diff options
Diffstat (limited to 'arch/mips/kernel/signal32.c')
| -rw-r--r-- | arch/mips/kernel/signal32.c | 94 |
1 files changed, 72 insertions, 22 deletions
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c index 19bbef00195..b9a014411f8 100644 --- a/arch/mips/kernel/signal32.c +++ b/arch/mips/kernel/signal32.c @@ -22,6 +22,7 @@ #include <linux/compat.h> #include <linux/suspend.h> #include <linux/compiler.h> +#include <linux/uaccess.h> #include <asm/abi.h> #include <asm/asm.h> @@ -29,7 +30,6 @@ #include <linux/bitops.h> #include <asm/cacheflush.h> #include <asm/sim.h> -#include <asm/uaccess.h> #include <asm/ucontext.h> #include <asm/system.h> #include <asm/fpu.h> @@ -176,11 +176,52 @@ struct rt_sigframe32 { /* * sigcontext handlers */ +static int protected_save_fp_context32(struct sigcontext32 __user *sc) +{ + int err; + while (1) { + lock_fpu_owner(); + own_fpu_inatomic(1); + err = save_fp_context32(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_context32(struct sigcontext32 __user *sc) +{ + int err, tmp; + while (1) { + lock_fpu_owner(); + own_fpu_inatomic(0); + err = restore_fp_context32(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; +} + static int setup_sigcontext32(struct pt_regs *regs, struct sigcontext32 __user *sc) { int err = 0; int i; + u32 used_math; err |= __put_user(regs->cp0_epc, &sc->sc_pc); @@ -200,26 +241,31 @@ static int setup_sigcontext32(struct pt_regs *regs, err |= __put_user(mflo3(), &sc->sc_lo3); } - 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); - } - err |= save_fp_context32(sc); - - preempt_enable(); + err |= protected_save_fp_context32(sc); } 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 |= protected_restore_fp_context32(sc); + return err ?: sig; +} + static int restore_sigcontext32(struct pt_regs *regs, struct sigcontext32 __user *sc) { @@ -250,19 +296,15 @@ static int restore_sigcontext32(struct pt_regs *regs, 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_context32(sc); + if (!err) + err = check_and_restore_fp_context32(sc); } else { /* signal handler may have used FPU. Give it up. */ - lose_fpu(); + lose_fpu(0); } - preempt_enable(); - return err; } @@ -508,6 +550,7 @@ asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs) { 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 +564,11 @@ asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext32(®s, &frame->sf_sc)) + sig = restore_sigcontext32(®s, &frame->sf_sc); + if (sig < 0) goto badframe; + else if (sig) + force_sig(sig, current); /* * Don't let your children do this ... @@ -545,6 +591,7 @@ asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) 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 +605,11 @@ asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext32(®s, &frame->rs_uc.uc_mcontext)) + sig = restore_sigcontext32(®s, &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)) |