syscall.c

/*
 *  BSD syscalls
 *
 *  Copyright (c) 2003 - 2008 Fabrice Bellard
 *
 *  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, see <http://www.gnu.org/licenses/>.
 */
#include "qemu/osdep.h"
#include "qemu/cutils.h"
#include "qemu/path.h"
#include <sys/syscall.h>
#include <sys/param.h>
#include <sys/sysctl.h>
#include <utime.h>

#include "qemu.h"
#include "qemu-common.h"

//#define DEBUG

static abi_ulong target_brk;
static abi_ulong target_original_brk;

static inline abi_long get_errno(abi_long ret)
{
    if (ret == -1)
        /* XXX need to translate host -> target errnos here */
        return -(errno);
    else
        return ret;
}

#define target_to_host_bitmask(x, tbl) (x)

static inline int is_error(abi_long ret)
{
    return (abi_ulong)ret >= (abi_ulong)(-4096);
}

void target_set_brk(abi_ulong new_brk)
{
    target_original_brk = target_brk = HOST_PAGE_ALIGN(new_brk);
}

/* do_obreak() must return target errnos. */
static abi_long do_obreak(abi_ulong new_brk)
{
    abi_ulong brk_page;
    abi_long mapped_addr;
    int new_alloc_size;

    if (!new_brk)
        return 0;
    if (new_brk < target_original_brk)
        return -TARGET_EINVAL;

    brk_page = HOST_PAGE_ALIGN(target_brk);

    /* If the new brk is less than this, set it and we're done... */
    if (new_brk < brk_page) {
        target_brk = new_brk;
        return 0;
    }

    /* We need to allocate more memory after the brk... */
    new_alloc_size = HOST_PAGE_ALIGN(new_brk - brk_page + 1);
    mapped_addr = get_errno(target_mmap(brk_page, new_alloc_size,
                                        PROT_READ|PROT_WRITE,
                                        MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0));

    if (!is_error(mapped_addr))
        target_brk = new_brk;
    else
        return mapped_addr;

    return 0;
}

#if defined(TARGET_I386)
static abi_long do_freebsd_sysarch(CPUX86State *env, int op, abi_ulong parms)
{
    abi_long ret = 0;
    abi_ulong val;
    int idx;

    switch(op) {
#ifdef TARGET_ABI32
    case TARGET_FREEBSD_I386_SET_GSBASE:
    case TARGET_FREEBSD_I386_SET_FSBASE:
        if (op == TARGET_FREEBSD_I386_SET_GSBASE)
#else
    case TARGET_FREEBSD_AMD64_SET_GSBASE:
    case TARGET_FREEBSD_AMD64_SET_FSBASE:
        if (op == TARGET_FREEBSD_AMD64_SET_GSBASE)
#endif
            idx = R_GS;
        else
            idx = R_FS;
        if (get_user(val, parms, abi_ulong))
            return -TARGET_EFAULT;
        cpu_x86_load_seg(env, idx, 0);
        env->segs[idx].base = val;
        break;
#ifdef TARGET_ABI32
    case TARGET_FREEBSD_I386_GET_GSBASE:
    case TARGET_FREEBSD_I386_GET_FSBASE:
        if (op == TARGET_FREEBSD_I386_GET_GSBASE)
#else
    case TARGET_FREEBSD_AMD64_GET_GSBASE:
    case TARGET_FREEBSD_AMD64_GET_FSBASE:
        if (op == TARGET_FREEBSD_AMD64_GET_GSBASE)
#endif
            idx = R_GS;
        else
            idx = R_FS;
        val = env->segs[idx].base;
        if (put_user(val, parms, abi_ulong))
            return -TARGET_EFAULT;
        break;
    /* XXX handle the others... */
    default:
        ret = -TARGET_EINVAL;
        break;
    }
    return ret;
}
#endif

#ifdef TARGET_SPARC
static abi_long do_freebsd_sysarch(void *env, int op, abi_ulong parms)
{
    /* XXX handle
     * TARGET_FREEBSD_SPARC_UTRAP_INSTALL,
     * TARGET_FREEBSD_SPARC_SIGTRAMP_INSTALL
     */
    return -TARGET_EINVAL;
}
#endif

#ifdef __FreeBSD__
/*
 * XXX this uses the undocumented oidfmt interface to find the kind of
 * a requested sysctl, see /sys/kern/kern_sysctl.c:sysctl_sysctl_oidfmt()
 * (this is mostly copied from src/sbin/sysctl/sysctl.c)
 */
static int
oidfmt(int *oid, int len, char *fmt, uint32_t *kind)
{
    int qoid[CTL_MAXNAME+2];
    uint8_t buf[BUFSIZ];
    int i;
    size_t j;

    qoid[0] = 0;
    qoid[1] = 4;
    memcpy(qoid + 2, oid, len * sizeof(int));

    j = sizeof(buf);
    i = sysctl(qoid, len + 2, buf, &j, 0, 0);
    if (i)
        return i;

    if (kind)
        *kind = *(uint32_t *)buf;

    if (fmt)
        strcpy(fmt, (char *)(buf + sizeof(uint32_t)));
    return (0);
}

/*
 * try and convert sysctl return data for the target.
 * XXX doesn't handle CTLTYPE_OPAQUE and CTLTYPE_STRUCT.
 */
static int sysctl_oldcvt(void *holdp, size_t holdlen, uint32_t kind)
{
    switch (kind & CTLTYPE) {
    case CTLTYPE_INT:
    case CTLTYPE_UINT:
        *(uint32_t *)holdp = tswap32(*(uint32_t *)holdp);
        break;
#ifdef TARGET_ABI32
    case CTLTYPE_LONG:
    case CTLTYPE_ULONG:
        *(uint32_t *)holdp = tswap32(*(long *)holdp);
        break;
#else
    case CTLTYPE_LONG:
        *(uint64_t *)holdp = tswap64(*(long *)holdp);
    case CTLTYPE_ULONG:
        *(uint64_t *)holdp = tswap64(*(unsigned long *)holdp);
        break;
#endif
#ifdef CTLTYPE_U64
    case CTLTYPE_S64:
    case CTLTYPE_U64:
#else
    case CTLTYPE_QUAD:
#endif
        *(uint64_t *)holdp = tswap64(*(uint64_t *)holdp);
        break;
    case CTLTYPE_STRING:
        break;
    default:
        /* XXX unhandled */
        return -1;
    }
    return 0;
}

/* XXX this needs to be emulated on non-FreeBSD hosts... */
static abi_long do_freebsd_sysctl(abi_ulong namep, int32_t namelen, abi_ulong oldp,
                          abi_ulong oldlenp, abi_ulong newp, abi_ulong newlen)
{
    abi_long ret;
    void *hnamep, *holdp, *hnewp = NULL;
    size_t holdlen;
    abi_ulong oldlen = 0;
    int32_t *snamep = g_malloc(sizeof(int32_t) * namelen), *p, *q, i;
    uint32_t kind = 0;

    if (oldlenp)
        get_user_ual(oldlen, oldlenp);
    if (!(hnamep = lock_user(VERIFY_READ, namep, namelen, 1)))
        return -TARGET_EFAULT;
    if (newp && !(hnewp = lock_user(VERIFY_READ, newp, newlen, 1)))
        return -TARGET_EFAULT;
    if (!(holdp = lock_user(VERIFY_WRITE, oldp, oldlen, 0)))
        return -TARGET_EFAULT;
    holdlen = oldlen;
    for (p = hnamep, q = snamep, i = 0; i < namelen; p++, i++)
       *q++ = tswap32(*p);
    oidfmt(snamep, namelen, NULL, &kind);
    /* XXX swap hnewp */
    ret = get_errno(sysctl(snamep, namelen, holdp, &holdlen, hnewp, newlen));
    if (!ret)
        sysctl_oldcvt(holdp, holdlen, kind);
    put_user_ual(holdlen, oldlenp);
    unlock_user(hnamep, namep, 0);
    unlock_user(holdp, oldp, holdlen);
    if (hnewp)
        unlock_user(hnewp, newp, 0);
    g_free(snamep);
    return ret;
}
#endif

/* FIXME
 * lock_iovec()/unlock_iovec() have a return code of 0 for success where
 * other lock functions have a return code of 0 for failure.
 */
static abi_long lock_iovec(int type, struct iovec *vec, abi_ulong target_addr,
                           int count, int copy)
{
    struct target_iovec *target_vec;
    abi_ulong base;
    int i;

    target_vec = lock_user(VERIFY_READ, target_addr, count * sizeof(struct target_iovec), 1);
    if (!target_vec)
        return -TARGET_EFAULT;
    for(i = 0;i < count; i++) {
        base = tswapl(target_vec[i].iov_base);
        vec[i].iov_len = tswapl(target_vec[i].iov_len);
        if (vec[i].iov_len != 0) {
            vec[i].iov_base = lock_user(type, base, vec[i].iov_len, copy);
            /* Don't check lock_user return value. We must call writev even
               if a element has invalid base address. */
        } else {
            /* zero length pointer is ignored */
            vec[i].iov_base = NULL;
        }
    }
    unlock_user (target_vec, target_addr, 0);
    return 0;
}

static abi_long unlock_iovec(struct iovec *vec, abi_ulong target_addr,
                             int count, int copy)
{
    struct target_iovec *target_vec;
    abi_ulong base;
    int i;

    target_vec = lock_user(VERIFY_READ, target_addr, count * sizeof(struct target_iovec), 1);
    if (!target_vec)
        return -TARGET_EFAULT;
    for(i = 0;i < count; i++) {
        if (target_vec[i].iov_base) {
            base = tswapl(target_vec[i].iov_base);
            unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
        }
    }
    unlock_user (target_vec, target_addr, 0);

    return 0;
}

/* do_syscall() should always have a single exit point at the end so
   that actions, such as logging of syscall results, can be performed.
   All errnos that do_syscall() returns must be -TARGET_<errcode>. */
abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
                            abi_long arg2, abi_long arg3, abi_long arg4,
                            abi_long arg5, abi_long arg6, abi_long arg7,
                            abi_long arg8)
{
    CPUState *cpu = ENV_GET_CPU(cpu_env);
    abi_long ret;
    void *p;

#ifdef DEBUG
    gemu_log("freebsd syscall %d\n", num);
#endif
    trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
    if(do_strace)
        print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);

    switch(num) {
    case TARGET_FREEBSD_NR_exit:
#ifdef TARGET_GPROF
        _mcleanup();
#endif
        gdb_exit(cpu_env, arg1);
        /* XXX: should free thread stack and CPU env */
        _exit(arg1);
        ret = 0; /* avoid warning */
        break;
    case TARGET_FREEBSD_NR_read:
        if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0)))
            goto efault;
        ret = get_errno(read(arg1, p, arg3));
        unlock_user(p, arg2, ret);
        break;
    case TARGET_FREEBSD_NR_write:
        if (!(p = lock_user(VERIFY_READ, arg2, arg3, 1)))
            goto efault;
        ret = get_errno(write(arg1, p, arg3));
        unlock_user(p, arg2, 0);
        break;
    case TARGET_FREEBSD_NR_writev:
        {
            int count = arg3;
            struct iovec *vec;

            vec = alloca(count * sizeof(struct iovec));
            if (lock_iovec(VERIFY_READ, vec, arg2, count, 1) < 0)
                goto efault;
            ret = get_errno(writev(arg1, vec, count));
            unlock_iovec(vec, arg2, count, 0);
        }
        break;
    case TARGET_FREEBSD_NR_open:
        if (!(p = lock_user_string(arg1)))
            goto efault;
        ret = get_errno(open(path(p),
                             target_to_host_bitmask(arg2, fcntl_flags_tbl),
                             arg3));
        unlock_user(p, arg1, 0);
        break;
    case TARGET_FREEBSD_NR_mmap:
        ret = get_errno(target_mmap(arg1, arg2, arg3,
                                    target_to_host_bitmask(arg4, mmap_flags_tbl),
                                    arg5,
                                    arg6));
        break;
    case TARGET_FREEBSD_NR_mprotect:
        ret = get_errno(target_mprotect(arg1, arg2, arg3));
        break;
    case TARGET_FREEBSD_NR_break:
        ret = do_obreak(arg1);
        break;
#ifdef __FreeBSD__
    case TARGET_FREEBSD_NR___sysctl:
        ret = do_freebsd_sysctl(arg1, arg2, arg3, arg4, arg5, arg6);
        break;
#endif
    case TARGET_FREEBSD_NR_sysarch:
        ret = do_freebsd_sysarch(cpu_env, arg1, arg2);
        break;
    case TARGET_FREEBSD_NR_syscall:
    case TARGET_FREEBSD_NR___syscall:
        ret = do_freebsd_syscall(cpu_env,arg1 & 0xffff,arg2,arg3,arg4,arg5,arg6,arg7,arg8,0);
        break;
    default:
        ret = get_errno(syscall(num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8));
        break;
    }
 fail:
#ifdef DEBUG
    gemu_log(" = %ld\n", ret);
#endif
    if (do_strace)
        print_freebsd_syscall_ret(num, ret);
    trace_guest_user_syscall_ret(cpu, num, ret);
    return ret;
 efault:
    ret = -TARGET_EFAULT;
    goto fail;
}

abi_long do_netbsd_syscall(void *cpu_env, int num, abi_long arg1,
                           abi_long arg2, abi_long arg3, abi_long arg4,
                           abi_long arg5, abi_long arg6)
{
    CPUState *cpu = ENV_GET_CPU(cpu_env);
    abi_long ret;
    void *p;

#ifdef DEBUG
    gemu_log("netbsd syscall %d\n", num);
#endif
    trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, 0, 0);
    if(do_strace)
        print_netbsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);

    switch(num) {
    case TARGET_NETBSD_NR_exit:
#ifdef TARGET_GPROF
        _mcleanup();
#endif
        gdb_exit(cpu_env, arg1);
        /* XXX: should free thread stack and CPU env */
        _exit(arg1);
        ret = 0; /* avoid warning */
        break;
    case TARGET_NETBSD_NR_read:
        if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0)))
            goto efault;
        ret = get_errno(read(arg1, p, arg3));
        unlock_user(p, arg2, ret);
        break;
    case TARGET_NETBSD_NR_write:
        if (!(p = lock_user(VERIFY_READ, arg2, arg3, 1)))
            goto efault;
        ret = get_errno(write(arg1, p, arg3));
        unlock_user(p, arg2, 0);
        break;
    case TARGET_NETBSD_NR_open:
        if (!(p = lock_user_string(arg1)))
            goto efault;
        ret = get_errno(open(path(p),
                             target_to_host_bitmask(arg2, fcntl_flags_tbl),
                             arg3));
        unlock_user(p, arg1, 0);
        break;
    case TARGET_NETBSD_NR_mmap:
        ret = get_errno(target_mmap(arg1, arg2, arg3,
                                    target_to_host_bitmask(arg4, mmap_flags_tbl),
                                    arg5,
                                    arg6));
        break;
    case TARGET_NETBSD_NR_mprotect:
        ret = get_errno(target_mprotect(arg1, arg2, arg3));
        break;
    case TARGET_NETBSD_NR_syscall:
    case TARGET_NETBSD_NR___syscall:
        ret = do_netbsd_syscall(cpu_env,arg1 & 0xffff,arg2,arg3,arg4,arg5,arg6,0);
        break;
    default:
        ret = syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
        break;
    }
 fail:
#ifdef DEBUG
    gemu_log(" = %ld\n", ret);
#endif
    if (do_strace)
        print_netbsd_syscall_ret(num, ret);
    trace_guest_user_syscall_ret(cpu, num, ret);
    return ret;
 efault:
    ret = -TARGET_EFAULT;
    goto fail;
}

abi_long do_openbsd_syscall(void *cpu_env, int num, abi_long arg1,
                            abi_long arg2, abi_long arg3, abi_long arg4,
                            abi_long arg5, abi_long arg6)
{
    CPUState *cpu = ENV_GET_CPU(cpu_env);
    abi_long ret;
    void *p;

#ifdef DEBUG
    gemu_log("openbsd syscall %d\n", num);
#endif
    trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, 0, 0);
    if(do_strace)
        print_openbsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);

    switch(num) {
    case TARGET_OPENBSD_NR_exit:
#ifdef TARGET_GPROF
        _mcleanup();
#endif
        gdb_exit(cpu_env, arg1);
        /* XXX: should free thread stack and CPU env */
        _exit(arg1);
        ret = 0; /* avoid warning */
        break;
    case TARGET_OPENBSD_NR_read:
        if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0)))
            goto efault;
        ret = get_errno(read(arg1, p, arg3));
        unlock_user(p, arg2, ret);
        break;
    case TARGET_OPENBSD_NR_write:
        if (!(p = lock_user(VERIFY_READ, arg2, arg3, 1)))
            goto efault;
        ret = get_errno(write(arg1, p, arg3));
        unlock_user(p, arg2, 0);
        break;
    case TARGET_OPENBSD_NR_open:
        if (!(p = lock_user_string(arg1)))
            goto efault;
        ret = get_errno(open(path(p),
                             target_to_host_bitmask(arg2, fcntl_flags_tbl),
                             arg3));
        unlock_user(p, arg1, 0);
        break;
    case TARGET_OPENBSD_NR_mmap:
        ret = get_errno(target_mmap(arg1, arg2, arg3,
                                    target_to_host_bitmask(arg4, mmap_flags_tbl),
                                    arg5,
                                    arg6));
        break;
    case TARGET_OPENBSD_NR_mprotect:
        ret = get_errno(target_mprotect(arg1, arg2, arg3));
        break;
    case TARGET_OPENBSD_NR_syscall:
    case TARGET_OPENBSD_NR___syscall:
        ret = do_openbsd_syscall(cpu_env,arg1 & 0xffff,arg2,arg3,arg4,arg5,arg6,0);
        break;
    default:
        ret = syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
        break;
    }
 fail:
#ifdef DEBUG
    gemu_log(" = %ld\n", ret);
#endif
    if (do_strace)
        print_openbsd_syscall_ret(num, ret);
    trace_guest_user_syscall_ret(cpu, num, ret);
    return ret;
 efault:
    ret = -TARGET_EFAULT;
    goto fail;
}

void syscall_init(void)
{
}