From a4b20f737cda06bb8706a83e27f7fa89863ae689 Mon Sep 17 00:00:00 2001 From: Aleksandr Partanen Date: Thu, 10 Apr 2025 17:46:04 +0300 Subject: [PATCH] xen: mapcache: Fix finding matching entry If we have request without lock and hit unlocked or invalid entry during the search, we remap it immediately, even if we have matching entry in next entries in bucket. This leads to duplication of mappings of the same size, and to possibility of selecting the wrong element during invalidation and underflow it's entry->lock counter Signed-off-by: Aleksandr Partanen Reviewed-by: Stefano Stabellini Reviewed-by: Edgar E. Iglesias Signed-off-by: Edgar E. Iglesias --- hw/xen/xen-mapcache.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c index 698b5c53ed..2c8f861fdb 100644 --- a/hw/xen/xen-mapcache.c +++ b/hw/xen/xen-mapcache.c @@ -376,12 +376,12 @@ tryagain: entry = &mc->entry[address_index % mc->nr_buckets]; - while (entry && (lock || entry->lock) && entry->vaddr_base && - (entry->paddr_index != address_index || entry->size != cache_size || + while (entry && (!entry->vaddr_base || + entry->paddr_index != address_index || entry->size != cache_size || !test_bits(address_offset >> XC_PAGE_SHIFT, test_bit_size >> XC_PAGE_SHIFT, entry->valid_mapping))) { - if (!free_entry && !entry->lock) { + if (!free_entry && (!entry->lock || !entry->vaddr_base)) { free_entry = entry; free_pentry = pentry; } -- 2.39.5