Re: [PATCH 1/3] ubsan: Add trap instrumentation option
From: Kees Cook
Date: Thu Nov 21 2019 - 12:57:41 EST
On Thu, Nov 21, 2019 at 03:52:52PM +0300, Andrey Ryabinin wrote:
> On 11/20/19 4:06 AM, Kees Cook wrote:
> > +config UBSAN_TRAP
> > + bool "On Sanitizer warnings, stop the offending kernel thread"
BTW, is there a way (with either GCC or Clang implementations) to
override the trap handler? If I could get the instrumentation to call
an arbitrarily named function, we could build a better version of this
that actually continued without the large increase in image size.
For example, instead of __builtin_trap(), call __ubsan_warning(), which
could be defined as something like:
static __always_inline void __ubsan_warning(void)
{
WARN_ON_ONCE(1);
}
That would make the warning survivable without the overhead of all the
debugging structures, etc.
--
Kees Cook