Re: Buggy commit tracked to: "Re: [PATCH 2/9] iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c"

On Thu, Oct 22, 2020 at 9:40 AM Matthew Wilcox [off-list ref] wrote:

On Thu, Oct 22, 2020 at 04:35:17PM +0000, David Laight wrote:

quoted

Wait...
readv(2) defines:
      ssize_t readv(int fd, const struct iovec *iov, int iovcnt);

It doesn't really matter what the manpage says.  What does the AOSP
libc header say?

Same: https://android.googlesource.com/platform/bionic/+/refs/heads/master/libc/include/sys/uio.h#38

Theoretically someone could bypass libc to make a system call, right?

quoted

But the syscall is defined as:

SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
                unsigned long, vlen)
{
        return do_readv(fd, vec, vlen, 0);
}

-- 
Thanks,
~Nick Desaulniers