@@ -749,6 +749,12 @@ KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
$(call cc-option,-fno-var-tracking)
endif
+ifdef CONFIG_NO_AUTO_INLINE
+KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions) \
+ $(call cc-option, -fno-inline-small-functions) \
+ $(call cc-option, -fno-inline-functions-called-once)
+endif
+
ifdef CONFIG_FUNCTION_TRACER
ifdef CONFIG_FTRACE_MCOUNT_RECORD
# gcc 5 supports generating the mcount tables directly
@@ -211,6 +211,23 @@ config GDB_SCRIPTS
instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
for further details.
+config NO_AUTO_INLINE
+ bool "Disable compiler auto-inline optimizations"
+ help
+ This will prevent the compiler from optimizing the kernel by
+ auto-inlining functions not marked with the inline keyword.
+ With this option, only functions explicitly marked with
+ "inline" will be inlined. This will allow the function tracer
+ to trace more functions because it only traces functions that
+ the compiler has not inlined.
+
+ Enabling this function can help debugging a kernel if using
+ the function tracer. But it can also change how the kernel
+ works, because inlining functions may change the timing,
+ which could make it difficult while debugging race conditions.
+
+ If unsure, select N.
+
config ENABLE_MUST_CHECK
bool "Enable __must_check logic"
default y