MIPS: Don't corrupt page tables on vmalloc fault.

The code after the vmalloc_fault: label in do_page_fault() modifies
user page tables, this is not correct for 64-bit kernels.

For 64-bit kernels we should go straight to the no_context handler
skipping vmalloc_fault.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index f956ecb..e97a7a2 100644 (file)
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -58,11 +58,17 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
         * only copy the information from the master page table,
         * nothing more.
         */
+#ifdef CONFIG_64BIT
+# define VMALLOC_FAULT_TARGET no_context
+#else
+# define VMALLOC_FAULT_TARGET vmalloc_fault
+#endif
+
        if (unlikely(address >= VMALLOC_START && address <= VMALLOC_END))
-               goto vmalloc_fault;
+               goto VMALLOC_FAULT_TARGET;
 #ifdef MODULE_START
        if (unlikely(address >= MODULE_START && address < MODULE_END))
-               goto vmalloc_fault;
+               goto VMALLOC_FAULT_TARGET;
 #endif
 
        /*
@@ -203,6 +209,7 @@ do_sigbus:
        force_sig_info(SIGBUS, &info, tsk);
 
        return;
+#ifndef CONFIG_64BIT
 vmalloc_fault:
        {
                /*
@@ -241,4 +248,5 @@ vmalloc_fault:
                        goto no_context;
                return;
        }
+#endif
 }