mm: Add address parameter to arch_validate_prot()

A protection flag may not be valid across entire address space and
hence arch_validate_prot() might need the address a protection bit is
being set on to ensure it is a valid protection flag. For example, sparc
processors support memory corruption detection (as part of ADI feature)
flag on memory addresses mapped on to physical RAM but not on PFN mapped
pages or addresses mapped on to devices. This patch adds address to the
parameters being passed to arch_validate_prot() so protection bits can
be validated in the relevant context.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 07e3f54..e3f1b5b 100644 (file)
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -43,7 +43,7 @@ static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
 }
 #define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
 
-static inline bool arch_validate_prot(unsigned long prot)
+static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
 {
        if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
                return false;
@@ -51,7 +51,7 @@ static inline bool arch_validate_prot(unsigned long prot)
                return false;
        return true;
 }
-#define arch_validate_prot(prot) arch_validate_prot(prot)
+#define arch_validate_prot arch_validate_prot
 
 #endif /* CONFIG_PPC64 */
 #endif /* _ASM_POWERPC_MMAN_H */

diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index a877bf8..6d90ddb 100644 (file)
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -48,7 +48,7 @@ static inline long do_mmap2(unsigned long addr, size_t len,
 {
        long ret = -EINVAL;
 
-       if (!arch_validate_prot(prot))
+       if (!arch_validate_prot(prot, addr))
                goto out;
 
        if (shift) {

diff --git a/include/linux/mman.h b/include/linux/mman.h
index 6a4d1ca..4b08e9c 100644 (file)
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -92,7 +92,7 @@ static inline void vm_unacct_memory(long pages)
  *
  * Returns true if the prot flags are valid
  */
-static inline bool arch_validate_prot(unsigned long prot)
+static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
 {
        return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
 }

diff --git a/mm/mprotect.c b/mm/mprotect.c
index e3309fc..088ea9c 100644 (file)
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -417,7 +417,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
        end = start + len;
        if (end <= start)
                return -ENOMEM;
-       if (!arch_validate_prot(prot))
+       if (!arch_validate_prot(prot, start))
                return -EINVAL;
 
        reqprot = prot;