2 files changed, 16 insertions, 13 deletions

diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c
index 45b66a3c991f..ce183aa1492c 100644
--- a/arch/tile/kernel/signal.c
+++ b/arch/tile/kernel/signal.c
@@ -61,13 +61,19 @@ int restore_sigcontext(struct pt_regs *regs,
         /* Always make any pending restarted system calls return -EINTR */
         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 
+        /*
+         * Enforce that sigcontext is like pt_regs, and doesn't mess
+         * up our stack alignment rules.
+         */
+        BUILD_BUG_ON(sizeof(struct sigcontext) != sizeof(struct pt_regs));
+        BUILD_BUG_ON(sizeof(struct sigcontext) % 8 != 0);
+
         for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i)
-                err |= __get_user(((long *)regs)[i],
-                                  &((long __user *)(&sc->regs))[i]);
+                err |= __get_user(regs->regs[i], &sc->gregs[i]);
 
         regs->faultnum = INT_SWINT_1_SIGRETURN;
 
-        err |= __get_user(*pr0, &sc->regs.regs[0]);
+        err |= __get_user(*pr0, &sc->gregs[0]);
         return err;
 }
 
@@ -112,8 +118,7 @@ int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
         int i, err = 0;
 
         for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i)
-                err |= __put_user(((long *)regs)[i],
-                                  &((long __user *)(&sc->regs))[i]);
+                err |= __put_user(regs->regs[i], &sc->gregs[i]);
 
         return err;
 }
@@ -203,19 +208,17 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
          * Set up registers for signal handler.
          * Registers that we don't modify keep the value they had from
          * user-space at the time we took the signal.
+         * We always pass siginfo and mcontext, regardless of SA_SIGINFO,
+         * since some things rely on this (e.g. glibc's debug/segfault.c).
          */
         regs->pc = (unsigned long) ka->sa.sa_handler;
         regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */
         regs->sp = (unsigned long) frame;
         regs->lr = restorer;
         regs->regs[0] = (unsigned long) usig;
-
-        if (ka->sa.sa_flags & SA_SIGINFO) {
-                /* Need extra arguments, so mark to restore caller-saves. */
-                regs->regs[1] = (unsigned long) &frame->info;
-                regs->regs[2] = (unsigned long) &frame->uc;
-                regs->flags |= PT_FLAGS_CALLER_SAVES;
-        }
+        regs->regs[1] = (unsigned long) &frame->info;
+        regs->regs[2] = (unsigned long) &frame->uc;
+        regs->flags |= PT_FLAGS_CALLER_SAVES;
 
         /*
          * Notify any tracer that was single-stepping it.
diff --git a/arch/tile/kernel/stack.c b/arch/tile/kernel/stack.c
index 38a68b0b4581..ea2e0ce28380 100644
--- a/arch/tile/kernel/stack.c
+++ b/arch/tile/kernel/stack.c
@@ -175,7 +175,7 @@ static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt)
                         pr_err("  <received signal %d>\n",
                                frame->info.si_signo);
                 }
-                return &frame->uc.uc_mcontext.regs;
+                return (struct pt_regs *)&frame->uc.uc_mcontext;
         }
         return NULL;
 }