driver/base/memory.c: validate memory block size early

Let's validate the memory block size early, when initializing the memory
device infrastructure.  Fail hard in case the value is not suitable.

As nobody checks the return value of memory_dev_init(), turn it into a
void function and fail with a panic in all scenarios instead.  Otherwise,
we'll crash later during boot when core/drivers expect that the memory
device infrastructure (including memory_block_size_bytes()) works as
expected.

I think long term, we should move the whole memory block size
configuration (set_memory_block_size_order() and
memory_block_size_bytes()) into drivers/base/memory.c.

Link: http://lkml.kernel.org/r/20190806090142.22709-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 22 deletions

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 63fc5aa51c21..763154c82eb3 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -100,21 +100,6 @@ unsigned long __weak memory_block_size_bytes(void)
 }
 EXPORT_SYMBOL_GPL(memory_block_size_bytes);
 
-static unsigned long get_memory_block_size(void)
-{
-	unsigned long block_sz;
-
-	block_sz = memory_block_size_bytes();
-
-	/* Validate blk_sz is a power of 2 and not less than section size */
-	if ((block_sz & (block_sz - 1)) || (block_sz < MIN_MEMORY_BLOCK_SIZE)) {
-		WARN_ON(1);
-		block_sz = MIN_MEMORY_BLOCK_SIZE;
-	}
-
-	return block_sz;
-}
-
 /*
  * Show the first physical section index (number) of this memory block.
  */
@@ -461,7 +446,7 @@ static DEVICE_ATTR_RO(removable);
 static ssize_t block_size_bytes_show(struct device *dev,
 				     struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%lx\n", get_memory_block_size());
+	return sprintf(buf, "%lx\n", memory_block_size_bytes());
 }
 
 static DEVICE_ATTR_RO(block_size_bytes);
@@ -812,19 +797,22 @@ static const struct attribute_group *memory_root_attr_groups[] = {
 /*
  * Initialize the sysfs support for memory devices...
  */
-int __init memory_dev_init(void)
+void __init memory_dev_init(void)
 {
 	int ret;
 	int err;
 	unsigned long block_sz, nr;
 
+	/* Validate the configured memory block size */
+	block_sz = memory_block_size_bytes();
+	if (!is_power_of_2(block_sz) || block_sz < MIN_MEMORY_BLOCK_SIZE)
+		panic("Memory block size not suitable: 0x%lx\n", block_sz);
+	sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
+
 	ret = subsys_system_register(&memory_subsys, memory_root_attr_groups);
 	if (ret)
 		goto out;
 
-	block_sz = get_memory_block_size();
-	sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
-
 	/*
 	 * Create entries for memory sections that were found
 	 * during boot and have been initialized
@@ -840,8 +828,7 @@ int __init memory_dev_init(void)
 
 out:
 	if (ret)
-		printk(KERN_ERR "%s() failed: %d\n", __func__, ret);
-	return ret;
+		panic("%s() failed: %d\n", __func__, ret);
 }
 
 /**