linux-kernel - [PATCH] PCI: create device, function symlinks in /sys/bus/pci/slots/N/

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 18 Aug 2008 14:21:00 -0600
From:	Alex Chiang <achiang@...com>
To:	jbarnes@...tuousgeek.org, matthew@....cx
Cc:	linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] PCI: create device, function symlinks in
	/sys/bus/pci/slots/N/

Create convenience symlinks in sysfs, linking slots to devices
and functions, and vice versa. These links make it easier for
users to figure out which devices actually live in what slots.

The device symlink points to the device's first function.

For example:

sapphire:/sys/bus/pci/slots # ls
1  10  2  3  4  5  6  7  8  9

sapphire:/sys/bus/pci/slots # ls -l 3
total 0
-r--r--r-- 1 root root 65536 Aug 18 14:10 address
lrwxrwxrwx 1 root root     0 Aug 18 14:10 device -> ../../../../devices/pci0000:23/0000:23:01.0
lrwxrwxrwx 1 root root     0 Aug 18 14:10 function0 -> ../../../../devices/pci0000:23/0000:23:01.0
lrwxrwxrwx 1 root root     0 Aug 18 14:10 function1 -> ../../../../devices/pci0000:23/0000:23:01.1

sapphire:/sys/bus/pci/slots # ls -l 3/device/slot
lrwxrwxrwx 1 root root 0 Aug 18 14:13 3/device/slot -> ../../../bus/pci/slots/3

The original form of this patch was written by Matthew Wilcox,
but did not have links from the sysfs slots/ directory pointing
back at devices and functions.

Cc: matthew@....cx
Signed-off-by: Alex Chiang <achiang@...com>
---
 slot.c |   58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index 7e5b85c..76095ac 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -47,6 +47,60 @@ static ssize_t address_read_file(struct pci_slot *slot, char *buf)
 				slot->number);
 }
 
+static void remove_sysfs_files(struct pci_slot *slot)
+{
+	char func[10];
+	struct list_head *tmp;
+
+	list_for_each(tmp, &slot->bus->devices) {
+		struct pci_dev *dev = pci_dev_b(tmp);
+		if (PCI_SLOT(dev->devfn) != slot->number)
+			continue;
+		sysfs_remove_link(&dev->dev.kobj, "slot");
+
+		snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+		sysfs_remove_link(&slot->kobj, func);
+	}
+	sysfs_remove_link(&slot->kobj, "device");
+}
+
+static int create_sysfs_files(struct pci_slot *slot)
+{
+	int result, lastdev = -1;
+	char func[10];
+	struct list_head *tmp;
+
+	list_for_each(tmp, &slot->bus->devices) {
+		struct pci_dev *dev = pci_dev_b(tmp);
+		if (PCI_SLOT(dev->devfn) != slot->number)
+			continue;
+
+		result = sysfs_create_link(&dev->dev.kobj, &slot->kobj, "slot");
+		if (result)
+			goto fail;
+
+		if (PCI_SLOT(dev->devfn) != lastdev) {
+			lastdev = PCI_SLOT(dev->devfn);
+			result = sysfs_create_link(&slot->kobj,
+						   &dev->dev.kobj,
+						   "device");
+			if (result)
+				goto fail;
+		}
+
+		snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+		result = sysfs_create_link(&slot->kobj, &dev->dev.kobj, func);
+		if (result)
+			goto fail;
+	}
+
+	return 0;
+
+fail:
+	remove_sysfs_files(slot);
+	return result;
+}
+
 static void pci_slot_release(struct kobject *kobj)
 {
 	struct pci_slot *slot = to_pci_slot(kobj);
@@ -54,6 +108,8 @@ static void pci_slot_release(struct kobject *kobj)
 	pr_debug("%s: releasing pci_slot on %x:%d\n", __func__,
 		 slot->bus->number, slot->number);
 
+	remove_sysfs_files(slot);
+
 	list_del(&slot->list);
 
 	kfree(slot);
@@ -150,6 +206,8 @@ placeholder:
 	INIT_LIST_HEAD(&slot->list);
 	list_add(&slot->list, &parent->slots);
 
+	create_sysfs_files(slot);
+
 	/* Don't care if debug printk has a -1 for slot_nr */
 	pr_debug("%s: created pci_slot on %04x:%02x:%02x\n",
 		 __func__, pci_domain_nr(parent), parent->number, slot_nr);
--
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/