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

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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>
This commit is contained in:
David Hildenbrand 2019-09-23 15:35:46 -07:00 committed by Linus Torvalds
parent f915fb7fb2
commit 902ce63b33
2 changed files with 12 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
drivers/base/memory.c
View File

@ -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);
}
/**

6
include/linux/memory.h
View File

@ -80,9 +80,9 @@ 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)
{
@ -113,7 +113,7 @@ 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 *);