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[MIPS] FPU ownership management & preemption fixes

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Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Atsushi Nemoto
2007-03-10 01:07:45 +09:00
committed by Ralf Baechle
parent c6a2f46793
commit 53dc80287d
10 changed files with 126 additions and 105 deletions
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29
arch/mips/kernel/signal.c
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@@ -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);
@@ -104,22 +105,18 @@ 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;
}
@@ -188,20 +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();
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;
}