lkml.org 
[lkml]   [2020]   [Jul]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 1/3] xen/balloon: fix accounting in alloc_xenballooned_pages error path
    Date
    target_unpopulated is incremented with nr_pages at the start of the
    function, but the call to free_xenballooned_pages will only subtract
    pgno number of pages, and thus the rest need to be subtracted before
    returning or else accounting will be skewed.

    Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
    Cc: stable@vger.kernel.org
    ---
    Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
    Cc: Juergen Gross <jgross@suse.com>
    Cc: Stefano Stabellini <sstabellini@kernel.org>
    Cc: xen-devel@lists.xenproject.org
    ---
    drivers/xen/balloon.c | 6 ++++++
    1 file changed, 6 insertions(+)

    diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
    index 77c57568e5d7..3cb10ed32557 100644
    --- a/drivers/xen/balloon.c
    +++ b/drivers/xen/balloon.c
    @@ -630,6 +630,12 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages)
    out_undo:
    mutex_unlock(&balloon_mutex);
    free_xenballooned_pages(pgno, pages);
    + /*
    + * NB: free_xenballooned_pages will only subtract pgno pages, but since
    + * target_unpopulated is incremented with nr_pages at the start we need
    + * to remove the remaining ones also, or accounting will be screwed.
    + */
    + balloon_stats.target_unpopulated -= nr_pages - pgno;
    return ret;
    }
    EXPORT_SYMBOL(alloc_xenballooned_pages);
    --
    2.27.0
    \
     
     \ /
      Last update: 2020-07-23 10:46    [W:3.400 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site