On Tue, Apr 3, 2018 at 12:41 PM, Steven Rostedt <rost...@goodmis.org> wrote: > Both trace_debug is set and kptr_restrict is set to zero in the same > code that produces the above banner. This will allow trace_printk() to > not be affected by security code, as trace_printk() should never be run > on a machine that needs security of this kind.
While I think it'd be nice to have a boot-time knob for this (a debate that was unsuccessful in earlier threads), I remain skeptical of having a _runtime_ knob for this, as then it becomes a target (and yes, there are plenty of targets, but why add another). If this was __ro_after_init, maybe that'd be nicer. CONFIG_TRACING=y is used everywhere, so this is really just the whole knob debate over again. Instead, I've been following Linus's distillation of %p usage in the kernel: http://lkml.kernel.org/r/ca+55afwqed_d40g4mucssvrzzrfpujt74vc6pppb675hynx...@mail.gmail.com -Kees -- Kees Cook Pixel Security
