// SPDX-License-Identifier: GPL-2.0-or-later
/*    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.
 */

#include <linux/compat.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 <linux/uaccess.h>

#include "signal32.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

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;
}