1 files changed, 30 insertions, 19 deletions

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index e7d22dbcb691..45e9ea6cd2a5 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -198,25 +198,16 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
 	barrier();
 }
 
-DEFINE_SPINLOCK(die_lock);
-
-/*
- * This function is protected against re-entrancy.
- */
-NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
+static void __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs)
 {
-	struct task_struct *tsk = current;
+	struct task_struct *tsk = thread->task;
 	static int die_counter;
 
-	console_verbose();
-	spin_lock_irq(&die_lock);
-	bust_spinlocks(1);
-
 	printk("Internal error: %s: %x [#%d]\n", str, err, ++die_counter);
 	print_modules();
 	__show_regs(regs);
 	printk("Process %s (pid: %d, stack limit = 0x%p)\n",
-		tsk->comm, tsk->pid, tsk->thread_info + 1);
+		tsk->comm, tsk->pid, thread + 1);
 
 	if (!user_mode(regs) || in_interrupt()) {
 		dump_mem("Stack: ", regs->ARM_sp,
@@ -224,7 +215,21 @@ NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
 		dump_backtrace(regs, tsk);
 		dump_instr(regs);
 	}
+}
+
+DEFINE_SPINLOCK(die_lock);
+
+/*
+ * This function is protected against re-entrancy.
+ */
+NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
+{
+	struct thread_info *thread = current_thread_info();
 
+	console_verbose();
+	spin_lock_irq(&die_lock);
+	bust_spinlocks(1);
+	__die(str, err, thread, regs);
 	bust_spinlocks(0);
 	spin_unlock_irq(&die_lock);
 	do_exit(SIGSEGV);
@@ -345,7 +350,9 @@ static int bad_syscall(int n, struct pt_regs *regs)
 	struct thread_info *thread = current_thread_info();
 	siginfo_t info;
 
-	if (current->personality != PER_LINUX && thread->exec_domain->handler) {
+	if (current->personality != PER_LINUX &&
+	    current->personality != PER_LINUX_32BIT &&
+	    thread->exec_domain->handler) {
 		thread->exec_domain->handler(n, regs);
 		return regs->ARM_r0;
 	}
@@ -481,30 +488,34 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
 		unsigned long addr = regs->ARM_r2;
 		struct mm_struct *mm = current->mm;
 		pgd_t *pgd; pmd_t *pmd; pte_t *pte;
+		spinlock_t *ptl;
 
 		regs->ARM_cpsr &= ~PSR_C_BIT;
-		spin_lock(&mm->page_table_lock);
+		down_read(&mm->mmap_sem);
 		pgd = pgd_offset(mm, addr);
 		if (!pgd_present(*pgd))
 			goto bad_access;
 		pmd = pmd_offset(pgd, addr);
 		if (!pmd_present(*pmd))
 			goto bad_access;
-		pte = pte_offset_map(pmd, addr);
-		if (!pte_present(*pte) || !pte_write(*pte))
+		pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
+		if (!pte_present(*pte) || !pte_write(*pte)) {
+			pte_unmap_unlock(pte, ptl);
 			goto bad_access;
+		}
 		val = *(unsigned long *)addr;
 		val -= regs->ARM_r0;
 		if (val == 0) {
 			*(unsigned long *)addr = regs->ARM_r1;
 			regs->ARM_cpsr |= PSR_C_BIT;
 		}
-		spin_unlock(&mm->page_table_lock);
+		pte_unmap_unlock(pte, ptl);
+		up_read(&mm->mmap_sem);
 		return val;
 
 		bad_access:
-		spin_unlock(&mm->page_table_lock);
-		/* simulate a read access fault */
+		up_read(&mm->mmap_sem);
+		/* simulate a write access fault */
 		do_DataAbort(addr, 15 + (1 << 11), regs);
 		return -1;
 	}