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Commit 26b02a1f authored by Sasha Levin's avatar Sasha Levin Committed by Linus Torvalds
Browse files

mm: cma: allocation trigger 



Provides a userspace interface to trigger a CMA allocation.

Usage:

        echo [pages] > alloc

This would provide testing/fuzzing access to the CMA allocation paths.

Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
Acked-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 28b24c1f

mm/cma.c

+6 −0
Original line number Diff line number Diff line
@@ -123,6 +123,12 @@ static int __init cma_activate_area(struct cma *cma) 
	} while (--i);



	mutex_init(&cma->lock);



#ifdef CONFIG_CMA_DEBUGFS

	INIT_HLIST_HEAD(&cma->mem_head);

	spin_lock_init(&cma->mem_head_lock);

#endif



	return 0;



err:

mm/cma.h

+4 −0
Original line number Diff line number Diff line
@@ -7,6 +7,10 @@ struct cma { 
	unsigned long   *bitmap;

	unsigned int order_per_bit; /* Order of pages represented by one bit */

	struct mutex    lock;

#ifdef CONFIG_CMA_DEBUGFS

	struct hlist_head mem_head;

	spinlock_t mem_head_lock;

#endif

};



extern struct cma cma_areas[MAX_CMA_AREAS];

mm/cma_debug.c

+53 −1
Original line number Diff line number Diff line
@@ -7,9 +7,18 @@ 


#include <linux/debugfs.h>

#include <linux/cma.h>

#include <linux/list.h>

#include <linux/kernel.h>

#include <linux/slab.h>



#include "cma.h"



struct cma_mem {

	struct hlist_node node;

	struct page *p;

	unsigned long n;

};



static struct dentry *cma_debugfs_root;



static int cma_debugfs_get(void *data, u64 *val)
@@ -23,6 +32,46 @@ static int cma_debugfs_get(void *data, u64 *val) 


DEFINE_SIMPLE_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n");



static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem)

{

	spin_lock(&cma->mem_head_lock);

	hlist_add_head(&mem->node, &cma->mem_head);

	spin_unlock(&cma->mem_head_lock);

}



static int cma_alloc_mem(struct cma *cma, int count)

{

	struct cma_mem *mem;

	struct page *p;



	mem = kzalloc(sizeof(*mem), GFP_KERNEL);

	if (!mem)

		return -ENOMEM;



	p = cma_alloc(cma, count, CONFIG_CMA_ALIGNMENT);

	if (!p) {

		kfree(mem);

		return -ENOMEM;

	}



	mem->p = p;

	mem->n = count;



	cma_add_to_cma_mem_list(cma, mem);



	return 0;

}



static int cma_alloc_write(void *data, u64 val)

{

	int pages = val;

	struct cma *cma = data;



	return cma_alloc_mem(cma, pages);

}



DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");



static void cma_debugfs_add_one(struct cma *cma, int idx)

{

	struct dentry *tmp;
@@ -33,6 +82,9 @@ static void cma_debugfs_add_one(struct cma *cma, int idx) 


	tmp = debugfs_create_dir(name, cma_debugfs_root);



	debugfs_create_file("alloc", S_IWUSR, cma_debugfs_root, cma,

				&cma_alloc_fops);



	debugfs_create_file("base_pfn", S_IRUGO, tmp,

				&cma->base_pfn, &cma_debugfs_fops);

	debugfs_create_file("count", S_IRUGO, tmp,