| Message ID | 20191031164637.48901-12-samitolvanen@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3,01/17] arm64: mm: avoid x18 in idmap_kpti_install_ng_mappings | expand |
On Thu, Oct 31, 2019 at 09:46:31AM -0700, samitolvanen@google.com wrote: > With CONFIG_FUNCTION_GRAPH_TRACER, function return addresses are > modified in ftrace_graph_caller and prepare_ftrace_return to redirect > control flow to ftrace_return_to_handler. This is incompatible with > SCS. IIRC, the argument was to disable these on a per-arch basis instead of doing it as a "depends on !SHADOW_CALL_STACK" in the top-level function graph tracer Kconfig? (I'm just thinking ahead to doing this again for other architectures, though, I guess, there is much more work than just that for, say, x86.) Regardless: Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > > Signed-off-by: Sami Tolvanen <samitolvanen@google.com> > --- > arch/arm64/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index e7b57a8a5531..42867174920f 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -148,7 +148,7 @@ 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 > -- > 2.24.0.rc0.303.g954a862665-goog >
On Thu, Oct 31, 2019 at 8:58 PM Kees Cook <keescook@chromium.org> wrote: > IIRC, the argument was to disable these on a per-arch basis instead of > doing it as a "depends on !SHADOW_CALL_STACK" in the top-level function > graph tracer Kconfig? Yes, that's correct. > (I'm just thinking ahead to doing this again for > other architectures, though, I guess, there is much more work than just > that for, say, x86.) We can always change this later if needed, and possibly figure out how to make function graph tracing and kretprobes work with SCS. Sami
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e7b57a8a5531..42867174920f 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -148,7 +148,7 @@ 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
With CONFIG_FUNCTION_GRAPH_TRACER, function return addresses are modified in ftrace_graph_caller and prepare_ftrace_return to redirect control flow to ftrace_return_to_handler. This is incompatible with SCS. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> --- arch/arm64/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)