On Fri, Apr 16, 2021 at 07:18:48PM +0200, Peter Zijlstra wrote:

On Fri, Apr 16, 2021 at 07:10:17PM +0200, Miguel Ojeda wrote:

quoted

Of course, UB is only a subset of errors, but it is a major one, and
particularly critical for privileged code.

I've seen relatively few UBSAN warnings that weren't due to UBSAN being
broken.

Lucky you.

84c34df158cf215b0cd1475ab3b8e6f212f81f23

(i'd argue this is C being broken; promoting only as far as int, when
assigning to an unsigned long is Bad, but until/unless either GCC fixes
that or the language committee realises that being stuck in the 1970s
is Bad, people are going to keep making this kind of mistake)