Re: [PATCH 22/27] score: create kernel files signal.c sys_score.c time.c

From: Arnd Bergmann
Date: Tue Jun 09 2009 - 13:53:20 EST


On Tuesday 09 June 2009, liqin.chen@xxxxxxxxxxxxx wrote:
> +asmlinkage long sys_mmap(unsigned long addr, size_t len,
> + unsigned long prot, unsigned long flags,
> + unsigned long fd, off_t offset)
> +{
> + int err = -EINVAL;
> +
> + if (offset & ~PAGE_MASK) {
> + printk(KERN_INFO "no pagemask in mmap\r\n");
> + goto out;
> + }
> +
> + err = sys_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
> +out:
> + return err;
> +}

A 32 bit kernel should only need sys_mmap2, not sys_mmap, because it is
trivial to convert in user space.

> +
> +asmlinkage long score_vfork(struct pt_regs *regs)
> +{
> + return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[0],
> + regs, 0, NULL, NULL);
> +}
> +
> +/*
> + * Fork a new task - this creates a new program thread.
> + * This is called indirectly via a small wrapper
> + */
> +asmlinkage int
> +score_fork(struct pt_regs *regs)
> +{
> + return do_fork(SIGCHLD, regs->regs[0], regs, 0, NULL, NULL);
> +}

Similarly, you should not need vfork and fork any more, because they can
be handled in user space through clone().

Arnd <><
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