/*    Signal support for 32-bit kernel builds
 *
 *    Copyright (C) 2001 Matthew Wilcox <willy at parisc-linux.org>
 *    Copyright (C) 2006 Kyle McMartin <kyle at parisc-linux.org>
 *
 *    Code was mostly borrowed from kernel/signal.c.
 *    See kernel/signal.c for additional Copyrights.
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/compat.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/unistd.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/syscalls.h>
#include <linux/types.h>
#include <linux/errno.h>

#include <asm/uaccess.h>

#include "signal32.h"
#include "sys32.h"

#define DEBUG_COMPAT_SIG 0 
#define DEBUG_COMPAT_SIG_LEVEL 2

#if DEBUG_COMPAT_SIG
#define DBG(LEVEL, ...) \
        ((DEBUG_COMPAT_SIG_LEVEL >= LEVEL) \
        ? printk(__VA_ARGS__) : (void) 0)
#else
#define DBG(LEVEL, ...)
#endif

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

inline void
sigset_32to64(sigset_t *s64, compat_sigset_t *s32)
{
        s64->sig[0] = s32->sig[0] | ((unsigned long)s32->sig[1] << 32);
}

inline void
sigset_64to32(compat_sigset_t *s32, sigset_t *s64)
{
        s32->sig[0] = s64->sig[0] & 0xffffffffUL;
        s32->sig[1] = (s64->sig[0] >> 32) & 0xffffffffUL;
}

static int
put_sigset32(compat_sigset_t __user *up, sigset_t *set, size_t sz)
{
        compat_sigset_t s;

        if (sz != sizeof *set) panic("put_sigset32()");
        sigset_64to32(&s, set);

        return copy_to_user(up, &s, sizeof s);
}

static int
get_sigset32(compat_sigset_t __user *up, sigset_t *set, size_t sz)
{
        compat_sigset_t s;
        int r;

        if (sz != sizeof *set) panic("put_sigset32()");

        if ((r = copy_from_user(&s, up, sz)) == 0) {
                sigset_32to64(set, &s);
        }

        return r;
}

int sys32_rt_sigprocmask(int how, compat_sigset_t __user *set, compat_sigset_t __user *oset,
                                    unsigned int sigsetsize)
{
        sigset_t old_set, new_set;
        int ret;

        if (set && get_sigset32(set, &new_set, sigsetsize))
                return -EFAULT;
        
        KERNEL_SYSCALL(ret, sys_rt_sigprocmask, how, set ? (sigset_t __user *)&new_set : NULL,
                                 oset ? (sigset_t __user *)&old_set : NULL, sigsetsize);

        if (!ret && oset && put_sigset32(oset, &old_set, sigsetsize))
                return -EFAULT;

        return ret;
}


int sys32_rt_sigpending(compat_sigset_t __user *uset, unsigned int sigsetsize)
{
        int ret;
        sigset_t set;

        KERNEL_SYSCALL(ret, sys_rt_sigpending, (sigset_t __user *)&set, sigsetsize);

        if (!ret && put_sigset32(uset, &set, sigsetsize))
                return -EFAULT;

        return ret;
}

long
sys32_rt_sigaction(int sig, const struct sigaction32 __user *act, struct sigaction32 __user *oact,
                 size_t sigsetsize)
{
        struct k_sigaction32 new_sa32, old_sa32;
        struct k_sigaction new_sa, old_sa;
        int ret = -EINVAL;

        if (act) {
                if (copy_from_user(&new_sa32.sa, act, sizeof new_sa32.sa))
                        return -EFAULT;
                new_sa.sa.sa_handler = (__sighandler_t)(unsigned long)new_sa32.sa.sa_handler;
                new_sa.sa.sa_flags = new_sa32.sa.sa_flags;
                sigset_32to64(&new_sa.sa.sa_mask, &new_sa32.sa.sa_mask);
        }

        ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL);

        if (!ret && oact) {
                sigset_64to32(&old_sa32.sa.sa_mask, &old_sa.sa.sa_mask);
                old_sa32.sa.sa_flags = old_sa.sa.sa_flags;
                old_sa32.sa.sa_handler = (__sighandler_t32)(unsigned long)old_sa.sa.sa_handler;
                if (copy_to_user(oact, &old_sa32.sa, sizeof old_sa32.sa))
                        return -EFAULT;
        }
        return ret;
}

int 
do_sigaltstack32 (const compat_stack_t __user *uss32, compat_stack_t __user *uoss32, unsigned long sp)
{
        compat_stack_t ss32, oss32;
        stack_t ss, oss;
        stack_t *ssp = NULL, *ossp = NULL;
        int ret;

        if (uss32) {
                if (copy_from_user(&ss32, uss32, sizeof ss32))
                        return -EFAULT;

                ss.ss_sp = (void __user *)(unsigned long)ss32.ss_sp;
                ss.ss_flags = ss32.ss_flags;
                ss.ss_size = ss32.ss_size;

                ssp = &ss;
        }

        if (uoss32)
                ossp = &oss;

        KERNEL_SYSCALL(ret, do_sigaltstack, (const stack_t __user *)ssp, (stack_t __user *)ossp, sp);

        if (!ret && uoss32) {
                oss32.ss_sp = (unsigned int)(unsigned long)oss.ss_sp;
                oss32.ss_flags = oss.ss_flags;
                oss32.ss_size = oss.ss_size;
                if (copy_to_user(uoss32, &oss32, sizeof *uoss32))
                        return -EFAULT;
        }

        return ret;
}

long
restore_sigcontext32(struct compat_sigcontext __user *sc, struct compat_regfile __user * rf,
                struct pt_regs *regs)
{
        long err = 0;
        compat_uint_t compat_reg;
        compat_uint_t compat_regt;
        int regn;
        
        /* When loading 32-bit values into 64-bit registers make
           sure to clear the upper 32-bits */
        DBG(2,"restore_sigcontext32: PER_LINUX32 process\n");
        DBG(2,"restore_sigcontext32: sc = 0x%p, rf = 0x%p, regs = 0x%p\n", sc, rf, regs);
        DBG(2,"restore_sigcontext32: compat_sigcontext is %#lx bytes\n", sizeof(*sc));
        for(regn=0; regn < 32; regn++){
                err |= __get_user(compat_reg,&sc->sc_gr[regn]);
                regs->gr[regn] = compat_reg;
                /* Load upper half */
                err |= __get_user(compat_regt,&rf->rf_gr[regn]);
                regs->gr[regn] = ((u64)compat_regt << 32) | (u64)compat_reg;
                DBG(3,"restore_sigcontext32: gr%02d = %#lx (%#x / %#x)\n", 
                                regn, regs->gr[regn], compat_regt, compat_reg);
        }
        DBG(2,"restore_sigcontext32: sc->sc_fr = 0x%p (%#lx)\n",sc->sc_fr, sizeof(sc->sc_fr));
        /* XXX: BE WARNED FR's are 64-BIT! */
        err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
                
        /* Better safe than sorry, pass __get_user two things of
           the same size and let gcc do the upward conversion to 
           64-bits */           
        err |= __get_user(compat_reg, &sc->sc_iaoq[0]);
        /* Load upper half */
        err |= __get_user(compat_regt, &rf->rf_iaoq[0]);
        regs->iaoq[0] = ((u64)compat_regt << 32) | (u64)compat_reg;
        DBG(2,"restore_sigcontext32: upper half of iaoq[0] = %#lx\n", compat_regt);
        DBG(2,"restore_sigcontext32: sc->sc_iaoq[0] = %p => %#x\n", 
                        &sc->sc_iaoq[0], compat_reg);

        err |= __get_user(compat_reg, &sc->sc_iaoq[1]);
        /* Load upper half */
        err |= __get_user(compat_regt, &rf->rf_iaoq[1]);
        regs->iaoq[1] = ((u64)compat_regt << 32) | (u64)compat_reg;
        DBG(2,"restore_sigcontext32: upper half of iaoq[1] = %#lx\n", compat_regt);
        DBG(2,"restore_sigcontext32: sc->sc_iaoq[1] = %p => %#x\n", 
                        &sc->sc_iaoq[1],compat_reg);    
        DBG(2,"restore_sigcontext32: iaoq is %#lx / %#lx\n", 
                        regs->iaoq[0],regs->iaoq[1]);           
                
        err |= __get_user(compat_reg, &sc->sc_iasq[0]);
        /* Load the upper half for iasq */
        err |= __get_user(compat_regt, &rf->rf_iasq[0]);
        regs->iasq[0] = ((u64)compat_regt << 32) | (u64)compat_reg;
        DBG(2,"restore_sigcontext32: upper half of iasq[0] = %#lx\n", compat_regt);
        
        err |= __get_user(compat_reg, &sc->sc_iasq[1]);
        /* Load the upper half for iasq */
        err |= __get_user(compat_regt, &rf->rf_iasq[1]);
        regs->iasq[1] = ((u64)compat_regt << 32) | (u64)compat_reg;
        DBG(2,"restore_sigcontext32: upper half of iasq[1] = %#lx\n", compat_regt);
        DBG(2,"restore_sigcontext32: iasq is %#lx / %#lx\n", 
                regs->iasq[0],regs->iasq[1]);           

        err |= __get_user(compat_reg, &sc->sc_sar);
        /* Load the upper half for sar */
        err |= __get_user(compat_regt, &rf->rf_sar);
        regs->sar = ((u64)compat_regt << 32) | (u64)compat_reg; 
        DBG(2,"restore_sigcontext32: upper_half & sar = %#lx\n", compat_regt);  
        DBG(2,"restore_sigcontext32: sar is %#lx\n", regs->sar);                
        DBG(2,"restore_sigcontext32: r28 is %ld\n", regs->gr[28]);
        
        return err;
}

/*
 * Set up the sigcontext structure for this process.
 * This is not an easy task if the kernel is 64-bit, it will require
 * that we examine the process personality to determine if we need to
 * truncate for a 32-bit userspace.
 */
long
setup_sigcontext32(struct compat_sigcontext __user *sc, struct compat_regfile __user * rf, 
                struct pt_regs *regs, int in_syscall)            
{
        compat_int_t flags = 0;
        long err = 0;
        compat_uint_t compat_reg;
        compat_uint_t compat_regb;
        int regn;
        
        if (on_sig_stack((unsigned long) sc))
                flags |= PARISC_SC_FLAG_ONSTACK;
        
        if (in_syscall) {
                
                DBG(1,"setup_sigcontext32: in_syscall\n");
                
                flags |= PARISC_SC_FLAG_IN_SYSCALL;
                /* Truncate gr31 */
                compat_reg = (compat_uint_t)(regs->gr[31]);
                /* regs->iaoq is undefined in the syscall return path */
                err |= __put_user(compat_reg, &sc->sc_iaoq[0]);
                DBG(2,"setup_sigcontext32: sc->sc_iaoq[0] = %p <= %#x\n",
                                &sc->sc_iaoq[0], compat_reg);
                
                /* Store upper half */
                compat_reg = (compat_uint_t)(regs->gr[31] >> 32);
                err |= __put_user(compat_reg, &rf->rf_iaoq[0]);
                DBG(2,"setup_sigcontext32: upper half iaoq[0] = %#x\n", compat_reg);
                
                
                compat_reg = (compat_uint_t)(regs->gr[31]+4);
                err |= __put_user(compat_reg, &sc->sc_iaoq[1]);
                DBG(2,"setup_sigcontext32: sc->sc_iaoq[1] = %p <= %#x\n",
                                &sc->sc_iaoq[1], compat_reg);
                /* Store upper half */
                compat_reg = (compat_uint_t)((regs->gr[31]+4) >> 32);
                err |= __put_user(compat_reg, &rf->rf_iaoq[1]);
                DBG(2,"setup_sigcontext32: upper half iaoq[1] = %#x\n", compat_reg);
                
                /* Truncate sr3 */
                compat_reg = (compat_uint_t)(regs->sr[3]);
                err |= __put_user(compat_reg, &sc->sc_iasq[0]);
                err |= __put_user(compat_reg, &sc->sc_iasq[1]);         
                
                /* Store upper half */
                compat_reg = (compat_uint_t)(regs->sr[3] >> 32);
                err |= __put_user(compat_reg, &rf->rf_iasq[0]);
                err |= __put_user(compat_reg, &rf->rf_iasq[1]);         
                
                DBG(2,"setup_sigcontext32: upper half iasq[0] = %#x\n", compat_reg);
                DBG(2,"setup_sigcontext32: upper half iasq[1] = %#x\n", compat_reg);            
                DBG(1,"setup_sigcontext32: iaoq %#lx / %#lx\n",                         
                        regs->gr[31], regs->gr[31]+4);
                
        } else {
                
                compat_reg = (compat_uint_t)(regs->iaoq[0]);
                err |= __put_user(compat_reg, &sc->sc_iaoq[0]);
                DBG(2,"setup_sigcontext32: sc->sc_iaoq[0] = %p <= %#x\n",
                                &sc->sc_iaoq[0], compat_reg);
                /* Store upper half */
                compat_reg = (compat_uint_t)(regs->iaoq[0] >> 32);
                err |= __put_user(compat_reg, &rf->rf_iaoq[0]); 
                DBG(2,"setup_sigcontext32: upper half iaoq[0] = %#x\n", compat_reg);
                
                compat_reg = (compat_uint_t)(regs->iaoq[1]);
                err |= __put_user(compat_reg, &sc->sc_iaoq[1]);
                DBG(2,"setup_sigcontext32: sc->sc_iaoq[1] = %p <= %#x\n",
                                &sc->sc_iaoq[1], compat_reg);
                /* Store upper half */
                compat_reg = (compat_uint_t)(regs->iaoq[1] >> 32);
                err |= __put_user(compat_reg, &rf->rf_iaoq[1]);
                DBG(2,"setup_sigcontext32: upper half iaoq[1] = %#x\n", compat_reg);
                
                
                compat_reg = (compat_uint_t)(regs->iasq[0]);
                err |= __put_user(compat_reg, &sc->sc_iasq[0]);
                DBG(2,"setup_sigcontext32: sc->sc_iasq[0] = %p <= %#x\n",
                                &sc->sc_iasq[0], compat_reg);
                /* Store upper half */
                compat_reg = (compat_uint_t)(regs->iasq[0] >> 32);
                err |= __put_user(compat_reg, &rf->rf_iasq[0]);
                DBG(2,"setup_sigcontext32: upper half iasq[0] = %#x\n", compat_reg);
                
                
                compat_reg = (compat_uint_t)(regs->iasq[1]);
                err |= __put_user(compat_reg, &sc->sc_iasq[1]);
                DBG(2,"setup_sigcontext32: sc->sc_iasq[1] = %p <= %#x\n",
                                &sc->sc_iasq[1], compat_reg);
                /* Store upper half */
                compat_reg = (compat_uint_t)(regs->iasq[1] >> 32);
                err |= __put_user(compat_reg, &rf->rf_iasq[1]);
                DBG(2,"setup_sigcontext32: upper half iasq[1] = %#x\n", compat_reg);

                /* Print out the IAOQ for debugging */          
                DBG(1,"setup_sigcontext32: ia0q %#lx / %#lx\n", 
                        regs->iaoq[0], regs->iaoq[1]);
        }

        err |= __put_user(flags, &sc->sc_flags);
        
        DBG(1,"setup_sigcontext32: Truncating general registers.\n");
        
        for(regn=0; regn < 32; regn++){
                /* Truncate a general register */
                compat_reg = (compat_uint_t)(regs->gr[regn]);
                err |= __put_user(compat_reg, &sc->sc_gr[regn]);
                /* Store upper half */
                compat_regb = (compat_uint_t)(regs->gr[regn] >> 32);
                err |= __put_user(compat_regb, &rf->rf_gr[regn]);

                /* DEBUG: Write out the "upper / lower" register data */
                DBG(2,"setup_sigcontext32: gr%02d = %#x / %#x\n", regn, 
                                compat_regb, compat_reg);
        }
        
        /* Copy the floating point registers (same size)
           XXX: BE WARNED FR's are 64-BIT! */   
        DBG(1,"setup_sigcontext32: Copying from regs to sc, "
              "sc->sc_fr size = %#lx, regs->fr size = %#lx\n",
                sizeof(regs->fr), sizeof(sc->sc_fr));
        err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));

        compat_reg = (compat_uint_t)(regs->sar);
        err |= __put_user(compat_reg, &sc->sc_sar);
        DBG(2,"setup_sigcontext32: sar is %#x\n", compat_reg);
        /* Store upper half */
        compat_reg = (compat_uint_t)(regs->sar >> 32);
        err |= __put_user(compat_reg, &rf->rf_sar);     
        DBG(2,"setup_sigcontext32: upper half sar = %#x\n", compat_reg);
        DBG(1,"setup_sigcontext32: r28 is %ld\n", regs->gr[28]);

        return err;
}

int
copy_siginfo_from_user32 (siginfo_t *to, compat_siginfo_t __user *from)
{
        compat_uptr_t addr;
        int err;

        if (!access_ok(VERIFY_READ, from, sizeof(compat_siginfo_t)))
                return -EFAULT;

        err = __get_user(to->si_signo, &from->si_signo);
        err |= __get_user(to->si_errno, &from->si_errno);
        err |= __get_user(to->si_code, &from->si_code);

        if (to->si_code < 0)
                err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
        else {
                switch (to->si_code >> 16) {
                      case __SI_CHLD >> 16:
                        err |= __get_user(to->si_utime, &from->si_utime);
                        err |= __get_user(to->si_stime, &from->si_stime);
                        err |= __get_user(to->si_status, &from->si_status);
                      default:
                        err |= __get_user(to->si_pid, &from->si_pid);
                        err |= __get_user(to->si_uid, &from->si_uid);
                        break;
                      case __SI_FAULT >> 16:
                        err |= __get_user(addr, &from->si_addr);
                        to->si_addr = compat_ptr(addr);
                        break;
                      case __SI_POLL >> 16:
                        err |= __get_user(to->si_band, &from->si_band);
                        err |= __get_user(to->si_fd, &from->si_fd);
                        break;
                      case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
                      case __SI_MESGQ >> 16:
                        err |= __get_user(to->si_pid, &from->si_pid);
                        err |= __get_user(to->si_uid, &from->si_uid);
                        err |= __get_user(to->si_int, &from->si_int);
                        break;
                }
        }
        return err;
}

int
copy_siginfo_to_user32 (compat_siginfo_t __user *to, siginfo_t *from)
{
        compat_uptr_t addr;
        compat_int_t val;
        int err;

        if (!access_ok(VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
                return -EFAULT;

        /* If you change siginfo_t structure, please be sure
           this code is fixed accordingly.
           It should never copy any pad contained in the structure
           to avoid security leaks, but must copy the generic
           3 ints plus the relevant union member.
           This routine must convert siginfo from 64bit to 32bit as well
           at the same time.  */
        err = __put_user(from->si_signo, &to->si_signo);
        err |= __put_user(from->si_errno, &to->si_errno);
        err |= __put_user((short)from->si_code, &to->si_code);
        if (from->si_code < 0)
                err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
        else {
                switch (from->si_code >> 16) {
                case __SI_CHLD >> 16:
                        err |= __put_user(from->si_utime, &to->si_utime);
                        err |= __put_user(from->si_stime, &to->si_stime);
                        err |= __put_user(from->si_status, &to->si_status);
                default:
                        err |= __put_user(from->si_pid, &to->si_pid);
                        err |= __put_user(from->si_uid, &to->si_uid);
                        break;
                case __SI_FAULT >> 16:
                        addr = ptr_to_compat(from->si_addr);
                        err |= __put_user(addr, &to->si_addr);
                        break;
                case __SI_POLL >> 16:
                        err |= __put_user(from->si_band, &to->si_band);
                        err |= __put_user(from->si_fd, &to->si_fd);
                        break;
                case __SI_TIMER >> 16:
                        err |= __put_user(from->si_tid, &to->si_tid);
                        err |= __put_user(from->si_overrun, &to->si_overrun);
                        val = (compat_int_t)from->si_int;
                        err |= __put_user(val, &to->si_int);
                        break;
                case __SI_RT >> 16:     /* Not generated by the kernel as of now.  */
                case __SI_MESGQ >> 16:
                        err |= __put_user(from->si_uid, &to->si_uid);
                        err |= __put_user(from->si_pid, &to->si_pid);
                        val = (compat_int_t)from->si_int;
                        err |= __put_user(val, &to->si_int);
                        break;
                }
        }
        return err;
}

asmlinkage long compat_sys_rt_sigqueueinfo(int pid, int sig,
        struct compat_siginfo __user *uinfo)
{
        siginfo_t info;

        if (copy_siginfo_from_user32(&info, uinfo))
                return -EFAULT;

        /* Not even root can pretend to send signals from the kernel.
           Nor can they impersonate a kill(), which adds source info.  */
        if (info.si_code >= 0)
                return -EPERM;
        info.si_signo = sig;

        /* POSIX.1b doesn't mention process groups.  */
        return kill_proc_info(sig, &info, pid);
}