platforms like arm64 where (!PTE_RDONLY) indicate

	 * dirty bit being set.
@@ -1106,14 +1106,14 @@ static int __init init_args(struct pgtable_debug_args *args) 
	/*

	 * Initialize the debugging data.

	 *

	 * protection_map[0] (or even protection_map[8]) will help create

	 * page table entries with PROT_NONE permission as required for

	 * pxx_protnone_tests().

	 * vm_get_page_prot(VM_NONE) or vm_get_page_prot(VM_SHARED|VM_NONE)

	 * will help create page table entries with PROT_NONE permission as

	 * required for pxx_protnone_tests().

	 */

	memset(args, 0, sizeof(*args));

	args->vaddr              = get_random_vaddr();

	args->page_prot          = vm_get_page_prot(VMFLAGS);

	args->page_prot_none     = protection_map[0];

	args->page_prot_none     = vm_get_page_prot(VM_NONE);

	args->is_contiguous_page = false;

	args->pud_pfn            = ULONG_MAX;

	args->pmd_pfn            = ULONG_MAX;
@@ -1248,12 +1248,19 @@ static int __init debug_vm_pgtable(void) 
		return ret;



	/*

	 * Iterate over the protection_map[] to make sure that all

	 * Iterate over each possible vm_flags to make sure that all

	 * the basic page table transformation validations just hold

	 * true irrespective of the starting protection value for a

	 * given page table entry.

	 *

	 * Protection based vm_flags combinatins are always linear

	 * and increasing i.e starting from VM_NONE and going upto

	 * (VM_SHARED | READ | WRITE | EXEC).

	 */

	for (idx = 0; idx < ARRAY_SIZE(protection_map); idx++) {

#define VM_FLAGS_START	(VM_NONE)

#define VM_FLAGS_END	(VM_SHARED | VM_EXEC | VM_WRITE | VM_READ)



	for (idx = VM_FLAGS_START; idx <= VM_FLAGS_END; idx++) {

		pte_basic_tests(&args, idx);

		pmd_basic_tests(&args, idx);

		pud_basic_tests(&args, idx);