mm/vma: convert __mmap_region() to use vma_flags_t

Update the mmap() implementation logic implemented in __mmap_region() and
functions invoked by it.  The mmap_region() function converts its input
vm_flags_t parameter to a vma_flags_t value which it then passes to
__mmap_region() which uses the vma_flags_t value consistently from then
on.

As part of the change, we convert map_deny_write_exec() to using
vma_flags_t (it was incorrectly using unsigned long before), and place it
in vma.h, as it is only used internal to mm.

With this change, we eliminate the legacy is_shared_maywrite_vm_flags()
helper function which is now no longer required.

We are also able to update the MMAP_STATE() and VMG_MMAP_STATE() macros to
use the vma_flags_t value.

Finally, we update the VMA tests to reflect the change.

Link: https://lkml.kernel.org/r/1fc33a404c962f02da778da100387cc19bd62153.1774034900.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Kees Cook <kees@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2 files changed, 13 insertions, 39 deletions

diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h
index 9dd57f50ea6d..ab92358b082c 100644
--- a/tools/testing/vma/include/dup.h
+++ b/tools/testing/vma/include/dup.h
@@ -1124,12 +1124,6 @@ static __always_inline void vma_desc_clear_flags_mask(struct vm_area_desc *desc,
 #define vma_desc_clear_flags(desc, ...) \
 	vma_desc_clear_flags_mask(desc, mk_vma_flags(__VA_ARGS__))
 
-static inline bool is_shared_maywrite_vm_flags(vm_flags_t vm_flags)
-{
-	return (vm_flags & (VM_SHARED | VM_MAYWRITE)) ==
-		(VM_SHARED | VM_MAYWRITE);
-}
-
 static inline bool is_shared_maywrite(const vma_flags_t *flags)
 {
 	return vma_flags_test_all(flags, VMA_SHARED_BIT, VMA_MAYWRITE_BIT);
@@ -1446,27 +1440,6 @@ static inline bool mlock_future_ok(const struct mm_struct *mm,
 	return locked_pages <= limit_pages;
 }
 
-static inline bool map_deny_write_exec(unsigned long old, unsigned long new)
-{
-	/* If MDWE is disabled, we have nothing to deny. */
-	if (mm_flags_test(MMF_HAS_MDWE, current->mm))
-		return false;
-
-	/* If the new VMA is not executable, we have nothing to deny. */
-	if (!(new & VM_EXEC))
-		return false;
-
-	/* Under MDWE we do not accept newly writably executable VMAs... */
-	if (new & VM_WRITE)
-		return true;
-
-	/* ...nor previously non-executable VMAs becoming executable. */
-	if (!(old & VM_EXEC))
-		return true;
-
-	return false;
-}
-
 static inline int mapping_map_writable(struct address_space *mapping)
 {
 	return atomic_inc_unless_negative(&mapping->i_mmap_writable) ?
@@ -1518,3 +1491,10 @@ static inline int get_sysctl_max_map_count(void)
 #ifndef pgtable_supports_soft_dirty
 #define pgtable_supports_soft_dirty()	IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)
 #endif
+
+static inline pgprot_t vma_get_page_prot(vma_flags_t vma_flags)
+{
+	const vm_flags_t vm_flags = vma_flags_to_legacy(vma_flags);
+
+	return vm_get_page_prot(vm_flags);
+}
diff --git a/tools/testing/vma/tests/mmap.c b/tools/testing/vma/tests/mmap.c
index bded4ecbe5db..c85bc000d1cb 100644
--- a/tools/testing/vma/tests/mmap.c
+++ b/tools/testing/vma/tests/mmap.c
@@ -2,6 +2,8 @@
 
 static bool test_mmap_region_basic(void)
 {
+	const vma_flags_t vma_flags = mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT,
+			VMA_MAYREAD_BIT, VMA_MAYWRITE_BIT);
 	struct mm_struct mm = {};
 	unsigned long addr;
 	struct vm_area_struct *vma;
@@ -10,27 +12,19 @@ static bool test_mmap_region_basic(void)
 	current->mm = &mm;
 
 	/* Map at 0x300000, length 0x3000. */
-	addr = __mmap_region(NULL, 0x300000, 0x3000,
-			     VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE,
-			     0x300, NULL);
+	addr = __mmap_region(NULL, 0x300000, 0x3000, vma_flags, 0x300, NULL);
 	ASSERT_EQ(addr, 0x300000);
 
 	/* Map at 0x250000, length 0x3000. */
-	addr = __mmap_region(NULL, 0x250000, 0x3000,
-			     VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE,
-			     0x250, NULL);
+	addr = __mmap_region(NULL, 0x250000, 0x3000, vma_flags, 0x250, NULL);
 	ASSERT_EQ(addr, 0x250000);
 
 	/* Map at 0x303000, merging to 0x300000 of length 0x6000. */
-	addr = __mmap_region(NULL, 0x303000, 0x3000,
-			     VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE,
-			     0x303, NULL);
+	addr = __mmap_region(NULL, 0x303000, 0x3000, vma_flags, 0x303, NULL);
 	ASSERT_EQ(addr, 0x303000);
 
 	/* Map at 0x24d000, merging to 0x250000 of length 0x6000. */
-	addr = __mmap_region(NULL, 0x24d000, 0x3000,
-			     VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE,
-			     0x24d, NULL);
+	addr = __mmap_region(NULL, 0x24d000, 0x3000, vma_flags, 0x24d, NULL);
 	ASSERT_EQ(addr, 0x24d000);
 
 	ASSERT_EQ(mm.map_count, 2);