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When attempting to satisfy mmap() requests for superpage alignment on

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64-bit MIPS, use superpage rather than physical-segment constants, or
we may improperly fail to apply suitable alignment -- yet still allow
mmap() to appear to succeed.

Reviewed by:	sson
MFC after:	1 week
Sponsored by:	DARPA, AFRL
This commit is contained in:
Robert Watson 2016-04-30 19:29:03 +00:00
parent b68ac8007d
commit a75a7d90e9
2 changed files with 9 additions and 7 deletions
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2
sys/mips/include/param.h
View File

@ -146,12 +146,14 @@
#define SEGSHIFT (PAGE_SHIFT + NPTEPGSHIFT + NPDEPGSHIFT)
#define NBSEG (1ul << SEGSHIFT)
#define PDRSHIFT (PAGE_SHIFT + NPTEPGSHIFT)
#define PDRSIZE (1ul << PDRSHIFT)
#define PDRMASK ((1 << PDRSHIFT) - 1)
#else
#define NPDEPGSHIFT 10 /* LOG2(NPTEPG) */
#define SEGSHIFT (PAGE_SHIFT + NPTEPGSHIFT)
#define NBSEG (1 << SEGSHIFT) /* bytes/segment */
#define PDRSHIFT SEGSHIFT /* alias for SEG in 32 bit */
#define PDRSIZE (1ul << PDRSHIFT)
#define PDRMASK ((1 << PDRSHIFT) - 1)
#endif
#define NBPDR (1 << PDRSHIFT) /* bytes/pagedir */

14
sys/mips/mips/pmap.c
View File

@ -3299,18 +3299,18 @@ pmap_align_superpage(vm_object_t object, vm_ooffset_t offset,
{
vm_offset_t superpage_offset;
if (size < NBSEG)
if (size < PDRSIZE)
return;
if (object != NULL && (object->flags & OBJ_COLORED) != 0)
offset += ptoa(object->pg_color);
superpage_offset = offset & SEGMASK;
if (size - ((NBSEG - superpage_offset) & SEGMASK) < NBSEG ||
(*addr & SEGMASK) == superpage_offset)
superpage_offset = offset & PDRMASK;
if (size - ((PDRSIZE - superpage_offset) & PDRMASK) < PDRSIZE ||
(*addr & PDRMASK) == superpage_offset)
return;
if ((*addr & SEGMASK) < superpage_offset)
*addr = (*addr & ~SEGMASK) + superpage_offset;
if ((*addr & PDRMASK) < superpage_offset)
*addr = (*addr & ~PDRMASK) + superpage_offset;
else
*addr = ((*addr + SEGMASK) & ~SEGMASK) + superpage_offset;
*addr = ((*addr + PDRMASK) & ~PDRMASK) + superpage_offset;
}
#ifdef DDB