4 files changed, 21 insertions, 24 deletions

diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index 98c00a2d4dd9..f46efd14059d 100644
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -155,8 +155,6 @@ int copy_thread(unsigned long clone_flags,
  */
 void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long usp)
 {
-	set_fs(USER_DS); /* user space */
-
 	regs->sp = usp;
 	regs->ret = pc;
 
diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c
index 114234e83caa..2251fb4bbfd7 100644
--- a/arch/arc/kernel/signal.c
+++ b/arch/arc/kernel/signal.c
@@ -67,7 +67,7 @@ stash_usr_regs(struct rt_sigframe __user *sf, struct pt_regs *regs,
 	       sigset_t *set)
 {
 	int err;
-	err = __copy_to_user(&(sf->uc.uc_mcontext.regs), regs,
+	err = __copy_to_user(&(sf->uc.uc_mcontext.regs.scratch), regs,
 			     sizeof(sf->uc.uc_mcontext.regs.scratch));
 	err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(sigset_t));
 
@@ -83,7 +83,7 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
 	if (!err)
 		set_current_blocked(&set);
 
-	err |= __copy_from_user(regs, &(sf->uc.uc_mcontext.regs),
+	err |= __copy_from_user(regs, &(sf->uc.uc_mcontext.regs.scratch),
 				sizeof(sf->uc.uc_mcontext.regs.scratch));
 
 	return err;
@@ -131,6 +131,15 @@ SYSCALL_DEFINE0(rt_sigreturn)
 	/* Don't restart from sigreturn */
 	syscall_wont_restart(regs);
 
+	/*
+	 * Ensure that sigreturn always returns to user mode (in case the
+	 * regs saved on user stack got fudged between save and sigreturn)
+	 * Otherwise it is easy to panic the kernel with a custom
+	 * signal handler and/or restorer which clobberes the status32/ret
+	 * to return to a bogus location in kernel mode.
+	 */
+	regs->status32 |= STATUS_U_MASK;
+
 	return regs->r0;
 
 badframe:
@@ -162,18 +171,6 @@ static inline void __user *get_sigframe(struct ksignal *ksig,
 	return frame;
 }
 
-/*
- * translate the signal
- */
-static inline int map_sig(int sig)
-{
-	struct thread_info *thread = current_thread_info();
-	if (thread->exec_domain && thread->exec_domain->signal_invmap
-	    && sig < 32)
-		sig = thread->exec_domain->signal_invmap[sig];
-	return sig;
-}
-
 static int
 setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
 {
@@ -222,15 +219,18 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
 		return err;
 
 	/* #1 arg to the user Signal handler */
-	regs->r0 = map_sig(ksig->sig);
+	regs->r0 = ksig->sig;
 
 	/* setup PC of user space signal handler */
 	regs->ret = (unsigned long)ksig->ka.sa.sa_handler;
 
 	/*
 	 * handler returns using sigreturn stub provided already by userpsace
+	 * If not, nuke the process right away
 	 */
-	BUG_ON(!(ksig->ka.sa.sa_flags & SA_RESTORER));
+	if(!(ksig->ka.sa.sa_flags & SA_RESTORER))
+		return 1;
+
 	regs->blink = (unsigned long)ksig->ka.sa.sa_restorer;
 
 	/* User Stack for signal handler will be above the frame just carved */
@@ -296,12 +296,12 @@ static void
 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *oldset = sigmask_to_save();
-	int ret;
+	int failed;
 
 	/* Set up the stack frame */
-	ret = setup_rt_frame(ksig, oldset, regs);
+	failed = setup_rt_frame(ksig, oldset, regs);
 
-	signal_setup_done(ret, ksig, 0);
+	signal_setup_done(failed, ksig, 0);
 }
 
 void do_signal(struct pt_regs *regs)
diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c
index 1badf9b84b51..e00a01879025 100644
--- a/arch/arc/kernel/troubleshoot.c
+++ b/arch/arc/kernel/troubleshoot.c
@@ -52,7 +52,7 @@ static void show_callee_regs(struct callee_regs *cregs)
 	print_reg_file(&(cregs->r13), 13);
 }
 
-void print_task_path_n_nm(struct task_struct *tsk, char *buf)
+static void print_task_path_n_nm(struct task_struct *tsk, char *buf)
 {
 	struct path path;
 	char *path_nm = NULL;
@@ -77,7 +77,6 @@ void print_task_path_n_nm(struct task_struct *tsk, char *buf)
 done:
 	pr_info("Path: %s\n", path_nm);
 }
-EXPORT_SYMBOL(print_task_path_n_nm);
 
 static void show_faulting_vma(unsigned long address, char *buf)
 {
diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index e550b117ec4f..93c6ea52b671 100644
--- a/arch/arc/kernel/unwind.c
+++ b/arch/arc/kernel/unwind.c
@@ -841,7 +841,7 @@ static int processCFI(const u8 *start, const u8 *end, unsigned long targetLoc,
 				break;
 			case DW_CFA_GNU_window_save:
 			default:
-				unw_debug("UNKNOW OPCODE 0x%x\n", opcode);
+				unw_debug("UNKNOWN OPCODE 0x%x\n", opcode);
 				result = 0;
 				break;
 			}