linux/arch/arm/mm/mm.h
Kees Cook 229a08a4f4 ARM/dma-mapping: Remove CMA code when not built with CMA
The MAX_CMA_AREAS could be set to 0, which would result in code that would
attempt to operate beyond the end of a zero-sized array. If CONFIG_CMA
is disabled, just remove this code entirely. Found when building arm
on GCC 10.x for several defconfigs (e.g. axm55xx_defconfig) under
-Warray-bounds:

arch/arm/mm/dma-mapping.c:396:22: warning: array subscript <unknown> is outside array bounds of 'struct dma_contig_early_reserve[0]' [-Warray-bounds]
  396 |         dma_mmu_remap[dma_mmu_remap_num].size = size;
      |         ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
arch/arm/mm/dma-mapping.c:389:40: note: while referencing 'dma_mmu_remap'
  389 | static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata;
      |                                        ^~~~~~~~~~~~~

Cc: Russell King <linux@armlinux.org.uk>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Martin Oliveira <martin.oliveira@eideticom.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/all/6243ee60.1c69fb81.16de6.7dbf@mx.google.com/
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/lkml/20220310070041.GA24874@lst.de
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/lkml/9059fa71-330f-f04f-b155-2850abb72a71@redhat.com
2022-03-31 11:19:25 -07:00

98 lines
2.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifdef CONFIG_MMU
#include <linux/list.h>
#include <linux/vmalloc.h>
#include <linux/pgtable.h>
/* the upper-most page table pointer */
extern pmd_t *top_pmd;
extern int icache_size;
/*
* 0xffff8000 to 0xffffffff is reserved for any ARM architecture
* specific hacks for copying pages efficiently, while 0xffff4000
* is reserved for VIPT aliasing flushing by generic code.
*
* Note that we don't allow VIPT aliasing caches with SMP.
*/
#define COPYPAGE_MINICACHE 0xffff8000
#define COPYPAGE_V6_FROM 0xffff8000
#define COPYPAGE_V6_TO 0xffffc000
/* PFN alias flushing, for VIPT caches */
#define FLUSH_ALIAS_START 0xffff4000
static inline void set_top_pte(unsigned long va, pte_t pte)
{
pte_t *ptep = pte_offset_kernel(top_pmd, va);
set_pte_ext(ptep, pte, 0);
local_flush_tlb_kernel_page(va);
}
static inline pte_t get_top_pte(unsigned long va)
{
pte_t *ptep = pte_offset_kernel(top_pmd, va);
return *ptep;
}
struct mem_type {
pteval_t prot_pte;
pteval_t prot_pte_s2;
pmdval_t prot_l1;
pmdval_t prot_sect;
unsigned int domain;
};
const struct mem_type *get_mem_type(unsigned int type);
extern void __flush_dcache_page(struct address_space *mapping, struct page *page);
/*
* ARM specific vm_struct->flags bits.
*/
/* (super)section-mapped I/O regions used by ioremap()/iounmap() */
#define VM_ARM_SECTION_MAPPING 0x80000000
/* permanent static mappings from iotable_init() */
#define VM_ARM_STATIC_MAPPING 0x40000000
/* empty mapping */
#define VM_ARM_EMPTY_MAPPING 0x20000000
/* mapping type (attributes) for permanent static mappings */
#define VM_ARM_MTYPE(mt) ((mt) << 20)
#define VM_ARM_MTYPE_MASK (0x1f << 20)
struct static_vm {
struct vm_struct vm;
struct list_head list;
};
extern struct list_head static_vmlist;
extern struct static_vm *find_static_vm_vaddr(void *vaddr);
extern __init void add_static_vm_early(struct static_vm *svm);
#endif
#ifdef CONFIG_ZONE_DMA
extern phys_addr_t arm_dma_limit;
extern unsigned long arm_dma_pfn_limit;
#else
#define arm_dma_limit ((phys_addr_t)~0)
#define arm_dma_pfn_limit (~0ul >> PAGE_SHIFT)
#endif
extern phys_addr_t arm_lowmem_limit;
void __init bootmem_init(void);
void arm_mm_memblock_reserve(void);
#ifdef CONFIG_CMA_AREAS
void dma_contiguous_remap(void);
#else
static inline void dma_contiguous_remap(void) { }
#endif
unsigned long __clear_cr(unsigned long mask);