From: Mathieu Desnoyers > Sent: 04 February 2019 19:15 > I notice this commit as a possible culprit of the illegal instructions my lttng > users are noticing on arm32 when using kprobes on a v4.19.13 Linux kernel > in a Yocto environment [1]. They were able to reproduce the issue with perf > as well. > > commit e46daee53bb50bde38805f1823a182979724c229 > Author: Kees Cook <keescook@xxxxxxxxxxxx> > Date: Tue Oct 30 22:12:56 2018 +0100 > > ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE > > I *think* the intent there was to do > > - memcpy(code, &optprobe_template_entry, > + memcpy(code, (unsigned long *)&optprobe_template_entry, > > But if you look at the commit, the "&" seems to have been stripped away, > which happens to change the behavior significantly. Which is why you shouldn't add casts to shut up compiler warnings .... David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
