Messages in this thread | | | Date | Thu, 09 Apr 2020 13:21:18 +0530 | From | Sai Prakash Ranjan <> | Subject | Re: [RFC PATCH] coresight: dynamic-replicator: Fix handling of multiple connections |
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Hi Suzuki,
On 2020-04-09 04:13, Suzuki K Poulose wrote: > On Tue, Apr 07, 2020 at 08:48:54PM +0530, Sai Prakash Ranjan wrote: > > Please find the untested patch below. > > ---8>--- > > [untested] coresight: Fix support for sparse port numbers > > On some systems the firmware may not describe all the ports > connected to a component (e.g, for security reasons). This > could be especially problematic for "funnels" where we could > end up in modifying memory beyond the allocated space for > refcounts. > > e.g, for a funnel with input ports listed 0, 3, 5, nr_inport = 3. > However the we could access refcnts[5] while checking for > references. > > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > .../hwtracing/coresight/coresight-platform.c | 74 ++++++++++++------- > drivers/hwtracing/coresight/coresight.c | 8 +- > 2 files changed, 56 insertions(+), 26 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-platform.c > b/drivers/hwtracing/coresight/coresight-platform.c > index 3c5bee429105..1c610d6e944b 100644 > --- a/drivers/hwtracing/coresight/coresight-platform.c > +++ b/drivers/hwtracing/coresight/coresight-platform.c > @@ -67,6 +67,7 @@ static void of_coresight_get_ports_legacy(const > struct device_node *node, > int *nr_inport, int *nr_outport) > { > struct device_node *ep = NULL; > + struct of_endpoint endpoint; > int in = 0, out = 0; > > do { > @@ -74,10 +75,16 @@ static void of_coresight_get_ports_legacy(const > struct device_node *node, > if (!ep) > break; > > - if (of_coresight_legacy_ep_is_input(ep)) > - in++; > - else > - out++; > + if (of_graph_parse_endpoint(ep, &endpoint)) > + continue; > + > + if (of_coresight_legacy_ep_is_input(ep)) { > + in = (endpoint.port + 1 > in) ? > + endpoint.port + 1 : in; > + } else { > + out = (endpoint.port + 1) > out ? > + endpoint.port + 1 : out; > + } > > } while (ep); > > @@ -117,9 +124,16 @@ of_coresight_count_ports(struct device_node > *port_parent) > { > int i = 0; > struct device_node *ep = NULL; > + struct of_endpoint endpoint; > + > + while ((ep = of_graph_get_next_endpoint(port_parent, ep))) { > + /* Defer error handling to parsing */ > + if (of_graph_parse_endpoint(ep, &endpoint)) > + continue; > + if (endpoint.port + 1 > i) > + i = endpoint.port + 1; > + } > > - while ((ep = of_graph_get_next_endpoint(port_parent, ep))) > - i++; > return i; > } > > @@ -171,14 +185,12 @@ static int of_coresight_get_cpu(struct device > *dev) > * Parses the local port, remote device name and the remote port. > * > * Returns : > - * 1 - If the parsing is successful and a connection record > - * was created for an output connection. > * 0 - If the parsing completed without any fatal errors. > * -Errno - Fatal error, abort the scanning. > */ > static int of_coresight_parse_endpoint(struct device *dev, > struct device_node *ep, > - struct coresight_connection *conn) > + struct coresight_platform_data *pdata) > { > int ret = 0; > struct of_endpoint endpoint, rendpoint; > @@ -186,6 +198,7 @@ static int of_coresight_parse_endpoint(struct > device *dev, > struct device_node *rep = NULL; > struct device *rdev = NULL; > struct fwnode_handle *rdev_fwnode; > + struct coresight_connection *conn; > > do { > /* Parse the local port details */ > @@ -212,6 +225,12 @@ static int of_coresight_parse_endpoint(struct > device *dev, > break; > } > > + conn = &pdata->conns[endpoint.port]; > + if (conn->child_fwnode) { > + dev_warn(dev, "Duplicate output port %d\n", endpoint.port); > + ret = -EINVAL; > + break; > + } > conn->outport = endpoint.port; > /* > * Hold the refcount to the target device. This could be > @@ -224,7 +243,6 @@ static int of_coresight_parse_endpoint(struct > device *dev, > conn->child_fwnode = fwnode_handle_get(rdev_fwnode); > conn->child_port = rendpoint.port; > /* Connection record updated */ > - ret = 1; > } while (0); > > of_node_put(rparent); > @@ -238,7 +256,6 @@ static int of_get_coresight_platform_data(struct > device *dev, > struct coresight_platform_data *pdata) > { > int ret = 0; > - struct coresight_connection *conn; > struct device_node *ep = NULL; > const struct device_node *parent = NULL; > bool legacy_binding = false; > @@ -267,8 +284,6 @@ static int of_get_coresight_platform_data(struct > device *dev, > dev_warn_once(dev, "Uses obsolete Coresight DT bindings\n"); > } > > - conn = pdata->conns; > - > /* Iterate through each output port to discover topology */ > while ((ep = of_graph_get_next_endpoint(parent, ep))) { > /* > @@ -280,15 +295,9 @@ static int of_get_coresight_platform_data(struct > device *dev, > if (legacy_binding && of_coresight_legacy_ep_is_input(ep)) > continue; > > - ret = of_coresight_parse_endpoint(dev, ep, conn); > - switch (ret) { > - case 1: > - conn++; /* Fall through */ > - case 0: > - break; > - default: > + ret = of_coresight_parse_endpoint(dev, ep, pdata); > + if (ret) > return ret; > - } > } > > return 0; > @@ -627,6 +636,11 @@ static int acpi_coresight_parse_link(struct > acpi_device *adev, > * coresight_remove_match(). > */ > conn->child_fwnode = fwnode_handle_get(&r_adev->fwnode); > + } else if (dir == ACPI_CORESIGHT_LINK_SLAVE) { > + conn->child_port = fields[0].integer.value; > + } else { > + /* Invalid direction */ > + return -EINVAL; > } > > return dir; > @@ -672,10 +686,14 @@ static int acpi_coresight_parse_graph(struct > acpi_device *adev, > return dir; > > if (dir == ACPI_CORESIGHT_LINK_MASTER) { > - pdata->nr_outport++; > + if (ptr->outport > pdata->nr_outport) > + pdata->nr_outport = ptr->outport; > ptr++; > } else { > - pdata->nr_inport++; > + WARN_ON(pdata->nr_inport == ptr->child_port); > + /* Do not move the ptr for input connections */ > + if (ptr->child_port > pdata->nr_inport) > + pdata->nr_inport = ptr->child_port; > } > } > > @@ -684,8 +702,13 @@ static int acpi_coresight_parse_graph(struct > acpi_device *adev, > return rc; > > /* Copy the connection information to the final location */ > - for (i = 0; i < pdata->nr_outport; i++) > - pdata->conns[i] = conns[i]; > + for (i = 0; conns + i < ptr; i++) { > + int port = conns[i].outport; > + > + /* Duplicate output port */ > + WARN_ON(pdata->conns[port].child_fwnode); > + pdata->conns[port] = conns[i]; > + } > > devm_kfree(&adev->dev, conns); > return 0; > @@ -787,6 +810,7 @@ coresight_get_platform_data(struct device *dev) > goto error; > > pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); > + pdata->nr_outport = pdata->nr_inport = -1; > if (!pdata) { > ret = -ENOMEM; > goto error; > diff --git a/drivers/hwtracing/coresight/coresight.c > b/drivers/hwtracing/coresight/coresight.c > index ef20f74c85fa..f07bc0a7ab88 100644 > --- a/drivers/hwtracing/coresight/coresight.c > +++ b/drivers/hwtracing/coresight/coresight.c > @@ -990,6 +990,9 @@ static int coresight_orphan_match(struct device > *dev, void *data) > for (i = 0; i < i_csdev->pdata->nr_outport; i++) { > conn = &i_csdev->pdata->conns[i]; > > + /* Skip the port if FW doesn't describe it */ > + if (!conn->child_fwnode) > + continue; > /* We have found at least one orphan connection */ > if (conn->child_dev == NULL) { > /* Does it match this newly added device? */ > @@ -1029,6 +1032,9 @@ static void coresight_fixup_device_conns(struct > coresight_device *csdev) > struct coresight_connection *conn = &csdev->pdata->conns[i]; > struct device *dev = NULL; > > + if (!conn->child_fwnode) > + continue; > + > dev = bus_find_device_by_fwnode(&coresight_bustype, > conn->child_fwnode); > if (dev) { > conn->child_dev = to_coresight_device(dev); > @@ -1061,7 +1067,7 @@ static int coresight_remove_match(struct device > *dev, void *data) > for (i = 0; i < iterator->pdata->nr_outport; i++) { > conn = &iterator->pdata->conns[i]; > > - if (conn->child_dev == NULL) > + if (conn->child_dev == NULL || conn->child_fwnode == NULL) > continue; > > if (csdev->dev.fwnode == conn->child_fwnode) {
Thanks Suzuki, I don't see the KASAN warning anymore with this patch. But somehow tmc_etr probe fails with error -12(ENOMEM).
Thanks, Sai
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