[PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering

[Steven Rostedt]

Sorry to be absent from this thread so far, I just got back from my
travels and I'm now catching up on email.


On Wed, 2011-05-11 at 22:02 -0500, Will Drewry wrote:

> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 377a7a5..22e1668 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1664,6 +1664,16 @@ config SECCOMP
>  	  and the task is only allowed to execute a few safe syscalls
>  	  defined by each seccomp mode.
>  
> +config SECCOMP_FILTER
> +	bool "Enable seccomp-based system call filtering"
> +	depends on SECCOMP && EXPERIMENTAL
> +	help
> +	  Per-process, inherited system call filtering using shared code
> +	  across seccomp and ftrace_syscalls.  If CONFIG_FTRACE_SYSCALLS
> +	  is not available, enhanced filters will not be available.
> +
> +	  See Documentation/prctl/seccomp_filter.txt for more detail.
> +
>  config CC_STACKPROTECTOR
>  	bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
>  	depends on EXPERIMENTAL
> diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
> index eccdefe..7641ee9 100644
> --- a/arch/microblaze/Kconfig
> +++ b/arch/microblaze/Kconfig
> @@ -129,6 +129,16 @@ config SECCOMP
>  
>  	  If unsure, say Y. Only embedded should say N here.
>  
> +config SECCOMP_FILTER
> +	bool "Enable seccomp-based system call filtering"
> +	depends on SECCOMP && EXPERIMENTAL
> +	help
> +	  Per-process, inherited system call filtering using shared code
> +	  across seccomp and ftrace_syscalls.  If CONFIG_FTRACE_SYSCALLS
> +	  is not available, enhanced filters will not be available.
> +
> +	  See Documentation/prctl/seccomp_filter.txt for more detail.
> +
>  endmenu
>  
>  menu "Advanced setup"
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index 8e256cc..fe4cbda 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -2245,6 +2245,16 @@ config SECCOMP
>  
>  	  If unsure, say Y. Only embedded should say N here.
>  
> +config SECCOMP_FILTER
> +	bool "Enable seccomp-based system call filtering"
> +	depends on SECCOMP && EXPERIMENTAL
> +	help
> +	  Per-process, inherited system call filtering using shared code
> +	  across seccomp and ftrace_syscalls.  If CONFIG_FTRACE_SYSCALLS
> +	  is not available, enhanced filters will not be available.
> +
> +	  See Documentation/prctl/seccomp_filter.txt for more detail.
> +
>  config USE_OF
>  	bool "Flattened Device Tree support"
>  	select OF
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 8f4d50b..83499e4 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -605,6 +605,16 @@ config SECCOMP
>  
>  	  If unsure, say Y. Only embedded should say N here.
>  
> +config SECCOMP_FILTER
> +	bool "Enable seccomp-based system call filtering"
> +	depends on SECCOMP && EXPERIMENTAL
> +	help
> +	  Per-process, inherited system call filtering using shared code
> +	  across seccomp and ftrace_syscalls.  If CONFIG_FTRACE_SYSCALLS
> +	  is not available, enhanced filters will not be available.
> +
> +	  See Documentation/prctl/seccomp_filter.txt for more detail.
> +
>  endmenu
>  
>  config ISA_DMA_API
> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
> index 2508a6f..2777515 100644
> --- a/arch/s390/Kconfig
> +++ b/arch/s390/Kconfig
> @@ -614,6 +614,16 @@ config SECCOMP
>  
>  	  If unsure, say Y.
>  
> +config SECCOMP_FILTER
> +	bool "Enable seccomp-based system call filtering"
> +	depends on SECCOMP && EXPERIMENTAL
> +	help
> +	  Per-process, inherited system call filtering using shared code
> +	  across seccomp and ftrace_syscalls.  If CONFIG_FTRACE_SYSCALLS
> +	  is not available, enhanced filters will not be available.
> +
> +	  See Documentation/prctl/seccomp_filter.txt for more detail.
> +
>  endmenu
>  
>  menu "Power Management"
> diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
> index 4b89da2..00c1521 100644
> --- a/arch/sh/Kconfig
> +++ b/arch/sh/Kconfig
> @@ -676,6 +676,16 @@ config SECCOMP
>  
>  	  If unsure, say N.
>  
> +config SECCOMP_FILTER
> +	bool "Enable seccomp-based system call filtering"
> +	depends on SECCOMP && EXPERIMENTAL
> +	help
> +	  Per-process, inherited system call filtering using shared code
> +	  across seccomp and ftrace_syscalls.  If CONFIG_FTRACE_SYSCALLS
> +	  is not available, enhanced filters will not be available.
> +
> +	  See Documentation/prctl/seccomp_filter.txt for more detail.
> +
>  config SMP
>  	bool "Symmetric multi-processing support"
>  	depends on SYS_SUPPORTS_SMP
> diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
> index e560d10..5b42255 100644
> --- a/arch/sparc/Kconfig
> +++ b/arch/sparc/Kconfig
> @@ -270,6 +270,16 @@ config SECCOMP
>  
>  	  If unsure, say Y. Only embedded should say N here.
>  
> +config SECCOMP_FILTER
> +	bool "Enable seccomp-based system call filtering"
> +	depends on SECCOMP && EXPERIMENTAL
> +	help
> +	  Per-process, inherited system call filtering using shared code
> +	  across seccomp and ftrace_syscalls.  If CONFIG_FTRACE_SYSCALLS
> +	  is not available, enhanced filters will not be available.
> +
> +	  See Documentation/prctl/seccomp_filter.txt for more detail.
> +
>  config HOTPLUG_CPU
>  	bool "Support for hot-pluggable CPUs"
>  	depends on SPARC64 && SMP
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index cc6c53a..d6d44d9 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -1485,6 +1485,16 @@ config SECCOMP
>  
>  	  If unsure, say Y. Only embedded should say N here.
>  
> +config SECCOMP_FILTER
> +	bool "Enable seccomp-based system call filtering"
> +	depends on SECCOMP && EXPERIMENTAL
> +	help
> +	  Per-process, inherited system call filtering using shared code
> +	  across seccomp and ftrace_syscalls.  If CONFIG_FTRACE_SYSCALLS
> +	  is not available, enhanced filters will not be available.
> +
> +	  See Documentation/prctl/seccomp_filter.txt for more detail.
> +
>  config CC_STACKPROTECTOR
>  	bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
>  	---help---

You just cut-and-pasted 8 copies of a config selection. The proper way
to do that is to add the Kconfig selection in a core kernel Kconfig,
have it depend on "HAVE_SECCOMP_FILTER" and then in each of these
configs, simply add in the arch Kconfig:

config <ARCH>
	[...]
	select HAVE_SECCOMP_FILTER


That way you don't need to duplicate the config option all over the
place.

-- Steve