From: David Hildenbrand <da...@redhat.com> We never read or write beyond the used_length of memory blocks when migrating. Make this clearer by using offset_in_ramblock() consistently.
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com> Signed-off-by: David Hildenbrand <da...@redhat.com> Message-Id: <20210429112708.12291-11-da...@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> --- migration/ram.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index 0ed1005f1a..7ea9c779cc 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1342,8 +1342,8 @@ static bool find_dirty_block(RAMState *rs, PageSearchStatus *pss, bool *again) *again = false; return false; } - if ((((ram_addr_t)pss->page) << TARGET_PAGE_BITS) - >= pss->block->used_length) { + if (!offset_in_ramblock(pss->block, + ((ram_addr_t)pss->page) << TARGET_PAGE_BITS)) { /* Didn't find anything in this RAM Block */ pss->page = 0; pss->block = QLIST_NEXT_RCU(pss->block, next); @@ -1863,7 +1863,7 @@ int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len) rs->last_req_rb = ramblock; } trace_ram_save_queue_pages(ramblock->idstr, start, len); - if (start + len > ramblock->used_length) { + if (!offset_in_ramblock(ramblock, start + len - 1)) { error_report("%s request overrun start=" RAM_ADDR_FMT " len=" RAM_ADDR_FMT " blocklen=" RAM_ADDR_FMT, __func__, start, len, ramblock->used_length); @@ -3696,8 +3696,8 @@ void colo_flush_ram_cache(void) while (block) { offset = migration_bitmap_find_dirty(ram_state, block, offset); - if (((ram_addr_t)offset) << TARGET_PAGE_BITS - >= block->used_length) { + if (!offset_in_ramblock(block, + ((ram_addr_t)offset) << TARGET_PAGE_BITS)) { offset = 0; block = QLIST_NEXT_RCU(block, next); } else { -- 2.31.1