Date: Thu, 16 Jan 2020 17:39:51 +0000 From: Will Deacon <will@...nel.org> To: Sami Tolvanen <samitolvanen@...gle.com> Cc: Catalin Marinas <catalin.marinas@....com>, Steven Rostedt <rostedt@...dmis.org>, Masami Hiramatsu <mhiramat@...nel.org>, Ard Biesheuvel <ard.biesheuvel@...aro.org>, Mark Rutland <mark.rutland@....com>, Dave Martin <Dave.Martin@....com>, Kees Cook <keescook@...omium.org>, Laura Abbott <labbott@...hat.com>, Marc Zyngier <maz@...nel.org>, Nick Desaulniers <ndesaulniers@...gle.com>, Jann Horn <jannh@...gle.com>, Miguel Ojeda <miguel.ojeda.sandonis@...il.com>, Masahiro Yamada <yamada.masahiro@...ionext.com>, clang-built-linux@...glegroups.com, kernel-hardening@...ts.openwall.com, linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org Subject: Re: [PATCH v6 08/15] arm64: disable function graph tracing with SCS On Fri, Dec 06, 2019 at 02:13:44PM -0800, Sami Tolvanen wrote: > The graph tracer hooks returns by modifying frame records on the > (regular) stack, but with SCS the return address is taken from the > shadow stack, and the value in the frame record has no effect. As we > don't currently have a mechanism to determine the corresponding slot > on the shadow stack (and to pass this through the ftrace > infrastructure), for now let's disable the graph tracer when SCS is > enabled. > > Signed-off-by: Sami Tolvanen <samitolvanen@...gle.com> > Reviewed-by: Kees Cook <keescook@...omium.org> > Reviewed-by: Mark Rutland <mark.rutland@....com> > --- > arch/arm64/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index b1b4476ddb83..49e5f94ff4af 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -149,7 +149,7 @@ config ARM64 > select HAVE_FTRACE_MCOUNT_RECORD > select HAVE_FUNCTION_TRACER > select HAVE_FUNCTION_ERROR_INJECTION > - select HAVE_FUNCTION_GRAPH_TRACER > + select HAVE_FUNCTION_GRAPH_TRACER if !SHADOW_CALL_STACK > select HAVE_GCC_PLUGINS > select HAVE_HW_BREAKPOINT if PERF_EVENTS > select HAVE_IRQ_TIME_ACCOUNTING I think this is the wrong way around, as we support the graph tracer today and so I think SHADOW_CALL_STACK should depend on !GRAPH_TRACER and possibly even EXPERT until this is resolved. Will
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.