From a0ddef81f4aeeeec3326f6b6a255d8ea13b41908 Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Wed, 22 Jul 2015 14:30:14 -0400 Subject: tile: enable full SECCOMP support Signed-off-by: Chris Metcalf --- arch/tile/Kconfig | 17 +++++++++++++++++ arch/tile/include/asm/Kbuild | 1 + arch/tile/include/asm/elf.h | 4 +--- arch/tile/include/asm/syscall.h | 28 +++++++++++++++++++++++++++- arch/tile/kernel/intvec_32.S | 1 + arch/tile/kernel/intvec_64.S | 1 + arch/tile/kernel/ptrace.c | 3 +++ 7 files changed, 51 insertions(+), 4 deletions(-) (limited to 'arch/tile') diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig index 9def1f52d03a..2ba12d761723 100644 --- a/arch/tile/Kconfig +++ b/arch/tile/Kconfig @@ -32,6 +32,7 @@ config TILE select EDAC_SUPPORT select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER + select HAVE_ARCH_SECCOMP_FILTER # FIXME: investigate whether we need/want these options. # select HAVE_IOREMAP_PROT @@ -221,6 +222,22 @@ config COMPAT If enabled, the kernel will support running TILE-Gx binaries that were built with the -m32 option. +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 SYSVIPC_COMPAT def_bool y depends on COMPAT && SYSVIPC diff --git a/arch/tile/include/asm/Kbuild b/arch/tile/include/asm/Kbuild index d8a843163471..ba35c41c71ff 100644 --- a/arch/tile/include/asm/Kbuild +++ b/arch/tile/include/asm/Kbuild @@ -28,6 +28,7 @@ generic-y += poll.h generic-y += posix_types.h generic-y += preempt.h generic-y += resource.h +generic-y += seccomp.h generic-y += sembuf.h generic-y += serial.h generic-y += shmbuf.h diff --git a/arch/tile/include/asm/elf.h b/arch/tile/include/asm/elf.h index 41d9878a9686..c505d77e4d06 100644 --- a/arch/tile/include/asm/elf.h +++ b/arch/tile/include/asm/elf.h @@ -22,6 +22,7 @@ #include #include +#include #include #include @@ -30,9 +31,6 @@ typedef unsigned long elf_greg_t; #define ELF_NGREG (sizeof(struct pt_regs) / sizeof(elf_greg_t)) typedef elf_greg_t elf_gregset_t[ELF_NGREG]; -#define EM_TILEPRO 188 -#define EM_TILEGX 191 - /* Provide a nominal data structure. */ #define ELF_NFPREG 0 typedef double elf_fpreg_t; diff --git a/arch/tile/include/asm/syscall.h b/arch/tile/include/asm/syscall.h index 9644b88f133d..373d73064ea1 100644 --- a/arch/tile/include/asm/syscall.h +++ b/arch/tile/include/asm/syscall.h @@ -20,6 +20,8 @@ #include #include +#include +#include #include /* The array of function pointers for syscalls. */ @@ -61,7 +63,15 @@ static inline void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, int error, long val) { - regs->regs[0] = (long) error ?: val; + if (error) { + /* R0 is the passed-in negative error, R1 is positive. */ + regs->regs[0] = error; + regs->regs[1] = -error; + } else { + /* R1 set to zero to indicate no error. */ + regs->regs[0] = val; + regs->regs[1] = 0; + } } static inline void syscall_get_arguments(struct task_struct *task, @@ -82,4 +92,20 @@ static inline void syscall_set_arguments(struct task_struct *task, memcpy(®s[i], args, n * sizeof(args[0])); } +/* + * We don't care about endianness (__AUDIT_ARCH_LE bit) here because + * tile has the same system calls both on little- and big- endian. + */ +static inline int syscall_get_arch(void) +{ + if (is_compat_task()) + return AUDIT_ARCH_TILEGX32; + +#ifdef CONFIG_TILEGX + return AUDIT_ARCH_TILEGX; +#else + return AUDIT_ARCH_TILEPRO; +#endif +} + #endif /* _ASM_TILE_SYSCALL_H */ diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S index cdbda45a4e4b..fbbe2ea882ea 100644 --- a/arch/tile/kernel/intvec_32.S +++ b/arch/tile/kernel/intvec_32.S @@ -1224,6 +1224,7 @@ handle_syscall: jal do_syscall_trace_enter } FEEDBACK_REENTER(handle_syscall) + blz r0, .Lsyscall_sigreturn_skip /* * We always reload our registers from the stack at this diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S index 800b91d3f9dc..58964d209d4d 100644 --- a/arch/tile/kernel/intvec_64.S +++ b/arch/tile/kernel/intvec_64.S @@ -1247,6 +1247,7 @@ handle_syscall: jal do_syscall_trace_enter } FEEDBACK_REENTER(handle_syscall) + bltz r0, .Lsyscall_sigreturn_skip /* * We always reload our registers from the stack at this diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c index f84eed8243da..bdc126faf741 100644 --- a/arch/tile/kernel/ptrace.c +++ b/arch/tile/kernel/ptrace.c @@ -262,6 +262,9 @@ int do_syscall_trace_enter(struct pt_regs *regs) if (work & _TIF_NOHZ) user_exit(); + if (secure_computing() == -1) + return -1; + if (work & _TIF_SYSCALL_TRACE) { if (tracehook_report_syscall_entry(regs)) regs->regs[TREG_SYSCALL_NR] = -1; -- cgit v1.2.3