From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45827) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fV5i0-0001cQ-Vp for qemu-devel@nongnu.org; Mon, 18 Jun 2018 21:45:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fV5hz-0008P3-F3 for qemu-devel@nongnu.org; Mon, 18 Jun 2018 21:45:25 -0400 Sender: fluxion From: Michael Roth Date: Mon, 18 Jun 2018 20:42:02 -0500 Message-Id: <20180619014319.28272-37-mdroth@linux.vnet.ibm.com> In-Reply-To: <20180619014319.28272-1-mdroth@linux.vnet.ibm.com> References: <20180619014319.28272-1-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 036/113] 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: qemu-stable@nongnu.org, Jack Schwartz , Kevin Wolf From: Jack Schwartz 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 Reviewed-by: Prasad J Pandit Signed-off-by: Kevin Wolf (cherry picked from commit 2a8fcd119eb7c6bb3837fc3669eb1b2dfb31daf8) Signed-off-by: Michael Roth --- 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 c7b70c91d5..ff2733d12e 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. -- 2.11.0