summaryrefslogtreecommitdiffstats
path: root/system/xen/xsa/xsa224-0004-gnttab-__gnttab_unmap_common_complete-is-all-or-noth.patch
diff options
context:
space:
mode:
Diffstat (limited to 'system/xen/xsa/xsa224-0004-gnttab-__gnttab_unmap_common_complete-is-all-or-noth.patch')
-rw-r--r--system/xen/xsa/xsa224-0004-gnttab-__gnttab_unmap_common_complete-is-all-or-noth.patch319
1 files changed, 0 insertions, 319 deletions
diff --git a/system/xen/xsa/xsa224-0004-gnttab-__gnttab_unmap_common_complete-is-all-or-noth.patch b/system/xen/xsa/xsa224-0004-gnttab-__gnttab_unmap_common_complete-is-all-or-noth.patch
deleted file mode 100644
index 9c1bd40bec..0000000000
--- a/system/xen/xsa/xsa224-0004-gnttab-__gnttab_unmap_common_complete-is-all-or-noth.patch
+++ /dev/null
@@ -1,319 +0,0 @@
-From d27237abe37e45a1f245e23484062b09ff3477ed Mon Sep 17 00:00:00 2001
-From: Jan Beulich <jbeulich@suse.com>
-Date: Thu, 15 Jun 2017 16:25:27 +0100
-Subject: [PATCH 4/4] gnttab: __gnttab_unmap_common_complete() is
- all-or-nothing
-
-All failures have to be detected in __gnttab_unmap_common(), the
-completion function must not skip part of its processing. In particular
-the GNTMAP_device_map related putting of page references and adjustment
-of pin count must not occur if __gnttab_unmap_common() signaled an
-error. Furthermore the function must not make adjustments to global
-state (here: clearing GNTTAB_device_map) before all possibly failing
-operations have been performed.
-
-There's one exception for IOMMU related failures: As IOMMU manipulation
-occurs after GNTMAP_*_map have been cleared already, the related page
-reference and pin count adjustments need to be done nevertheless. A
-fundamental requirement for the correctness of this is that
-iommu_{,un}map_page() crash any affected DomU in case of failure.
-
-The version check appears to be pointless (or could perhaps be a
-BUG_ON() or ASSERT()), but for the moment also move it.
-
-This is part of XSA-224.
-
-Reported-by: Jan Beulich <jbeulich@suse.com>
-Signed-off-by: Jan Beulich <jbeulich@suse.com>
----
- xen/common/grant_table.c | 108 ++++++++++++++++++--------------------
- xen/include/asm-arm/grant_table.h | 2 +-
- xen/include/asm-x86/grant_table.h | 5 +-
- 3 files changed, 55 insertions(+), 60 deletions(-)
-
-diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
-index d07b931..7ea68b1 100644
---- a/xen/common/grant_table.c
-+++ b/xen/common/grant_table.c
-@@ -96,7 +96,7 @@ struct gnttab_unmap_common {
- int16_t status;
-
- /* Shared state beteen *_unmap and *_unmap_complete */
-- u16 flags;
-+ u16 done;
- unsigned long frame;
- struct domain *rd;
- grant_ref_t ref;
-@@ -944,7 +944,8 @@ __gnttab_map_grant_ref(
- refcnt++;
- }
-
-- if ( gnttab_host_mapping_get_page_type(op, ld, rd) )
-+ if ( gnttab_host_mapping_get_page_type(op->flags & GNTMAP_readonly,
-+ ld, rd) )
- {
- if ( (owner == dom_cow) ||
- !get_page_type(pg, PGT_writable_page) )
-@@ -1091,6 +1092,7 @@ __gnttab_unmap_common(
- struct active_grant_entry *act;
- s16 rc = 0;
- struct grant_mapping *map;
-+ unsigned int flags;
- bool put_handle = false;
-
- ld = current->domain;
-@@ -1140,6 +1142,20 @@ __gnttab_unmap_common(
-
- grant_read_lock(rgt);
-
-+ if ( rgt->gt_version == 0 )
-+ {
-+ /*
-+ * This ought to be impossible, as such a mapping should not have
-+ * been established (see the nr_grant_entries(rgt) bounds check in
-+ * __gnttab_map_grant_ref()). Doing this check only in
-+ * __gnttab_unmap_common_complete() - as it used to be done - would,
-+ * however, be too late.
-+ */
-+ rc = GNTST_bad_gntref;
-+ flags = 0;
-+ goto unlock_out;
-+ }
-+
- op->rd = rd;
- op->ref = map->ref;
-
-@@ -1155,6 +1171,7 @@ __gnttab_unmap_common(
- {
- gdprintk(XENLOG_WARNING, "Unstable handle %u\n", op->handle);
- rc = GNTST_bad_handle;
-+ flags = 0;
- goto unlock_out;
- }
-
-@@ -1168,9 +1185,9 @@ __gnttab_unmap_common(
- * hold anyway; see docs/misc/grant-tables.txt's "Locking" section.
- */
-
-- op->flags = read_atomic(&map->flags);
-+ flags = read_atomic(&map->flags);
- smp_rmb();
-- if ( unlikely(!op->flags) || unlikely(map->domid != dom) ||
-+ if ( unlikely(!flags) || unlikely(map->domid != dom) ||
- unlikely(map->ref != op->ref) )
- {
- gdprintk(XENLOG_WARNING, "Unstable handle %#x\n", op->handle);
-@@ -1180,24 +1197,27 @@ __gnttab_unmap_common(
-
- op->frame = act->frame;
-
-- if ( op->dev_bus_addr )
-- {
-- if ( unlikely(op->dev_bus_addr != pfn_to_paddr(act->frame)) )
-- PIN_FAIL(act_release_out, GNTST_general_error,
-- "Bus address doesn't match gntref (%"PRIx64" != %"PRIpaddr")\n",
-- op->dev_bus_addr, pfn_to_paddr(act->frame));
--
-- map->flags &= ~GNTMAP_device_map;
-- }
-+ if ( op->dev_bus_addr &&
-+ unlikely(op->dev_bus_addr != pfn_to_paddr(act->frame)) )
-+ PIN_FAIL(act_release_out, GNTST_general_error,
-+ "Bus address doesn't match gntref (%"PRIx64" != %"PRIpaddr")\n",
-+ op->dev_bus_addr, pfn_to_paddr(act->frame));
-
-- if ( (op->host_addr != 0) && (op->flags & GNTMAP_host_map) )
-+ if ( op->host_addr && (flags & GNTMAP_host_map) )
- {
- if ( (rc = replace_grant_host_mapping(op->host_addr,
- op->frame, op->new_addr,
-- op->flags)) < 0 )
-+ flags)) < 0 )
- goto act_release_out;
-
- map->flags &= ~GNTMAP_host_map;
-+ op->done |= GNTMAP_host_map | (flags & GNTMAP_readonly);
-+ }
-+
-+ if ( op->dev_bus_addr && (flags & GNTMAP_device_map) )
-+ {
-+ map->flags &= ~GNTMAP_device_map;
-+ op->done |= GNTMAP_device_map | (flags & GNTMAP_readonly);
- }
-
- if ( !(map->flags & (GNTMAP_device_map|GNTMAP_host_map)) )
-@@ -1234,7 +1254,7 @@ __gnttab_unmap_common(
- }
-
- /* If just unmapped a writable mapping, mark as dirtied */
-- if ( rc == GNTST_okay && !(op->flags & GNTMAP_readonly) )
-+ if ( rc == GNTST_okay && !(flags & GNTMAP_readonly) )
- gnttab_mark_dirty(rd, op->frame);
-
- op->status = rc;
-@@ -1251,13 +1271,9 @@ __gnttab_unmap_common_complete(struct gnttab_unmap_common *op)
- struct page_info *pg;
- uint16_t *status;
-
-- if ( rd == NULL )
-+ if ( !op->done )
- {
-- /*
-- * Suggests that __gntab_unmap_common failed in
-- * rcu_lock_domain_by_id() or earlier, and so we have nothing
-- * to complete
-- */
-+ /* __gntab_unmap_common() didn't do anything - nothing to complete. */
- return;
- }
-
-@@ -1267,8 +1283,6 @@ __gnttab_unmap_common_complete(struct gnttab_unmap_common *op)
- rgt = rd->grant_table;
-
- grant_read_lock(rgt);
-- if ( rgt->gt_version == 0 )
-- goto unlock_out;
-
- act = active_entry_acquire(rgt, op->ref);
- sha = shared_entry_header(rgt, op->ref);
-@@ -1278,72 +1292,50 @@ __gnttab_unmap_common_complete(struct gnttab_unmap_common *op)
- else
- status = &status_entry(rgt, op->ref);
-
-- if ( op->dev_bus_addr &&
-- unlikely(op->dev_bus_addr != pfn_to_paddr(act->frame)) )
-- {
-- /*
-- * Suggests that __gntab_unmap_common failed early and so
-- * nothing further to do
-- */
-- goto act_release_out;
-- }
--
- pg = mfn_to_page(op->frame);
-
-- if ( op->dev_bus_addr && (op->flags & GNTMAP_device_map) )
-+ if ( op->done & GNTMAP_device_map )
- {
- if ( !is_iomem_page(act->frame) )
- {
-- if ( op->flags & GNTMAP_readonly )
-+ if ( op->done & GNTMAP_readonly )
- put_page(pg);
- else
- put_page_and_type(pg);
- }
-
- ASSERT(act->pin & (GNTPIN_devw_mask | GNTPIN_devr_mask));
-- if ( op->flags & GNTMAP_readonly )
-+ if ( op->done & GNTMAP_readonly )
- act->pin -= GNTPIN_devr_inc;
- else
- act->pin -= GNTPIN_devw_inc;
- }
-
-- if ( (op->host_addr != 0) && (op->flags & GNTMAP_host_map) )
-+ if ( op->done & GNTMAP_host_map )
- {
-- if ( op->status != 0 )
-+ if ( !is_iomem_page(op->frame) )
- {
-- /*
-- * Suggests that __gntab_unmap_common failed in
-- * replace_grant_host_mapping() or IOMMU handling, so nothing
-- * further to do (short of re-establishing the mapping in the
-- * latter case).
-- */
-- goto act_release_out;
-- }
--
-- if ( !is_iomem_page(op->frame) )
-- {
-- if ( gnttab_host_mapping_get_page_type(op, ld, rd) )
-+ if ( gnttab_host_mapping_get_page_type(op->done & GNTMAP_readonly,
-+ ld, rd) )
- put_page_type(pg);
- put_page(pg);
- }
-
- ASSERT(act->pin & (GNTPIN_hstw_mask | GNTPIN_hstr_mask));
-- if ( op->flags & GNTMAP_readonly )
-+ if ( op->done & GNTMAP_readonly )
- act->pin -= GNTPIN_hstr_inc;
- else
- act->pin -= GNTPIN_hstw_inc;
- }
-
- if ( ((act->pin & (GNTPIN_devw_mask|GNTPIN_hstw_mask)) == 0) &&
-- !(op->flags & GNTMAP_readonly) )
-+ !(op->done & GNTMAP_readonly) )
- gnttab_clear_flag(_GTF_writing, status);
-
- if ( act->pin == 0 )
- gnttab_clear_flag(_GTF_reading, status);
-
-- act_release_out:
- active_entry_release(act);
-- unlock_out:
- grant_read_unlock(rgt);
-
- rcu_unlock_domain(rd);
-@@ -1359,6 +1351,7 @@ __gnttab_unmap_grant_ref(
- common->handle = op->handle;
-
- /* Intialise these in case common contains old state */
-+ common->done = 0;
- common->new_addr = 0;
- common->rd = NULL;
- common->frame = 0;
-@@ -1424,6 +1417,7 @@ __gnttab_unmap_and_replace(
- common->handle = op->handle;
-
- /* Intialise these in case common contains old state */
-+ common->done = 0;
- common->dev_bus_addr = 0;
- common->rd = NULL;
- common->frame = 0;
-@@ -3385,7 +3379,9 @@ gnttab_release_mappings(
- if ( gnttab_release_host_mappings(d) &&
- !is_iomem_page(act->frame) )
- {
-- if ( gnttab_host_mapping_get_page_type(map, d, rd) )
-+ if ( gnttab_host_mapping_get_page_type((map->flags &
-+ GNTMAP_readonly),
-+ d, rd) )
- put_page_type(pg);
- put_page(pg);
- }
-diff --git a/xen/include/asm-arm/grant_table.h b/xen/include/asm-arm/grant_table.h
-index eb02423..bc4d61a 100644
---- a/xen/include/asm-arm/grant_table.h
-+++ b/xen/include/asm-arm/grant_table.h
-@@ -9,7 +9,7 @@ void gnttab_clear_flag(unsigned long nr, uint16_t *addr);
- int create_grant_host_mapping(unsigned long gpaddr,
- unsigned long mfn, unsigned int flags, unsigned int
- cache_flags);
--#define gnttab_host_mapping_get_page_type(op, d, rd) (0)
-+#define gnttab_host_mapping_get_page_type(ro, ld, rd) (0)
- int replace_grant_host_mapping(unsigned long gpaddr, unsigned long mfn,
- unsigned long new_gpaddr, unsigned int flags);
- void gnttab_mark_dirty(struct domain *d, unsigned long l);
-diff --git a/xen/include/asm-x86/grant_table.h b/xen/include/asm-x86/grant_table.h
-index 8c9bbcf..9ca631c 100644
---- a/xen/include/asm-x86/grant_table.h
-+++ b/xen/include/asm-x86/grant_table.h
-@@ -58,9 +58,8 @@ static inline void gnttab_clear_flag(unsigned int nr, uint16_t *st)
- }
-
- /* Foreign mappings of HHVM-guest pages do not modify the type count. */
--#define gnttab_host_mapping_get_page_type(op, ld, rd) \
-- (!((op)->flags & GNTMAP_readonly) && \
-- (((ld) == (rd)) || !paging_mode_external(rd)))
-+#define gnttab_host_mapping_get_page_type(ro, ld, rd) \
-+ (!(ro) && (((ld) == (rd)) || !paging_mode_external(rd)))
-
- /* Done implicitly when page tables are destroyed. */
- #define gnttab_release_host_mappings(domain) ( paging_mode_external(domain) )
---
-2.1.4
-
generated by cgit v1.2.3 (git 2.26.2) at 2024-04-30 23:21:31 +0000