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author | truckman <truckman@FreeBSD.org> | 2014-07-02 17:32:43 +0000 |
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committer | truckman <truckman@FreeBSD.org> | 2014-07-02 17:32:43 +0000 |
commit | eca942517b0f7ca74b31bad5ebc3c7d26f34804a (patch) | |
tree | da1d32ed7a26c796b24cdb659ae6d5b5d78ebb17 /sys/kern/subr_rman.c | |
parent | a33844e926a330bdb5c1966b112da53d2735b82a (diff) | |
download | FreeBSD-src-eca942517b0f7ca74b31bad5ebc3c7d26f34804a.zip FreeBSD-src-eca942517b0f7ca74b31bad5ebc3c7d26f34804a.tar.gz |
MFC r266814
Initialize r_flags the same way in all cases using a sanitized copy of
flags that has several bits cleared. The RF_WANTED and RF_FIRSTSHARE
bits are invalid in this context, and we want to defer setting RF_ACTIVE
in r_flags until later. This should make rman_get_flags() return
the correct answer in all cases.
Add a KASSERT() to catch callers which incorrectly pass the RF_WANTED
or RF_FIRSTSHARE flags.
Do a strict equality check on the share type bits of flags. In
particular, do an equality check on RF_PREFETCHABLE. The previous
code would allow one type of mismatch of RF_PREFETCHABLE but disallow
the other type of mismatch. Also, ignore the the RF_ALIGNMENT_MASK
bits since alignment validity should be handled by the amask check.
This field contains an integer value, but previous code did a strange
bitwise comparison on it.
Leave the original value of flags unmolested as a minor debug aid.
Change the start+amask overflow check to a KASSERT() since it is just
meant to catch a highly unlikely programming error in the caller.
Reviewed by: jhb
Diffstat (limited to 'sys/kern/subr_rman.c')
-rw-r--r-- | sys/kern/subr_rman.c | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/sys/kern/subr_rman.c b/sys/kern/subr_rman.c index 5ae96e9..c466b44 100644 --- a/sys/kern/subr_rman.c +++ b/sys/kern/subr_rman.c @@ -435,12 +435,14 @@ rman_adjust_resource(struct resource *rr, u_long start, u_long end) return (0); } +#define SHARE_TYPE(f) (f & (RF_SHAREABLE | RF_TIMESHARE | RF_PREFETCHABLE)) + struct resource * rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, u_long count, u_long bound, u_int flags, struct device *dev) { - u_int want_activate; + u_int new_rflags; struct resource_i *r, *s, *rv; u_long rstart, rend, amask, bmask; @@ -450,8 +452,10 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, "length %#lx, flags %u, device %s\n", rm->rm_descr, start, end, count, flags, dev == NULL ? "<null>" : device_get_nameunit(dev))); - want_activate = (flags & RF_ACTIVE); - flags &= ~RF_ACTIVE; + KASSERT((flags & (RF_WANTED | RF_FIRSTSHARE)) == 0, + ("invalid flags %#x", flags)); + new_rflags = (flags & ~(RF_ACTIVE | RF_WANTED | RF_FIRSTSHARE)) | + RF_ALLOCATED; mtx_lock(rm->rm_mtx); @@ -466,10 +470,8 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, } amask = (1ul << RF_ALIGNMENT(flags)) - 1; - if (start > ULONG_MAX - amask) { - DPRINTF(("start+amask would wrap around\n")); - goto out; - } + KASSERT(start <= ULONG_MAX - amask, + ("start (%#lx) + amask (%#lx) would wrap around", start, amask)); /* If bound is 0, bmask will also be 0 */ bmask = ~(bound - 1); @@ -522,7 +524,7 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, if ((s->r_end - s->r_start + 1) == count) { DPRINTF(("candidate region is entire chunk\n")); rv = s; - rv->r_flags |= RF_ALLOCATED | flags; + rv->r_flags = new_rflags; rv->r_dev = dev; goto out; } @@ -542,7 +544,7 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, goto out; rv->r_start = rstart; rv->r_end = rstart + count - 1; - rv->r_flags = flags | RF_ALLOCATED; + rv->r_flags = new_rflags; rv->r_dev = dev; rv->r_rm = rm; @@ -603,7 +605,7 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, goto out; for (s = r; s && s->r_end <= end; s = TAILQ_NEXT(s, r_link)) { - if ((s->r_flags & flags) == flags && + if (SHARE_TYPE(s->r_flags) == SHARE_TYPE(flags) && s->r_start >= start && (s->r_end - s->r_start + 1) == count && (s->r_start & amask) == 0 && @@ -613,8 +615,7 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, goto out; rv->r_start = s->r_start; rv->r_end = s->r_end; - rv->r_flags = s->r_flags & - (RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE); + rv->r_flags = new_rflags; rv->r_dev = dev; rv->r_rm = rm; if (s->r_sharehead == NULL) { @@ -641,13 +642,12 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, */ out: /* - * If the user specified RF_ACTIVE in the initial flags, - * which is reflected in `want_activate', we attempt to atomically + * If the user specified RF_ACTIVE in flags, we attempt to atomically * activate the resource. If this fails, we release the resource * and indicate overall failure. (This behavior probably doesn't * make sense for RF_TIMESHARE-type resources.) */ - if (rv && want_activate) { + if (rv && (flags & RF_ACTIVE) != 0) { struct resource_i *whohas; if (int_rman_activate_resource(rm, rv, &whohas)) { int_rman_release_resource(rm, rv); |