commit c6a2f4679331206ef5d353fc9a6cda2fa4aef8c6
author Atsushi Nemoto <anemo@mba.ocn.ne.jp> Sat Mar 10 01:03:48 2007 +0900
committer Ralf Baechle <ralf@linux-mips.org> Sat Mar 17 01:03:25 2007 +0000
tree 9634ba2d5b6c6c97f4301b28088c68254201bf74
parent f1dbf8e718ef0ddb196a28bcc71925ac7da881af

[MIPS] Check FCSR for pending interrupts, alternative version

Commit 6d6671066a311703bca1b91645bb1e04cc983387 is incomplete and misses
non-r4k CPUs.  This patch reverts the commit and fixes in other way.

 o Do FCSR checking in caller of restore_fp_context.
 o Send SIGFPE if the signal handler set any FPU exception bits.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/signal32.c

diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c
index 19bbef0..20013b6 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -220,6 +220,18 @@
 	return err;
 }
 
+static int
+check_and_restore_fp_context32(struct sigcontext32 __user *sc)
+{
+	int err, sig;
+
+	err = sig = fpcsr_pending(&sc->sc_fpc_csr);
+	if (err > 0)
+		err = 0;
+	err |= restore_fp_context32(sc);
+	return err ?: sig;
+}
+
 static int restore_sigcontext32(struct pt_regs *regs,
 				struct sigcontext32 __user *sc)
 {
@@ -255,7 +267,8 @@
 	if (used_math()) {
 		/* restore fpu context if we have used it before */
 		own_fpu();
-		err |= restore_fp_context32(sc);
+		if (!err)
+			err = check_and_restore_fp_context32(sc);
 	} else {
 		/* signal handler may have used FPU.  Give it up. */
 		lose_fpu();
@@ -508,6 +521,7 @@
 {
 	struct sigframe32 __user *frame;
 	sigset_t blocked;
+	int sig;
 
 	frame = (struct sigframe32 __user *) regs.regs[29];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -521,8 +535,11 @@
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	if (restore_sigcontext32(&regs, &frame->sf_sc))
+	sig = restore_sigcontext32(&regs, &frame->sf_sc);
+	if (sig < 0)
 		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
 
 	/*
 	 * Don't let your children do this ...
@@ -545,6 +562,7 @@
 	sigset_t set;
 	stack_t st;
 	s32 sp;
+	int sig;
 
 	frame = (struct rt_sigframe32 __user *) regs.regs[29];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -558,8 +576,11 @@
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	if (restore_sigcontext32(&regs, &frame->rs_uc.uc_mcontext))
+	sig = restore_sigcontext32(&regs, &frame->rs_uc.uc_mcontext);
+	if (sig < 0)
 		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
 
 	/* The ucontext contains a stack32_t, so we must convert!  */
 	if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))