um/mm: enable ARCH_HAS_VM_GET_PAGE_PROT

This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array.  Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.

Link: https://lkml.kernel.org/r/20220711070600.2378316-25-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.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: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 4ec22e1..7fb4365 100644 (file)
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -10,6 +10,7 @@ config UML
        select ARCH_HAS_KCOV
        select ARCH_HAS_STRNCPY_FROM_USER
        select ARCH_HAS_STRNLEN_USER
+       select ARCH_HAS_VM_GET_PAGE_PROT
        select ARCH_NO_PREEMPT
        select HAVE_ARCH_AUDITSYSCALL
        select HAVE_ARCH_SECCOMP_FILTER

diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
index 167e236..66bc3f9 100644 (file)
--- a/arch/um/include/asm/pgtable.h
+++ b/arch/um/include/asm/pgtable.h
@@ -68,23 +68,6 @@ extern unsigned long end_iomem;
  * Also, write permissions imply read permissions. This is the closest we can
  * get..
  */
-#define __P000 PAGE_NONE
-#define __P001 PAGE_READONLY
-#define __P010 PAGE_COPY
-#define __P011 PAGE_COPY
-#define __P100 PAGE_READONLY
-#define __P101 PAGE_READONLY
-#define __P110 PAGE_COPY
-#define __P111 PAGE_COPY
-
-#define __S000 PAGE_NONE
-#define __S001 PAGE_READONLY
-#define __S010 PAGE_SHARED
-#define __S011 PAGE_SHARED
-#define __S100 PAGE_READONLY
-#define __S101 PAGE_READONLY
-#define __S110 PAGE_SHARED
-#define __S111 PAGE_SHARED
 
 /*
  * ZERO_PAGE is a global shared page that is always zero: used

diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 15295c3..5b259f0 100644 (file)
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -197,3 +197,23 @@ void *uml_kmalloc(int size, int flags)
 {
        return kmalloc(size, flags);
 }
+
+static const pgprot_t protection_map[16] = {
+       [VM_NONE]                                       = PAGE_NONE,
+       [VM_READ]                                       = PAGE_READONLY,
+       [VM_WRITE]                                      = PAGE_COPY,
+       [VM_WRITE | VM_READ]                            = PAGE_COPY,
+       [VM_EXEC]                                       = PAGE_READONLY,
+       [VM_EXEC | VM_READ]                             = PAGE_READONLY,
+       [VM_EXEC | VM_WRITE]                            = PAGE_COPY,
+       [VM_EXEC | VM_WRITE | VM_READ]                  = PAGE_COPY,
+       [VM_SHARED]                                     = PAGE_NONE,
+       [VM_SHARED | VM_READ]                           = PAGE_READONLY,
+       [VM_SHARED | VM_WRITE]                          = PAGE_SHARED,
+       [VM_SHARED | VM_WRITE | VM_READ]                = PAGE_SHARED,
+       [VM_SHARED | VM_EXEC]                           = PAGE_READONLY,
+       [VM_SHARED | VM_EXEC | VM_READ]                 = PAGE_READONLY,
+       [VM_SHARED | VM_EXEC | VM_WRITE]                = PAGE_SHARED,
+       [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]      = PAGE_SHARED
+};
+DECLARE_VM_GET_PAGE_PROT

diff --git a/arch/x86/um/mem_32.c b/arch/x86/um/mem_32.c
index 19c5dbd..cafd01f 100644 (file)
--- a/arch/x86/um/mem_32.c
+++ b/arch/x86/um/mem_32.c
@@ -17,7 +17,7 @@ static int __init gate_vma_init(void)
        gate_vma.vm_start = FIXADDR_USER_START;
        gate_vma.vm_end = FIXADDR_USER_END;
        gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
-       gate_vma.vm_page_prot = __P101;
+       gate_vma.vm_page_prot = PAGE_READONLY;
 
        return 0;
 }