Pull asus into release branch

[pandora-kernel.git] / arch / mips / kernel / signal.c

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 8c3c5a5..07d6730 100644 (file)
--- 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>
@@ -78,6 +78,46 @@ 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;
@@ -113,10 +153,7 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
                 * Save FPU state to signal context. Signal handler
                 * will "inherit" current FPU state.
                 */
-               own_fpu(1);
-               enable_fp_in_kernel();
-               err |= save_fp_context(sc);
-               disable_fp_in_kernel();
+               err |= protected_save_fp_context(sc);
        }
        return err;
 }
@@ -148,7 +185,7 @@ check_and_restore_fp_context(struct sigcontext __user *sc)
        err = sig = fpcsr_pending(&sc->sc_fpc_csr);
        if (err > 0)
                err = 0;
-       err |= restore_fp_context(sc);
+       err |= protected_restore_fp_context(sc);
        return err ?: sig;
 }
 
@@ -187,11 +224,8 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 
        if (used_math) {
                /* restore fpu context if we have used it before */
-               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(0);