remoteproc: Fix wrong rvring index computation

BugLink: https://bugs.launchpad.net/bugs/1877461
commit 00a0eec59ddbb1ce966b19097d8a8d2f777e726a upstream.

Index of rvring is computed using pointer arithmetic. However, since
rvring->rvdev->vring is the base of the vring array, computation
of rvring idx should be reversed. It previously lead to writing at negative
indices in the resource table.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Link: https://lore.kernel.org/r/20191004073736.8327-1-cleger@kalray.eu
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Doug Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index cc733b89560a1e322b84a82f43ba0ba9b2c09e11..8f4fa1a52f0578c05f6bd3046a90982d65e20453 100644 (file)
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -288,7 +288,7 @@ void rproc_free_vring(struct rproc_vring *rvring)
 {
        int size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
        struct rproc *rproc = rvring->rvdev->rproc;
-       int idx = rvring->rvdev->vring - rvring;
+       int idx = rvring - rvring->rvdev->vring;
        struct fw_rsc_vdev *rsc;
 
        dma_free_coherent(rproc->dev.parent, size, rvring->va, rvring->dma);