acm: fix deadlock and bogus loop.
It is very likly to overlook the outside loop.
for ( pd = &domain_list; *pd != NULL; pd = &(*pd)->next_in_list ) {
...
spin_lock(&(*pd)->grant_table->lock);
for ( i = 0; i < nr_grant_entries((*pd)->grant_table); i++ ) {
...
}
spin_unlock(&(*pd)->grant_table->lock); <<< necessary
}
out_gnttab:
spin_unlock(&(*pd)->grant_table->lock); <<< bogus
On Mon, Feb 19, 2007 at 05:20:09PM -0800, Xen patchbot-unstable wrote:
> # HG changeset patch
> # User kfraser@xxxxxxxxxxxxxxxxxxxxx
> # Date 1171901134 0
> # Node ID 184db7a674d93d92d0d963a7b3c80f1889983a9e
> # Parent 3b7bdb7bd1303eff6db3e223fc5bb8d06c86c570
> acm: Further fixes after grant-table changes.
> Based on a patch from Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
> Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
> ---
> xen/acm/acm_simple_type_enforcement_hooks.c | 20 ++++++++++----------
> 1 files changed, 10 insertions(+), 10 deletions(-)
>
> diff -r 3b7bdb7bd130 -r 184db7a674d9
> xen/acm/acm_simple_type_enforcement_hooks.c
> --- a/xen/acm/acm_simple_type_enforcement_hooks.c Mon Feb 19 15:52:51
> 2007 +0000
> +++ b/xen/acm/acm_simple_type_enforcement_hooks.c Mon Feb 19 16:05:34
> 2007 +0000
> @@ -177,7 +177,7 @@ ste_init_state(struct acm_ste_policy_buf
> ssidref_t ste_ssidref, ste_rssidref;
> struct domain **pd, *rdom;
> domid_t rdomid;
> - struct grant_entry *sha_copy;
> + struct grant_entry sha_copy;
> int port, i;
>
> read_lock(&domlist_lock); /* go by domain? or directly by global?
> event/grant list */
> @@ -234,20 +234,18 @@ ste_init_state(struct acm_ste_policy_buf
> }
> }
> /* b) check for grant table conflicts on shared pages */
> - if ((*pd)->grant_table->shared == NULL) {
> - printkd("%s: Grant ... sharing for domain %x not setup!\n",
> __func__, (*pd)->domain_id);
> - continue;
> - }
> + spin_lock(&(*pd)->grant_table->lock);
> for ( i = 0; i < nr_grant_frames((*pd)->grant_table); i++ ) {
> - sha_copy = (*pd)->grant_table->shared[i];
> - if ( sha_copy->flags ) {
> +#define SPP (PAGE_SIZE / sizeof(struct grant_entry))
> + sha_copy = (*pd)->grant_table->shared[i/SPP][i%SPP];
> + if ( sha_copy.flags ) {
> printkd("%s: grant dom (%hu) SHARED (%d) flags:(%hx)
> dom:(%hu) frame:(%lx)\n",
> __func__, (*pd)->domain_id, i, sha_copy.flags,
> sha_copy.domid,
> (unsigned long)sha_copy.frame);
> - rdomid = sha_copy->domid;
> + rdomid = sha_copy.domid;
> if ((rdom = get_domain_by_id(rdomid)) == NULL) {
> printkd("%s: domain not found ERROR!\n", __func__);
> - goto out;
> + goto out_gnttab;
> };
> /* rdom now has remote domain */
> ste_rssid = GET_SSIDP(ACM_SIMPLE_TYPE_ENFORCEMENT_POLICY,
> @@ -257,12 +255,14 @@ ste_init_state(struct acm_ste_policy_buf
> if (!have_common_type(ste_ssidref, ste_rssidref)) {
> printkd("%s: Policy violation in grant table sharing
> domain %x -> domain %x.\n",
> __func__, (*pd)->domain_id, rdomid);
> - goto out;
> + goto out_gnttab;
> }
> }
> }
> }
> violation = 0;
> + out_gnttab:
> + spin_unlock(&(*pd)->grant_table->lock);
> out:
> read_unlock(&domlist_lock);
> return violation;
>
> _______________________________________________
> Xen-changelog mailing list
> Xen-changelog@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-changelog
>
--
yamahata
13997_fe78383d8218_acm_fix_13991.patch
Description: Text Data
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