diff options
Diffstat (limited to 'arch/mips/kernel/signal.c')
| -rw-r--r-- | arch/mips/kernel/signal.c | 52 |
1 files changed, 43 insertions, 9 deletions
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index 8c3c5a5789b..07d67309451 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> @@ -78,6 +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); |