xen: Use guest atomics helpers when modifying atomically guest memory

On Arm, exclusive load-store atomics should only be used between trusted
thread. As not all the guests are trusted, it may be possible to DoS Xen
when updating shared memory with guest atomically.

This patch replaces all the atomics operations on shared memory with
a guest by the new guest atomics helpers. The x86 code was not audited
to know where guest atomics helpers could be used. I will leave that
to the x86 folks.

Note that some rework was required in order to plumb use the new guest
atomics in event channel and grant-table.

Because guest_test_bit is ignoring the parameter "d" for now, it
means there a lot of places do not need to drop the const. We may want
to revisit this in the future if the parameter "d" becomes necessary.

This is part of XSA-295.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index ec0f042bf7e4109990f270919fe7e2072ed37855..112a146fd94ac8150574cd4035231fb1ecdabafd 100644 (file)
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -26,6 +26,7 @@
 #include <asm/event.h>
 #include <asm/gic.h>
 #include <asm/guest_access.h>
+#include <asm/guest_atomics.h>
 #include <asm/irq.h>
 #include <asm/p2m.h>
 #include <asm/platform.h>
@@ -961,7 +962,7 @@ void arch_dump_vcpu_info(struct vcpu *v)
 
 void vcpu_mark_events_pending(struct vcpu *v)
 {
-    int already_pending = test_and_set_bit(
+    bool already_pending = guest_test_and_set_bit(v->domain,
         0, (unsigned long *)&vcpu_info(v, evtchn_upcall_pending));
 
     if ( already_pending )

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index bdf427ca645f90183480ca5d97b4b85d6499fcf9..26dd9263a44bdd1ef8160987ab76454aa45a0933 100644 (file)
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -40,6 +40,8 @@
 #include <xen/pfn.h>
 #include <xen/sizes.h>
 #include <xen/libfdt/libfdt.h>
+
+#include <asm/guest_atomics.h>
 #include <asm/setup.h>
 
 struct domain *dom_xen, *dom_io, *dom_cow;
@@ -1390,7 +1392,7 @@ void put_page_type(struct page_info *page)
     return;
 }
 
-void gnttab_clear_flag(unsigned long nr, uint16_t *addr)
+void gnttab_clear_flag(struct domain *d, unsigned long nr, uint16_t *addr)
 {
     /*
      * Note that this cannot be clear_bit(), as the access must be
@@ -1400,7 +1402,7 @@ void gnttab_clear_flag(unsigned long nr, uint16_t *addr)
 
     do {
         old = *addr;
-    } while (cmpxchg(addr, old, old & mask) != old);
+    } while (guest_cmpxchg(d, addr, old, old & mask) != old);
 }
 
 void gnttab_mark_dirty(struct domain *d, mfn_t mfn)

diff --git a/xen/common/event_2l.c b/xen/common/event_2l.c
index 8ca90899ab65751ed8938999e5dc966f9afd9662..e1dbb860f49002158a5c59667bb9050c4f3d6bae 100644 (file)
--- a/xen/common/event_2l.c
+++ b/xen/common/event_2l.c
@@ -13,6 +13,8 @@
 #include <xen/sched.h>
 #include <xen/event.h>
 
+#include <asm/guest_atomics.h>
+
 static void evtchn_2l_set_pending(struct vcpu *v, struct evtchn *evtchn)
 {
     struct domain *d = v->domain;
@@ -25,12 +27,12 @@ static void evtchn_2l_set_pending(struct vcpu *v, struct evtchn *evtchn)
      * others may require explicit memory barriers.
      */
 
-    if ( test_and_set_bit(port, &shared_info(d, evtchn_pending)) )
+    if ( guest_test_and_set_bit(d, port, &shared_info(d, evtchn_pending)) )
         return;
 
-    if ( !test_bit        (port, &shared_info(d, evtchn_mask)) &&
-         !test_and_set_bit(port / BITS_PER_EVTCHN_WORD(d),
-                           &vcpu_info(v, evtchn_pending_sel)) )
+    if ( !guest_test_bit(d, port, &shared_info(d, evtchn_mask)) &&
+         !guest_test_and_set_bit(d, port / BITS_PER_EVTCHN_WORD(d),
+                                 &vcpu_info(v, evtchn_pending_sel)) )
     {
         vcpu_mark_events_pending(v);
     }
@@ -40,7 +42,7 @@ static void evtchn_2l_set_pending(struct vcpu *v, struct evtchn *evtchn)
 
 static void evtchn_2l_clear_pending(struct domain *d, struct evtchn *evtchn)
 {
-    clear_bit(evtchn->port, &shared_info(d, evtchn_pending));
+    guest_clear_bit(d, evtchn->port, &shared_info(d, evtchn_pending));
 }
 
 static void evtchn_2l_unmask(struct domain *d, struct evtchn *evtchn)
@@ -52,10 +54,10 @@ static void evtchn_2l_unmask(struct domain *d, struct evtchn *evtchn)
      * These operations must happen in strict order. Based on
      * evtchn_2l_set_pending() above.
      */
-    if ( test_and_clear_bit(port, &shared_info(d, evtchn_mask)) &&
-         test_bit          (port, &shared_info(d, evtchn_pending)) &&
-         !test_and_set_bit (port / BITS_PER_EVTCHN_WORD(d),
-                            &vcpu_info(v, evtchn_pending_sel)) )
+    if ( guest_test_and_clear_bit(d, port, &shared_info(d, evtchn_mask)) &&
+         guest_test_bit(d, port, &shared_info(d, evtchn_pending)) &&
+         !guest_test_and_set_bit(d, port / BITS_PER_EVTCHN_WORD(d),
+                                 &vcpu_info(v, evtchn_pending_sel)) )
     {
         vcpu_mark_events_pending(v);
     }
@@ -66,7 +68,8 @@ static bool evtchn_2l_is_pending(const struct domain *d, evtchn_port_t port)
     unsigned int max_ports = BITS_PER_EVTCHN_WORD(d) * BITS_PER_EVTCHN_WORD(d);
 
     ASSERT(port < max_ports);
-    return port < max_ports && test_bit(port, &shared_info(d, evtchn_pending));
+    return (port < max_ports &&
+            guest_test_bit(d, port, &shared_info(d, evtchn_pending)));
 }
 
 static bool evtchn_2l_is_masked(const struct domain *d, evtchn_port_t port)
@@ -74,7 +77,8 @@ static bool evtchn_2l_is_masked(const struct domain *d, evtchn_port_t port)
     unsigned int max_ports = BITS_PER_EVTCHN_WORD(d) * BITS_PER_EVTCHN_WORD(d);
 
     ASSERT(port < max_ports);
-    return port >= max_ports || test_bit(port, &shared_info(d, evtchn_mask));
+    return (port >= max_ports ||
+            guest_test_bit(d, port, &shared_info(d, evtchn_mask)));
 }
 
 static void evtchn_2l_print_state(struct domain *d,

diff --git a/xen/common/event_fifo.c b/xen/common/event_fifo.c
index c49f446754a2f73b2ea5e523c6d4d6ce818dac96..3f4c835518c9a1e723b1f9235d5dad802ebed7c3 100644 (file)
--- a/xen/common/event_fifo.c
+++ b/xen/common/event_fifo.c
@@ -17,6 +17,8 @@
 #include <xen/mm.h>
 #include <xen/domain_page.h>
 
+#include <asm/guest_atomics.h>
+
 #include <public/event_channel.h>
 
 static inline event_word_t *evtchn_fifo_word_from_port(const struct domain *d,
@@ -50,7 +52,7 @@ static void evtchn_fifo_init(struct domain *d, struct evtchn *evtchn)
      * on the wrong VCPU or with an unexpected priority.
      */
     word = evtchn_fifo_word_from_port(d, evtchn->port);
-    if ( word && test_bit(EVTCHN_FIFO_LINKED, word) )
+    if ( word && guest_test_bit(d, EVTCHN_FIFO_LINKED, word) )
         gdprintk(XENLOG_WARNING, "domain %d, port %d already on a queue\n",
                  d->domain_id, evtchn->port);
 }
@@ -115,7 +117,7 @@ static int try_set_link(event_word_t *word, event_word_t *w, uint32_t link)
  * We block unmasking by the guest by marking the tail word as BUSY,
  * therefore, the cmpxchg() may fail at most 4 times.
  */
-static bool_t evtchn_fifo_set_link(const struct domain *d, event_word_t *word,
+static bool_t evtchn_fifo_set_link(struct domain *d, event_word_t *word,
                                    uint32_t link)
 {
     event_word_t w;
@@ -129,7 +131,7 @@ static bool_t evtchn_fifo_set_link(const struct domain *d, event_word_t *word,
         return ret;
 
     /* Lock the word to prevent guest unmasking. */
-    set_bit(EVTCHN_FIFO_BUSY, word);
+    guest_set_bit(d, EVTCHN_FIFO_BUSY, word);
 
     w = read_atomic(word);
 
@@ -139,13 +141,13 @@ static bool_t evtchn_fifo_set_link(const struct domain *d, event_word_t *word,
         if ( ret >= 0 )
         {
             if ( ret == 0 )
-                clear_bit(EVTCHN_FIFO_BUSY, word);
+                guest_clear_bit(d, EVTCHN_FIFO_BUSY, word);
             return ret;
         }
     }
     gdprintk(XENLOG_WARNING, "domain %d, port %d not linked\n",
              d->domain_id, link);
-    clear_bit(EVTCHN_FIFO_BUSY, word);
+    guest_clear_bit(d, EVTCHN_FIFO_BUSY, word);
     return 1;
 }
 
@@ -170,13 +172,13 @@ static void evtchn_fifo_set_pending(struct vcpu *v, struct evtchn *evtchn)
         return;
     }
 
-    was_pending = test_and_set_bit(EVTCHN_FIFO_PENDING, word);
+    was_pending = guest_test_and_set_bit(d, EVTCHN_FIFO_PENDING, word);
 
     /*
      * Link the event if it unmasked and not already linked.
      */
-    if ( !test_bit(EVTCHN_FIFO_MASKED, word)
-         && !test_bit(EVTCHN_FIFO_LINKED, word) )
+    if ( !guest_test_bit(d, EVTCHN_FIFO_MASKED, word) &&
+         !guest_test_bit(d, EVTCHN_FIFO_LINKED, word) )
     {
         struct evtchn_fifo_queue *q, *old_q;
         event_word_t *tail_word;
@@ -205,7 +207,7 @@ static void evtchn_fifo_set_pending(struct vcpu *v, struct evtchn *evtchn)
         if ( !old_q )
             goto done;
 
-        if ( test_and_set_bit(EVTCHN_FIFO_LINKED, word) )
+        if ( guest_test_and_set_bit(d, EVTCHN_FIFO_LINKED, word) )
         {
             spin_unlock_irqrestore(&old_q->lock, flags);
             goto done;
@@ -251,8 +253,8 @@ static void evtchn_fifo_set_pending(struct vcpu *v, struct evtchn *evtchn)
         spin_unlock_irqrestore(&q->lock, flags);
 
         if ( !linked
-             && !test_and_set_bit(q->priority,
-                                  &v->evtchn_fifo->control_block->ready) )
+             && !guest_test_and_set_bit(d, q->priority,
+                                        &v->evtchn_fifo->control_block->ready) )
             vcpu_mark_events_pending(v);
     }
  done:
@@ -274,7 +276,7 @@ static void evtchn_fifo_clear_pending(struct domain *d, struct evtchn *evtchn)
      * No need to unlink as the guest will unlink and ignore
      * non-pending events.
      */
-    clear_bit(EVTCHN_FIFO_PENDING, word);
+    guest_clear_bit(d, EVTCHN_FIFO_PENDING, word);
 }
 
 static void evtchn_fifo_unmask(struct domain *d, struct evtchn *evtchn)
@@ -286,10 +288,10 @@ static void evtchn_fifo_unmask(struct domain *d, struct evtchn *evtchn)
     if ( unlikely(!word) )
         return;
 
-    clear_bit(EVTCHN_FIFO_MASKED, word);
+    guest_clear_bit(d, EVTCHN_FIFO_MASKED, word);
 
     /* Relink if pending. */
-    if ( test_bit(EVTCHN_FIFO_PENDING, word) )
+    if ( guest_test_bit(d, EVTCHN_FIFO_PENDING, word) )
         evtchn_fifo_set_pending(v, evtchn);
 }
 
@@ -297,21 +299,21 @@ static bool evtchn_fifo_is_pending(const struct domain *d, evtchn_port_t port)
 {
     const event_word_t *word = evtchn_fifo_word_from_port(d, port);
 
-    return word && test_bit(EVTCHN_FIFO_PENDING, word);
+    return word && guest_test_bit(d, EVTCHN_FIFO_PENDING, word);
 }
 
 static bool_t evtchn_fifo_is_masked(const struct domain *d, evtchn_port_t port)
 {
     const event_word_t *word = evtchn_fifo_word_from_port(d, port);
 
-    return !word || test_bit(EVTCHN_FIFO_MASKED, word);
+    return !word || guest_test_bit(d, EVTCHN_FIFO_MASKED, word);
 }
 
 static bool_t evtchn_fifo_is_busy(const struct domain *d, evtchn_port_t port)
 {
     const event_word_t *word = evtchn_fifo_word_from_port(d, port);
 
-    return word && test_bit(EVTCHN_FIFO_LINKED, word);
+    return word && guest_test_bit(d, EVTCHN_FIFO_LINKED, word);
 }
 
 static int evtchn_fifo_set_priority(struct domain *d, struct evtchn *evtchn,
@@ -338,11 +340,11 @@ static void evtchn_fifo_print_state(struct domain *d,
     word = evtchn_fifo_word_from_port(d, evtchn->port);
     if ( !word )
         printk("?     ");
-    else if ( test_bit(EVTCHN_FIFO_LINKED, word) )
-        printk("%c %-4u", test_bit(EVTCHN_FIFO_BUSY, word) ? 'B' : ' ',
+    else if ( guest_test_bit(d, EVTCHN_FIFO_LINKED, word) )
+        printk("%c %-4u", guest_test_bit(d, EVTCHN_FIFO_BUSY, word) ? 'B' : ' ',
                *word & EVTCHN_FIFO_LINK_MASK);
     else
-        printk("%c -   ", test_bit(EVTCHN_FIFO_BUSY, word) ? 'B' : ' ');
+        printk("%c -   ", guest_test_bit(d, EVTCHN_FIFO_BUSY, word) ? 'B' : ' ');
 }
 
 static const struct evtchn_port_ops evtchn_port_ops_fifo =
@@ -494,7 +496,7 @@ static void setup_ports(struct domain *d)
 
         evtchn = evtchn_from_port(d, port);
 
-        if ( test_bit(port, &shared_info(d, evtchn_pending)) )
+        if ( guest_test_bit(d, port, &shared_info(d, evtchn_pending)) )
             evtchn->pending = 1;
 
         evtchn_fifo_set_priority(d, evtchn, EVTCHN_FIFO_PRIORITY_DEFAULT);

diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index c3a806fe473c703a690b7da53fdc00895339e013..221563a232bcd42b88b79eb1eac308650bb487a6 100644 (file)
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -39,6 +39,7 @@
 #include <xen/vmap.h>
 #include <xsm/xsm.h>
 #include <asm/flushtlb.h>
+#include <asm/guest_atomics.h>
 
 /* Per-domain grant information. */
 struct grant_table {
@@ -653,6 +654,7 @@ static unsigned int nr_grant_entries(struct grant_table *gt)
 }
 
 static int _set_status_v1(const grant_entry_header_t *shah,
+                          struct domain *rd,
                           struct active_grant_entry *act,
                           int readonly,
                           int mapflag,
@@ -708,8 +710,8 @@ static int _set_status_v1(const grant_entry_header_t *shah,
                          "Attempt to write-pin a r/o grant entry\n");
         }
 
-        prev_scombo.word = cmpxchg((u32 *)shah,
-                                   scombo.word, new_scombo.word);
+        prev_scombo.word = guest_cmpxchg(rd, (u32 *)shah,
+                                         scombo.word, new_scombo.word);
         if ( likely(prev_scombo.word == scombo.word) )
             break;
 
@@ -726,6 +728,7 @@ done:
 
 static int _set_status_v2(const grant_entry_header_t *shah,
                           grant_status_t *status,
+                          struct domain *rd,
                           struct active_grant_entry *act,
                           int readonly,
                           int mapflag,
@@ -788,8 +791,8 @@ static int _set_status_v2(const grant_entry_header_t *shah,
              (id != ldomid) ||
              (!readonly && (flags & GTF_readonly)) )
         {
-            gnttab_clear_flag(_GTF_writing, status);
-            gnttab_clear_flag(_GTF_reading, status);
+            gnttab_clear_flag(rd, _GTF_writing, status);
+            gnttab_clear_flag(rd, _GTF_reading, status);
             PIN_FAIL(done, GNTST_general_error,
                      "Unstable flags (%x) or dom (%d); expected d%d (r/w: %d)\n",
                      flags, id, ldomid, !readonly);
@@ -799,7 +802,7 @@ static int _set_status_v2(const grant_entry_header_t *shah,
     {
         if ( unlikely(flags & GTF_readonly) )
         {
-            gnttab_clear_flag(_GTF_writing, status);
+            gnttab_clear_flag(rd, _GTF_writing, status);
             PIN_FAIL(done, GNTST_general_error,
                      "Unstable grant readonly flag\n");
         }
@@ -812,6 +815,7 @@ done:
 
 static int _set_status(const grant_entry_header_t *shah,
                        grant_status_t *status,
+                       struct domain *rd,
                        unsigned rgt_version,
                        struct active_grant_entry *act,
                        int readonly,
@@ -820,9 +824,9 @@ static int _set_status(const grant_entry_header_t *shah,
 {
 
     if ( rgt_version == 1 )
-        return _set_status_v1(shah, act, readonly, mapflag, ldomid);
+        return _set_status_v1(shah, rd, act, readonly, mapflag, ldomid);
     else
-        return _set_status_v2(shah, status, act, readonly, mapflag, ldomid);
+        return _set_status_v2(shah, status, rd, act, readonly, mapflag, ldomid);
 }
 
 static struct active_grant_entry *grant_map_exists(const struct domain *ld,
@@ -994,7 +998,7 @@ map_grant_ref(
          (!(op->flags & GNTMAP_readonly) &&
           !(act->pin & (GNTPIN_hstw_mask|GNTPIN_devw_mask))) )
     {
-        if ( (rc = _set_status(shah, status, rgt->gt_version, act,
+        if ( (rc = _set_status(shah, status, rd, rgt->gt_version, act,
                                op->flags & GNTMAP_readonly, 1,
                                ld->domain_id) != GNTST_okay) )
             goto act_release_out;
@@ -1218,10 +1222,10 @@ map_grant_ref(
  unlock_out_clear:
     if ( !(op->flags & GNTMAP_readonly) &&
          !(act->pin & (GNTPIN_hstw_mask|GNTPIN_devw_mask)) )
-        gnttab_clear_flag(_GTF_writing, status);
+        gnttab_clear_flag(rd, _GTF_writing, status);
 
     if ( !act->pin )
-        gnttab_clear_flag(_GTF_reading, status);
+        gnttab_clear_flag(rd, _GTF_reading, status);
 
  act_release_out:
     active_entry_release(act);
@@ -1505,10 +1509,10 @@ unmap_common_complete(struct gnttab_unmap_common *op)
 
     if ( ((act->pin & (GNTPIN_devw_mask|GNTPIN_hstw_mask)) == 0) &&
          !(op->done & GNTMAP_readonly) )
-        gnttab_clear_flag(_GTF_writing, status);
+        gnttab_clear_flag(rd, _GTF_writing, status);
 
     if ( act->pin == 0 )
-        gnttab_clear_flag(_GTF_reading, status);
+        gnttab_clear_flag(rd, _GTF_reading, status);
 
     active_entry_release(act);
     grant_read_unlock(rgt);
@@ -2073,8 +2077,8 @@ gnttab_prepare_for_transfer(
         new_scombo = scombo;
         new_scombo.shorts.flags |= GTF_transfer_committed;
 
-        prev_scombo.word = cmpxchg((u32 *)&sha->flags,
-                                   scombo.word, new_scombo.word);
+        prev_scombo.word = guest_cmpxchg(rd, (u32 *)&sha->flags,
+                                         scombo.word, new_scombo.word);
         if ( likely(prev_scombo.word == scombo.word) )
             break;
 
@@ -2359,11 +2363,11 @@ release_grant_for_copy(
 
         act->pin -= GNTPIN_hstw_inc;
         if ( !(act->pin & (GNTPIN_devw_mask|GNTPIN_hstw_mask)) )
-            gnttab_clear_flag(_GTF_writing, status);
+            gnttab_clear_flag(rd, _GTF_writing, status);
     }
 
     if ( !act->pin )
-        gnttab_clear_flag(_GTF_reading, status);
+        gnttab_clear_flag(rd, _GTF_reading, status);
 
     active_entry_release(act);
     grant_read_unlock(rgt);
@@ -2385,14 +2389,15 @@ release_grant_for_copy(
    under the domain's grant table lock. */
 /* Only safe on transitive grants.  Even then, note that we don't
    attempt to drop any pin on the referent grant. */
-static void fixup_status_for_copy_pin(const struct active_grant_entry *act,
+static void fixup_status_for_copy_pin(struct domain *rd,
+                                      const struct active_grant_entry *act,
                                       uint16_t *status)
 {
     if ( !(act->pin & (GNTPIN_hstw_mask | GNTPIN_devw_mask)) )
-        gnttab_clear_flag(_GTF_writing, status);
+        gnttab_clear_flag(rd, _GTF_writing, status);
 
     if ( !act->pin )
-        gnttab_clear_flag(_GTF_reading, status);
+        gnttab_clear_flag(rd, _GTF_reading, status);
 }
 
 /* Grab a frame number from a grant entry and update the flags and pin
@@ -2452,7 +2457,7 @@ acquire_grant_for_copy(
     {
         if ( (!old_pin || (!readonly &&
                            !(old_pin & (GNTPIN_devw_mask|GNTPIN_hstw_mask)))) &&
-             (rc = _set_status_v2(shah, status, act, readonly, 0,
+             (rc = _set_status_v2(shah, status, rd, act, readonly, 0,
                                   ldom)) != GNTST_okay )
             goto unlock_out;
 
@@ -2501,7 +2506,7 @@ acquire_grant_for_copy(
 
         if ( rc != GNTST_okay )
         {
-            fixup_status_for_copy_pin(act, status);
+            fixup_status_for_copy_pin(rd, act, status);
             rcu_unlock_domain(td);
             active_entry_release(act);
             grant_read_unlock(rgt);
@@ -2524,7 +2529,7 @@ acquire_grant_for_copy(
                           !act->is_sub_page)) )
         {
             release_grant_for_copy(td, trans_gref, readonly);
-            fixup_status_for_copy_pin(act, status);
+            fixup_status_for_copy_pin(rd, act, status);
             rcu_unlock_domain(td);
             active_entry_release(act);
             grant_read_unlock(rgt);
@@ -2553,7 +2558,7 @@ acquire_grant_for_copy(
     else if ( !old_pin ||
               (!readonly && !(old_pin & (GNTPIN_devw_mask|GNTPIN_hstw_mask))) )
     {
-        if ( (rc = _set_status(shah, status, rgt->gt_version, act,
+        if ( (rc = _set_status(shah, status, rd, rgt->gt_version, act,
                                readonly, 0, ldom)) != GNTST_okay )
              goto unlock_out;
 
@@ -2641,10 +2646,10 @@ acquire_grant_for_copy(
  unlock_out_clear:
     if ( !(readonly) &&
          !(act->pin & (GNTPIN_hstw_mask | GNTPIN_devw_mask)) )
-        gnttab_clear_flag(_GTF_writing, status);
+        gnttab_clear_flag(rd, _GTF_writing, status);
 
     if ( !act->pin )
-        gnttab_clear_flag(_GTF_reading, status);
+        gnttab_clear_flag(rd, _GTF_reading, status);
 
  unlock_out:
     active_entry_release(act);
@@ -3712,11 +3717,11 @@ gnttab_release_mappings(
             }
 
             if ( (act->pin & (GNTPIN_devw_mask|GNTPIN_hstw_mask)) == 0 )
-                gnttab_clear_flag(_GTF_writing, status);
+                gnttab_clear_flag(rd, _GTF_writing, status);
         }
 
         if ( act->pin == 0 )
-            gnttab_clear_flag(_GTF_reading, status);
+            gnttab_clear_flag(rd, _GTF_reading, status);
 
         active_entry_release(act);
         grant_read_unlock(rgt);

diff --git a/xen/include/asm-arm/grant_table.h b/xen/include/asm-arm/grant_table.h
index 24958e4670c5ec2dea121a49db31adeec084d472..8ae8ba47a11d6f27f2c0c5594eb440c56ae89eea 100644 (file)
--- a/xen/include/asm-arm/grant_table.h
+++ b/xen/include/asm-arm/grant_table.h
@@ -14,7 +14,7 @@ struct grant_table_arch {
     gfn_t *status_gfn;
 };
 
-void gnttab_clear_flag(unsigned long nr, uint16_t *addr);
+void gnttab_clear_flag(struct domain *d, unsigned long nr, uint16_t *addr);
 int create_grant_host_mapping(unsigned long gpaddr, mfn_t mfn,
                               unsigned int flags, unsigned int cache_flags);
 #define gnttab_host_mapping_get_page_type(ro, ld, rd) (0)

diff --git a/xen/include/asm-x86/grant_table.h b/xen/include/asm-x86/grant_table.h
index e42030936b244e7cabbb5b17a3e96045cc4661b8..2a54fc8e1de6f2869cfb1e5681a26cea1e378928 100644 (file)
--- a/xen/include/asm-x86/grant_table.h
+++ b/xen/include/asm-x86/grant_table.h
@@ -82,7 +82,8 @@ static inline unsigned int gnttab_dom0_max(void)
 
 #define gnttab_mark_dirty(d, f) paging_mark_dirty((d), f)
 
-static inline void gnttab_clear_flag(unsigned int nr, uint16_t *st)
+static inline void gnttab_clear_flag(struct domain *d, unsigned int nr,
+                                     uint16_t *st)
 {
     /*
      * Note that this cannot be clear_bit(), as the access must be