sys_sparc_32.c

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/* linux/arch/sparc/kernel/sys_sparc.c
 *
 * This file contains various random system calls that
 * have a non-standard calling sequence on the Linux/sparc
 * platform.
 */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/syscalls.h>
#include <linux/mman.h>
#include <linux/utsname.h>
#include <linux/smp.h>
#include <linux/ipc.h>

#include <asm/uaccess.h>
#include <asm/unistd.h>

/* #define DEBUG_UNIMP_SYSCALL */

/* XXX Make this per-binary type, this way we can detect the type of
 * XXX a binary.  Every Sparc executable calls this very early on.
 */
asmlinkage unsigned long sys_getpagesize(void)
{
    return PAGE_SIZE; /* Possibly older binaries want 8192 on sun4's? */
}

#define COLOUR_ALIGN(addr)      (((addr)+SHMLBA-1)&~(SHMLBA-1))

unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
{
    struct vm_area_struct * vmm;

    if (flags & MAP_FIXED) {
        /* We do not accept a shared mapping if it would violate
         * cache aliasing constraints.
         */
        if ((flags & MAP_SHARED) &&
            ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
            return -EINVAL;
        return addr;
    }

    /* See asm-sparc/uaccess.h */
    if (len > TASK_SIZE - PAGE_SIZE)
        return -ENOMEM;
    if (!addr)
        addr = TASK_UNMAPPED_BASE;

    if (flags & MAP_SHARED)
        addr = COLOUR_ALIGN(addr);
    else
        addr = PAGE_ALIGN(addr);

    for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
        /* At this point:  (!vmm || addr < vmm->vm_end). */
        if (TASK_SIZE - PAGE_SIZE - len < addr)
            return -ENOMEM;
        if (!vmm || addr + len <= vmm->vm_start)
            return addr;
        addr = vmm->vm_end;
        if (flags & MAP_SHARED)
            addr = COLOUR_ALIGN(addr);
    }
}

/*
 * sys_pipe() is the normal C calling standard for creating
 * a pipe. It's not the way unix traditionally does this, though.
 */
asmlinkage int sparc_pipe(struct pt_regs *regs)
{
    int fd[2];
    int error;

    error = do_pipe_flags(fd, 0);
    if (error)
        goto out;
    regs->u_regs[UREG_I1] = fd[1];
    error = fd[0];
out:
    return error;
}

int sparc_mmap_check(unsigned long addr, unsigned long len)
{
    /* See asm-sparc/uaccess.h */
    if (len > TASK_SIZE - PAGE_SIZE || addr + len > TASK_SIZE - PAGE_SIZE)
        return -EINVAL;

    return 0;
}

/* Linux version of mmap */

asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
    unsigned long prot, unsigned long flags, unsigned long fd,
    unsigned long pgoff)
{
    /* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
       we have. */
    return sys_mmap_pgoff(addr, len, prot, flags, fd,
                  pgoff >> (PAGE_SHIFT - 12));
}

asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
    unsigned long prot, unsigned long flags, unsigned long fd,
    unsigned long off)
{
    /* no alignment check? */
    return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
}

long sparc_remap_file_pages(unsigned long start, unsigned long size,
               unsigned long prot, unsigned long pgoff,
               unsigned long flags)
{
    /* This works on an existing mmap so we don't need to validate
     * the range as that was done at the original mmap call.
     */
    return sys_remap_file_pages(start, size, prot,
                    (pgoff >> (PAGE_SHIFT - 12)), flags);
}

/* we come to here via sys_nis_syscall so it can setup the regs argument */
asmlinkage unsigned long
c_sys_nis_syscall (struct pt_regs *regs)
{
    static int count = 0;

    if (count++ > 5)
        return -ENOSYS;
    printk ("%s[%d]: Unimplemented SPARC system call %d\n",
        current->comm, task_pid_nr(current), (int)regs->u_regs[1]);
#ifdef DEBUG_UNIMP_SYSCALL  
    show_regs (regs);
#endif
    return -ENOSYS;
}

/* #define DEBUG_SPARC_BREAKPOINT */

asmlinkage void
sparc_breakpoint (struct pt_regs *regs)
{
    siginfo_t info;

#ifdef DEBUG_SPARC_BREAKPOINT
        printk ("TRAP: Entering kernel PC=%x, nPC=%x\n", regs->pc, regs->npc);
#endif
    info.si_signo = SIGTRAP;
    info.si_errno = 0;
    info.si_code = TRAP_BRKPT;
    info.si_addr = (void __user *)regs->pc;
    info.si_trapno = 0;
    force_sig_info(SIGTRAP, &info, current);

#ifdef DEBUG_SPARC_BREAKPOINT
    printk ("TRAP: Returning to space: PC=%x nPC=%x\n", regs->pc, regs->npc);
#endif
}

asmlinkage int
sparc_sigaction (int sig, const struct old_sigaction __user *act,
         struct old_sigaction __user *oact)
{
    struct k_sigaction new_ka, old_ka;
    int ret;

    WARN_ON_ONCE(sig >= 0);
    sig = -sig;

    if (act) {
        unsigned long mask;

        if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
            __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
            __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
            __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
            __get_user(mask, &act->sa_mask))
            return -EFAULT;
        siginitset(&new_ka.sa.sa_mask, mask);
        new_ka.ka_restorer = NULL;
    }

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

    if (!ret && oact) {
        if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
            __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
            __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
            __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
            __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
            return -EFAULT;
    }

    return ret;
}

asmlinkage long
sys_rt_sigaction(int sig,
         const struct sigaction __user *act,
         struct sigaction __user *oact,
         void __user *restorer,
         size_t sigsetsize)
{
    struct k_sigaction new_ka, old_ka;
    int ret;

    /* XXX: Don't preclude handling different sized sigset_t's.  */
    if (sigsetsize != sizeof(sigset_t))
        return -EINVAL;

    if (act) {
        new_ka.ka_restorer = restorer;
        if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
            return -EFAULT;
    }

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

    if (!ret && oact) {
        if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
            return -EFAULT;
    }

    return ret;
}

asmlinkage int sys_getdomainname(char __user *name, int len)
{
    int nlen, err;
    
    if (len < 0)
        return -EINVAL;

    down_read(&uts_sem);
    
    nlen = strlen(utsname()->domainname) + 1;
    err = -EINVAL;
    if (nlen > len)
        goto out;

    err = -EFAULT;
    if (!copy_to_user(name, utsname()->domainname, nlen))
        err = 0;

out:
    up_read(&uts_sem);
    return err;
}

/*
 * Do a system call from kernel instead of calling sys_execve so we
 * end up with proper pt_regs.
 */
int kernel_execve(const char *filename,
          const char *const argv[],
          const char *const envp[])
{
    long __res;
    register long __g1 __asm__ ("g1") = __NR_execve;
    register long __o0 __asm__ ("o0") = (long)(filename);
    register long __o1 __asm__ ("o1") = (long)(argv);
    register long __o2 __asm__ ("o2") = (long)(envp);
    asm volatile ("t 0x10\n\t"
              "bcc 1f\n\t"
              "mov %%o0, %0\n\t"
              "sub %%g0, %%o0, %0\n\t"
              "1:\n\t"
              : "=r" (__res), "=&r" (__o0)
              : "1" (__o0), "r" (__o1), "r" (__o2), "r" (__g1)
              : "cc");
    return __res;
}