diff options
| -rw-r--r-- | arch/arm/Kconfig | 14 | ||||
| -rw-r--r-- | arch/arm/include/asm/seccomp.h | 11 | ||||
| -rw-r--r-- | arch/arm/include/asm/thread_info.h | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 15 |
4 files changed, 40 insertions, 2 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 88c97bc..1273ee8 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1463,6 +1463,20 @@ 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 CC_STACKPROTECTOR bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" help diff --git a/arch/arm/include/asm/seccomp.h b/arch/arm/include/asm/seccomp.h new file mode 100644 index 0000000..52b156b --- /dev/null +++ b/arch/arm/include/asm/seccomp.h @@ -0,0 +1,11 @@ +#ifndef _ASM_ARM_SECCOMP_H +#define _ASM_ARM_SECCOMP_H + +#include <linux/unistd.h> + +#define __NR_seccomp_read __NR_read +#define __NR_seccomp_write __NR_write +#define __NR_seccomp_exit __NR_exit +#define __NR_seccomp_sigreturn __NR_rt_sigreturn + +#endif /* _ASM_ARM_SECCOMP_H */ diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index 763e29f..7b5cc8d 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -144,6 +144,7 @@ extern void vfp_flush_hwstate(struct thread_info *); #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ #define TIF_FREEZE 19 #define TIF_RESTORE_SIGMASK 20 +#define TIF_SECCOMP 21 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) @@ -153,6 +154,7 @@ extern void vfp_flush_hwstate(struct thread_info *); #define _TIF_USING_IWMMXT (1 << TIF_USING_IWMMXT) #define _TIF_FREEZE (1 << TIF_FREEZE) #define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK) +#define _TIF_SECCOMP (1 << TIF_SECCOMP) /* * Change these and you break ASM code in entry-common.S diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 7885722b..0385a82 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -295,7 +295,6 @@ ENTRY(vector_swi) get_thread_info tsk adr tbl, sys_call_table @ load syscall table pointer - ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing #if defined(CONFIG_OABI_COMPAT) /* @@ -312,8 +311,20 @@ ENTRY(vector_swi) eor scno, scno, #__NR_SYSCALL_BASE @ check OS number #endif + ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing stmdb sp!, {r4, r5} @ push fifth and sixth args - tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls? + +#ifdef CONFIG_SECCOMP + tst r10, #_TIF_SECCOMP + beq 1f + mov r0, scno + bl __secure_computing + add r0, sp, #S_R0 + S_OFF @ pointer to regs + ldmia r0, {r0 - r3} @ have to reload r0 - r3 +1: +#endif + + tst r10, #_TIF_SYSCALL_TRACE @ are we tracing syscalls? bne __sys_trace cmp scno, #NR_syscalls @ check upper syscall limit |
