Hexagon: check to if we will overflow the signal stack

Signed-off-by: Richard Kuo <rkuo@codeaurora.org>

diff --git a/arch/hexagon/kernel/signal.c b/arch/hexagon/kernel/signal.c
index 8a20e8e..097623c 100644 (file)
--- a/arch/hexagon/kernel/signal.c
+++ b/arch/hexagon/kernel/signal.c
@@ -41,6 +41,10 @@ static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
 {
        unsigned long sp = regs->r29;
 
+       /* check if we would overflow the alt stack */
+       if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
+               return (void __user __force *)-1UL;
+
        /* Switch to signal stack if appropriate */
        if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
                sp = current->sas_ss_sp + current->sas_ss_size;