18e98e56f4
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>
32 lines
671 B
C
32 lines
671 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __MM_CMA_H__
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#define __MM_CMA_H__
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#include <linux/debugfs.h>
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#define CMA_MAX_NAME 64
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struct cma {
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unsigned long base_pfn;
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unsigned long count;
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unsigned long *bitmap;
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unsigned int order_per_bit; /* Order of pages represented by one bit */
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struct mutex lock;
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#ifdef CONFIG_CMA_DEBUGFS
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struct hlist_head mem_head;
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spinlock_t mem_head_lock;
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struct debugfs_u32_array dfs_bitmap;
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#endif
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char name[CMA_MAX_NAME];
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};
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extern struct cma cma_areas[MAX_CMA_AREAS];
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extern unsigned cma_area_count;
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static inline unsigned long cma_bitmap_maxno(struct cma *cma)
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{
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return cma->count >> cma->order_per_bit;
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}
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#endif
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