diff options
Diffstat (limited to 'arch/mips/kernel/signal.c')
| -rw-r--r-- | arch/mips/kernel/signal.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index 9a44053..7d5a631 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -39,6 +39,145 @@ #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) /* + * Helper routines + */ +int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) +{ + int err = 0; + int i; + + err |= __put_user(regs->cp0_epc, &sc->sc_pc); + + err |= __put_user(0, &sc->sc_regs[0]); + for (i = 1; i < 32; i++) + err |= __put_user(regs->regs[i], &sc->sc_regs[i]); + + err |= __put_user(regs->hi, &sc->sc_mdhi); + err |= __put_user(regs->lo, &sc->sc_mdlo); + if (cpu_has_dsp) { + err |= __put_user(mfhi1(), &sc->sc_hi1); + err |= __put_user(mflo1(), &sc->sc_lo1); + err |= __put_user(mfhi2(), &sc->sc_hi2); + err |= __put_user(mflo2(), &sc->sc_lo2); + err |= __put_user(mfhi3(), &sc->sc_hi3); + err |= __put_user(mflo3(), &sc->sc_lo3); + err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); + } + + err |= __put_user(!!used_math(), &sc->sc_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_context(sc); + + preempt_enable(); + } + return err; +} + +int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) +{ + unsigned int used_math; + unsigned long treg; + int err = 0; + int i; + + /* Always make any pending restarted system calls return -EINTR */ + current_thread_info()->restart_block.fn = do_no_restart_syscall; + + err |= __get_user(regs->cp0_epc, &sc->sc_pc); + err |= __get_user(regs->hi, &sc->sc_mdhi); + err |= __get_user(regs->lo, &sc->sc_mdlo); + if (cpu_has_dsp) { + err |= __get_user(treg, &sc->sc_hi1); mthi1(treg); + err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg); + err |= __get_user(treg, &sc->sc_hi2); mthi2(treg); + err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg); + err |= __get_user(treg, &sc->sc_hi3); mthi3(treg); + err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg); + err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK); + } + + for (i = 1; i < 32; i++) + err |= __get_user(regs->regs[i], &sc->sc_regs[i]); + + err |= __get_user(used_math, &sc->sc_used_math); + conditional_used_math(used_math); + + preempt_disable(); + + if (used_math()) { + /* restore fpu context if we have used it before */ + own_fpu(); + err |= restore_fp_context(sc); + } else { + /* signal handler may have used FPU. Give it up. */ + lose_fpu(); + } + + preempt_enable(); + + return err; +} + +void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, + size_t frame_size) +{ + unsigned long sp; + + /* Default to using normal stack */ + sp = regs->regs[29]; + + /* + * FPU emulator may have it's own trampoline active just + * above the user stack, 16-bytes before the next lowest + * 16 byte boundary. Try to avoid trashing it. + */ + sp -= 32; + + /* This is the X/Open sanctioned signal stack switching. */ + if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0)) + sp = current->sas_ss_sp + current->sas_ss_size; + + return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK)); +} + +int install_sigtramp(unsigned int __user *tramp, unsigned int syscall) +{ + int err; + + /* + * Set up the return code ... + * + * li v0, __NR__foo_sigreturn + * syscall + */ + + err = __put_user(0x24020000 + syscall, tramp + 0); + err |= __put_user(0x0000000c , tramp + 1); + if (ICACHE_REFILLS_WORKAROUND_WAR) { + err |= __put_user(0, tramp + 2); + err |= __put_user(0, tramp + 3); + err |= __put_user(0, tramp + 4); + err |= __put_user(0, tramp + 5); + err |= __put_user(0, tramp + 6); + err |= __put_user(0, tramp + 7); + } + flush_cache_sigtramp((unsigned long) tramp); + + return err; +} + +/* * Atomically swap in the new signal mask, and wait for a signal. */ |