lkml.org 
[lkml]   [2001]   [Nov]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Subject2.4.14 + Bug in swap_out.
From
Date
In swap_out we have the following code:

spin_lock(&mmlist_lock);
mm = swap_mm;
while (mm->swap_address == TASK_SIZE || mm == &init_mm) {
mm->swap_address = 0;
mm = list_entry(mm->mmlist.next, struct mm_struct, mmlist);
if (mm == swap_mm)
goto empty;
swap_mm = mm;
}

/* Make sure the mm doesn't disappear when we drop the lock.. */
atomic_inc(&mm->mm_users);
spin_unlock(&mmlist_lock);

nr_pages = swap_out_mm(mm, nr_pages, &counter, classzone);

mmput(mm);


And looking in fork.c mmput under with right circumstances becomes.
kmem_cache_free(mm_cachep, (mm)))

So it appears that there is nothing that keeps the mm_struct that
swap_mm points to as being valid.

I guess the easy fix would be to increment the count on swap_mm,
and then do an mmput we assign something else to the value of swap_mm. But
I don't know if that is what we want.

Thoughts?

Eric








-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:13    [W:0.063 / U:1.584 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site