From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35486) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YlKIE-0002wM-5D for qemu-devel@nongnu.org; Thu, 23 Apr 2015 12:48:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YlKI9-0004Fz-M4 for qemu-devel@nongnu.org; Thu, 23 Apr 2015 12:48:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50775) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YlKI9-0004Fo-E2 for qemu-devel@nongnu.org; Thu, 23 Apr 2015 12:47:57 -0400 Message-ID: <55392236.5020803@redhat.com> Date: Thu, 23 Apr 2015 18:47:50 +0200 From: Max Reitz MIME-Version: 1.0 References: <1429756938-17186-1-git-send-email-chenxg@linux.vnet.ibm.com> <1429756938-17186-6-git-send-email-chenxg@linux.vnet.ibm.com> In-Reply-To: <1429756938-17186-6-git-send-email-chenxg@linux.vnet.ibm.com> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH RFC v7 5/7] qemu-iotests: s390x: fix test 049 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Xiao Guang Chen , qemu-devel@nongnu.org Cc: kwolf@redhat.com, armbru@redhat.com, mimu@linux.vnet.ibm.com On 23.04.2015 04:42, Xiao Guang Chen wrote: > From: Bo Tu Hm, why is Bo Tu the patch author, but doesn't have an S-o-b in the commit message? > when creating an image qemu-img enable us specifying the size of the > image using -o size=xx options. But when we specify an invalid size > such as a negtive size then different platform gives different result. > > parse_option_size() function in util/qemu-option.c will be called to > parse the size, a cast was called in the function to cast the input > (saved as a double in the function) size to an unsigned int64 value, > when the input is a negtive value or exceeds the maximum of uint64, then > the result is undefined. > > Language spec 6.3.1.4 Real floating and integers: > the result of this assignment/cast is undefined if the float is not > in the open interval (-1, U_MAX+1). Thank you for pointing to the specific section. I guess there are always new things to discover in C... > Signed-off-by: Xiao Guang Chen > --- > tests/qemu-iotests/049.out | 10 ++++------ > util/qemu-option.c | 5 +++++ > 2 files changed, 9 insertions(+), 6 deletions(-) > > diff --git a/tests/qemu-iotests/049.out b/tests/qemu-iotests/049.out > index 9f93666..75d90b2 100644 > --- a/tests/qemu-iotests/049.out > +++ b/tests/qemu-iotests/049.out > @@ -95,17 +95,15 @@ qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- -1024 > qemu-img: Image size must be less than 8 EiB! > > qemu-img create -f qcow2 -o size=-1024 TEST_DIR/t.qcow2 > -qemu-img: qcow2 doesn't support shrinking images yet > -qemu-img: TEST_DIR/t.qcow2: Could not resize image: Operation not supported > -Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=-1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16 > +qemu-img: Parameter 'size' expects a positive number and must not exceeds the maximum UINT64 > +qemu-img: TEST_DIR/t.qcow2: Invalid options for file format 'qcow2' > > qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- -1k > qemu-img: Image size must be less than 8 EiB! > > qemu-img create -f qcow2 -o size=-1k TEST_DIR/t.qcow2 > -qemu-img: qcow2 doesn't support shrinking images yet > -qemu-img: TEST_DIR/t.qcow2: Could not resize image: Operation not supported > -Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=-1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16 > +qemu-img: Parameter 'size' expects a positive number and must not exceeds the maximum UINT64 > +qemu-img: TEST_DIR/t.qcow2: Invalid options for file format 'qcow2' > > qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- 1kilobyte > qemu-img: Invalid image size specified! You may use k, M, G, T, P or E suffixes for > diff --git a/util/qemu-option.c b/util/qemu-option.c > index fda4e5f..1c50fa4 100644 > --- a/util/qemu-option.c > +++ b/util/qemu-option.c > @@ -179,6 +179,11 @@ void parse_option_size(const char *name, const char *value, > > if (value != NULL) { > sizef = strtod(value, &postfix); > + if (sizef < 0 || sizef > UINT64_MAX) { > + error_set(errp, QERR_INVALID_PARAMETER_VALUE, name, "a positive " > + "number and must not exceeds the maximum UINT64"); I think Markus would like to see these error macros not getting used anymore, so I think it should be dropped and the full string should be given here. I'll let him do the arguing, though. :-) If you keep the macro, I'd propose "a non-negative number below 2^64" (or actually give the decimal value of UINT64_MAX, using 'a non-negative number not exceeding "%" PRIu64, UINT64_MAX'). Remember that 0 is not positive, but still a valid choice. If you drop the macro, I'd propose error_setg(errp, "'%s' must be a non-negative number below 2^64", name) or, like it is now, error_setg(errp, "Parameter '%s' expects a non-negative number below 2^64", name). Max > + return; > + } > switch (*postfix) { > case 'T': > sizef *= 1024;