diff mbox series

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

Message ID 20240517042839.544650-3-kris.van.hees@oracle.com (mailing list archive)
State Superseded
Headers show
Series Generate address range data for built-in modules | expand

Commit Message

Kris Van Hees May 17, 2024, 4:28 a.m. UTC
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 v2:
 - Add explicit dependency on FTRACE for CONFIG_BUILTIN_MODULE_RANGES
---
 kernel/trace/Kconfig | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

Comments

Masahiro Yamada May 20, 2024, 9:29 a.m. UTC | #1
On Fri, May 17, 2024 at 1:30 PM Kris Van Hees <kris.van.hees@oracle.com> wrote:
>
> 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 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


This 'depends on' is redundant because this config is
already located between 'if FTRACE' and 'endif'.



I believe 2/6 thru 5/6 should be squashed into one commit.
Adding only the config option does not make much sense.




> +       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
>
Masahiro Yamada May 20, 2024, 9:38 a.m. UTC | #2
On Fri, May 17, 2024 at 1:30 PM Kris Van Hees <kris.van.hees@oracle.com> wrote:
>
> 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 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



I still got this warning.


WARNING: unmet direct dependencies detected for VMLINUX_MAP
  Depends on [n]: EXPERT [=n]
  Selected by [y]:
  - BUILTIN_MODULE_RANGES [=y] && FTRACE [=y]





I recommend changing 'select VMLINUX_MAP'
to 'depends on VMLINUX_MAP'.



BTW, do you need to put this inside 'if FTRACE'?

FTRACE is not required to generate the ranges file.
diff mbox series

Patch

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