Commit fcae96ff authored Apr 05, 2019 by Jann Horn Committed by Linus Torvalds Apr 05, 2019

mm: fix vm_fault_t cast in VM_FAULT_GET_HINDEX()

Symmetrically to VM_FAULT_SET_HINDEX(), we need a force-cast in
VM_FAULT_GET_HINDEX() to tell sparse that this is intentional.

Sparse complains about the current code when building a kernel with
CONFIG_MEMORY_FAILURE:

  arch/x86/mm/fault.c:1058:53: warning: restricted vm_fault_t degrades to integer

Link: http://lkml.kernel.org/r/20190327204117.35215-1-jannh@google.com


Fixes: 3d353901 ("mm: create the new vm_fault_t type")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent b11ed18e

include/linux/mm_types.h

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -671,7 +671,7 @@ enum vm_fault_reason {

	/* Encode hstate index for a hwpoisoned large page */		/* Encode hstate index for a hwpoisoned large page */
	#define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16))		#define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16))
	#define VM_FAULT_GET_HINDEX(x) (((x) >> 16) & 0xf)		#define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf)

	#define VM_FAULT_ERROR (VM_FAULT_OOM \| VM_FAULT_SIGBUS \| \		#define VM_FAULT_ERROR (VM_FAULT_OOM \| VM_FAULT_SIGBUS \| \
	VM_FAULT_SIGSEGV \| VM_FAULT_HWPOISON \| \		VM_FAULT_SIGSEGV \| VM_FAULT_HWPOISON \| \

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