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.
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
drivers/base/memory.c | 31 +++++++++----------------------
include/linux/memory.h | 6 +++---
2 files changed, 12 insertions(+), 25 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 790b3bcd63a6..6bea4f3f8040 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);
@@ -811,19 +796,22 @@ 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
@@ -839,8 +827,7 @@ 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);
}
/**
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 704215d7258a..0ebb105eb261 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -79,9 +79,9 @@ struct mem_section;
#define IPC_CALLBACK_PRI 10
#ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
-static inline int memory_dev_init(void)
+static inline void memory_dev_init(void)
{
- return 0;
+ return;
}
static inline int register_memory_notifier(struct notifier_block *nb)
{
@@ -112,7 +112,7 @@ extern int register_memory_isolate_notifier(struct notifier_block *nb);
extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
int create_memory_block_devices(unsigned long start, unsigned long size);
void remove_memory_block_devices(unsigned long start, unsigned long size);
-extern int memory_dev_init(void);
+extern void memory_dev_init(void);
extern int memory_notify(unsigned long val, void *v);
extern int memory_isolate_notify(unsigned long val, void *v);
extern struct memory_block *find_memory_block(struct mem_section *);
--
2.21.0
