diff options
Diffstat (limited to 'system/xen/xsa/xsa222-1.patch')
| -rw-r--r-- | system/xen/xsa/xsa222-1.patch | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/system/xen/xsa/xsa222-1.patch b/system/xen/xsa/xsa222-1.patch new file mode 100644 index 0000000000..6f1290b6a8 --- /dev/null +++ b/system/xen/xsa/xsa222-1.patch @@ -0,0 +1,124 @@ +From: Andrew Cooper <andrew.cooper3@citrix.com> +Subject: xen/memory: Fix return value handing of guest_remove_page() + +Despite the description in mm.h, guest_remove_page() previously returned 0 for +paging errors. + +Switch guest_remove_page() to having regular 0/-error semantics, and propagate +the return values from clear_mmio_p2m_entry() and mem_sharing_unshare_page() +to the callers (although decrease_reservation() is the only caller which +currently cares). + +This is part of XSA-222. + +Reported-by: Julien Grall <julien.grall@arm.com> +Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> + +diff --git a/xen/common/memory.c b/xen/common/memory.c +index 52879e7..a40bc1c 100644 +--- a/xen/common/memory.c ++++ b/xen/common/memory.c +@@ -265,6 +265,7 @@ int guest_remove_page(struct domain *d, unsigned long gmfn) + p2m_type_t p2mt; + #endif + mfn_t mfn; ++ int rc; + + #ifdef CONFIG_X86 + mfn = get_gfn_query(d, gmfn, &p2mt); +@@ -282,13 +283,15 @@ int guest_remove_page(struct domain *d, unsigned long gmfn) + put_page(page); + } + p2m_mem_paging_drop_page(d, gmfn, p2mt); +- return 1; ++ ++ return 0; + } + if ( p2mt == p2m_mmio_direct ) + { +- clear_mmio_p2m_entry(d, gmfn, mfn, 0); ++ rc = clear_mmio_p2m_entry(d, gmfn, mfn, PAGE_ORDER_4K); + put_gfn(d, gmfn); +- return 1; ++ ++ return rc; + } + #else + mfn = gfn_to_mfn(d, _gfn(gmfn)); +@@ -298,21 +301,25 @@ int guest_remove_page(struct domain *d, unsigned long gmfn) + put_gfn(d, gmfn); + gdprintk(XENLOG_INFO, "Domain %u page number %lx invalid\n", + d->domain_id, gmfn); +- return 0; ++ ++ return -EINVAL; + } + + #ifdef CONFIG_X86 + if ( p2m_is_shared(p2mt) ) + { +- /* Unshare the page, bail out on error. We unshare because +- * we might be the only one using this shared page, and we +- * need to trigger proper cleanup. Once done, this is +- * like any other page. */ +- if ( mem_sharing_unshare_page(d, gmfn, 0) ) ++ /* ++ * Unshare the page, bail out on error. We unshare because we ++ * might be the only one using this shared page, and we need to ++ * trigger proper cleanup. Once done, this is like any other page. ++ */ ++ rc = mem_sharing_unshare_page(d, gmfn, 0); ++ if ( rc ) + { + put_gfn(d, gmfn); + (void)mem_sharing_notify_enomem(d, gmfn, 0); +- return 0; ++ ++ return rc; + } + /* Maybe the mfn changed */ + mfn = get_gfn_query_unlocked(d, gmfn, &p2mt); +@@ -325,7 +332,8 @@ int guest_remove_page(struct domain *d, unsigned long gmfn) + { + put_gfn(d, gmfn); + gdprintk(XENLOG_INFO, "Bad page free for domain %u\n", d->domain_id); +- return 0; ++ ++ return -ENXIO; + } + + if ( test_and_clear_bit(_PGT_pinned, &page->u.inuse.type_info) ) +@@ -348,7 +356,7 @@ int guest_remove_page(struct domain *d, unsigned long gmfn) + put_page(page); + put_gfn(d, gmfn); + +- return 1; ++ return 0; + } + + static void decrease_reservation(struct memop_args *a) +@@ -392,7 +400,7 @@ static void decrease_reservation(struct memop_args *a) + continue; + + for ( j = 0; j < (1 << a->extent_order); j++ ) +- if ( !guest_remove_page(a->domain, gmfn + j) ) ++ if ( guest_remove_page(a->domain, gmfn + j) ) + goto out; + } + +diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h +index 88de3c1..b367930 100644 +--- a/xen/include/xen/mm.h ++++ b/xen/include/xen/mm.h +@@ -553,9 +553,8 @@ int xenmem_add_to_physmap_one(struct domain *d, unsigned int space, + union xen_add_to_physmap_batch_extra extra, + unsigned long idx, gfn_t gfn); + +-/* Returns 1 on success, 0 on error, negative if the ring +- * for event propagation is full in the presence of paging */ +-int guest_remove_page(struct domain *d, unsigned long gfn); ++/* Returns 0 on success, or negative on error. */ ++int guest_remove_page(struct domain *d, unsigned long gmfn); + + #define RAM_TYPE_CONVENTIONAL 0x00000001 + #define RAM_TYPE_RESERVED 0x00000002 |