From ff78a721700f8b7d3c8dae14fc14c04f3a82b970 Mon Sep 17 00:00:00 2001 From: lubinszARM <34124929+lubinszARM@users.noreply.github.com> Date: Tue, 14 Jan 2020 22:22:45 -0800 Subject: enable pkg/sentry/arch to support arm64 basically Signed-off-by: Bin Lu Change-Id: I9cce23db4e5caec82ce42b4970fdb7f7e8c08f1d COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/773 from lubinszARM:pr_arch_basic 3fe2fd8e6286766bbe489ef971dce204f924feba PiperOrigin-RevId: 289795569 --- pkg/sentry/arch/syscalls_arm64.go | 62 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 pkg/sentry/arch/syscalls_arm64.go (limited to 'pkg/sentry/arch/syscalls_arm64.go') diff --git a/pkg/sentry/arch/syscalls_arm64.go b/pkg/sentry/arch/syscalls_arm64.go new file mode 100644 index 000000000..00d5ef461 --- /dev/null +++ b/pkg/sentry/arch/syscalls_arm64.go @@ -0,0 +1,62 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// +build arm64 + +package arch + +const restartSyscallNr = uintptr(128) + +// SyscallNo returns the syscall number according to the 64-bit convention. +func (c *context64) SyscallNo() uintptr { + return uintptr(c.Regs.Regs[8]) +} + +// SyscallArgs provides syscall arguments according to the 64-bit convention. +// +// Due to the way addresses are mapped for the sentry this binary *must* be +// built in 64-bit mode. So we can just assume the syscall numbers that come +// back match the expected host system call numbers. +// General purpose registers usage on Arm64: +// R0...R7: parameter/result registers. +// R8: indirect result location register. +// R9...R15: temporary registers. +// R16: the first intra-procedure-call scratch register. +// R17: the second intra-procedure-call scratch register. +// R18: the platform register. +// R19...R28: callee-saved registers. +// R29: the frame pointer. +// R30: the link register. +func (c *context64) SyscallArgs() SyscallArguments { + return SyscallArguments{ + SyscallArgument{Value: uintptr(c.Regs.Regs[0])}, + SyscallArgument{Value: uintptr(c.Regs.Regs[1])}, + SyscallArgument{Value: uintptr(c.Regs.Regs[2])}, + SyscallArgument{Value: uintptr(c.Regs.Regs[3])}, + SyscallArgument{Value: uintptr(c.Regs.Regs[4])}, + SyscallArgument{Value: uintptr(c.Regs.Regs[5])}, + } +} + +// RestartSyscall implements Context.RestartSyscall. +func (c *context64) RestartSyscall() { + c.Regs.Pc -= SyscallWidth + c.Regs.Regs[8] = uint64(restartSyscallNr) +} + +// RestartSyscallWithRestartBlock implements Context.RestartSyscallWithRestartBlock. +func (c *context64) RestartSyscallWithRestartBlock() { + c.Regs.Pc -= SyscallWidth + c.Regs.Regs[8] = uint64(restartSyscallNr) +} -- cgit v1.2.3 From 7df936f359766618470ae31a7cbf1b761bd19b59 Mon Sep 17 00:00:00 2001 From: Bin Lu Date: Wed, 4 Mar 2020 04:20:36 -0500 Subject: passed the syscall test case 'alarm' on Arm64 platform This issue was caused by 'restart_syscall'. The value of Register R0 should be stored after finishing sysemu. So that we can restore the value and restart syscall. Signed-off-by: Bin Lu --- pkg/sentry/arch/arch_aarch64.go | 4 ++++ pkg/sentry/arch/syscalls_arm64.go | 10 +++++++++- 2 files changed, 13 insertions(+), 1 deletion(-) (limited to 'pkg/sentry/arch/syscalls_arm64.go') diff --git a/pkg/sentry/arch/arch_aarch64.go b/pkg/sentry/arch/arch_aarch64.go index 5053393c1..01940bca4 100644 --- a/pkg/sentry/arch/arch_aarch64.go +++ b/pkg/sentry/arch/arch_aarch64.go @@ -97,6 +97,9 @@ type State struct { // FeatureSet is a pointer to the currently active feature set. FeatureSet *cpuid.FeatureSet + + // OrigR0 stores the value of register R0. + OrigR0 uint64 } // Proto returns a protobuf representation of the system registers in State. @@ -146,6 +149,7 @@ func (s *State) Fork() State { Regs: s.Regs, aarch64FPState: s.aarch64FPState.fork(), FeatureSet: s.FeatureSet, + OrigR0: s.OrigR0, } } diff --git a/pkg/sentry/arch/syscalls_arm64.go b/pkg/sentry/arch/syscalls_arm64.go index 00d5ef461..dc13b6124 100644 --- a/pkg/sentry/arch/syscalls_arm64.go +++ b/pkg/sentry/arch/syscalls_arm64.go @@ -50,13 +50,21 @@ func (c *context64) SyscallArgs() SyscallArguments { } // RestartSyscall implements Context.RestartSyscall. +// Prepare for system call restart, OrigR0 will be restored to R0. +// Please see the linux code as reference: +// arch/arm64/kernel/signal.c:do_signal() func (c *context64) RestartSyscall() { c.Regs.Pc -= SyscallWidth - c.Regs.Regs[8] = uint64(restartSyscallNr) + // R0 will be backed up into OrigR0 when entering doSyscall(). + // Please see the linux code as reference: + // arch/arm64/kernel/syscall.c:el0_svc_common(). + // Here we restore it back. + c.Regs.Regs[0] = uint64(c.OrigR0) } // RestartSyscallWithRestartBlock implements Context.RestartSyscallWithRestartBlock. func (c *context64) RestartSyscallWithRestartBlock() { c.Regs.Pc -= SyscallWidth + c.Regs.Regs[0] = uint64(c.OrigR0) c.Regs.Regs[8] = uint64(restartSyscallNr) } -- cgit v1.2.3 From 7aa5caae71c29b0be9047a7c156a9daaa435ebb8 Mon Sep 17 00:00:00 2001 From: Haibo Xu Date: Wed, 11 Mar 2020 03:21:34 +0000 Subject: Enable syscall ptrace test on arm64. Signed-off-by: Haibo Xu Change-Id: I5bb8fa7d580d173b1438d6465e1adb442216c8fa --- pkg/sentry/arch/arch.go | 3 +++ pkg/sentry/arch/syscalls_amd64.go | 7 +++++++ pkg/sentry/arch/syscalls_arm64.go | 13 ++++++++++++- pkg/sentry/kernel/task_syscall.go | 14 ++++++++++++++ test/syscalls/linux/ptrace.cc | 31 ++++++++++++++++++++++++------- 5 files changed, 60 insertions(+), 8 deletions(-) (limited to 'pkg/sentry/arch/syscalls_arm64.go') diff --git a/pkg/sentry/arch/arch.go b/pkg/sentry/arch/arch.go index 1d11cc472..a903d031c 100644 --- a/pkg/sentry/arch/arch.go +++ b/pkg/sentry/arch/arch.go @@ -88,6 +88,9 @@ type Context interface { // SyscallNo returns the syscall number. SyscallNo() uintptr + // SyscallSaveOrig save orignal register value. + SyscallSaveOrig() + // SyscallArgs returns the syscall arguments in an array. SyscallArgs() SyscallArguments diff --git a/pkg/sentry/arch/syscalls_amd64.go b/pkg/sentry/arch/syscalls_amd64.go index 8b4f23007..3859f41ee 100644 --- a/pkg/sentry/arch/syscalls_amd64.go +++ b/pkg/sentry/arch/syscalls_amd64.go @@ -18,6 +18,13 @@ package arch const restartSyscallNr = uintptr(219) +// SyscallSaveOrig save the value of the register which is clobbered in +// syscall handler(doSyscall()). +// +// Noop on x86. +func (c *context64) SyscallSaveOrig() { +} + // SyscallNo returns the syscall number according to the 64-bit convention. func (c *context64) SyscallNo() uintptr { return uintptr(c.Regs.Orig_rax) diff --git a/pkg/sentry/arch/syscalls_arm64.go b/pkg/sentry/arch/syscalls_arm64.go index dc13b6124..92d062513 100644 --- a/pkg/sentry/arch/syscalls_arm64.go +++ b/pkg/sentry/arch/syscalls_arm64.go @@ -18,6 +18,17 @@ package arch const restartSyscallNr = uintptr(128) +// SyscallSaveOrig save the value of the register R0 which is clobbered in +// syscall handler(doSyscall()). +// +// In linux, at the entry of the syscall handler(el0_svc_common()), value of R0 +// is saved to the pt_regs.orig_x0 in kernel code. But currently, the orig_x0 +// was not accessible to the user space application, so we have to do the same +// operation in the sentry code to save the R0 value into the App context. +func (c *context64) SyscallSaveOrig() { + c.OrigR0 = c.Regs.Regs[0] +} + // SyscallNo returns the syscall number according to the 64-bit convention. func (c *context64) SyscallNo() uintptr { return uintptr(c.Regs.Regs[8]) @@ -40,7 +51,7 @@ func (c *context64) SyscallNo() uintptr { // R30: the link register. func (c *context64) SyscallArgs() SyscallArguments { return SyscallArguments{ - SyscallArgument{Value: uintptr(c.Regs.Regs[0])}, + SyscallArgument{Value: uintptr(c.OrigR0)}, SyscallArgument{Value: uintptr(c.Regs.Regs[1])}, SyscallArgument{Value: uintptr(c.Regs.Regs[2])}, SyscallArgument{Value: uintptr(c.Regs.Regs[3])}, diff --git a/pkg/sentry/kernel/task_syscall.go b/pkg/sentry/kernel/task_syscall.go index d555d69a8..3d7a734ef 100644 --- a/pkg/sentry/kernel/task_syscall.go +++ b/pkg/sentry/kernel/task_syscall.go @@ -194,6 +194,19 @@ func (t *Task) executeSyscall(sysno uintptr, args arch.SyscallArguments) (rval u // // The syscall path is very hot; avoid defer. func (t *Task) doSyscall() taskRunState { + // Save value of the register which is clobbered in the following + // t.Arch().SetReturn(-ENOSYS) operation. This is dedicated to arm64. + // + // On x86, register rax was shared by syscall number and return + // value, and at the entry of the syscall handler, the rax was + // saved to regs.orig_rax which was exposed to user space. + // But on arm64, syscall number was passed through X8, and the X0 + // was shared by the first syscall argument and return value. The + // X0 was saved to regs.orig_x0 which was not exposed to user space. + // So we have to do the same operation here to save the X0 value + // into the task context. + t.Arch().SyscallSaveOrig() + sysno := t.Arch().SyscallNo() args := t.Arch().SyscallArgs() @@ -269,6 +282,7 @@ func (*runSyscallAfterSyscallEnterStop) execute(t *Task) taskRunState { return (*runSyscallExit)(nil) } args := t.Arch().SyscallArgs() + return t.doSyscallInvoke(sysno, args) } diff --git a/test/syscalls/linux/ptrace.cc b/test/syscalls/linux/ptrace.cc index cb828ff88..926690eb8 100644 --- a/test/syscalls/linux/ptrace.cc +++ b/test/syscalls/linux/ptrace.cc @@ -400,9 +400,11 @@ TEST(PtraceTest, GetRegSet) { // Read exactly the full register set. EXPECT_EQ(iov.iov_len, sizeof(regs)); -#ifdef __x86_64__ +#if defined(__x86_64__) // Child called kill(2), with SIGSTOP as arg 2. EXPECT_EQ(regs.rsi, SIGSTOP); +#elif defined(__aarch64__) + EXPECT_EQ(regs.regs[1], SIGSTOP); #endif // Suppress SIGSTOP and resume the child. @@ -752,15 +754,23 @@ TEST(PtraceTest, SyscallSucceeds()); EXPECT_TRUE(siginfo.si_code == SIGTRAP || siginfo.si_code == (SIGTRAP | 0x80)) << "si_code = " << siginfo.si_code; -#ifdef __x86_64__ + { struct user_regs_struct regs = {}; - ASSERT_THAT(ptrace(PTRACE_GETREGS, child_pid, 0, ®s), SyscallSucceeds()); + struct iovec iov; + iov.iov_base = ®s; + iov.iov_len = sizeof(regs); + EXPECT_THAT(ptrace(PTRACE_GETREGSET, child_pid, NT_PRSTATUS, &iov), + SyscallSucceeds()); +#if defined(__x86_64__) EXPECT_TRUE(regs.orig_rax == SYS_vfork || regs.orig_rax == SYS_clone) << "orig_rax = " << regs.orig_rax; EXPECT_EQ(grandchild_pid, regs.rax); - } +#elif defined(__aarch64__) + EXPECT_TRUE(regs.regs[8] == SYS_clone) << "regs[8] = " << regs.regs[8]; + EXPECT_EQ(grandchild_pid, regs.regs[0]); #endif // defined(__x86_64__) + } // After this point, the child will be making wait4 syscalls that will be // interrupted by saving, so saving is not permitted. Note that this is @@ -805,14 +815,21 @@ TEST(PtraceTest, SyscallSucceedsWithValue(child_pid)); EXPECT_TRUE(WIFSTOPPED(status) && WSTOPSIG(status) == (SIGTRAP | 0x80)) << " status " << status; -#ifdef __x86_64__ { struct user_regs_struct regs = {}; - ASSERT_THAT(ptrace(PTRACE_GETREGS, child_pid, 0, ®s), SyscallSucceeds()); + struct iovec iov; + iov.iov_base = ®s; + iov.iov_len = sizeof(regs); + EXPECT_THAT(ptrace(PTRACE_GETREGSET, child_pid, NT_PRSTATUS, &iov), + SyscallSucceeds()); +#if defined(__x86_64__) EXPECT_EQ(SYS_wait4, regs.orig_rax); EXPECT_EQ(grandchild_pid, regs.rax); - } +#elif defined(__aarch64__) + EXPECT_EQ(SYS_wait4, regs.regs[8]); + EXPECT_EQ(grandchild_pid, regs.regs[0]); #endif // defined(__x86_64__) + } // Detach from the child and wait for it to exit. ASSERT_THAT(ptrace(PTRACE_DETACH, child_pid, 0, 0), SyscallSucceeds()); -- cgit v1.2.3