Hi,

> On 9 Jun 2020, at 18:53, Peter Müller <peter.mueller(a)ipfire.org> wrote:
> 
> Quoted from https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings:
> 
>> # Wipe stack contents on syscall exit (reduces stale data lifetime in stack)
>> CONFIG_GCC_PLUGIN_STACKLEAK=y
> 
> Not sure what performance penalities this introduces in real life...

Well, should we not find out before we make this generally available for all users?

-Michael

> 
> Fixes: #12382
> 
> Cc: Arne Fitzenreiter <arne.fitzenreiter(a)ipfire.org>
> Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
> ---
> config/kernel/kernel.config.aarch64-ipfire        | 1 +
> config/kernel/kernel.config.armv5tel-ipfire-multi | 1 +
> config/kernel/kernel.config.i586-ipfire           | 1 +
> config/kernel/kernel.config.x86_64-ipfire         | 1 +
> 4 files changed, 4 insertions(+)
> 
> diff --git a/config/kernel/kernel.config.aarch64-ipfire b/config/kernel/kernel.config.aarch64-ipfire
> index e0f2f6df8..f4240e0ae 100644
> --- a/config/kernel/kernel.config.aarch64-ipfire
> +++ b/config/kernel/kernel.config.aarch64-ipfire
> @@ -256,6 +256,7 @@ CONFIG_HAVE_GCC_PLUGINS=y
> CONFIG_GCC_PLUGINS=y
> # CONFIG_GCC_PLUGIN_CYC_COMPLEXITY is not set
> CONFIG_GCC_PLUGIN_LATENT_ENTROPY=y
> +CONFIG_GCC_PLUGIN_STACKLEAK=y
> CONFIG_GCC_PLUGIN_STRUCTLEAK=y
> CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y
> # CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE is not set
> diff --git a/config/kernel/kernel.config.armv5tel-ipfire-multi b/config/kernel/kernel.config.armv5tel-ipfire-multi
> index 15183300f..2bcfbdbdd 100644
> --- a/config/kernel/kernel.config.armv5tel-ipfire-multi
> +++ b/config/kernel/kernel.config.armv5tel-ipfire-multi
> @@ -252,6 +252,7 @@ CONFIG_HAVE_GCC_PLUGINS=y
> CONFIG_GCC_PLUGINS=y
> # CONFIG_GCC_PLUGIN_CYC_COMPLEXITY is not set
> CONFIG_GCC_PLUGIN_LATENT_ENTROPY=y
> +CONFIG_GCC_PLUGIN_STACKLEAK=y
> CONFIG_GCC_PLUGIN_STRUCTLEAK=y
> CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y
> # CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE is not set
> diff --git a/config/kernel/kernel.config.i586-ipfire b/config/kernel/kernel.config.i586-ipfire
> index 578931497..a72cde41a 100644
> --- a/config/kernel/kernel.config.i586-ipfire
> +++ b/config/kernel/kernel.config.i586-ipfire
> @@ -283,6 +283,7 @@ CONFIG_HAVE_GCC_PLUGINS=y
> CONFIG_GCC_PLUGINS=y
> # CONFIG_GCC_PLUGIN_CYC_COMPLEXITY is not set
> CONFIG_GCC_PLUGIN_LATENT_ENTROPY=y
> +CONFIG_GCC_PLUGIN_STACKLEAK=y
> CONFIG_GCC_PLUGIN_STRUCTLEAK=y
> CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y
> # CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE is not set
> diff --git a/config/kernel/kernel.config.x86_64-ipfire b/config/kernel/kernel.config.x86_64-ipfire
> index 6a5fbbfe9..cd116d780 100644
> --- a/config/kernel/kernel.config.x86_64-ipfire
> +++ b/config/kernel/kernel.config.x86_64-ipfire
> @@ -293,6 +293,7 @@ CONFIG_HAVE_GCC_PLUGINS=y
> CONFIG_GCC_PLUGINS=y
> # CONFIG_GCC_PLUGIN_CYC_COMPLEXITY is not set
> CONFIG_GCC_PLUGIN_LATENT_ENTROPY=y
> +CONFIG_GCC_PLUGIN_STACKLEAK=y
> CONFIG_GCC_PLUGIN_STRUCTLEAK=y
> CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y
> # CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE is not set
> -- 
> 2.26.2