[PATCH v2 2/6] trace: add CONFIG_BUILTIN_MODULE_RANGES option

From: Kris Van Hees <kris.van.hees@oracle.com>
To: linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org,
	linux-modules@vger.kernel.org,
	linux-trace-kernel@vger.kernel.org
Cc: Kris Van Hees <kris.van.hees@oracle.com>,
	Nick Alcock <nick.alcock@oracle.com>,
	Alan Maguire <alan.maguire@oracle.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Luis Chamberlain <mcgrof@kernel.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Jiri Olsa <olsajiri@gmail.com>,
	Elena Zannoni <elena.zannoni@oracle.com>
Subject: [PATCH v2 2/6] trace: add CONFIG_BUILTIN_MODULE_RANGES option
Date: Sat, 11 May 2024 18:40:31 -0400	[thread overview]
Message-ID: <20240511224035.27775-3-kris.van.hees@oracle.com> (raw)
In-Reply-To: <20240511224035.27775-1-kris.van.hees@oracle.com>

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@oracle.com>
Reviewed-by: Nick Alcock <nick.alcock@oracle.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
---
Changes since v1:
 - Renamed CONFIG_BUILTIN_RANGES to CONFIG_BUILTIN_MODULE_RANGES
 - Moved the config option to the tracers section
---
 kernel/trace/Kconfig | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 47345bf1d4a9f..839a56e971cc0 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -188,6 +188,23 @@ menuconfig FTRACE
 
 if FTRACE
 
+config BUILTIN_MODULE_RANGES
+	bool "Generate address range information for builtin modules"
+	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

