[PATCH v2 seccomp 1/6] seccomp: Move config option SECCOMP to arch/Kconfig

From: YiFei Zhu
Date: Thu Sep 24 2020 - 08:45:24 EST

From: YiFei Zhu <yifeifz2@xxxxxxxxxxxx>

In order to make adding configurable features into seccomp
easier, it's better to have the options at one single location,
considering easpecially that the bulk of seccomp code is
arch-independent. An quick look also show that many SECCOMP
descriptions are outdated; they talk about /proc rather than
prctl.

As a result of moving the config option and keeping it default
on, architectures arm, arm64, csky, riscv, sh, and xtensa
did not have SECCOMP on by default prior to this and SECCOMP will
be default in this change.

Architectures microblaze, mips, powerpc, s390, sh, and sparc
have an outdated depend on PROC_FS and this dependency is removed
in this change.

Suggested-by: Jann Horn <jannh@xxxxxxxxxx>
Link: https://lore.kernel.org/lkml/CAG48ez1YWz9cnp08UZgeieYRhHdqh-ch7aNwc4JRBnGyrmgfMg@xxxxxxxxxxxxxx/
Signed-off-by: YiFei Zhu <yifeifz2@xxxxxxxxxxxx>
---
arch/Kconfig | 21 +++++++++++++++++++++
arch/arm/Kconfig | 15 +--------------
arch/arm64/Kconfig | 13 -------------
arch/csky/Kconfig | 13 -------------
arch/microblaze/Kconfig | 18 +-----------------
arch/mips/Kconfig | 17 -----------------
arch/parisc/Kconfig | 16 ----------------
arch/powerpc/Kconfig | 17 -----------------
arch/riscv/Kconfig | 13 -------------
arch/s390/Kconfig | 17 -----------------
arch/sh/Kconfig | 16 ----------------
arch/sparc/Kconfig | 18 +-----------------
arch/um/Kconfig | 16 ----------------
arch/x86/Kconfig | 16 ----------------
arch/xtensa/Kconfig | 14 --------------
15 files changed, 24 insertions(+), 216 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index af14a567b493..6dfc5673215d 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -444,8 +444,12 @@ config ARCH_WANT_OLD_COMPAT_IPC
select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
bool

+config HAVE_ARCH_SECCOMP
+ bool
+
config HAVE_ARCH_SECCOMP_FILTER
bool
+ select HAVE_ARCH_SECCOMP
help
An arch should select this symbol if it provides all of these things:
- syscall_get_arch()
@@ -458,6 +462,23 @@ config HAVE_ARCH_SECCOMP_FILTER
results in the system call being skipped immediately.
- seccomp syscall wired up

+config SECCOMP
+ def_bool y
+ depends on HAVE_ARCH_SECCOMP
+ prompt "Enable seccomp to safely compute untrusted bytecode"
+ help
+ This kernel feature is useful for number crunching applications
+ that may need to compute untrusted bytecode during their
+ execution. By using pipes or other transports made available to
+ the process as file descriptors supporting the read/write
+ syscalls, it's possible to isolate those applications in
+ their own address space using seccomp. Once seccomp is
+ enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
+ and the task is only allowed to execute a few safe syscalls
+ defined by each seccomp mode.
+
+ If unsure, say Y. Only embedded should say N here.
+
config SECCOMP_FILTER
def_bool y
depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e00d94b16658..e26c19a16284 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -67,6 +67,7 @@ config ARM
select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
select HAVE_ARCH_MMAP_RND_BITS if MMU
+ select HAVE_ARCH_SECCOMP
select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
select HAVE_ARCH_THREAD_STRUCT_WHITELIST
select HAVE_ARCH_TRACEHOOK
@@ -1617,20 +1618,6 @@ config UACCESS_WITH_MEMCPY
However, if the CPU data cache is using a write-allocate mode,
this option is unlikely to provide any performance gain.

-config SECCOMP
- bool
- prompt "Enable seccomp to safely compute untrusted bytecode"
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
config PARAVIRT
bool "Enable paravirtualization code"
help
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6d232837cbee..98c4e34cbec1 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1033,19 +1033,6 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK
config CC_HAVE_SHADOW_CALL_STACK
def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)

-config SECCOMP
- bool "Enable seccomp to safely compute untrusted bytecode"
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
config PARAVIRT
bool "Enable paravirtualization code"
help
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 3d5afb5f5685..7f424c85772c 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -309,16 +309,3 @@ endmenu
source "arch/csky/Kconfig.platforms"

source "kernel/Kconfig.hz"
-
-config SECCOMP
- bool "Enable seccomp to safely compute untrusted bytecode"
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index d262ac0c8714..37bd6a5f38fb 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -26,6 +26,7 @@ config MICROBLAZE
select GENERIC_SCHED_CLOCK
select HAVE_ARCH_HASH
select HAVE_ARCH_KGDB
+ select HAVE_ARCH_SECCOMP
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
@@ -120,23 +121,6 @@ config CMDLINE_FORCE
Set this to have arguments from the default kernel command string
override those passed by the boot loader.

-config SECCOMP
- bool "Enable seccomp to safely compute untrusted bytecode"
- depends on PROC_FS
- default y
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via /proc/<pid>/seccomp, it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
- If unsure, say Y. Only embedded should say N here.
-
endmenu

menu "Kernel features"
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index c95fa3a2484c..5f88a8fc11fc 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -3004,23 +3004,6 @@ config PHYSICAL_START
specified in the "crashkernel=YM@XM" command line boot parameter
passed to the panic-ed kernel).

-config SECCOMP
- bool "Enable seccomp to safely compute untrusted bytecode"
- depends on PROC_FS
- default y
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via /proc/<pid>/seccomp, it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
- If unsure, say Y. Only embedded should say N here.
-
config MIPS_O32_FP64_SUPPORT
bool "Support for O32 binaries using 64-bit FP" if !CPU_MIPSR6
depends on 32BIT || MIPS32_O32
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 3b0f53dd70bc..cd4afe1e7a6c 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -378,19 +378,3 @@ endmenu


source "drivers/parisc/Kconfig"
-
-config SECCOMP
- def_bool y
- prompt "Enable seccomp to safely compute untrusted bytecode"
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
- If unsure, say Y. Only embedded should say N here.
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1f48bbfb3ce9..136fe860caef 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -934,23 +934,6 @@ config ARCH_WANTS_FREEZER_CONTROL

source "kernel/power/Kconfig"

-config SECCOMP
- bool "Enable seccomp to safely compute untrusted bytecode"
- depends on PROC_FS
- default y
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via /proc/<pid>/seccomp, it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
- If unsure, say Y. Only embedded should say N here.
-
config PPC_MEM_KEYS
prompt "PowerPC Memory Protection Keys"
def_bool y
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index df18372861d8..c456b558fab9 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -333,19 +333,6 @@ menu "Kernel features"

source "kernel/Kconfig.hz"

-config SECCOMP
- bool "Enable seccomp to safely compute untrusted bytecode"
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
config RISCV_SBI_V01
bool "SBI v0.1 support"
default y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 3d86e12e8e3c..7f7b40ec699e 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -791,23 +791,6 @@ config CRASH_DUMP

endmenu

-config SECCOMP
- def_bool y
- prompt "Enable seccomp to safely compute untrusted bytecode"
- depends on PROC_FS
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via /proc/<pid>/seccomp, it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
- If unsure, say Y.
-
config CCW
def_bool y

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index d20927128fce..18278152c91c 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -600,22 +600,6 @@ config PHYSICAL_START
where the fail safe kernel needs to run at a different address
than the panic-ed kernel.

-config SECCOMP
- bool "Enable seccomp to safely compute untrusted bytecode"
- depends on PROC_FS
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via prctl, it cannot be disabled and the task is only
- allowed to execute a few safe syscalls defined by each seccomp
- mode.
-
- If unsure, say N.
-
config SMP
bool "Symmetric multi-processing support"
depends on SYS_SUPPORTS_SMP
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index efeff2c896a5..d62ce83cf009 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -23,6 +23,7 @@ config SPARC
select HAVE_OPROFILE
select HAVE_ARCH_KGDB if !SMP || SPARC64
select HAVE_ARCH_TRACEHOOK
+ select HAVE_ARCH_SECCOMP if SPARC64
select HAVE_EXIT_THREAD
select HAVE_PCI
select SYSCTL_EXCEPTION_TRACE
@@ -226,23 +227,6 @@ config EARLYFB
help
Say Y here to enable a faster early framebuffer boot console.

-config SECCOMP
- bool "Enable seccomp to safely compute untrusted bytecode"
- depends on SPARC64 && PROC_FS
- default y
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via /proc/<pid>/seccomp, it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
- If unsure, say Y. Only embedded should say N here.
-
config HOTPLUG_CPU
bool "Support for hot-pluggable CPUs"
depends on SPARC64 && SMP
diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index eb51fec75948..d49f471b02e3 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -173,22 +173,6 @@ config PGTABLE_LEVELS
default 3 if 3_LEVEL_PGTABLES
default 2

-config SECCOMP
- def_bool y
- prompt "Enable seccomp to safely compute untrusted bytecode"
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
- If unsure, say Y.
-
config UML_TIME_TRAVEL_SUPPORT
bool
prompt "Support time-travel mode (e.g. for test execution)"
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7101ac64bb20..1ab22869a765 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1968,22 +1968,6 @@ config EFI_MIXED

If unsure, say N.

-config SECCOMP
- def_bool y
- prompt "Enable seccomp to safely compute untrusted bytecode"
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
- If unsure, say Y. Only embedded should say N here.
-
source "kernel/Kconfig.hz"

config KEXEC
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index e997e0119c02..d8a29dc5a284 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -217,20 +217,6 @@ config HOTPLUG_CPU

Say N if you want to disable CPU hotplug.

-config SECCOMP
- bool
- prompt "Enable seccomp to safely compute untrusted bytecode"
- help
- This kernel feature is useful for number crunching applications
- that may need to compute untrusted bytecode during their
- execution. By using pipes or other transports made available to
- the process as file descriptors supporting the read/write
- syscalls, it's possible to isolate those applications in
- their own address space using seccomp. Once seccomp is
- enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
- and the task is only allowed to execute a few safe syscalls
- defined by each seccomp mode.
-
config FAST_SYSCALL_XTENSA
bool "Enable fast atomic syscalls"
default n
--
2.28.0