> other 10 are questionable. Those 10 are all simple variations on the
> following code:
>
> Start --->
> if (!tmp_buf) {
> page = get_free_page(GFP_KERNEL);
>
> Error --->
> if (tmp_buf)
> free_page(page);
> else
> tmp_buf = (unsigned char *) page;
> }
That one is not a bug. The serial drivers do this to handle a race. Really
it should be
page = get_free_page(GFP_KERNEL)
rmb();
if (tmp_buf)
..
but this will go away as and when someone switches the tty layer to new
style locking. The precise code flow (under lock_kernel in both cases) is
if (!tmp_buf)
{
/* tmp_buf was 0
page = get_free_page (...)
[SLEEPS, TASK SWITCH]
if(tmp_buf)
/* tmp buf was non zero - another thread allocated it */
Alan
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This archive was generated by hypermail 2b29 : Tue Jul 31 2001 - 21:00:22 EST