PCI: check the return value of device_create_bin_file() in pci_create_bus()

Check the return value of device_create_bin_file in pci_create_bus and
unwind if necessary. Don't propagate error to caller, as failure to create
these files shouldn't prevent PCI from being initialised. Instead, just
log a warning.

Cc: Sven Wegener <sven.wegener@stealer.net>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/probe.c

@@ -52,27 +52,49 @@ EXPORT_SYMBOL(no_pci_devices);
  * Some platforms allow access to legacy I/O port and ISA memory space on
  * a per-bus basis.  This routine creates the files and ties them into
  * their associated read, write and mmap files from pci-sysfs.c
+ *
+ * On error unwind, but don't propogate the error to the caller
+ * as it is ok to set up the PCI bus without these files.
  */
 static void pci_create_legacy_files(struct pci_bus *b)
 {
+	int error;
+
 	b->legacy_io = kzalloc(sizeof(struct bin_attribute) * 2,
 			       GFP_ATOMIC);
-	if (b->legacy_io) {
-		b->legacy_io->attr.name = "legacy_io";
-		b->legacy_io->size = 0xffff;
-		b->legacy_io->attr.mode = S_IRUSR | S_IWUSR;
-		b->legacy_io->read = pci_read_legacy_io;
-		b->legacy_io->write = pci_write_legacy_io;
-		device_create_bin_file(&b->dev, b->legacy_io);
-
-		/* Allocated above after the legacy_io struct */
-		b->legacy_mem = b->legacy_io + 1;
-		b->legacy_mem->attr.name = "legacy_mem";
-		b->legacy_mem->size = 1024*1024;
-		b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
-		b->legacy_mem->mmap = pci_mmap_legacy_mem;
-		device_create_bin_file(&b->dev, b->legacy_mem);
-	}
+	if (!b->legacy_io)
+		goto kzalloc_err;
+
+	b->legacy_io->attr.name = "legacy_io";
+	b->legacy_io->size = 0xffff;
+	b->legacy_io->attr.mode = S_IRUSR | S_IWUSR;
+	b->legacy_io->read = pci_read_legacy_io;
+	b->legacy_io->write = pci_write_legacy_io;
+	error = device_create_bin_file(&b->dev, b->legacy_io);
+	if (error)
+		goto legacy_io_err;
+
+	/* Allocated above after the legacy_io struct */
+	b->legacy_mem = b->legacy_io + 1;
+	b->legacy_mem->attr.name = "legacy_mem";
+	b->legacy_mem->size = 1024*1024;
+	b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
+	b->legacy_mem->mmap = pci_mmap_legacy_mem;
+	error = device_create_bin_file(&b->dev, b->legacy_mem);
+	if (error)
+		goto legacy_mem_err;
+
+	return;
+
+legacy_mem_err:
+	device_remove_bin_file(&b->dev, b->legacy_io);
+legacy_io_err:
+	kfree(b->legacy_io);
+	b->legacy_io = NULL;
+kzalloc_err:
+	printk(KERN_WARNING "pci: warning: could not create legacy I/O port "
+	       "and ISA memory resources to sysfs\n");
+	return;
 }
 
 void pci_remove_legacy_files(struct pci_bus *b)