Re: [PATCH 2/6] module: add CONFIG_BUILTIN_RANGES option

From: Google
Date: Fri Dec 08 2023 - 17:59:26 EST


On Fri, 8 Dec 2023 00:07:48 -0500
Kris Van Hees <kris.van.hees@xxxxxxxxxx> wrote:

> The CONFIG_BUILTIN_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>
> ---
> kernel/module/Kconfig | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
> index 33a2e991f608..0798439b11ac 100644
> --- a/kernel/module/Kconfig
> +++ b/kernel/module/Kconfig
> @@ -389,4 +389,21 @@ config MODULES_TREE_LOOKUP
> def_bool y
> depends on PERF_EVENTS || TRACING || CFI_CLANG
>
> +config BUILTIN_RANGES

BUILTIN_MODULE_RANGES ?
BTW, even if CONFIG_MODULES=n, we can embed the kernel module code.
So should this visible if the CONFIG_MODULES=n ?

Thank you,

> + bool "Generate address range information for builtin modules"
> + depends on 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.
> +
> endif # MODULES
> --
> 2.42.0
>


--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>