Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*  $Id: signal.c,v 1.110 2002/02/08 03:57:14 davem Exp $

 *  linux/arch/sparc/kernel/signal.c

 *

 *  Copyright (C) 1991, 1992  Linus Torvalds

 *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)

 *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)

 *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)

 */

#include <linux/sched.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/mm.h>

#include <linux/tty.h>

#include <linux/smp.h>

#include <linux/binfmts.h>      /* do_coredum */

#include <linux/bitops.h>

#include <asm/uaccess.h>

#include <asm/ptrace.h>

#include <asm/svr4.h>

#include <asm/pgalloc.h>

#include <asm/pgtable.h>

#include <asm/cacheflush.h>     /* flush_sig_insns */

#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

extern void fpsave(unsigned long *fpregs, unsigned long *fsr,

                   void *fpqueue, unsigned long *fpqdepth);

extern void fpload(unsigned long *fpregs, unsigned long *fsr);

/* Signal frames: the original one (compatible with SunOS):

 *

 * Set up a signal frame... Make the stack look the way SunOS

 * expects it to look which is basically:

 *

 * ---------------------------------- <-- %sp at signal time

 * Struct sigcontext

 * Signal address

 * Ptr to sigcontext area above

 * Signal code

 * The signal number itself

 * One register window

 * ---------------------------------- <-- New %sp

 */

struct signal_sframe {

        struct reg_window       sig_window;

        int                     sig_num;

        int                     sig_code;

        struct sigcontext __user *sig_scptr;

        int                     sig_address;

        struct sigcontext       sig_context;

        unsigned int            extramask[_NSIG_WORDS - 1];

};

/*

 * And the new one, intended to be used for Linux applications only

 * (we have enough in there to work with clone).

 * All the interesting bits are in the info field.

 */

struct new_signal_frame {

        struct sparc_stackf     ss;

        __siginfo_t             info;

        __siginfo_fpu_t __user  *fpu_save;

        unsigned long           insns[2] __attribute__ ((aligned (8)));

        unsigned int            extramask[_NSIG_WORDS - 1];

        unsigned int            extra_size; /* Should be 0 */

        __siginfo_fpu_t         fpu_state;

};

struct rt_signal_frame {

        struct sparc_stackf     ss;

        siginfo_t               info;

        struct pt_regs          regs;

        sigset_t                mask;

        __siginfo_fpu_t __user  *fpu_save;

        unsigned int            insns[2];

        stack_t                 stack;

        unsigned int            extra_size; /* Should be 0 */

        __siginfo_fpu_t         fpu_state;

};

/* Align macros */

#define SF_ALIGNEDSZ  (((sizeof(struct signal_sframe) + 7) & (~7)))

#define NF_ALIGNEDSZ  (((sizeof(struct new_signal_frame) + 7) & (~7)))

#define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))

static int _sigpause_common(old_sigset_t set)

{

        set &= _BLOCKABLE;

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

        current->saved_sigmask = current->blocked;

        siginitset(&current->blocked, set);

        recalc_sigpending();

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

        current->state = TASK_INTERRUPTIBLE;

        schedule();

        set_thread_flag(TIF_RESTORE_SIGMASK);

        return -ERESTARTNOHAND;

}

asmlinkage int sys_sigpause(unsigned int set)

{

        return _sigpause_common(set);

}

asmlinkage int sys_sigsuspend(old_sigset_t set)

{

        return _sigpause_common(set);

}

static inline int

restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)

{

        int err;

#ifdef CONFIG_SMP

        if (test_tsk_thread_flag(current, TIF_USEDFPU))

                regs->psr &= ~PSR_EF;

#else

        if (current == last_task_used_math) {

                last_task_used_math = NULL;

                regs->psr &= ~PSR_EF;

        }

#endif

        set_used_math();

        clear_tsk_thread_flag(current, TIF_USEDFPU);

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

                return -EFAULT;

        err = __copy_from_user(&current->thread.float_regs[0], &fpu->si_float_regs[0],

                               (sizeof(unsigned long) * 32));

        err |= __get_user(current->thread.fsr, &fpu->si_fsr);

        err |= __get_user(current->thread.fpqdepth, &fpu->si_fpqdepth);

        if (current->thread.fpqdepth != 0)

                err |= __copy_from_user(&current->thread.fpqueue[0],

                                        &fpu->si_fpqueue[0],

                                        ((sizeof(unsigned long) +

                                        (sizeof(unsigned long *)))*16));

        return err;

}

static inline void do_new_sigreturn (struct pt_regs *regs)

{

        struct new_signal_frame __user *sf;

        unsigned long up_psr, pc, npc;

        sigset_t set;

        __siginfo_fpu_t __user *fpu_save;

        int err;

        sf = (struct new_signal_frame __user *) regs->u_regs[UREG_FP];

        /* 1. Make sure we are not getting garbage from the user */

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

                goto segv_and_exit;

        if (((unsigned long) sf) & 3)

                goto segv_and_exit;

        err = __get_user(pc,  &sf->info.si_regs.pc);

        err |= __get_user(npc, &sf->info.si_regs.npc);

        if ((pc | npc) & 3)

                goto segv_and_exit;

        /* 2. Restore the state */

        up_psr = regs->psr;

        err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));

        /* User can only change condition codes and FPU enabling in %psr. */

        regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))

                  | (regs->psr & (PSR_ICC | PSR_EF));

        err |= __get_user(fpu_save, &sf->fpu_save);

        if (fpu_save)

                err |= restore_fpu_state(regs, fpu_save);

        /* This is pretty much atomic, no amount locking would prevent

         * the races which exist anyways.

         */

        err |= __get_user(set.sig[0], &sf->info.si_mask);

        err |= __copy_from_user(&set.sig[1], &sf->extramask,

                                (_NSIG_WORDS-1) * sizeof(unsigned int));

        if (err)

                goto segv_and_exit;

        sigdelsetmask(&set, ~_BLOCKABLE);

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

        current->blocked = set;

        recalc_sigpending();

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

        return;

segv_and_exit:

        force_sig(SIGSEGV, current);

}

asmlinkage void do_sigreturn(struct pt_regs *regs)

{

        struct sigcontext __user *scptr;

        unsigned long pc, npc, psr;

        sigset_t set;

        int err;

        /* Always make any pending restarted system calls return -EINTR */

        current_thread_info()->restart_block.fn = do_no_restart_syscall;

        synchronize_user_stack();

        if (current->thread.new_signal) {

                do_new_sigreturn(regs);

                return;

        }

        scptr = (struct sigcontext __user *) regs->u_regs[UREG_I0];

        /* Check sanity of the user arg. */

        if (!access_ok(VERIFY_READ, scptr, sizeof(struct sigcontext)) ||

            (((unsigned long) scptr) & 3))

                goto segv_and_exit;

        err = __get_user(pc, &scptr->sigc_pc);

        err |= __get_user(npc, &scptr->sigc_npc);

        if ((pc | npc) & 3)

                goto segv_and_exit;

        /* This is pretty much atomic, no amount locking would prevent

         * the races which exist anyways.

         */

        err |= __get_user(set.sig[0], &scptr->sigc_mask);

        /* Note that scptr + 1 points to extramask */

        err |= __copy_from_user(&set.sig[1], scptr + 1,

                                (_NSIG_WORDS - 1) * sizeof(unsigned int));

        if (err)

                goto segv_and_exit;

        sigdelsetmask(&set, ~_BLOCKABLE);

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

        current->blocked = set;

        recalc_sigpending();

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

        regs->pc = pc;

        regs->npc = npc;

        err = __get_user(regs->u_regs[UREG_FP], &scptr->sigc_sp);

        err |= __get_user(regs->u_regs[UREG_I0], &scptr->sigc_o0);

        err |= __get_user(regs->u_regs[UREG_G1], &scptr->sigc_g1);

        /* User can only change condition codes in %psr. */

        err |= __get_user(psr, &scptr->sigc_psr);

        if (err)

                goto segv_and_exit;

        regs->psr &= ~(PSR_ICC);

        regs->psr |= (psr & PSR_ICC);

        return;

segv_and_exit:

        force_sig(SIGSEGV, current);

}

asmlinkage void do_rt_sigreturn(struct pt_regs *regs)

{

        struct rt_signal_frame __user *sf;

        unsigned int psr, pc, npc;

        __siginfo_fpu_t __user *fpu_save;

        mm_segment_t old_fs;

        sigset_t set;

        stack_t st;

        int err;

        synchronize_user_stack();

        sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];

        if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||

            (((unsigned long) sf) & 0x03))

                goto segv;

        err = __get_user(pc, &sf->regs.pc);

        err |= __get_user(npc, &sf->regs.npc);

        err |= ((pc | npc) & 0x03);

        err |= __get_user(regs->y, &sf->regs.y);

        err |= __get_user(psr, &sf->regs.psr);

        err |= __copy_from_user(&regs->u_regs[UREG_G1],

                                &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));

        regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);

        err |= __get_user(fpu_save, &sf->fpu_save);

        if (fpu_save)

                err |= restore_fpu_state(regs, fpu_save);

        err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));

        err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));

        if (err)

                goto segv;

        regs->pc = pc;

        regs->npc = npc;

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

         * call it and ignore errors.

         */

        old_fs = get_fs();

        set_fs(KERNEL_DS);

        do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);

        set_fs(old_fs);

        sigdelsetmask(&set, ~_BLOCKABLE);

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

        current->blocked = set;

        recalc_sigpending();

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

        return;

segv:

        force_sig(SIGSEGV, current);

}

/* Checks if the fp is valid */

static inline int invalid_frame_pointer(void __user *fp, int fplen)

{

        if ((((unsigned long) fp) & 7) ||

            !__access_ok((unsigned long)fp, fplen) ||

            ((sparc_cpu_model == sun4 || sparc_cpu_model == sun4c) &&

             ((unsigned long) fp < 0xe0000000 && (unsigned long) fp >= 0x20000000)))

                return 1;

        return 0;

}

static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)

{

        unsigned long sp;

        sp = regs->u_regs[UREG_FP];

        /* This is the X/Open sanctioned signal stack switching.  */

        if (sa->sa_flags & SA_ONSTACK) {

                if (!on_sig_stack(sp) && !((current->sas_ss_sp + current->sas_ss_size) & 7))

                        sp = current->sas_ss_sp + current->sas_ss_size;

        }

        return (void __user *)(sp - framesize);

}

static inline void

setup_frame(struct sigaction *sa, struct pt_regs *regs, int signr, sigset_t *oldset, siginfo_t *info)

{

        struct signal_sframe __user *sframep;

        struct sigcontext __user *sc;

        int window = 0, err;

        unsigned long pc = regs->pc;

        unsigned long npc = regs->npc;

        struct thread_info *tp = current_thread_info();

        void __user *sig_address;

        int sig_code;

        synchronize_user_stack();

        sframep = (struct signal_sframe __user *)

                get_sigframe(sa, regs, SF_ALIGNEDSZ);

        if (invalid_frame_pointer(sframep, sizeof(*sframep))){

                /* Don't change signal code and address, so that

                 * post mortem debuggers can have a look.

                 */

                goto sigill_and_return;

        }

        sc = &sframep->sig_context;

        /* We've already made sure frame pointer isn't in kernel space... */

        err  = __put_user((sas_ss_flags(regs->u_regs[UREG_FP]) == SS_ONSTACK),

                         &sc->sigc_onstack);

        err |= __put_user(oldset->sig[0], &sc->sigc_mask);

        err |= __copy_to_user(sframep->extramask, &oldset->sig[1],

                              (_NSIG_WORDS - 1) * sizeof(unsigned int));

        err |= __put_user(regs->u_regs[UREG_FP], &sc->sigc_sp);

        err |= __put_user(pc, &sc->sigc_pc);

        err |= __put_user(npc, &sc->sigc_npc);

        err |= __put_user(regs->psr, &sc->sigc_psr);

        err |= __put_user(regs->u_regs[UREG_G1], &sc->sigc_g1);

        err |= __put_user(regs->u_regs[UREG_I0], &sc->sigc_o0);

        err |= __put_user(tp->w_saved, &sc->sigc_oswins);

        if (tp->w_saved)

                for (window = 0; window < tp->w_saved; window++) {

                        put_user((char *)tp->rwbuf_stkptrs[window],

                                 &sc->sigc_spbuf[window]);

                        err |= __copy_to_user(&sc->sigc_wbuf[window],

                                              &tp->reg_window[window],

                                              sizeof(struct reg_window));

                }

        else

                err |= __copy_to_user(sframep, (char *) regs->u_regs[UREG_FP],

                                      sizeof(struct reg_window));

        tp->w_saved = 0; /* So process is allowed to execute. */

        err |= __put_user(signr, &sframep->sig_num);

        sig_address = NULL;

        sig_code = 0;

        if (SI_FROMKERNEL (info) && (info->si_code & __SI_MASK) == __SI_FAULT) {

                sig_address = info->si_addr;

                switch (signr) {

                case SIGSEGV:

                        switch (info->si_code) {

                        case SEGV_MAPERR: sig_code = SUBSIG_NOMAPPING; break;

                        default: sig_code = SUBSIG_PROTECTION; break;

                        }

                        break;

                case SIGILL:

                        switch (info->si_code) {

                        case ILL_ILLOPC: sig_code = SUBSIG_ILLINST; break;

                        case ILL_PRVOPC: sig_code = SUBSIG_PRIVINST; break;

                        case ILL_ILLTRP: sig_code = SUBSIG_BADTRAP(info->si_trapno); break;

                        default: sig_code = SUBSIG_STACK; break;

                        }

                        break;

                case SIGFPE:

                        switch (info->si_code) {

                        case FPE_INTDIV: sig_code = SUBSIG_IDIVZERO; break;

                        case FPE_INTOVF: sig_code = SUBSIG_FPINTOVFL; break;

                        case FPE_FLTDIV: sig_code = SUBSIG_FPDIVZERO; break;

                        case FPE_FLTOVF: sig_code = SUBSIG_FPOVFLOW; break;

                        case FPE_FLTUND: sig_code = SUBSIG_FPUNFLOW; break;

                        case FPE_FLTRES: sig_code = SUBSIG_FPINEXACT; break;

                        case FPE_FLTINV: sig_code = SUBSIG_FPOPERROR; break;

                        default: sig_code = SUBSIG_FPERROR; break;

                        }

                        break;

                case SIGBUS:

                        switch (info->si_code) {

                        case BUS_ADRALN: sig_code = SUBSIG_ALIGNMENT; break;

                        case BUS_ADRERR: sig_code = SUBSIG_MISCERROR; break;

                        default: sig_code = SUBSIG_BUSTIMEOUT; break;

                        }

                        break;

                case SIGEMT:

                        switch (info->si_code) {

                        case EMT_TAGOVF: sig_code = SUBSIG_TAG; break;

                        }

                        break;

                case SIGSYS:

                        if (info->si_code == (__SI_FAULT|0x100)) {

                                /* See sys_sunos.c */

                                sig_code = info->si_trapno;

                                break;

                        }

                default:

                        sig_address = NULL;

                }

        }

        err |= __put_user((unsigned long)sig_address, &sframep->sig_address);

        err |= __put_user(sig_code, &sframep->sig_code);

        err |= __put_user(sc, &sframep->sig_scptr);

        if (err)

                goto sigsegv;

        regs->u_regs[UREG_FP] = (unsigned long) sframep;

        regs->pc = (unsigned long) sa->sa_handler;

        regs->npc = (regs->pc + 4);

        return;

sigill_and_return:

        do_exit(SIGILL);

sigsegv:

        force_sigsegv(signr, current);

}

static inline int

save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)

{

        int err = 0;

#ifdef CONFIG_SMP

        if (test_tsk_thread_flag(current, TIF_USEDFPU)) {

                put_psr(get_psr() | PSR_EF);

                fpsave(&current->thread.float_regs[0], &current->thread.fsr,

                       &current->thread.fpqueue[0], &current->thread.fpqdepth);

                regs->psr &= ~(PSR_EF);

                clear_tsk_thread_flag(current, TIF_USEDFPU);

        }

#else

        if (current == last_task_used_math) {

                put_psr(get_psr() | PSR_EF);

                fpsave(&current->thread.float_regs[0], &current->thread.fsr,

                       &current->thread.fpqueue[0], &current->thread.fpqdepth);

                last_task_used_math = NULL;

                regs->psr &= ~(PSR_EF);

        }

#endif

        err |= __copy_to_user(&fpu->si_float_regs[0],

                              &current->thread.float_regs[0],

                              (sizeof(unsigned long) * 32));

        err |= __put_user(current->thread.fsr, &fpu->si_fsr);

        err |= __put_user(current->thread.fpqdepth, &fpu->si_fpqdepth);

        if (current->thread.fpqdepth != 0)

                err |= __copy_to_user(&fpu->si_fpqueue[0],

                                      &current->thread.fpqueue[0],

                                      ((sizeof(unsigned long) +

                                      (sizeof(unsigned long *)))*16));

        clear_used_math();

        return err;

}

static inline void

new_setup_frame(struct k_sigaction *ka, struct pt_regs *regs,

                int signo, sigset_t *oldset)

{

        struct new_signal_frame __user *sf;

        int sigframe_size, err;

        /* 1. Make sure everything is clean */

        synchronize_user_stack();

        sigframe_size = NF_ALIGNEDSZ;

        if (!used_math())

                sigframe_size -= sizeof(__siginfo_fpu_t);

        sf = (struct new_signal_frame __user *)

                get_sigframe(&ka->sa, regs, sigframe_size);

        if (invalid_frame_pointer(sf, sigframe_size))

                goto sigill_and_return;

        if (current_thread_info()->w_saved != 0)

                goto sigill_and_return;

        /* 2. Save the current process state */

        err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));

        err |= __put_user(0, &sf->extra_size);

        if (used_math()) {

                err |= save_fpu_state(regs, &sf->fpu_state);

                err |= __put_user(&sf->fpu_state, &sf->fpu_save);

        } else {

                err |= __put_user(0, &sf->fpu_save);

        }

        err |= __put_user(oldset->sig[0], &sf->info.si_mask);

        err |= __copy_to_user(sf->extramask, &oldset->sig[1],

                              (_NSIG_WORDS - 1) * sizeof(unsigned int));

        err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],

                              sizeof(struct reg_window));

        if (err)

                goto sigsegv;

        /* 3. signal handler back-trampoline and parameters */

        regs->u_regs[UREG_FP] = (unsigned long) sf;

        regs->u_regs[UREG_I0] = signo;

        regs->u_regs[UREG_I1] = (unsigned long) &sf->info;

        regs->u_regs[UREG_I2] = (unsigned long) &sf->info;

        /* 4. signal handler */

        regs->pc = (unsigned long) ka->sa.sa_handler;

        regs->npc = (regs->pc + 4);

        /* 5. return to kernel instructions */

        if (ka->ka_restorer)

                regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;

        else {

                regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

                /* mov __NR_sigreturn, %g1 */

                err |= __put_user(0x821020d8, &sf->insns[0]);

                /* t 0x10 */

                err |= __put_user(0x91d02010, &sf->insns[1]);

                if (err)

                        goto sigsegv;

                /* Flush instruction space. */

                flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));

        }

        return;

sigill_and_return:

        do_exit(SIGILL);

sigsegv:

        force_sigsegv(signo, current);

}

static inline void

new_setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,

                   int signo, sigset_t *oldset, siginfo_t *info)

{

        struct rt_signal_frame __user *sf;

        int sigframe_size;

        unsigned int psr;

        int err;

        synchronize_user_stack();

        sigframe_size = RT_ALIGNEDSZ;

        if (!used_math())

                sigframe_size -= sizeof(__siginfo_fpu_t);

        sf = (struct rt_signal_frame __user *)

                get_sigframe(&ka->sa, regs, sigframe_size);

        if (invalid_frame_pointer(sf, sigframe_size))