Commit 51a71ab2 authored by Kees Cook's avatar Kees Cook
Browse files

virt: acrn: Annotate struct vm_memory_region_batch with __counted_by 

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct vm_memory_region_batch.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci



Cc: Fei Li <fei1.li@intel.com>
Reviewed-by: default avatar"Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230922175102.work.020-kees@kernel.org


Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 4a530cb9

drivers/virt/acrn/acrn_drv.h

+1 −1
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ struct vm_memory_region_batch { 
	u16			   reserved[3];

	u32			   regions_num;

	u64			   regions_gpa;

	struct vm_memory_region_op regions_op[];

	struct vm_memory_region_op regions_op[] __counted_by(regions_num);

};



/**

drivers/virt/acrn/mm.c

+1 −1
Original line number Diff line number Diff line
@@ -250,11 +250,11 @@ int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap) 
		ret = -ENOMEM;

		goto unmap_kernel_map;

	}

	regions_info->regions_num = nr_regions;



	/* Fill each vm_memory_region_op */

	vm_region = regions_info->regions_op;

	regions_info->vmid = vm->vmid;

	regions_info->regions_num = nr_regions;

	regions_info->regions_gpa = virt_to_phys(vm_region);

	user_vm_pa = memmap->user_vm_pa;

	i = 0;