linux/mm/cma.h
Barry Song 18e98e56f4 mm: cma: fix the name of CMA areas
Patch series "mm: fix the names of general cma and hugetlb cma", v2.

The current code of CMA can only work when users pass a const string as
name parameter.  we need to fix the way to handle names in CMA.  On the
other hand, to avoid name conflicts after enabling CMA_DEBUGFS, each
hugetlb should get a different CMA name.

This patch (of 2):

If users give a name saved in stack, the current code will generate magic
pointer.  if users don't give a name(NULL), kasprintf() will always return
NULL as we are at the early stage.  that means cma_init_reserved_mem()
will return -ENOMEM if users set name parameter as NULL.

[natechancellor@gmail.com: return cma->name directly in cma_get_name]
  Link: https://github.com/ClangBuiltLinux/linux/issues/1063
  Link: http://lkml.kernel.org/r/20200623015840.621964-1-natechancellor@gmail.com

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/20200616223131.33828-2-song.bao.hua@hisilicon.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:57:57 -07:00

32 lines
671 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __MM_CMA_H__
#define __MM_CMA_H__
#include <linux/debugfs.h>
#define CMA_MAX_NAME 64
struct cma {
unsigned long base_pfn;
unsigned long count;
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;
struct debugfs_u32_array dfs_bitmap;
#endif
char name[CMA_MAX_NAME];
};
extern struct cma cma_areas[MAX_CMA_AREAS];
extern unsigned cma_area_count;
static inline unsigned long cma_bitmap_maxno(struct cma *cma)
{
return cma->count >> cma->order_per_bit;
}
#endif