[MIPS] Fix mprotect() syscall for MIPS32 w/36-bit physical address support

    
Fix mprotect() syscall for MIPS32 CPUs with 36-bit physical address
support: pte_modify() macro didn't clear the hardware page protection bits
before modifying...
    
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/include/asm-mips/pgtable.h b/include/asm-mips/pgtable.h
index f80fe75c7800..d0af2a3b0152 100644
--- a/include/asm-mips/pgtable.h
+++ b/include/asm-mips/pgtable.h
@@ -353,8 +353,9 @@ static inline pgprot_t pgprot_noncached(pgprot_t _prot)
 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32_R1)
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
-        pte.pte_low &= _PAGE_CHG_MASK;
-        pte.pte_low |= pgprot_val(newprot);
+        pte.pte_low  &= _PAGE_CHG_MASK;
+        pte.pte_high &= ~0x3f;
+        pte.pte_low  |= pgprot_val(newprot);
         pte.pte_high |= pgprot_val(newprot) & 0x3f;
         return pte;
 }