diff options
Diffstat (limited to 'arch/ppc')
| -rw-r--r-- | arch/ppc/Kconfig | 17 | ||||
| -rw-r--r-- | arch/ppc/kernel/entry.S | 16 | ||||
| -rw-r--r-- | arch/ppc/kernel/ppc_ksyms.c | 2 | ||||
| -rw-r--r-- | arch/ppc/kernel/ptrace.c | 40 |
4 files changed, 62 insertions, 13 deletions
diff --git a/arch/ppc/Kconfig b/arch/ppc/Kconfig index 6e6377a69d5..54ce6da2264 100644 --- a/arch/ppc/Kconfig +++ b/arch/ppc/Kconfig @@ -1083,6 +1083,23 @@ source "drivers/zorro/Kconfig" 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. + endmenu config ISA_DMA_API diff --git a/arch/ppc/kernel/entry.S b/arch/ppc/kernel/entry.S index 5f075dbc4ee..661523707e8 100644 --- a/arch/ppc/kernel/entry.S +++ b/arch/ppc/kernel/entry.S @@ -202,7 +202,7 @@ _GLOBAL(DoSyscall) rlwinm r11,r11,0,~_TIFL_FORCE_NOERROR stw r11,TI_LOCAL_FLAGS(r10) lwz r11,TI_FLAGS(r10) - andi. r11,r11,_TIF_SYSCALL_TRACE + andi. r11,r11,_TIF_SYSCALL_T_OR_A bne- syscall_dotrace syscall_dotrace_cont: cmplwi 0,r0,NR_syscalls @@ -237,7 +237,7 @@ ret_from_syscall: SYNC MTMSRD(r10) lwz r9,TI_FLAGS(r12) - andi. r0,r9,(_TIF_SYSCALL_TRACE|_TIF_SIGPENDING|_TIF_NEED_RESCHED) + andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SIGPENDING|_TIF_NEED_RESCHED) bne- syscall_exit_work syscall_exit_cont: #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) @@ -277,7 +277,8 @@ syscall_dotrace: SAVE_NVGPRS(r1) li r0,0xc00 stw r0,TRAP(r1) - bl do_syscall_trace + addi r3,r1,STACK_FRAME_OVERHEAD + bl do_syscall_trace_enter lwz r0,GPR0(r1) /* Restore original registers */ lwz r3,GPR3(r1) lwz r4,GPR4(r1) @@ -291,7 +292,7 @@ syscall_dotrace: syscall_exit_work: stw r6,RESULT(r1) /* Save result */ stw r3,GPR3(r1) /* Update return value */ - andi. r0,r9,_TIF_SYSCALL_TRACE + andi. r0,r9,_TIF_SYSCALL_T_OR_A beq 5f ori r10,r10,MSR_EE SYNC @@ -303,7 +304,8 @@ syscall_exit_work: li r4,0xc00 stw r4,TRAP(r1) 4: - bl do_syscall_trace + addi r3,r1,STACK_FRAME_OVERHEAD + bl do_syscall_trace_leave REST_NVGPRS(r1) 2: lwz r3,GPR3(r1) @@ -627,8 +629,8 @@ sigreturn_exit: subi r1,r3,STACK_FRAME_OVERHEAD rlwinm r12,r1,0,0,18 /* current_thread_info() */ lwz r9,TI_FLAGS(r12) - andi. r0,r9,_TIF_SYSCALL_TRACE - bnel- do_syscall_trace + andi. r0,r9,_TIF_SYSCALL_T_OR_A + bnel- do_syscall_trace_leave /* fall through */ .globl ret_from_except_full diff --git a/arch/ppc/kernel/ppc_ksyms.c b/arch/ppc/kernel/ppc_ksyms.c index 2ccb58fe4fc..d59ad07de8e 100644 --- a/arch/ppc/kernel/ppc_ksyms.c +++ b/arch/ppc/kernel/ppc_ksyms.c @@ -55,7 +55,6 @@ #define EXPORT_SYMTAB_STROPS extern void transfer_to_handler(void); -extern void do_syscall_trace(void); extern void do_IRQ(struct pt_regs *regs); extern void MachineCheckException(struct pt_regs *regs); extern void AlignmentException(struct pt_regs *regs); @@ -74,7 +73,6 @@ extern unsigned long mm_ptov (unsigned long paddr); EXPORT_SYMBOL(clear_pages); EXPORT_SYMBOL(clear_user_page); EXPORT_SYMBOL(do_signal); -EXPORT_SYMBOL(do_syscall_trace); EXPORT_SYMBOL(transfer_to_handler); EXPORT_SYMBOL(do_IRQ); EXPORT_SYMBOL(MachineCheckException); diff --git a/arch/ppc/kernel/ptrace.c b/arch/ppc/kernel/ptrace.c index 59d59a8dc24..e7aee4108de 100644 --- a/arch/ppc/kernel/ptrace.c +++ b/arch/ppc/kernel/ptrace.c @@ -27,6 +27,9 @@ #include <linux/user.h> #include <linux/security.h> #include <linux/signal.h> +#include <linux/seccomp.h> +#include <linux/audit.h> +#include <linux/module.h> #include <asm/uaccess.h> #include <asm/page.h> @@ -455,11 +458,10 @@ out: return ret; } -void do_syscall_trace(void) +static void do_syscall_trace(void) { - if (!test_thread_flag(TIF_SYSCALL_TRACE) - || !(current->ptrace & PT_PTRACED)) - return; + /* the 0x80 provides a way for the tracing parent to distinguish + between a syscall stop and SIGTRAP delivery */ ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); @@ -473,3 +475,33 @@ void do_syscall_trace(void) current->exit_code = 0; } } + +void do_syscall_trace_enter(struct pt_regs *regs) +{ + if (test_thread_flag(TIF_SYSCALL_TRACE) + && (current->ptrace & PT_PTRACED)) + do_syscall_trace(); + + if (unlikely(current->audit_context)) + audit_syscall_entry(current, AUDIT_ARCH_PPC, + regs->gpr[0], + regs->gpr[3], regs->gpr[4], + regs->gpr[5], regs->gpr[6]); +} + +void do_syscall_trace_leave(struct pt_regs *regs) +{ + secure_computing(regs->gpr[0]); + + if (unlikely(current->audit_context)) + audit_syscall_exit(current, + (regs->ccr&0x1000)?AUDITSC_FAILURE:AUDITSC_SUCCESS, + regs->result); + + if ((test_thread_flag(TIF_SYSCALL_TRACE)) + && (current->ptrace & PT_PTRACED)) + do_syscall_trace(); +} + +EXPORT_SYMBOL(do_syscall_trace_enter); +EXPORT_SYMBOL(do_syscall_trace_leave); |