lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [day] [month] [year] [list]
Message-Id: <200702210001.21273.hnguyen@linux.vnet.ibm.com>
Date:	Wed, 21 Feb 2007 00:01:21 +0100
From:	Hoang-Nam Nguyen <hnguyen@...ux.vnet.ibm.com>
To:	paulus@...ba.org, linuxppc-dev@...abs.org,
	linux-kernel@...r.kernel.org, johnrose@...ibm.com
Cc:	pmac@....ibm.com, fenkes@...ibm.com
Subject: [PATCH 2.6.21-rc1] ibmebus: more error reporting in dynamic add/remove code

Writing the ibmebus probe and remove attributes now throws an appropriate
error if something goes wrong. This way, userspace tools can check for
success or failure of an addition or removal. The write will block until
the probe/remove operation completes, so, when the write operation returns
without an error, you can be sure the probe was successful and the device
is present in the system.

As an added bonus, an eventual trailing newline is now removed from the
written string.


Signed-off-by: Joachim Fenkes <fenkes@...ibm.com>
---


 ibmebus.c |   54 ++++++++++++++++++++++++++++++++++++------------------
 1 files changed, 36 insertions(+), 18 deletions(-)


diff -urp a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
--- a/arch/powerpc/kernel/ibmebus.c	2007-02-20 21:54:22.366443424 +0100
+++ b/arch/powerpc/kernel/ibmebus.c	2007-02-20 23:31:39.950486616 +0100
@@ -167,7 +167,7 @@ static ssize_t ibmebusdev_show_name(stru
 static DEVICE_ATTR(name, S_IRUSR | S_IRGRP | S_IROTH, ibmebusdev_show_name,
 		   NULL);
 
-static struct ibmebus_dev* __devinit ibmebus_register_device_common(
+static int __devinit ibmebus_register_device_common(
 	struct ibmebus_dev *dev, const char *name)
 {
 	int err = 0;
@@ -186,12 +186,12 @@ static struct ibmebus_dev* __devinit ibm
 	if ((err = of_device_register(&dev->ofdev)) != 0) {
 		printk(KERN_ERR "%s: failed to register device (%d).\n",
 		       __FUNCTION__, err);
-		return NULL;
+		return -ENODEV;
 	}
 
 	device_create_file(&dev->ofdev.dev, &dev_attr_name);
 
-	return dev;
+	return 0;
 }
 
 static struct ibmebus_dev* __devinit ibmebus_register_device_node(
@@ -205,18 +205,18 @@ static struct ibmebus_dev* __devinit ibm
 	if (!loc_code) {
                 printk(KERN_WARNING "%s: node %s missing 'ibm,loc-code'\n",
 		       __FUNCTION__, dn->name ? dn->name : "<unknown>");
-		return NULL;
+		return ERR_PTR(-EINVAL);
         }
 
 	if (strlen(loc_code) == 0) {
 	        printk(KERN_WARNING "%s: 'ibm,loc-code' is invalid\n",
 		       __FUNCTION__);
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 
 	dev = kzalloc(sizeof(struct ibmebus_dev), GFP_KERNEL);
 	if (!dev) {
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	dev->ofdev.node = of_node_get(dn);
@@ -227,9 +227,9 @@ static struct ibmebus_dev* __devinit ibm
 		min(length, BUS_ID_SIZE - 1));
 
 	/* Register with generic device framework. */
-	if (ibmebus_register_device_common(dev, dn->name) == NULL) {
+	if (ibmebus_register_device_common(dev, dn->name) != 0) {
 		kfree(dev);
-		return NULL;
+		return ERR_PTR(-ENODEV);
 	}
 
 	return dev;
@@ -240,9 +240,8 @@ static void ibmebus_probe_of_nodes(char*
 	struct device_node *dn = NULL;
 
 	while ((dn = of_find_node_by_name(dn, name))) {
-		if (ibmebus_register_device_node(dn) == NULL) {
+		if (IS_ERR(ibmebus_register_device_node(dn))) {
 			of_node_put(dn);
-
 			return;
 		}
 	}
@@ -390,30 +389,40 @@ static int ibmebus_match_helper_loc_code
 	return 0;
 }
 
-static ssize_t ibmebus_store_probe(struct bus_type *dev,
+static ssize_t ibmebus_store_probe(struct bus_type *bus,
 				   const char *buf, size_t count)
 {
 	struct device_node *dn = NULL;
+	struct ibmebus_dev *dev;
 	char *loc_code;
 
+	buf[count] = '\0';
+	if (buf[count-1] == '\n')
+		buf[count-1] = '\0';
+
 	if (bus_find_device(&ibmebus_bus_type, NULL, (char*)buf,
 			     ibmebus_match_helper_loc_code)) {
 		printk(KERN_WARNING "%s: loc_code %s has already been probed\n",
 		       __FUNCTION__, buf);
-		return count;
+		return -EINVAL;
 	}
 
 	while ((dn = of_find_all_nodes(dn))) {
 		loc_code = (char *)get_property(dn, "ibm,loc-code", NULL);
 		if (loc_code && (strncmp(loc_code, buf, count) == 0)) {
-			if (ibmebus_register_device_node(dn) == NULL) {
+			dev = ibmebus_register_device_node(dn);
+			if (IS_ERR(dev)) {
 				of_node_put(dn);
-				break;
-			}
+				return PTR_ERR(dev);
+			} else
+				return count; /* success */
 		}
 	}
 
-	return count;
+	/* if we drop out of the loop, the loc code was invalid */
+	printk(KERN_WARNING "%s: no device with loc_code %s found\n",
+	       __FUNCTION__, buf);
+	return -ENODEV;
 }
 static BUS_ATTR(probe, S_IWUSR, NULL, ibmebus_store_probe);
 
@@ -422,9 +431,18 @@ static ssize_t ibmebus_store_remove(stru
 {
 	struct device *dev;
 
-	while ((dev = bus_find_device(&ibmebus_bus_type, NULL, (char*)buf,
-				      ibmebus_match_helper_loc_code))) {
+	buf[count] = '\0';
+	if (buf[count-1] == '\n')
+		buf[count-1] = '\0';
+
+	/* The location code is unique, so we will find one device at most */
+	if ((dev = bus_find_device(&ibmebus_bus_type, NULL, (char*)buf,
+				   ibmebus_match_helper_loc_code))) {
 		ibmebus_unregister_device(dev);
+	} else {
+		printk(KERN_WARNING "%s: loc_code %s not on the bus\n",
+		       __FUNCTION__, buf);
+		return -ENODEV;
 	}
 
 	return count;

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ