In commit 06aeaaeabf69da4, many ftrace-related config options are
consolidated. By accident, I guess, the choice about DYNAMIC_FTRACE
and DYNAMIC_FTRACE_WITH_REGS is no longer available explicitly but
determined by the sole availability on the architecture.
This makes it hard to introduce DYNAMIC_FTRACE_WITH_REGS if it depends
on new compiler features or other new properties of the toolchain
without breaking existing configurations.
This patch turns the def_bool into an actual choice. Should the toolchain
not meet the requirements for _WITH_REGS it can be turned off.
Signed-off-by: Torsten Duwe <d...@suse.de>
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -508,9 +508,15 @@ config DYNAMIC_FTRACE
otherwise has native performance as long as no tracing is active.
config DYNAMIC_FTRACE_WITH_REGS
- def_bool y
+ bool "Include register content tracking in dynamic ftrace facility"
+ default y
depends on DYNAMIC_FTRACE
depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
+ help
+ This architecture supports the inspection of register contents,
+ as passed between functions, at the dynamic ftrace points.
+ This is also a prerequisite for Kernel Live Patching (KLP).
+ When in doubt, say Y.
config FUNCTION_PROFILER
bool "Kernel function profiler"
