On Fri, 21 Apr 2017 22:41:54 +0300 Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > On Wed, Apr 19, 2017 at 11:38 PM, Jérémy Lefaure > <jeremy.lefaure@xxxxxxxxxxxx> wrote: > > When building object-list.o, gcc 6 raises a warning on the sprintf call > > in fscache_objlist_show: > > > > CC fs/fscache/object-list.o > > fs/fscache/object-list.c: In function ‘fscache_objlist_show’: > > fs/fscache/object-list.c:265:19: warning: ‘sprintf’ may write a > > terminating nul past the end of the destination [-Wformat-overflow=] > > sprintf(_type, "%02u", cookie->def->type); > > ^~~~~~ > > fs/fscache/object-list.c:265:4: note: ‘sprintf’ output between 3 and 4 > > bytes into a destination of size 3 > > sprintf(_type, "%02u", cookie->def->type); > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > Moreover, the documentation says that we should have an hex value for > > special cookies (see Documentation/filesystems/caching/fscache.txt). > > > > Printing hexadecimal value for special cookies fixes the overflow > > warning and complies with the documentation. > > If this is used by some user space tool the safest fix is to print in > BCD and fix documentation. > Are you talking about the Binary Coded Decimal format ? I don't get why it would be better. If we change the printed format, it would break user space tool anyway, right ? > > Signed-off-by: Jérémy Lefaure <jeremy.lefaure@xxxxxxxxxxxx> > > --- > > fs/fscache/object-list.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c > > index 67f940892ef8..d51303124889 100644 > > --- a/fs/fscache/object-list.c > > +++ b/fs/fscache/object-list.c > > @@ -262,7 +262,7 @@ static int fscache_objlist_show(struct seq_file *m, void *v) > > type = "DT"; > > break; > > default: > > - sprintf(_type, "%02u", cookie->def->type); > > + sprintf(_type, "%02x", cookie->def->type); > > type = _type; > > break; > > } > > -- > > 2.12.2 > > > > > -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cachefs
