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For /dev/mem and /dev/kmem accesses, avoid asserting that addresses

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are within direct map.  We want to return error instead of panicing.

PR:	194995
Sponsored by:	The FreeBSD Foundation
This commit is contained in:
kib 2015-01-03 01:28:58 +00:00
parent 5606bb1e5a
commit 771035aa6c
2 changed files with 6 additions and 4 deletions
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4
sys/amd64/amd64/mem.c
View File

@ -98,7 +98,7 @@ memrw(struct cdev *dev, struct uio *uio, int flags)
kmemphys:
o = v & PAGE_MASK;
c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o));
vd = PHYS_TO_DMAP(v);
vd = PHYS_TO_DMAP_RAW(v);
if (vd < DMAP_MIN_ADDRESS ||
(vd > DMAP_MIN_ADDRESS + dmaplimit &&
vd <= DMAP_MAX_ADDRESS) ||
@ -112,7 +112,7 @@ memrw(struct cdev *dev, struct uio *uio, int flags)
v = uio->uio_offset;
if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) {
v = DMAP_TO_PHYS(v);
v = DMAP_TO_PHYS_RAW(v);
goto kmemphys;
}

6
sys/amd64/include/vmparam.h
View File

@ -183,6 +183,8 @@
#define VM_MAX_ADDRESS UPT_MAX_ADDRESS
#define VM_MIN_ADDRESS (0)
#define PHYS_TO_DMAP_RAW(x) ((x) | DMAP_MIN_ADDRESS)
#define DMAP_TO_PHYS_RAW(x) ((x) & ~DMAP_MIN_ADDRESS)
/*
* XXX Allowing dmaplimit == 0 is a temporary workaround for vt(4) efifb's
* early use of PHYS_TO_DMAP before the mapping is actually setup. This works
@ -193,14 +195,14 @@
KASSERT(dmaplimit == 0 || (x) < dmaplimit, \
("physical address %#jx not covered by the DMAP", \
(uintmax_t)x)); \
(x) | DMAP_MIN_ADDRESS; })
PHYS_TO_DMAP_RAW(x); })
#define DMAP_TO_PHYS(x) ({ \
KASSERT((x) < (DMAP_MIN_ADDRESS + dmaplimit) && \
(x) >= DMAP_MIN_ADDRESS, \
("virtual address %#jx not covered by the DMAP", \
(uintmax_t)x)); \
(x) & ~DMAP_MIN_ADDRESS; })
DMAP_TO_PHYS_RAW(x); })
/*
* How many physical pages per kmem arena virtual page.