Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 *

 * Copyright (C) 1991, 1992  Linus Torvalds

 * Copyright (C) 1994 - 2000  Ralf Baechle

 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.

 */

#include <linux/cache.h>

#include <linux/sched.h>

#include <linux/mm.h>

#include <linux/personality.h>

#include <linux/smp.h>

#include <linux/kernel.h>

#include <linux/signal.h>

#include <linux/errno.h>

#include <linux/wait.h>

#include <linux/ptrace.h>

#include <linux/unistd.h>

#include <linux/compiler.h>

#include <linux/uaccess.h>

#include <asm/abi.h>

#include <asm/asm.h>

#include <linux/bitops.h>

#include <asm/cacheflush.h>

#include <asm/fpu.h>

#include <asm/sim.h>

#include <asm/ucontext.h>

#include <asm/cpu-features.h>

#include <asm/war.h>

#include "signal-common.h"

/*

 * Horribly complicated - with the bloody RM9000 workarounds enabled

 * the signal trampolines is moving to the end of the structure so we can

 * increase the alignment without breaking software compatibility.

 */

#if ICACHE_REFILLS_WORKAROUND_WAR == 0

struct sigframe {

        u32 sf_ass[4];          /* argument save space for o32 */

        u32 sf_code[2];         /* signal trampoline */

        struct sigcontext sf_sc;

        sigset_t sf_mask;

};

struct rt_sigframe {

        u32 rs_ass[4];          /* argument save space for o32 */

        u32 rs_code[2];         /* signal trampoline */

        struct siginfo rs_info;

        struct ucontext rs_uc;

};

#else

struct sigframe {

        u32 sf_ass[4];                  /* argument save space for o32 */

        u32 sf_pad[2];

        struct sigcontext sf_sc;        /* hw context */

        sigset_t sf_mask;

        u32 sf_code[8] ____cacheline_aligned;   /* signal trampoline */

};

struct rt_sigframe {

        u32 rs_ass[4];                  /* argument save space for o32 */

        u32 rs_pad[2];

        struct siginfo rs_info;

        struct ucontext rs_uc;

        u32 rs_code[8] ____cacheline_aligned;   /* signal trampoline */

};

#endif

/*

 * 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);

        err |= __put_user(0, &sc->sc_regs[0]);

        for (i = 1; i < 32; i++)

                err |= __put_user(regs->regs[i], &sc->sc_regs[i]);

#ifdef CONFIG_CPU_HAS_SMARTMIPS

        err |= __put_user(regs->acx, &sc->sc_acx);

#endif

        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);

        }

        used_math = !!used_math();

        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.

                 */

                err |= protected_save_fp_context(sc);

        }

        return err;

}

int fpcsr_pending(unsigned int __user *fpcsr)

{

        int err, sig = 0;

        unsigned int csr, enabled;

        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 ?: 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)

{

        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);

#ifdef CONFIG_CPU_HAS_SMARTMIPS

        err |= __get_user(regs->acx, &sc->sc_acx);

#endif

        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);

        if (used_math) {

                /* restore fpu context if we have used it before */

                if (!err)

                        err = check_and_restore_fp_context(sc);

        } else {

                /* signal handler may have used FPU.  Give it up. */

                lose_fpu(0);

        }

        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.

 */

#ifdef CONFIG_TRAD_SIGNALS

asmlinkage int sys_sigsuspend(nabi_no_regargs struct pt_regs regs)

{

        sigset_t newset;

        sigset_t __user *uset;

        uset = (sigset_t __user *) regs.regs[4];

        if (copy_from_user(&newset, uset, sizeof(sigset_t)))

                return -EFAULT;

        sigdelsetmask(&newset, ~_BLOCKABLE);

        spin_lock_irq(&current->sighand->siglock);

        current->saved_sigmask = current->blocked;

        current->blocked = newset;

        recalc_sigpending();

        spin_unlock_irq(&current->sighand->siglock);

        current->state = TASK_INTERRUPTIBLE;

        schedule();

        set_thread_flag(TIF_RESTORE_SIGMASK);

        return -ERESTARTNOHAND;

}

#endif

asmlinkage int sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)

{

        sigset_t newset;

        sigset_t __user *unewset;

        size_t sigsetsize;

        /* XXX Don't preclude handling different sized sigset_t's.  */

        sigsetsize = regs.regs[5];

        if (sigsetsize != sizeof(sigset_t))

                return -EINVAL;

        unewset = (sigset_t __user *) regs.regs[4];

        if (copy_from_user(&newset, unewset, sizeof(newset)))

                return -EFAULT;

        sigdelsetmask(&newset, ~_BLOCKABLE);

        spin_lock_irq(&current->sighand->siglock);

        current->saved_sigmask = current->blocked;

        current->blocked = newset;

        recalc_sigpending();

        spin_unlock_irq(&current->sighand->siglock);

        current->state = TASK_INTERRUPTIBLE;

        schedule();

        set_thread_flag(TIF_RESTORE_SIGMASK);

        return -ERESTARTNOHAND;

}

#ifdef CONFIG_TRAD_SIGNALS

asmlinkage int sys_sigaction(int sig, const struct sigaction __user *act,

        struct sigaction __user *oact)

{

        struct k_sigaction new_ka, old_ka;

        int ret;

        int err = 0;

        if (act) {

                old_sigset_t mask;

                if (!access_ok(VERIFY_READ, act, sizeof(*act)))

                        return -EFAULT;

                err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);

                err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);

                err |= __get_user(mask, &act->sa_mask.sig[0]);

                if (err)

                        return -EFAULT;

                siginitset(&new_ka.sa.sa_mask, mask);

        }

        ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

        if (!ret && oact) {

                if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))

                        return -EFAULT;

                err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);

                err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);

                err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);

                err |= __put_user(0, &oact->sa_mask.sig[1]);

                err |= __put_user(0, &oact->sa_mask.sig[2]);

                err |= __put_user(0, &oact->sa_mask.sig[3]);

                if (err)

                        return -EFAULT;

        }

        return ret;

}

#endif

asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)

{

        const stack_t __user *uss = (const stack_t __user *) regs.regs[4];

        stack_t __user *uoss = (stack_t __user *) regs.regs[5];

        unsigned long usp = regs.regs[29];

        return do_sigaltstack(uss, uoss, usp);

}

#ifdef CONFIG_TRAD_SIGNALS

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)))

                goto badframe;

        if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))

                goto badframe;

        sigdelsetmask(&blocked, ~_BLOCKABLE);

        spin_lock_irq(&current->sighand->siglock);

        current->blocked = blocked;

        recalc_sigpending();

        spin_unlock_irq(&current->sighand->siglock);

        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 ...

         */

        __asm__ __volatile__(

                "move\t$29, %0\n\t"

                "j\tsyscall_exit"

                :/* no outputs */

                :"r" (&regs));

        /* Unreached */

badframe:

        force_sig(SIGSEGV, current);

}

#endif /* CONFIG_TRAD_SIGNALS */

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)))

                goto badframe;

        if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))

                goto badframe;

        sigdelsetmask(&set, ~_BLOCKABLE);

        spin_lock_irq(&current->sighand->siglock);

        current->blocked = set;

        recalc_sigpending();

        spin_unlock_irq(&current->sighand->siglock);

        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;

        /* It is more difficult to avoid calling this function than to

           call it and ignore errors.  */

        do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);

        /*

         * Don't let your children do this ...

         */

        __asm__ __volatile__(

                "move\t$29, %0\n\t"

                "j\tsyscall_exit"

                :/* no outputs */

                :"r" (&regs));

        /* Unreached */

badframe:

        force_sig(SIGSEGV, current);

}

#ifdef CONFIG_TRAD_SIGNALS

static int setup_frame(struct k_sigaction * ka, struct pt_regs *regs,

        int signr, sigset_t *set)

{

        struct sigframe __user *frame;

        int err = 0;

        frame = get_sigframe(ka, regs, sizeof(*frame));

        if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))

                goto give_sigsegv;

        err |= install_sigtramp(frame->sf_code, __NR_sigreturn);

        err |= setup_sigcontext(regs, &frame->sf_sc);

        err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));

        if (err)

                goto give_sigsegv;

        /*

         * Arguments to signal handler:

         *

         *   a0 = signal number

         *   a1 = 0 (should be cause)

         *   a2 = pointer to struct sigcontext

         *

         * $25 and c0_epc point to the signal handler, $29 points to the

         * struct sigframe.

         */

        regs->regs[ 4] = signr;

        regs->regs[ 5] = 0;

        regs->regs[ 6] = (unsigned long) &frame->sf_sc;

        regs->regs[29] = (unsigned long) frame;

        regs->regs[31] = (unsigned long) frame->sf_code;

        regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;

        DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",

               current->comm, current->pid,

               frame, regs->cp0_epc, regs->regs[31]);

        return 0;

give_sigsegv:

        force_sigsegv(signr, current);

        return -EFAULT;

}

#endif

static int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,

        int signr, sigset_t *set, siginfo_t *info)

{

        struct rt_sigframe __user *frame;

        int err = 0;

        frame = get_sigframe(ka, regs, sizeof(*frame));

        if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))

                goto give_sigsegv;

        err |= install_sigtramp(frame->rs_code, __NR_rt_sigreturn);

        /* Create siginfo.  */

        err |= copy_siginfo_to_user(&frame->rs_info, info);

        /* Create the ucontext.  */

        err |= __put_user(0, &frame->rs_uc.uc_flags);

        err |= __put_user(NULL, &frame->rs_uc.uc_link);

        err |= __put_user((void __user *)current->sas_ss_sp,

                          &frame->rs_uc.uc_stack.ss_sp);

        err |= __put_user(sas_ss_flags(regs->regs[29]),

                          &frame->rs_uc.uc_stack.ss_flags);

        err |= __put_user(current->sas_ss_size,

                          &frame->rs_uc.uc_stack.ss_size);

        err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);

        err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));

        if (err)

                goto give_sigsegv;

        /*

         * Arguments to signal handler:

         *

         *   a0 = signal number

         *   a1 = 0 (should be cause)

         *   a2 = pointer to ucontext

         *

         * $25 and c0_epc point to the signal handler, $29 points to

         * the struct rt_sigframe.

         */

        regs->regs[ 4] = signr;

        regs->regs[ 5] = (unsigned long) &frame->rs_info;

        regs->regs[ 6] = (unsigned long) &frame->rs_uc;

        regs->regs[29] = (unsigned long) frame;

        regs->regs[31] = (unsigned long) frame->rs_code;

        regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;

        DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",

               current->comm, current->pid,

               frame, regs->cp0_epc, regs->regs[31]);

        return 0;

give_sigsegv:

        force_sigsegv(signr, current);

        return -EFAULT;

}

struct mips_abi mips_abi = {

#ifdef CONFIG_TRAD_SIGNALS

        .setup_frame    = setup_frame,

#endif

        .setup_rt_frame = setup_rt_frame,

        .restart        = __NR_restart_syscall

};

static int handle_signal(unsigned long sig, siginfo_t *info,

        struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)

{

        int ret;

        switch(regs->regs[0]) {

        case ERESTART_RESTARTBLOCK:

        case ERESTARTNOHAND:

                regs->regs[2] = EINTR;

                break;

        case ERESTARTSYS:

                if (!(ka->sa.sa_flags & SA_RESTART)) {

                        regs->regs[2] = EINTR;

                        break;

                }

        /* fallthrough */

        case ERESTARTNOINTR:            /* Userland will reload $v0.  */

                regs->regs[7] = regs->regs[26];

                regs->cp0_epc -= 8;

        }

        regs->regs[0] = 0;                /* Don't deal with this again.  */

        if (sig_uses_siginfo(ka))

                ret = current->thread.abi->setup_rt_frame(ka, regs, sig, oldset, info);

        else

                ret = current->thread.abi->setup_frame(ka, regs, sig, oldset);

        spin_lock_irq(&current->sighand->siglock);

        sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);

        if (!(ka->sa.sa_flags & SA_NODEFER))

                sigaddset(&current->blocked, sig);

        recalc_sigpending();

        spin_unlock_irq(&current->sighand->siglock);

        return ret;

}

static void do_signal(struct pt_regs *regs)

{

        struct k_sigaction ka;

        sigset_t *oldset;

        siginfo_t info;

        int signr;

        /*