Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753063AbcC2Ih6 (ORCPT ); Tue, 29 Mar 2016 04:37:58 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:42662 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755946AbcC2Ifv (ORCPT ); Tue, 29 Mar 2016 04:35:51 -0400 From: Matt Redfearn To: CC: Matt Redfearn , Andy Lutomirski , Kees Cook , , Shuah Khan , , Will Drewry Subject: [PATCH v2 1/6] selftests/seccomp: add MIPS self-test support Date: Tue, 29 Mar 2016 09:35:29 +0100 Message-ID: <1459240534-8658-2-git-send-email-matt.redfearn@imgtec.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1459240534-8658-1-git-send-email-matt.redfearn@imgtec.com> References: <1459240534-8658-1-git-send-email-matt.redfearn@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [192.168.154.116] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3657 Lines: 116 This adds self-test support on MIPS, based on RFC patch from Kees Cook. Modifications from the RFC: - support the O32 syscall which passes the real syscall number in a0. - Use PTRACE_{GET,SET}REGS - Because SYSCALL_NUM and SYSCALL_RET are the same register, it is not possible to test modifying the syscall return value when skipping, since both would need to set the same register. Therefore modify that test case to just detect the skipped test. Tested on MIPS32r2 / MIPS64r2 with O32, N32 and N64 userlands. Signed-off-by: Matt Redfearn Acked-by: Kees Cook --- Changes in v2: - Tested on additional platforms - Replace __NR_syscall which isn't defined for N32 / N64 ABIs tools/testing/selftests/seccomp/seccomp_bpf.c | 30 +++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index b9453b838162..4c3e032d7224 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -5,6 +5,7 @@ * Test code for seccomp bpf. */ +#include #include #define __have_siginfo_t 1 #define __have_sigval_t 1 @@ -14,7 +15,6 @@ #include #include #include -#include #include #include #include @@ -1242,6 +1242,12 @@ TEST_F(TRACE_poke, getpid_runs_normally) # define ARCH_REGS s390_regs # define SYSCALL_NUM gprs[2] # define SYSCALL_RET gprs[2] +#elif defined(__mips__) +# define ARCH_REGS struct pt_regs +# define SYSCALL_NUM regs[2] +# define SYSCALL_SYSCALL_NUM regs[4] +# define SYSCALL_RET regs[2] +# define SYSCALL_NUM_RET_SHARE_REG #else # error "Do not know how to find your architecture's registers and syscalls" #endif @@ -1249,7 +1255,7 @@ TEST_F(TRACE_poke, getpid_runs_normally) /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux). */ -#if defined(__x86_64__) || defined(__i386__) +#if defined(__x86_64__) || defined(__i386__) || defined(__mips__) #define HAVE_GETREGS #endif @@ -1273,6 +1279,10 @@ int get_syscall(struct __test_metadata *_metadata, pid_t tracee) } #endif +#if defined(__mips__) + if (regs.SYSCALL_NUM == __NR_O32_Linux) + return regs.SYSCALL_SYSCALL_NUM; +#endif return regs.SYSCALL_NUM; } @@ -1297,6 +1307,13 @@ void change_syscall(struct __test_metadata *_metadata, { regs.SYSCALL_NUM = syscall; } +#elif defined(__mips__) + { + if (regs.SYSCALL_NUM == __NR_O32_Linux) + regs.SYSCALL_SYSCALL_NUM = syscall; + else + regs.SYSCALL_NUM = syscall; + } #elif defined(__arm__) # ifndef PTRACE_SET_SYSCALL @@ -1327,7 +1344,11 @@ void change_syscall(struct __test_metadata *_metadata, /* If syscall is skipped, change return value. */ if (syscall == -1) +#ifdef SYSCALL_NUM_RET_SHARE_REG + TH_LOG("Can't modify syscall return on this architecture"); +#else regs.SYSCALL_RET = 1; +#endif #ifdef HAVE_GETREGS ret = ptrace(PTRACE_SETREGS, tracee, 0, ®s); @@ -1465,8 +1486,13 @@ TEST_F(TRACE_syscall, syscall_dropped) ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); ASSERT_EQ(0, ret); +#ifdef SYSCALL_NUM_RET_SHARE_REG + /* gettid has been skipped */ + EXPECT_EQ(-1, syscall(__NR_gettid)); +#else /* gettid has been skipped and an altered return value stored. */ EXPECT_EQ(1, syscall(__NR_gettid)); +#endif EXPECT_NE(self->mytid, syscall(__NR_gettid)); } -- 2.5.0