mm: convert do_brk_flags() to use vma_flags_t

In order to be able to do this, we need to change VM_DATA_DEFAULT_FLAGS
and friends and update the architecture-specific definitions also.

We then have to update some KSM logic to handle VMA flags, and introduce
VMA_STACK_FLAGS to define the vma_flags_t equivalent of VM_STACK_FLAGS.

We also introduce two helper functions for use during the time we are
converting legacy flags to vma_flags_t values - vma_flags_to_legacy() and
legacy_to_vma_flags().

This enables us to iteratively make changes to break these changes up into
separate parts.

We use these explicitly here to keep VM_STACK_FLAGS around for certain
users which need to maintain the legacy vm_flags_t values for the time
being.

We are no longer able to rely on the simple VM_xxx being set to zero if
the feature is not enabled, so in the case of VM_DROPPABLE we introduce
VMA_DROPPABLE as the vma_flags_t equivalent, which is set to
EMPTY_VMA_FLAGS if the droppable flag is not available.

While we're here, we make the description of do_brk_flags() into a kdoc
comment, as it almost was already.

We use vma_flags_to_legacy() to not need to update the vm_get_page_prot()
logic as this time.

Note that in create_init_stack_vma() we have to replace the BUILD_BUG_ON()
with a VM_WARN_ON_ONCE() as the tested values are no longer build time
available.

We also update mprotect_fixup() to use VMA flags where possible, though we
have to live with a little duplication between vm_flags_t and vma_flags_t
values for the time being until further conversions are made.

While we're here, update VM_SPECIAL to be defined in terms of
VMA_SPECIAL_FLAGS now we have vma_flags_to_legacy().

Finally, we update the VMA tests to reflect these changes.

Link: https://lkml.kernel.org/r/d02e3e45d9a33d7904b149f5604904089fd640ae.1774034900.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>	[SELinux]
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: 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>

14 files changed, 26 insertions, 21 deletions

diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h
index 38214e126c6d..facc7a03b250 100644
--- a/arch/arc/include/asm/page.h
+++ b/arch/arc/include/asm/page.h
@@ -131,7 +131,7 @@ static inline unsigned long virt_to_pfn(const void *kaddr)
 #define virt_addr_valid(kaddr)  pfn_valid(virt_to_pfn(kaddr))
 
 /* Default Permissions for stack/heaps pages (Non Executable) */
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_NON_EXEC
 
 #define WANT_PAGE_VIRTUAL   1
 
diff --git a/arch/arm/include/asm/page.h b/arch/arm/include/asm/page.h
index ef11b721230e..fa4c1225dde5 100644
--- a/arch/arm/include/asm/page.h
+++ b/arch/arm/include/asm/page.h
@@ -184,7 +184,7 @@ extern int pfn_valid(unsigned long);
 
 #include <asm/memory.h>
 
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_TSK_EXEC
 
 #include <asm-generic/getorder.h>
 #include <asm-generic/memory_model.h>
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index b39cc1127e1f..e25d0d18f6d7 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -46,7 +46,12 @@ int pfn_is_map_memory(unsigned long pfn);
 
 #endif /* !__ASSEMBLER__ */
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_DATA_FLAGS_TSK_EXEC | VM_MTE_ALLOWED)
+#ifdef CONFIG_ARM64_MTE
+#define VMA_DATA_DEFAULT_FLAGS	append_vma_flags(VMA_DATA_FLAGS_TSK_EXEC, \
+						 VMA_MTE_ALLOWED_BIT)
+#else
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_TSK_EXEC
+#endif
 
 #include <asm-generic/getorder.h>
 
diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h
index f0aed3ed812b..6d82572a7f21 100644
--- a/arch/hexagon/include/asm/page.h
+++ b/arch/hexagon/include/asm/page.h
@@ -90,7 +90,7 @@ struct page;
 #define virt_to_page(kaddr) pfn_to_page(PFN_DOWN(__pa(kaddr)))
 
 /* Default vm area behavior is non-executable.  */
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_NON_EXEC
 
 #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 
diff --git a/arch/loongarch/include/asm/page.h b/arch/loongarch/include/asm/page.h
index 327bf0bc92bf..79235f4fc399 100644
--- a/arch/loongarch/include/asm/page.h
+++ b/arch/loongarch/include/asm/page.h
@@ -104,7 +104,7 @@ struct page *tlb_virt_to_page(unsigned long kaddr);
 extern int __virt_addr_valid(volatile void *kaddr);
 #define virt_addr_valid(kaddr)	__virt_addr_valid((volatile void *)(kaddr))
 
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_TSK_EXEC
 
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h
index 5ec428fcc887..50a382a0d8f6 100644
--- a/arch/mips/include/asm/page.h
+++ b/arch/mips/include/asm/page.h
@@ -213,7 +213,7 @@ extern bool __virt_addr_valid(const volatile void *kaddr);
 #define virt_addr_valid(kaddr)						\
 	__virt_addr_valid((const volatile void *) (kaddr))
 
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_TSK_EXEC
 
 extern unsigned long __kaslr_offset;
 static inline unsigned long kaslr_offset(void)
diff --git a/arch/nios2/include/asm/page.h b/arch/nios2/include/asm/page.h
index 722956ac0bf8..71eb7c1b67d4 100644
--- a/arch/nios2/include/asm/page.h
+++ b/arch/nios2/include/asm/page.h
@@ -85,7 +85,7 @@ extern struct page *mem_map;
 # define virt_to_page(vaddr)	pfn_to_page(PFN_DOWN(virt_to_phys(vaddr)))
 # define virt_addr_valid(vaddr)	pfn_valid(PFN_DOWN(virt_to_phys(vaddr)))
 
-# define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
+# define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_NON_EXEC
 
 #include <asm-generic/memory_model.h>
 
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index f2bb1f98eebe..281f25e071a3 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -240,8 +240,8 @@ static inline const void *pfn_to_kaddr(unsigned long pfn)
  * and needs to be executable.  This means the whole heap ends
  * up being executable.
  */
-#define VM_DATA_DEFAULT_FLAGS32	VM_DATA_FLAGS_TSK_EXEC
-#define VM_DATA_DEFAULT_FLAGS64	VM_DATA_FLAGS_NON_EXEC
+#define VMA_DATA_DEFAULT_FLAGS32	VMA_DATA_FLAGS_TSK_EXEC
+#define VMA_DATA_DEFAULT_FLAGS64	VMA_DATA_FLAGS_NON_EXEC
 
 #ifdef __powerpc64__
 #include <asm/page_64.h>
diff --git a/arch/powerpc/include/asm/page_32.h b/arch/powerpc/include/asm/page_32.h
index 25482405a811..1fd8c21f0a42 100644
--- a/arch/powerpc/include/asm/page_32.h
+++ b/arch/powerpc/include/asm/page_32.h
@@ -10,7 +10,7 @@
 #endif
 #endif
 
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_DEFAULT_FLAGS32
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_DEFAULT_FLAGS32
 
 #if defined(CONFIG_PPC_256K_PAGES) || \
     (defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES))
diff --git a/arch/powerpc/include/asm/page_64.h b/arch/powerpc/include/asm/page_64.h
index 0f564a06bf68..d96c984d023b 100644
--- a/arch/powerpc/include/asm/page_64.h
+++ b/arch/powerpc/include/asm/page_64.h
@@ -84,9 +84,9 @@ extern u64 ppc64_pft_size;
 
 #endif /* __ASSEMBLER__ */
 
-#define VM_DATA_DEFAULT_FLAGS \
+#define VMA_DATA_DEFAULT_FLAGS \
 	(is_32bit_task() ? \
-	 VM_DATA_DEFAULT_FLAGS32 : VM_DATA_DEFAULT_FLAGS64)
+	 VMA_DATA_DEFAULT_FLAGS32 : VMA_DATA_DEFAULT_FLAGS64)
 
 /*
  * This is the default if a program doesn't have a PT_GNU_STACK
@@ -94,12 +94,12 @@ extern u64 ppc64_pft_size;
  * stack by default, so in the absence of a PT_GNU_STACK program header
  * we turn execute permission off.
  */
-#define VM_STACK_DEFAULT_FLAGS32	VM_DATA_FLAGS_EXEC
-#define VM_STACK_DEFAULT_FLAGS64	VM_DATA_FLAGS_NON_EXEC
+#define VMA_STACK_DEFAULT_FLAGS32	VMA_DATA_FLAGS_EXEC
+#define VMA_STACK_DEFAULT_FLAGS64	VMA_DATA_FLAGS_NON_EXEC
 
-#define VM_STACK_DEFAULT_FLAGS \
+#define VMA_STACK_DEFAULT_FLAGS \
 	(is_32bit_task() ? \
-	 VM_STACK_DEFAULT_FLAGS32 : VM_STACK_DEFAULT_FLAGS64)
+	 VMA_STACK_DEFAULT_FLAGS32 : VMA_STACK_DEFAULT_FLAGS64)
 
 #include <asm-generic/getorder.h>
 
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 187aad0a7b03..c78017061b17 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -204,7 +204,7 @@ static __always_inline void *pfn_to_kaddr(unsigned long pfn)
 	(unsigned long)(_addr) >= PAGE_OFFSET && pfn_valid(virt_to_pfn(_addr));	\
 })
 
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_NON_EXEC
 
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index f339258135f7..56da819a79e6 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -277,7 +277,7 @@ static inline unsigned long virt_to_pfn(const void *kaddr)
 
 #define virt_addr_valid(kaddr)	pfn_valid(phys_to_pfn(__pa_nodebug((unsigned long)(kaddr))))
 
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_NON_EXEC
 
 #endif /* !__ASSEMBLER__ */
 
diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
index 018a8d906ca3..3e0801a0f782 100644
--- a/arch/x86/include/asm/page_types.h
+++ b/arch/x86/include/asm/page_types.h
@@ -26,7 +26,7 @@
 
 #define PAGE_OFFSET		((unsigned long)__PAGE_OFFSET)
 
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_TSK_EXEC
 
 /* Physical address where kernel should be loaded. */
 #define LOAD_PHYSICAL_ADDR	__ALIGN_KERNEL_MASK(CONFIG_PHYSICAL_START, CONFIG_PHYSICAL_ALIGN - 1)
diff --git a/arch/x86/um/asm/vm-flags.h b/arch/x86/um/asm/vm-flags.h
index df7a3896f5dd..622d36d6ddff 100644
--- a/arch/x86/um/asm/vm-flags.h
+++ b/arch/x86/um/asm/vm-flags.h
@@ -9,11 +9,11 @@
 
 #ifdef CONFIG_X86_32
 
-#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
+#define VMA_DATA_DEFAULT_FLAGS	VMA_DATA_FLAGS_TSK_EXEC
 
 #else
 
-#define VM_STACK_DEFAULT_FLAGS (VM_GROWSDOWN | VM_DATA_FLAGS_EXEC)
+#define VMA_STACK_DEFAULT_FLAGS append_vma_flags(VMA_DATA_FLAGS_EXEC, VMA_GROWSDOWN_BIT)
 
 #endif
 #endif