From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56220) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eS4jd-0003CZ-Er for qemu-devel@nongnu.org; Thu, 21 Dec 2017 12:34:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eS4ja-0007W2-AI for qemu-devel@nongnu.org; Thu, 21 Dec 2017 12:34:21 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:47448) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eS4ja-0007VK-3U for qemu-devel@nongnu.org; Thu, 21 Dec 2017 12:34:18 -0500 From: Jack Schwartz Date: Thu, 21 Dec 2017 09:25:15 -0800 Message-Id: <1513877118-3149-2-git-send-email-jack.schwartz@oracle.com> In-Reply-To: <1513877118-3149-1-git-send-email-jack.schwartz@oracle.com> References: <1513877118-3149-1-git-send-email-jack.schwartz@oracle.com> Subject: [Qemu-devel] [PATCH QEMU v1 1/4] multiboot: bss_end_addr can be zero List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: mst@redhat.com, pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com, daniel.kiper@oracle.com, konrad.wilk@oracle.com The multiboot spec (https://www.gnu.org/software/grub/manual/multiboot/), section 3.1.3, allows for bss_end_addr to be zero. A zero bss_end_addr signifies there is no .bss section. Suggested-by: Daniel Kiper Signed-off-by: Jack Schwartz Reviewed-by: Daniel Kiper --- hw/i386/multiboot.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c index c7b70c9..ff2733d 100644 --- a/hw/i386/multiboot.c +++ b/hw/i386/multiboot.c @@ -233,12 +233,6 @@ int load_multiboot(FWCfgState *fw_cfg, mh_entry_addr = ldl_p(header+i+28); if (mh_load_end_addr) { - if (mh_bss_end_addr < mh_load_addr) { - fprintf(stderr, "invalid mh_bss_end_addr address\n"); - exit(1); - } - mb_kernel_size = mh_bss_end_addr - mh_load_addr; - if (mh_load_end_addr < mh_load_addr) { fprintf(stderr, "invalid mh_load_end_addr address\n"); exit(1); @@ -249,8 +243,16 @@ int load_multiboot(FWCfgState *fw_cfg, fprintf(stderr, "invalid kernel_file_size\n"); exit(1); } - mb_kernel_size = kernel_file_size - mb_kernel_text_offset; - mb_load_size = mb_kernel_size; + mb_load_size = kernel_file_size - mb_kernel_text_offset; + } + if (mh_bss_end_addr) { + if (mh_bss_end_addr < (mh_load_addr + mb_load_size)) { + fprintf(stderr, "invalid mh_bss_end_addr address\n"); + exit(1); + } + mb_kernel_size = mh_bss_end_addr - mh_load_addr; + } else { + mb_kernel_size = mb_load_size; } /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_VBE. -- 1.8.3.1