On Wed, Aug 16, 2023 at 10:31:30PM -0700, Kees Cook wrote:
> On Fri, Aug 04, 2023 at 07:44:28PM +0000, Qing Zhao wrote:
> > This is the 2nd version of the patch, per our discussion based on the
> > review comments for the 1st version, the major changes in this version
>
> I've been using Coccinelle to find and annotate[1] structures (193 so
> far...), and I've encountered 2 cases of GCC internal errors. I'm working
> on a minimized test case, but just in case these details are immediately
> helpful, here's what I'm seeing:
Okay, I got it minimized:
$ cat poc.c
struct a {
unsigned long c;
char d[] __attribute__((__counted_by__(c)));
} *b;
void f(long);
void e(void) {
long g = __builtin_dynamic_object_size(b->d, 1);
f(g);
}
$ gcc -O2 -c -o /dev/null poc.c
poc.c: In function 'e':
poc.c:8:6: error: incorrect sharing of tree nodes
8 | void e(void) {
| ^
*b.0_1
_2 = &b.0_1->d;
during GIMPLE pass: objsz
poc.c:8:6: internal compiler error: verify_gimple failed
0xfe97fd verify_gimple_in_cfg(function*, bool, bool)
../../../../gcc/gcc/tree-cfg.cc:5646
0xe84894 execute_function_todo
../../../../gcc/gcc/passes.cc:2088
0xe84dee execute_todo
../../../../gcc/gcc/passes.cc:2142
--
Kees Cook
