From patchwork Wed Oct 31 03:43:08 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Fix off-by-1 error in RAM migration code Date: Tue, 30 Oct 2012 17:43:08 -0000 From: David Gibson X-Patchwork-Id: 195728 Message-Id: <1351654988-13165-1-git-send-email-david@gibson.dropbear.id.au> To: aliguori@us.ibm.com Cc: qemu-devel@nongnu.org, David Gibson The code for migrating (or savevm-ing) memory pages starts off by creating a dirty bitmap and filling it with 1s. Except, actually, because bit addresses are 0-based it fills every bit except bit 0 with 1s and puts an extra 1 beyond the end of the bitmap, potentially corrupting unrelated memory. Oops. This patch fixes it. Signed-off-by: David Gibson Reviewed-by: Orit Wasserman Reviewed-by: Juan Quintela --- arch_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch_init.c b/arch_init.c index e6effe8..b75a4c5 100644 --- a/arch_init.c +++ b/arch_init.c @@ -568,7 +568,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque) int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS; migration_bitmap = bitmap_new(ram_pages); - bitmap_set(migration_bitmap, 1, ram_pages); + bitmap_set(migration_bitmap, 0, ram_pages); migration_dirty_pages = ram_pages; bytes_transferred = 0;