8 files changed, 153 insertions, 22 deletions
diff --git a/test/syscalls/linux/rseq/BUILD b/test/syscalls/linux/rseq/BUILD
index ed488dbc2..853258b04 100644
--- a/test/syscalls/linux/rseq/BUILD
+++ b/test/syscalls/linux/rseq/BUILD
@@ -1,7 +1,7 @@
 # This package contains a standalone rseq test binary. This binary must not
 # depend on libc, which might use rseq itself.
 
-load("//tools:defs.bzl", "cc_flags_supplier", "cc_library", "cc_toolchain")
+load("//tools:defs.bzl", "cc_flags_supplier", "cc_library", "cc_toolchain", "select_arch")
 
 package(licenses = ["notice"])
 
@@ -9,32 +9,35 @@ genrule(
     name = "rseq_binary",
     srcs = [
         "critical.h",
-        "critical.S",
+        "critical_amd64.S",
+        "critical_arm64.S",
         "rseq.cc",
         "syscalls.h",
-        "start.S",
+        "start_amd64.S",
+        "start_arm64.S",
         "test.h",
         "types.h",
         "uapi.h",
     ],
     outs = ["rseq"],
-    cmd = " ".join([
-        "$(CC)",
-        "$(CC_FLAGS) ",
-        "-I.",
-        "-Wall",
-        "-Werror",
-        "-O2",
-        "-std=c++17",
-        "-static",
-        "-nostdlib",
-        "-ffreestanding",
-        "-o",
-        "$(location rseq)",
-        "$(location critical.S)",
-        "$(location rseq.cc)",
-        "$(location start.S)",
-    ]),
+    cmd = "$(CC) " +
+          "$(CC_FLAGS) " +
+          "-I. " +
+          "-Wall " +
+          "-Werror " +
+          "-O2 " +
+          "-std=c++17 " +
+          "-static " +
+          "-nostdlib " +
+          "-ffreestanding " +
+          "-o " +
+          "$(location rseq) " +
+          select_arch(
+              amd64 = "$(location critical_amd64.S) $(location start_amd64.S) ",
+              arm64 = "$(location critical_arm64.S) $(location start_arm64.S) ",
+              no_match_error = "unsupported architecture",
+          ) +
+          "$(location rseq.cc)",
     toolchains = [
         cc_toolchain,
         ":no_pie_cc_flags",
diff --git a/test/syscalls/linux/rseq/critical.S b/test/syscalls/linux/rseq/critical_amd64.S
index 8c0687e6d..8c0687e6d 100644
--- a/test/syscalls/linux/rseq/critical.S
+++ b/test/syscalls/linux/rseq/critical_amd64.S
diff --git a/test/syscalls/linux/rseq/critical_arm64.S b/test/syscalls/linux/rseq/critical_arm64.S
new file mode 100644
index 000000000..bfe7e8307
--- /dev/null
+++ b/test/syscalls/linux/rseq/critical_arm64.S
@@ -0,0 +1,66 @@
+// 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.
+
+// Restartable sequences critical sections.
+
+// Loops continuously until aborted.
+//
+// void rseq_loop(struct rseq* r, struct rseq_cs* cs)
+
+  .text
+  .globl  rseq_loop
+  .type   rseq_loop, @function
+
+rseq_loop:
+  b begin
+
+  // Abort block before the critical section.
+  // Abort signature.
+  .byte 0x90, 0x90, 0x90, 0x90
+  .globl  rseq_loop_early_abort
+rseq_loop_early_abort:
+  ret
+
+begin:
+  // r->rseq_cs = cs
+  str x1, [x0, #8]
+
+  // N.B. rseq_cs will be cleared by any preempt, even outside the critical
+  // section. Thus it must be set in or immediately before the critical section
+  // to ensure it is not cleared before the section begins.
+  .globl  rseq_loop_start
+rseq_loop_start:
+  b rseq_loop_start
+
+  // "Pre-commit": extra instructions inside the critical section.  These are
+  // used as the abort point in TestAbortPreCommit, which is not valid.
+  .globl  rseq_loop_pre_commit
+rseq_loop_pre_commit:
+  // Extra abort signature + nop for TestAbortPostCommit.
+  .byte 0x90, 0x90, 0x90, 0x90
+  nop
+
+  // "Post-commit": never reached in this case.
+  .globl  rseq_loop_post_commit
+rseq_loop_post_commit:
+
+  // Abort signature.
+  .byte 0x90, 0x90, 0x90, 0x90
+
+  .globl  rseq_loop_abort
+rseq_loop_abort:
+  ret
+
+  .size  rseq_loop,.-rseq_loop
+  .section  .note.GNU-stack,"",@progbits
diff --git a/test/syscalls/linux/rseq/start.S b/test/syscalls/linux/rseq/start_amd64.S
index b9611b276..b9611b276 100644
--- a/test/syscalls/linux/rseq/start.S
+++ b/test/syscalls/linux/rseq/start_amd64.S
diff --git a/test/syscalls/linux/rseq/start_arm64.S b/test/syscalls/linux/rseq/start_arm64.S
new file mode 100644
index 000000000..693c1c6eb
--- /dev/null
+++ b/test/syscalls/linux/rseq/start_arm64.S
@@ -0,0 +1,45 @@
+// 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.
+
+
+  .text
+  .align 4
+  .type  _start,@function
+  .globl  _start
+
+_start:
+  mov  x29, sp
+  bl   __init
+  wfi
+
+  .size  _start,.-_start
+  .section  .note.GNU-stack,"",@progbits
+
+  .text
+  .globl  raw_syscall
+  .type   raw_syscall, @function
+
+raw_syscall:
+  mov  x8,x0   // syscall #
+  mov  x0,x1   // arg0
+  mov  x1,x2   // arg1
+  mov  x2,x3   // arg2
+  mov  x3,x4   // arg3
+  mov  x4,x5   // arg4
+  mov  x5,x6   // arg5
+  svc  #0
+  ret
+
+  .size  raw_syscall,.-raw_syscall
+  .section  .note.GNU-stack,"",@progbits
diff --git a/test/syscalls/linux/rseq/syscalls.h b/test/syscalls/linux/rseq/syscalls.h
index e5299c188..c4118e6c5 100644
--- a/test/syscalls/linux/rseq/syscalls.h
+++ b/test/syscalls/linux/rseq/syscalls.h
@@ -17,10 +17,13 @@
 
 #include "test/syscalls/linux/rseq/types.h"
 
-#ifdef __x86_64__
 // Syscall numbers.
+#if defined(__x86_64__)
 constexpr int kGetpid = 39;
 constexpr int kExitGroup = 231;
+#elif defined(__aarch64__)
+constexpr int kGetpid = 172;
+constexpr int kExitGroup = 94;
 #else
 #error "Unknown architecture"
 #endif
diff --git a/test/syscalls/linux/rseq/uapi.h b/test/syscalls/linux/rseq/uapi.h
index ca1d67691..d3e60d0a4 100644
--- a/test/syscalls/linux/rseq/uapi.h
+++ b/test/syscalls/linux/rseq/uapi.h
@@ -19,9 +19,11 @@
 
 // User-kernel ABI for restartable sequences.
 
-#ifdef __x86_64__
 // Syscall numbers.
+#if defined(__x86_64__)
 constexpr int kRseqSyscall = 334;
+#elif defined(__aarch64__)
+constexpr int kRseqSyscall = 293;
 #else
 #error "Unknown architecture"
 #endif  // __x86_64__
diff --git a/test/syscalls/linux/uidgid.cc b/test/syscalls/linux/uidgid.cc
index 6218fbce1..ff66a79f4 100644
--- a/test/syscalls/linux/uidgid.cc
+++ b/test/syscalls/linux/uidgid.cc
@@ -14,6 +14,7 @@
 
 #include <errno.h>
 #include <grp.h>
+#include <sys/resource.h>
 #include <sys/types.h>
 #include <unistd.h>
 
@@ -249,6 +250,17 @@ TEST(UidGidRootTest, Setgroups) {
               SyscallFailsWithErrno(EFAULT));
 }
 
+TEST(UidGidRootTest, Setuid_prlimit) {
+  SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(IsRoot()));
+
+  // Change our UID.
+  EXPECT_THAT(seteuid(65534), SyscallSucceeds());
+
+  // Despite the UID change, we should be able to get our own limits.
+  struct rlimit rl = {};
+  ASSERT_THAT(prlimit(0, RLIMIT_NOFILE, NULL, &rl), SyscallSucceeds());
+}
+
 }  // namespace
 
 }  // namespace testing