Re: [PATCH] RAS/AMD/FMPM: Fix build when debugfs is not enabled

[Yazen Ghannam <yazen.ghannam@amd.com>]

On 3/25/24 14:37, Borislav Petkov wrote:
> From: "Borislav Petkov (AMD)" <bp@alien8.de>
> 
> Have the driver depend on DEBUG_FS as it is useless without it.

This isn't true which is why the module doesn't fail to load if debugfs
is not available.

> 
> Fixes: 6f15e617cc99 ("RAS: Introduce a FRU memory poison manager")
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218640
> Reported-by: anthony s.k. <akira.2020@protonmail.com>
> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
> Cc: Yazen Ghannam <yazen.ghannam@amd.com>
> ---
>   drivers/ras/Kconfig | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/ras/Kconfig b/drivers/ras/Kconfig
> index fc4f4bb94a4c..41697e326fa6 100644
> --- a/drivers/ras/Kconfig
> +++ b/drivers/ras/Kconfig
> @@ -37,7 +37,7 @@ source "drivers/ras/amd/atl/Kconfig"
>   config RAS_FMPM
>   	tristate "FRU Memory Poison Manager"
>   	default m
> -	depends on AMD_ATL && ACPI_APEI
> +	depends on AMD_ATL && ACPI_APEI && DEBUG_FS

This was my first thought too. However, besides not true as stated
above, this also leaves the issue open for others to hit.

I think the fix below (not tested) would be more appropriate.

What do you think?

Thanks,
Yazen

diff --git a/drivers/ras/debugfs.h b/drivers/ras/debugfs.h
index 4749ccdeeba1..ab95831e7710 100644
--- a/drivers/ras/debugfs.h
+++ b/drivers/ras/debugfs.h
@@ -4,6 +4,10 @@

  #include <linux/debugfs.h>

+#if IS_ENABLED(DEBUG_FS)
  struct dentry *ras_get_debugfs_root(void);
+#else
+static inline struct dentry *ras_get_debugfs_root(void) { return NULL; }
+#endif /* DEBUG_FS */

  #endif /* __RAS_DEBUGFS_H__ */