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@chromium.org Date: Tue Oct 30 22:12:56 2018 +0100
ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCEI *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)