Message ID | 8736w4ppq6.fsf@tromey.com |
---|---|
State | New |
Headers | show |
Series | RFA: libiberty: avoid UBSAN complaint in cplus-dem.c | expand |
On Fri, Jul 27, 2018 at 10:12 AM, Tom Tromey <tom@tromey.com> wrote: > I built gdb with -fsanitize=undefined, and there was a complaint coming > from cplus-dem.c. remember_Btype can call memcpy with a NULL pointer, > which is undefined behavior according to the C standard. > > This patch fixes the problem for me. I tested this by rebuilding gdb > (with -fsanitize=undefined) and re-running the test suite. > > Ok? > > Tom > > 2018-07-27 Tom Tromey <tom@tromey.com> > > * cplus-dem.c (remember_Btype): Don't call memcpy with LEN==0. This is OK. Thanks. Ian
diff --git a/libiberty/cplus-dem.c b/libiberty/cplus-dem.c index 6d58bd899bf..4f29d54d089 100644 --- a/libiberty/cplus-dem.c +++ b/libiberty/cplus-dem.c @@ -4471,7 +4471,8 @@ remember_Btype (struct work_stuff *work, const char *start, char *tem; tem = XNEWVEC (char, len + 1); - memcpy (tem, start, len); + if (len > 0) + memcpy (tem, start, len); tem[len] = '\0'; work -> btypevec[index] = tem; }