1 files changed, 110 insertions, 26 deletions

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index b2e9ab1..07d6730 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -20,6 +20,7 @@
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/compiler.h>
+#include <linux/uaccess.h>
 
 #include <asm/abi.h>
 #include <asm/asm.h>
@@ -27,7 +28,6 @@
 #include <asm/cacheflush.h>
 #include <asm/fpu.h>
 #include <asm/sim.h>
-#include <asm/uaccess.h>
 #include <asm/ucontext.h>
 #include <asm/cpu-features.h>
 #include <asm/war.h>
@@ -78,10 +78,51 @@ struct rt_sigframe {
 /*
  * Helper routines
  */
+static int protected_save_fp_context(struct sigcontext __user *sc)
+{
+	int err;
+	while (1) {
+		lock_fpu_owner();
+		own_fpu_inatomic(1);
+		err = save_fp_context(sc); /* this might fail */
+		unlock_fpu_owner();
+		if (likely(!err))
+			break;
+		/* touch the sigcontext and try again */
+		err = __put_user(0, &sc->sc_fpregs[0]) |
+			__put_user(0, &sc->sc_fpregs[31]) |
+			__put_user(0, &sc->sc_fpc_csr);
+		if (err)
+			break;	/* really bad sigcontext */
+	}
+	return err;
+}
+
+static int protected_restore_fp_context(struct sigcontext __user *sc)
+{
+	int err, tmp;
+	while (1) {
+		lock_fpu_owner();
+		own_fpu_inatomic(0);
+		err = restore_fp_context(sc); /* this might fail */
+		unlock_fpu_owner();
+		if (likely(!err))
+			break;
+		/* touch the sigcontext and try again */
+		err = __get_user(tmp, &sc->sc_fpregs[0]) |
+			__get_user(tmp, &sc->sc_fpregs[31]) |
+			__get_user(tmp, &sc->sc_fpc_csr);
+		if (err)
+			break;	/* really bad sigcontext */
+	}
+	return err;
+}
+
 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);
 
@@ -89,6 +130,9 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 	for (i = 1; i < 32; i++)
 		err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
 
+#ifdef CONFIG_CPU_HAS_SMARTMIPS
+	err |= __put_user(regs->acx, &sc->sc_acx);
+#endif
 	err |= __put_user(regs->hi, &sc->sc_mdhi);
 	err |= __put_user(regs->lo, &sc->sc_mdlo);
 	if (cpu_has_dsp) {
@@ -101,24 +145,48 @@ 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();
+		err |= protected_save_fp_context(sc);
+	}
+	return err;
+}
 
-		if (!is_fpu_owner()) {
-			own_fpu();
-			restore_fp(current);
-		}
-		err |= save_fp_context(sc);
+int fpcsr_pending(unsigned int __user *fpcsr)
+{
+	int err, sig = 0;
+	unsigned int csr, enabled;
 
-		preempt_enable();
+	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;
+	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 |= protected_restore_fp_context(sc);
+	return err ?: sig;
 }
 
 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
@@ -132,6 +200,10 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
 
 	err |= __get_user(regs->cp0_epc, &sc->sc_pc);
+
+#ifdef CONFIG_CPU_HAS_SMARTMIPS
+	err |= __get_user(regs->acx, &sc->sc_acx);
+#endif
 	err |= __get_user(regs->hi, &sc->sc_mdhi);
 	err |= __get_user(regs->lo, &sc->sc_mdlo);
 	if (cpu_has_dsp) {
@@ -150,19 +222,15 @@ 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);
+		if (!err)
+			err = check_and_restore_fp_context(sc);
 	} else {
 		/* signal handler may have used FPU.  Give it up. */
-		lose_fpu();
+		lose_fpu(0);
 	}
 
-	preempt_enable();
-
 	return err;
 }
 
@@ -325,6 +393,7 @@ 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)))
@@ -338,8 +407,11 @@ 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 ...
@@ -361,6 +433,7 @@ 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)))
@@ -374,8 +447,11 @@ 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;
@@ -398,7 +474,7 @@ badframe:
 }
 
 #ifdef CONFIG_TRAD_SIGNALS
-int setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
+static int setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
 	int signr, sigset_t *set)
 {
 	struct sigframe __user *frame;
@@ -443,7 +519,7 @@ give_sigsegv:
 }
 #endif
 
-int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
+static int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
 	int signr, sigset_t *set, siginfo_t *info)
 {
 	struct rt_sigframe __user *frame;
@@ -501,6 +577,14 @@ give_sigsegv:
 	return -EFAULT;
 }
 
+struct mips_abi mips_abi = {
+#ifdef CONFIG_TRAD_SIGNALS
+	.setup_frame	= setup_frame,
+#endif
+	.setup_rt_frame	= setup_rt_frame,
+	.restart	= __NR_restart_syscall
+};
+
 static int handle_signal(unsigned long sig, siginfo_t *info,
 	struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
 {
@@ -539,7 +623,7 @@ static int handle_signal(unsigned long sig, siginfo_t *info,
 	return ret;
 }
 
-void do_signal(struct pt_regs *regs)
+static void do_signal(struct pt_regs *regs)
 {
 	struct k_sigaction ka;
 	sigset_t *oldset;
@@ -589,7 +673,7 @@ void do_signal(struct pt_regs *regs)
 			regs->cp0_epc -= 8;
 		}
 		if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
-			regs->regs[2] = __NR_restart_syscall;
+			regs->regs[2] = current->thread.abi->restart;
 			regs->regs[7] = regs->regs[26];
 			regs->cp0_epc -= 4;
 		}
@@ -615,5 +699,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 {
 	/* deal with pending signal delivery */
 	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
-		current->thread.abi->do_signal(regs);
+		do_signal(regs);
 }