sh: cleanup of do_address_error()

This patch fixes a few problems with the existing code in do_address_error().

a) the variable used to printk()d the offending instruction wasn't
   initialized correctly. This is a fix to bug 5727

b) behaviour for CONFIG_CPU_SH2A wasn't correct

c) the 'ignore address error' behaviour didn't update the PC, causing an
   infinite loop.

Signed-off-by: Andre Draszik <andre.draszik@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c
index 0ad356d..c581dc3 100644 (file)
--- a/arch/sh/kernel/traps_32.c
+++ b/arch/sh/kernel/traps_32.c
@@ -621,12 +621,21 @@ asmlinkage void do_address_error(struct pt_regs *regs,
 
                se_user += 1;
 
+#ifndef CONFIG_CPU_SH2A
+               set_fs(USER_DS);
+               if (copy_from_user(&instruction, (u16 *)(regs->pc & ~1), 2)) {
+                       set_fs(oldfs);
+                       goto uspace_segv;
+               }
+               set_fs(oldfs);
+
                /* shout about userspace fixups */
                if (se_usermode & 1)
                        printk(KERN_NOTICE "Unaligned userspace access "
                               "in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
                               current->comm, current->pid, (void *)regs->pc,
                               instruction);
+#endif
 
                if (se_usermode & 2)
                        goto fixup;
@@ -635,7 +644,7 @@ asmlinkage void do_address_error(struct pt_regs *regs,
                        goto uspace_segv;
                else {
                        /* ignore */
-                       trace_mark(kernel_arch_trap_exit, MARK_NOARGS);
+                       regs->pc += instruction_size(instruction);
                        return;
                }
 
@@ -647,15 +656,6 @@ fixup:
                }
 
                set_fs(USER_DS);
-               if (copy_from_user(&instruction, (void __user *)(regs->pc),
-                                  sizeof(instruction))) {
-                       /* Argh. Fault on the instruction itself.
-                          This should never happen non-SMP
-                       */
-                       set_fs(oldfs);
-                       goto uspace_segv;
-               }
-
                tmp = handle_unaligned_access(instruction, regs,
                                              &user_mem_access);
                set_fs(oldfs);