Merge master.kernel.org:/pub/scm/linux/kernel/git/herbert/crypto-2.6

[linux-drm-fsl-dcu.git] / arch / mips / kernel / signal.c

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index f091786187a69b8b7b41c596b0cbec573a8fe16a..2a08ce41bf2bd250350f40bee2344c1f01796b7e 100644 (file)
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -12,7 +12,6 @@
 #include <linux/mm.h>
 #include <linux/personality.h>
 #include <linux/smp.h>
-#include <linux/smp_lock.h>
 #include <linux/kernel.h>
 #include <linux/signal.h>
 #include <linux/errno.h>
@@ -20,6 +19,7 @@
 #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 +27,6 @@
 #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 +77,51 @@ 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);
 
@@ -104,24 +144,48 @@ 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)
@@ -157,19 +221,15 @@ 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;
 }
 
@@ -332,6 +392,7 @@ 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 +406,11 @@ 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 +432,7 @@ 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 +446,11 @@ 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;