Re: [LTP] [PATCH] mprotect04: fix powerpc crash when copying exec_func

[Cyril H. <ch...@su...>]

Hi!
> It doesn't seem reliable:
> 
> open("/dev/null", O_WRONLY|O_CREAT, 0644) = 3
> write(3, NULL, 1)                       = 1
> close(3)                                = 0
> 
> I'm seeing this on RHEL6.7 kernel, I haven't tried latest upstream yet.

Ah, you are right, the memory is not touched in the write_null()
function at all.

drivers/char/mem.c:

static ssize_t write_null(struct file *file, const char __user *buf,
                          size_t count, loff_t *ppos)
{
        return count;
}

-- 
Cyril Hrubis
ch...@su...