[PATCH v3 17/20] remoteproc: core: Add function to verify resource table consistency

From: Loic Pallardy
Date: Wed Oct 12 2016 - 12:04:25 EST


As resource table could be parsed several times, at different times,
to avoid sanity check duplication, let's introduce a new function
to verify the complete integrity of one resource table.

This new function is called before copying it in cache and
accessing it.

Signed-off-by: Loic Pallardy <loic.pallardy@xxxxxx>
---
drivers/remoteproc/remoteproc_core.c | 70 ++++++++++++++++++++++++++++++++++++
1 file changed, 70 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 559a63b..849460e 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -785,6 +785,69 @@ static void rproc_resource_cleanup(struct rproc *rproc)
rproc_remove_virtio_dev(rvdev);
}

+static int rproc_resource_table_sanity_check(struct rproc *rproc,
+ struct resource_table *table_ptr, int len)
+{
+ struct device *dev = &rproc->dev;
+ int i;
+
+ if (len < sizeof(*table_ptr))
+ goto out;
+
+ for (i = 0; i < table_ptr->num; i++) {
+ int offset = table_ptr->offset[i];
+ struct fw_rsc_hdr *hdr = (void *)table_ptr + offset;
+ int avail = len - offset - sizeof(*hdr);
+ void *rsc = (void *)hdr + sizeof(*hdr);
+ struct fw_rsc_vdev *v;
+
+ /* Make sure table isn't truncated */
+ if (avail < 0)
+ goto out;
+
+ if (offset == FW_RSC_ADDR_ANY || offset == 0) {
+ dev_err(dev, "Entry %d: bad offset value %x\n", i, offset);
+ return -EINVAL;
+ }
+
+ dev_dbg(dev, "rsc: type %d\n", hdr->type);
+
+ switch (hdr->type) {
+ case RSC_CARVEOUT:
+ avail -= sizeof(struct fw_rsc_carveout);
+ break;
+ case RSC_DEVMEM:
+ avail -= sizeof(struct fw_rsc_devmem);
+ break;
+ case RSC_TRACE:
+ avail -= sizeof(struct fw_rsc_trace);
+ break;
+ case RSC_VDEV:
+ v = rsc;
+ avail -= sizeof(struct fw_rsc_vdev);
+ if (avail < 0)
+ goto out;
+
+ avail -= v->num_of_vrings * sizeof(struct fw_rsc_vdev_vring)
+ + v->config_len;
+ break;
+ default:
+ dev_err(&rproc->dev, "Unsupported resource type: %d\n",
+ hdr->type);
+ return -EINVAL;
+ }
+ if (avail < 0)
+ goto out;
+ }
+
+ return 0;
+
+out:
+ dev_err(dev, "Invalid resource table format\n");
+ dump_stack();
+ return -EINVAL;
+}
+
static void rproc_dump_resource_table(struct rproc *rproc,
struct resource_table *table, int size)
{
@@ -1246,6 +1309,13 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
goto clean_up;
}

+ /* Verify resource table consistency */
+ ret = rproc_resource_table_sanity_check(rproc, table, tablesz);
+ if (ret) {
+ dev_err(dev, "Failed to get valid resource table,%d\n", ret);
+ goto clean_up;
+ }
+
/*
* Create a copy of the resource table. When a virtio device starts
* and calls vring_new_virtqueue() the address of the allocated vring
--
1.9.1