lkml.org 
[lkml]   [2019]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.1 44/62] dma-buf: Discard old fence_excl on retrying get_fences_rcu for realloc
    Date
    From: Chris Wilson <chris@chris-wilson.co.uk>

    commit f5b07b04e5f090a85d1e96938520f2b2b58e4a8e upstream.

    If we have to drop the seqcount & rcu lock to perform a krealloc, we
    have to restart the loop. In doing so, be careful not to lose track of
    the already acquired exclusive fence.

    Fixes: fedf54132d24 ("dma-buf: Restart reservation_object_get_fences_rcu() after writes")
    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
    Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
    Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
    Cc: Christian König <christian.koenig@amd.com>
    Cc: Alex Deucher <alexander.deucher@amd.com>
    Cc: Sumit Semwal <sumit.semwal@linaro.org>
    Cc: stable@vger.kernel.org #v4.10
    Reviewed-by: Christian König <christian.koenig@amd.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20190604125323.21396-1-chris@chris-wilson.co.uk
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/dma-buf/reservation.c | 4 ++++
    1 file changed, 4 insertions(+)

    --- a/drivers/dma-buf/reservation.c
    +++ b/drivers/dma-buf/reservation.c
    @@ -357,6 +357,10 @@ int reservation_object_get_fences_rcu(st
    GFP_NOWAIT | __GFP_NOWARN);
    if (!nshared) {
    rcu_read_unlock();
    +
    + dma_fence_put(fence_excl);
    + fence_excl = NULL;
    +
    nshared = krealloc(shared, sz, GFP_KERNEL);
    if (nshared) {
    shared = nshared;

    \
     
     \ /
      Last update: 2019-07-26 17:32    [W:2.975 / U:0.780 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site