On Fri, 5 Feb 2016 15:05:17 +0100 Petr Mladek <pmladek@xxxxxxxx> wrote: > On Mon 2016-01-25 16:29:54, Torsten Duwe wrote: > > diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c > > index ef8b916..29b7014 100644 > > --- a/arch/powerpc/kernel/ftrace.c > > +++ b/arch/powerpc/kernel/ftrace.c > > @@ -28,6 +28,11 @@ > > > > > > #ifdef CONFIG_DYNAMIC_FTRACE > > +#if defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && defined(CONFIG_PPC64) && \ > > + !defined(CC_USING_MPROFILE_KERNEL) > > +#error "DYNAMIC_FTRACE_WITH_REGS requires working -mprofile-kernel" > > +#endif > > CONFIG_DYNAMIC_FTRACE_WITH_REGS is automatically enabled when > both CONFIG_DYNAMIC_FTRACE and HAVE_DYNAMIC_FTRACE_WITH_REGS > are enabled. > > Therefore it is not possible to build kernel with broken gcc > and DYNAMIC_FTRACE. > > IMHO, we need to allow to explicitely disable DYNAMIC_FTRACE_WITH_REGS > if the compiler is broken to get around this build error. > > We either need to define DYNAMIC_FTRACE_WITH_REGS as a proper > bool with description, help text, ... Or we need a way to > explicitely disable HAVE_DYNAMIC_FTRACE_WITH_REGS. Or something > like this. > You mean something like this? (not tested) -- Steve diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index e45db6b0d878..19377bacebfc 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -470,6 +470,19 @@ config DYNAMIC_FTRACE_WITH_REGS def_bool y depends on DYNAMIC_FTRACE depends on HAVE_DYNAMIC_FTRACE_WITH_REGS + depends on !DISABLE_DYNAMIC_FTRACE_WITH_REGS + +config DISABLE_DYNAMIC_FTRACE_WITH_REGS + bool "Force build to not have function tracer pass in registers" + depends on DYNAMIC_FTRACE + depends on HAVE_DYNAMIC_FTRACE_WITH_REGS + help + If the architecture supports passing in registers to the function + tracer, then that is automatically enabled. But there may be some + compilers out there that are broken and cause this to fail. + This option makes the build think that the architecture does not + support the register passing and allows the build to work even + with compilers that do not support the feature.g config FUNCTION_PROFILER bool "Kernel function profiler" -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
