On Thu, Feb 23, 2017 at 09:41:12AM +0100, Michal Privoznik wrote:
On 02/22/2017 06:52 PM, Daniel P. Berrange wrote:
GCC 7 gets upset by
if (!tmp && (size * count))
warning
util/viralloc.c: In function 'virReallocN': util/viralloc.c:246:23: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context] if (!tmp && (size * count)) { ~~~~~~^~~~~~~~
Keep it happy by adding != 0 to the right hand expression so it realizes we really are wanting to treat the result of the arithmetic expression as a boolean
Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- src/util/viralloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/util/viralloc.c b/src/util/viralloc.c index 812aa5b..81f99d9 100644 --- a/src/util/viralloc.c +++ b/src/util/viralloc.c @@ -243,7 +243,7 @@ int virReallocN(void *ptrptr, return -1; } tmp = realloc(*(void**)ptrptr, size * count); - if (!tmp && (size * count)) { + if (!tmp && ((size * count) != 0)) { if (report) virReportOOMErrorFull(domcode, filename, funcname, linenr); return -1;
This is just stupid. I mean the warning, not your fix.
It is a warning that is certainly going to trigger a non-negligible number of false positives across various codebases, but I don't think it is stupid. The pattern it is looking for here with mixed integer and boolean operators has been a repeated source of bugs in software and a number of them have resulted in CVEs before when they've been mis-handling untrusted input validation or breaking crypto algorithms, etc. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|