1 files changed, 55 insertions, 20 deletions

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index f091786187a..8c3c5a5789b 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -82,6 +82,7 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
 	int err = 0;
 	int i;
+	unsigned int used_math;
 
 	err |= __put_user(regs->cp0_epc, &sc->sc_pc);
 
@@ -104,26 +105,53 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 		err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
 	}
 
-	err |= __put_user(!!used_math(), &sc->sc_used_math);
+	used_math = !!used_math();
+	err |= __put_user(used_math, &sc->sc_used_math);
 
-	if (used_math()) {
+	if (used_math) {
 		/*
 		 * Save FPU state to signal context. Signal handler
 		 * will "inherit" current FPU state.
 		 */
-		preempt_disable();
-
-		if (!is_fpu_owner()) {
-			own_fpu();
-			restore_fp(current);
-		}
+		own_fpu(1);
+		enable_fp_in_kernel();
 		err |= save_fp_context(sc);
-
-		preempt_enable();
+		disable_fp_in_kernel();
 	}
 	return err;
 }
 
+int fpcsr_pending(unsigned int __user *fpcsr)
+{
+	int err, sig = 0;
+	unsigned int csr, enabled;
+
+	err = __get_user(csr, fpcsr);
+	enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
+	/*
+	 * If the signal handler set some FPU exceptions, clear it and
+	 * send SIGFPE.
+	 */
+	if (csr & enabled) {
+		csr &= ~enabled;
+		err |= __put_user(csr, fpcsr);
+		sig = SIGFPE;
+	}
+	return err ?: sig;
+}
+
+static int
+check_and_restore_fp_context(struct sigcontext __user *sc)
+{
+	int err, sig;
+
+	err = sig = fpcsr_pending(&sc->sc_fpc_csr);
+	if (err > 0)
+		err = 0;
+	err |= restore_fp_context(sc);
+	return err ?: sig;
+}
+
 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
 	unsigned int used_math;
@@ -157,19 +185,18 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 	err |= __get_user(used_math, &sc->sc_used_math);
 	conditional_used_math(used_math);
 
-	preempt_disable();
-
-	if (used_math()) {
+	if (used_math) {
 		/* restore fpu context if we have used it before */
-		own_fpu();
-		err |= restore_fp_context(sc);
+		own_fpu(0);
+		enable_fp_in_kernel();
+		if (!err)
+			err = check_and_restore_fp_context(sc);
+		disable_fp_in_kernel();
 	} else {
 		/* signal handler may have used FPU.  Give it up. */
-		lose_fpu();
+		lose_fpu(0);
 	}
 
-	preempt_enable();
-
 	return err;
 }
 
@@ -332,6 +359,7 @@ asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
 {
 	struct sigframe __user *frame;
 	sigset_t blocked;
+	int sig;
 
 	frame = (struct sigframe __user *) regs.regs[29];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -345,8 +373,11 @@ asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	if (restore_sigcontext(&regs, &frame->sf_sc))
+	sig = restore_sigcontext(&regs, &frame->sf_sc);
+	if (sig < 0)
 		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
 
 	/*
 	 * Don't let your children do this ...
@@ -368,6 +399,7 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 	struct rt_sigframe __user *frame;
 	sigset_t set;
 	stack_t st;
+	int sig;
 
 	frame = (struct rt_sigframe __user *) regs.regs[29];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -381,8 +413,11 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
+	sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
+	if (sig < 0)
 		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
 
 	if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
 		goto badframe;