From 80961525880e58e0efcf536fd357d642c68f4176 Mon Sep 17 00:00:00 2001 From: Mike Leach Date: Mon, 18 May 2020 12:02:22 -0600 Subject: coresight: Add generic sysfs link creation functions To allow the connections between coresight components to be represented in sysfs, generic methods for creating sysfs links between two coresight devices are added. Signed-off-by: Mike Leach Reviewed-by: Suzuki K Poulose Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20200518180242.7916-4-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman --- include/linux/coresight.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include/linux/coresight.h') diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 193cc9dbf448..a2ec25e02ca9 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -148,6 +148,20 @@ struct coresight_connection { struct coresight_device *child_dev; }; +/** + * struct coresight_sysfs_link - representation of a connection in sysfs. + * @orig: Originating (master) coresight device for the link. + * @orig_name: Name to use for the link orig->target. + * @target: Target (slave) coresight device for the link. + * @target_name: Name to use for the link target->orig. + */ +struct coresight_sysfs_link { + struct coresight_device *orig; + const char *orig_name; + struct coresight_device *target; + const char *target_name; +}; + /** * struct coresight_device - representation of a device as used by the framework * @pdata: Platform data with device connections associated to this device. @@ -165,6 +179,9 @@ struct coresight_connection { * @ea: Device attribute for sink representation under PMU directory. * @ect_dev: Associated cross trigger device. Not part of the trace data * path or connections. + * @nr_links: number of sysfs links created to other components from this + * device. These will appear in the "connections" group. + * @has_conns_grp: Have added a "connections" group for sysfs links. */ struct coresight_device { struct coresight_platform_data *pdata; @@ -180,6 +197,9 @@ struct coresight_device { struct dev_ext_attribute *ea; /* cross trigger handling */ struct coresight_device *ect_dev; + /* sysfs links between components */ + int nr_links; + bool has_conns_grp; }; /* -- cgit v1.2.3 From 8a7365c2d41898f2376efa929aadf2723dc281b0 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Mon, 18 May 2020 12:02:23 -0600 Subject: coresight: Expose device connections via sysfs Coresight device connections are a bit complicated and is not exposed currently to the user. One has to look at the platform descriptions (DT bindings or ACPI bindings) to make an understanding. Given the new naming scheme, it will be helpful to have this information to choose the appropriate devices for tracing. This patch exposes the device connections via links in the sysfs directories. e.g, for a connection devA[OutputPort_X] -> devB[InputPort_Y] is represented as two symlinks: /sys/bus/coresight/.../devA/out:X -> /sys/bus/coresight/.../devB /sys/bus/coresight/.../devB/in:Y -> /sys/bus/coresight/.../devA Signed-off-by: Suzuki K Poulose [Revised to use the generic sysfs links functions & link structures. Provides a connections sysfs group in each device to hold the links.] Co-developed-by: Mike Leach Signed-off-by: Mike Leach Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20200518180242.7916-5-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-priv.h | 5 ++ drivers/hwtracing/coresight/coresight-sysfs.c | 80 +++++++++++++++++++++++++++ drivers/hwtracing/coresight/coresight.c | 46 +++++++++++---- include/linux/coresight.h | 2 + 4 files changed, 121 insertions(+), 12 deletions(-) (limited to 'include/linux/coresight.h') diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index a4a658d46045..5a36f0f50899 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -157,6 +157,11 @@ int coresight_add_sysfs_link(struct coresight_sysfs_link *info); void coresight_remove_sysfs_link(struct coresight_sysfs_link *info); int coresight_create_conns_sysfs_group(struct coresight_device *csdev); void coresight_remove_conns_sysfs_group(struct coresight_device *csdev); +int coresight_make_links(struct coresight_device *orig, + struct coresight_connection *conn, + struct coresight_device *target); +void coresight_remove_links(struct coresight_device *orig, + struct coresight_connection *conn); #ifdef CONFIG_CORESIGHT_SOURCE_ETM3X extern int etm_readl_cp14(u32 off, unsigned int *val); diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index 6759f78733ab..82afeaf2ccc4 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -122,3 +122,83 @@ void coresight_remove_sysfs_link(struct coresight_sysfs_link *info) info->orig->nr_links--; info->target->nr_links--; } + +/* + * coresight_make_links: Make a link for a connection from a @orig + * device to @target, represented by @conn. + * + * e.g, for devOrig[output_X] -> devTarget[input_Y] is represented + * as two symbolic links : + * + * /sys/.../devOrig/out:X -> /sys/.../devTarget/ + * /sys/.../devTarget/in:Y -> /sys/.../devOrig/ + * + * The link names are allocated for a device where it appears. i.e, the + * "out" link on the master and "in" link on the slave device. + * The link info is stored in the connection record for avoiding + * the reconstruction of names for removal. + */ +int coresight_make_links(struct coresight_device *orig, + struct coresight_connection *conn, + struct coresight_device *target) +{ + int ret = -ENOMEM; + char *outs = NULL, *ins = NULL; + struct coresight_sysfs_link *link = NULL; + + do { + outs = devm_kasprintf(&orig->dev, GFP_KERNEL, + "out:%d", conn->outport); + if (!outs) + break; + ins = devm_kasprintf(&target->dev, GFP_KERNEL, + "in:%d", conn->child_port); + if (!ins) + break; + link = devm_kzalloc(&orig->dev, + sizeof(struct coresight_sysfs_link), + GFP_KERNEL); + if (!link) + break; + + link->orig = orig; + link->target = target; + link->orig_name = outs; + link->target_name = ins; + + ret = coresight_add_sysfs_link(link); + if (ret) + break; + + conn->link = link; + + /* + * Install the device connection. This also indicates that + * the links are operational on both ends. + */ + conn->child_dev = target; + return 0; + } while (0); + + return ret; +} + +/* + * coresight_remove_links: Remove the sysfs links for a given connection @conn, + * from @orig device to @target device. See coresight_make_links() for more + * details. + */ +void coresight_remove_links(struct coresight_device *orig, + struct coresight_connection *conn) +{ + if (!orig || !conn->link) + return; + + coresight_remove_sysfs_link(conn->link); + + devm_kfree(&conn->child_dev->dev, conn->link->target_name); + devm_kfree(&orig->dev, conn->link->orig_name); + devm_kfree(&orig->dev, conn->link); + conn->link = NULL; + conn->child_dev = NULL; +} diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 07f66a3968f1..4f10cfa9dc18 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -1031,7 +1031,7 @@ static void coresight_device_release(struct device *dev) static int coresight_orphan_match(struct device *dev, void *data) { - int i; + int i, ret = 0; bool still_orphan = false; struct coresight_device *csdev, *i_csdev; struct coresight_connection *conn; @@ -1056,19 +1056,23 @@ static int coresight_orphan_match(struct device *dev, void *data) /* We have found at least one orphan connection */ if (conn->child_dev == NULL) { /* Does it match this newly added device? */ - if (conn->child_fwnode == csdev->dev.fwnode) - conn->child_dev = csdev; - else + if (conn->child_fwnode == csdev->dev.fwnode) { + ret = coresight_make_links(i_csdev, + conn, csdev); + if (ret) + return ret; + } else { /* This component still has an orphan */ still_orphan = true; + } } } i_csdev->orphan = still_orphan; /* - * Returning '0' ensures that all known component on the - * bus will be checked. + * Returning '0' in case we didn't encounter any error, + * ensures that all known component on the bus will be checked. */ return 0; } @@ -1082,15 +1086,21 @@ static int coresight_fixup_orphan_conns(struct coresight_device *csdev) static int coresight_fixup_device_conns(struct coresight_device *csdev) { - int i; + int i, ret = 0; for (i = 0; i < csdev->pdata->nr_outport; i++) { struct coresight_connection *conn = &csdev->pdata->conns[i]; conn->child_dev = coresight_find_csdev_by_fwnode(conn->child_fwnode); - if (!conn->child_dev) + if (conn->child_dev) { + ret = coresight_make_links(csdev, conn, + conn->child_dev); + if (ret) + break; + } else { csdev->orphan = true; + } } return 0; @@ -1121,7 +1131,7 @@ static int coresight_remove_match(struct device *dev, void *data) if (csdev->dev.fwnode == conn->child_fwnode) { iterator->orphan = true; - conn->child_dev = NULL; + coresight_remove_links(iterator, conn); /* * Drop the reference to the handle for the remote * device acquired in parsing the connections from @@ -1215,13 +1225,23 @@ void coresight_release_platform_data(struct coresight_device *csdev, struct coresight_platform_data *pdata) { int i; + struct coresight_connection *conns = pdata->conns; for (i = 0; i < pdata->nr_outport; i++) { - if (pdata->conns[i].child_fwnode) { - fwnode_handle_put(pdata->conns[i].child_fwnode); + /* If we have made the links, remove them now */ + if (csdev && conns[i].child_dev) + coresight_remove_links(csdev, &conns[i]); + /* + * Drop the refcount and clear the handle as this device + * is going away + */ + if (conns[i].child_fwnode) { + fwnode_handle_put(conns[i].child_fwnode); pdata->conns[i].child_fwnode = NULL; } } + if (csdev) + coresight_remove_conns_sysfs_group(csdev); } struct coresight_device *coresight_register(struct coresight_desc *desc) @@ -1303,7 +1323,9 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) mutex_lock(&coresight_mutex); - ret = coresight_fixup_device_conns(csdev); + ret = coresight_create_conns_sysfs_group(csdev); + if (!ret) + ret = coresight_fixup_device_conns(csdev); if (!ret) ret = coresight_fixup_orphan_conns(csdev); if (!ret) diff --git a/include/linux/coresight.h b/include/linux/coresight.h index a2ec25e02ca9..ccd17304d7bd 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -140,12 +140,14 @@ struct coresight_desc { * @chid_fwnode: remote component's fwnode handle. * @child_dev: a @coresight_device representation of the component connected to @outport. + * @link: Representation of the connection as a sysfs link. */ struct coresight_connection { int outport; int child_port; struct fwnode_handle *child_fwnode; struct coresight_device *child_dev; + struct coresight_sysfs_link *link; }; /** -- cgit v1.2.3 From d375b356e687f2eefb51ddc3f1f2414cfa498f86 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Mon, 18 May 2020 12:02:31 -0600 Subject: coresight: Fix support for sparsely populated ports 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, like : [ 526.110401] ================================================================== [ 526.117988] BUG: KASAN: slab-out-of-bounds in funnel_enable+0x54/0x1b0 [ 526.124706] Read of size 4 at addr ffffff8135f9549c by task bash/1114 [ 526.131324] [ 526.132886] CPU: 3 PID: 1114 Comm: bash Tainted: G S 5.4.25 #232 [ 526.140397] Hardware name: Qualcomm Technologies, Inc. SC7180 IDP (DT) [ 526.147113] Call trace: [ 526.149653] dump_backtrace+0x0/0x188 [ 526.153431] show_stack+0x20/0x2c [ 526.156852] dump_stack+0xdc/0x144 [ 526.160370] print_address_description+0x3c/0x494 [ 526.165211] __kasan_report+0x144/0x168 [ 526.169170] kasan_report+0x10/0x18 [ 526.172769] check_memory_region+0x1a4/0x1b4 [ 526.177164] __kasan_check_read+0x18/0x24 [ 526.181292] funnel_enable+0x54/0x1b0 [ 526.185072] coresight_enable_path+0x104/0x198 [ 526.189649] coresight_enable+0x118/0x26c ... [ 526.237782] Allocated by task 280: [ 526.241298] __kasan_kmalloc+0xf0/0x1ac [ 526.245249] kasan_kmalloc+0xc/0x14 [ 526.248849] __kmalloc+0x28c/0x3b4 [ 526.252361] coresight_register+0x88/0x250 [ 526.256587] funnel_probe+0x15c/0x228 [ 526.260365] dynamic_funnel_probe+0x20/0x2c [ 526.264679] amba_probe+0xbc/0x158 [ 526.268193] really_probe+0x144/0x408 [ 526.271970] driver_probe_device+0x70/0x140 ... [ 526.316810] [ 526.318364] Freed by task 0: [ 526.321344] (stack is not available) [ 526.325024] [ 526.326580] The buggy address belongs to the object at ffffff8135f95480 [ 526.326580] which belongs to the cache kmalloc-128 of size 128 [ 526.339439] The buggy address is located 28 bytes inside of [ 526.339439] 128-byte region [ffffff8135f95480, ffffff8135f95500) [ 526.351399] The buggy address belongs to the page: [ 526.356342] page:ffffffff04b7e500 refcount:1 mapcount:0 mapping:ffffff814b00c380 index:0x0 compound_mapcount: 0 [ 526.366711] flags: 0x4000000000010200(slab|head) [ 526.371475] raw: 4000000000010200 ffffffff05034008 ffffffff0501eb08 ffffff814b00c380 [ 526.379435] raw: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000 [ 526.387393] page dumped because: kasan: bad access detected [ 526.393128] [ 526.394681] Memory state around the buggy address: [ 526.399619] ffffff8135f95380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.407046] ffffff8135f95400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.414473] >ffffff8135f95480: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.421900] ^ [ 526.426029] ffffff8135f95500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.433456] ffffff8135f95580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.440883] ================================================================== To keep the code simple, we now track the maximum number of possible input/output connections to/from this component @ nr_inport and nr_outport in platform_data, respectively. Thus the output connections could be sparse and code is adjusted to skip the unspecified connections. Cc: Mathieu Poirier Cc: Mike Leach Reported-by: Sai Prakash Ranjan Tested-by: Sai Prakash Ranjan Tested-by: Stephen Boyd Signed-off-by: Suzuki K Poulose Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20200518180242.7916-13-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-platform.c | 85 +++++++++++++++++------- drivers/hwtracing/coresight/coresight.c | 7 +- include/linux/coresight.h | 10 +-- 3 files changed, 72 insertions(+), 30 deletions(-) (limited to 'include/linux/coresight.h') diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c index 4b78e1ac5285..d58dcd0ab514 100644 --- a/drivers/hwtracing/coresight/coresight-platform.c +++ b/drivers/hwtracing/coresight/coresight-platform.c @@ -87,6 +87,7 @@ 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 { @@ -94,10 +95,16 @@ 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); @@ -137,9 +144,16 @@ 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; } @@ -191,14 +205,12 @@ 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; @@ -206,6 +218,7 @@ 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 */ @@ -232,6 +245,13 @@ 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 @@ -244,7 +264,6 @@ 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); @@ -258,7 +277,6 @@ 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; @@ -287,8 +305,6 @@ 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))) { /* @@ -300,15 +316,9 @@ 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; @@ -647,6 +657,16 @@ 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) { + /* + * We are only interested in the port number + * for the input ports at this component. + * Store the port number in child_port. + */ + conn->child_port = fields[0].integer.value; + } else { + /* Invalid direction */ + return -EINVAL; } return dir; @@ -692,10 +712,20 @@ 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); + /* + * We do not track input port connections for a device. + * However we need the highest port number described, + * which can be recorded now and reuse this connection + * record for an output connection. Hence, do not move + * the ptr for input connections + */ + if (ptr->child_port > pdata->nr_inport) + pdata->nr_inport = ptr->child_port; } } @@ -704,8 +734,13 @@ 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; diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 4f10cfa9dc18..f3efbb3b2b4d 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -1053,6 +1053,9 @@ 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? */ @@ -1091,6 +1094,8 @@ static int coresight_fixup_device_conns(struct coresight_device *csdev) for (i = 0; i < csdev->pdata->nr_outport; i++) { struct coresight_connection *conn = &csdev->pdata->conns[i]; + if (!conn->child_fwnode) + continue; conn->child_dev = coresight_find_csdev_by_fwnode(conn->child_fwnode); if (conn->child_dev) { @@ -1126,7 +1131,7 @@ 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) { diff --git a/include/linux/coresight.h b/include/linux/coresight.h index ccd17304d7bd..e3e9f0e3a878 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -100,10 +100,12 @@ union coresight_dev_subtype { }; /** - * struct coresight_platform_data - data harvested from the DT specification - * @nr_inport: number of input ports for this component. - * @nr_outport: number of output ports for this component. - * @conns: Array of nr_outport connections from this component + * struct coresight_platform_data - data harvested from the firmware + * specification. + * + * @nr_inport: Number of elements for the input connections. + * @nr_outport: Number of elements for the output connections. + * @conns: Sparse array of nr_outport connections from this component. */ struct coresight_platform_data { int nr_inport; -- cgit v1.2.3