[PATCH v3 2/6] trace: add CONFIG_BUILTIN_MODULE_RANGES option

[Kris Van Hees]

The CONFIG_BUILTIN_MODULE_RANGES option controls whether offset range data
is generated for kernel modules that are built into the kernel image.

Signed-off-by: Kris Van Hees <kris.van.hees@xxxxxxxxxx>
Reviewed-by: Nick Alcock <nick.alcock@xxxxxxxxxx>
Reviewed-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
---
Changes since v2:
 - Add explicit dependency on FTRACE for CONFIG_BUILTIN_MODULE_RANGES
---
 kernel/trace/Kconfig | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 47345bf1d4a9f..d0c82b4b3a61e 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -188,6 +188,24 @@ menuconfig FTRACE
 
 if FTRACE
 
+config BUILTIN_MODULE_RANGES
+	bool "Generate address range information for builtin modules"
+	depends on FTRACE
+	select VMLINUX_MAP
+	help
+	  When modules are built into the kernel, there will be no module name
+	  associated with its symbols in /proc/kallsyms.  Tracers may want to
+	  identify symbols by module name and symbol name regardless of whether
+	  the module is configured as loadable or not.
+
+	  This option generates modules.builtin.ranges in the build tree with
+	  offset ranges (per ELF section) for the module(s) they belong to.
+	  It also records an anchor symbol to determine the load address of the
+	  section.
+
+	  It is fully compatible with CONFIG_RANDOMIZE_BASE and similar late-
+	  address-modification options.
+
 config BOOTTIME_TRACING
 	bool "Boot-time Tracing support"
 	depends on TRACING
-- 
2.43.0