MFD: mcp-core: sanitize host creation/removal
host_unregister() gives us no chance between removing the device
and the mcp data structure being freed to access the data inbetween,
which drivers may need to do if they need to iounmap() pointers in
their private data structures.
Therefore, re-jig the interfaces, which are now, on creation:
mcp = mcp_host_alloc()
if (mcp) {
ret = mcp_host_add(mcp, data);
if (!ret)
mcp_host_free(mcp);
}
and on removal:
mcp_host_del(mcp);
... access mcp ...
mcp_host_free(mcp);
The free does the final put_device() on the struct device as one would
expect.
Acked-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/mfd/mcp-core.c b/drivers/mfd/mcp-core.c
index 86cc3f7..cc76431 100644
--- a/drivers/mfd/mcp-core.c
+++ b/drivers/mfd/mcp-core.c
@@ -208,6 +208,7 @@
mcp = kzalloc(sizeof(struct mcp) + size, GFP_KERNEL);
if (mcp) {
spin_lock_init(&mcp->lock);
+ device_initialize(&mcp->attached_device);
mcp->attached_device.parent = parent;
mcp->attached_device.bus = &mcp_bus_type;
mcp->attached_device.dma_mask = parent->dma_mask;
@@ -217,18 +218,24 @@
}
EXPORT_SYMBOL(mcp_host_alloc);
-int mcp_host_register(struct mcp *mcp)
+int mcp_host_add(struct mcp *mcp)
{
dev_set_name(&mcp->attached_device, "mcp0");
- return device_register(&mcp->attached_device);
+ return device_add(&mcp->attached_device);
}
-EXPORT_SYMBOL(mcp_host_register);
+EXPORT_SYMBOL(mcp_host_add);
-void mcp_host_unregister(struct mcp *mcp)
+void mcp_host_del(struct mcp *mcp)
{
- device_unregister(&mcp->attached_device);
+ device_del(&mcp->attached_device);
}
-EXPORT_SYMBOL(mcp_host_unregister);
+EXPORT_SYMBOL(mcp_host_del);
+
+void mcp_host_free(struct mcp *mcp)
+{
+ put_device(&mcp->attached_device);
+}
+EXPORT_SYMBOL(mcp_host_free);
int mcp_driver_register(struct mcp_driver *mcpdrv)
{
diff --git a/drivers/mfd/mcp-sa11x0.c b/drivers/mfd/mcp-sa11x0.c
index 02c53a0..33cadc0 100644
--- a/drivers/mfd/mcp-sa11x0.c
+++ b/drivers/mfd/mcp-sa11x0.c
@@ -195,10 +195,11 @@
mcp->rw_timeout = (64 * 3 * 1000000 + mcp->sclk_rate - 1) /
mcp->sclk_rate;
- ret = mcp_host_register(mcp);
+ ret = mcp_host_add(mcp);
if (ret == 0)
goto out;
+ mcp_host_free(mcp);
release:
release_mem_region(0x80060000, 0x60);
platform_set_drvdata(pdev, NULL);
@@ -212,7 +213,8 @@
struct mcp *mcp = platform_get_drvdata(dev);
platform_set_drvdata(dev, NULL);
- mcp_host_unregister(mcp);
+ mcp_host_del(mcp);
+ mcp_host_free(mcp);
release_mem_region(0x80060000, 0x60);
return 0;
diff --git a/include/linux/mfd/mcp.h b/include/linux/mfd/mcp.h
index f88c1cc..79a6b13 100644
--- a/include/linux/mfd/mcp.h
+++ b/include/linux/mfd/mcp.h
@@ -47,8 +47,9 @@
#define mcp_get_sclk_rate(mcp) ((mcp)->sclk_rate)
struct mcp *mcp_host_alloc(struct device *, size_t);
-int mcp_host_register(struct mcp *);
-void mcp_host_unregister(struct mcp *);
+int mcp_host_add(struct mcp *);
+void mcp_host_del(struct mcp *);
+void mcp_host_free(struct mcp *);
struct mcp_driver {
struct device_driver drv;