Add a platform-specific syscall number iterator.

sandbox/linux/seccomp-bpf/syscall_iterator_unittest.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
+#include "sandbox/linux/seccomp-bpf/syscall_iterator.h"
+#include "sandbox/linux/tests/unit_tests.h"
+
+using namespace playground2;
+
+namespace {
+
+SANDBOX_TEST(SyscallIterator, Monotonous) {
+  for (int i = 0; i < 2; ++i) {
+    bool invalid_only = !i;   // Testing both |invalid_only| cases.
+    SyscallIterator iter(invalid_only);
+    uint32_t next = iter.Next();
+
+    if (!invalid_only) {
+      // The iterator should start at 0.
+      SANDBOX_ASSERT(next == 0);
+    }
+    for (uint32_t last = next; !iter.Done(); last = next) {
+      next = iter.Next();
+      SANDBOX_ASSERT(last < next);
+    }
+    // The iterator should always return 0xFFFFFFFFu as the last value.
+    SANDBOX_ASSERT(next == 0xFFFFFFFFu);
+  }
+}
+
+SANDBOX_TEST(SyscallIterator, PublicSyscallRange) {
+  SyscallIterator iter(false);
+  uint32_t next = iter.Next();
+
+  // The iterator should cover the public syscall range
+  // MIN_SYSCALL..MAX_PUBLIC_SYSCALL, without skipping syscalls.
+  // We're assuming MIN_SYSCALL == 0 for all architectures,
+  // this is currently valid for Intel and ARM EABI.
+  SANDBOX_ASSERT(MIN_SYSCALL == 0);
+  SANDBOX_ASSERT(next == MIN_SYSCALL);
+  for (uint32_t last = next; next < MAX_PUBLIC_SYSCALL + 1; last = next) {
+    SANDBOX_ASSERT((next = iter.Next()) == last + 1);
+  }
+  SANDBOX_ASSERT(next == MAX_PUBLIC_SYSCALL + 1);
+}
+
+#if defined(__arm__)
+SANDBOX_TEST(SyscallIterator, ARMPrivateSyscallRange) {
+  SyscallIterator iter(false);
+  uint32_t next = iter.Next();
+  while (next < MIN_PRIVATE_SYSCALL - 1) {
+    next = iter.Next();
+  }
+  // The iterator should cover the ARM private syscall range
+  // without skipping syscalls.
+  SANDBOX_ASSERT(next == MIN_PRIVATE_SYSCALL - 1);
+  for (uint32_t last = next; next < MAX_PRIVATE_SYSCALL + 1; last = next) {
+    SANDBOX_ASSERT((next = iter.Next()) == last + 1);
+  }
+  SANDBOX_ASSERT(next == MAX_PRIVATE_SYSCALL + 1);
+}
+
+SANDBOX_TEST(SyscallIterator, ARMHiddenSyscallRange) {
+  SyscallIterator iter(false);
+  uint32_t next = iter.Next();
+  while (next < MIN_GHOST_SYSCALL - 1) {
+    next = iter.Next();
+  }
+  // The iterator should cover the ARM hidden syscall range
+  // without skipping syscalls.
+  SANDBOX_ASSERT(next == MIN_GHOST_SYSCALL - 1);
+  for (uint32_t last = next; next < MAX_SYSCALL + 1; last = next) {
+    SANDBOX_ASSERT((next = iter.Next()) == last + 1);
+  }
+  SANDBOX_ASSERT(next == MAX_SYSCALL + 1);
+}
+#endif
+
+SANDBOX_TEST(SyscallIterator, Invalid) {
+  for (int i = 0; i < 2; ++i) {
+    bool invalid_only = !i;   // Testing both |invalid_only| cases.
+    SyscallIterator iter(invalid_only);
+    uint32_t next = iter.Next();
+
+    while (next < MAX_SYSCALL + 1) {
+      next = iter.Next();
+    }
+
+    SANDBOX_ASSERT(next == MAX_SYSCALL + 1);
+    while (next < 0x7FFFFFFFu) {
+      next = iter.Next();
+    }
+
+    // The iterator should return the signed/unsigned corner cases.
+    SANDBOX_ASSERT(next == 0x7FFFFFFFu);
+    next = iter.Next();
+    SANDBOX_ASSERT(next == 0x80000000u);
+    SANDBOX_ASSERT(!iter.Done());
+    next = iter.Next();
+    SANDBOX_ASSERT(iter.Done());
+    SANDBOX_ASSERT(next == 0xFFFFFFFFu);
+  }
+}
+
+SANDBOX_TEST(SyscallIterator, InvalidOnly) {
+  bool invalid_only = true;
+  SyscallIterator iter(invalid_only);
+  uint32_t next = iter.Next();
+  // We're assuming MIN_SYSCALL == 0 for all architectures,
+  // this is currently valid for Intel and ARM EABI.
+  // First invalid syscall should then be |MAX_PUBLIC_SYSCALL + 1|.
+  SANDBOX_ASSERT(MIN_SYSCALL == 0);
+  SANDBOX_ASSERT(next == MAX_PUBLIC_SYSCALL + 1);
+
+#if defined(__arm__)
+  next = iter.Next();
+  // The iterator should skip until the last invalid syscall in this range.
+  SANDBOX_ASSERT(next == MIN_PRIVATE_SYSCALL - 1);
+  while (next <= MAX_PRIVATE_SYSCALL) {
+    next = iter.Next();
+  }
+
+  next = iter.Next();
+  // The iterator should skip until the last invalid syscall in this range.
+  SANDBOX_ASSERT(next == MIN_GHOST_SYSCALL - 1);
+  while (next <= MAX_SYSCALL) {
+    next = iter.Next();
+  }
+  SANDBOX_ASSERT(next == MAX_SYSCALL + 1);
+#endif
+}
+
+}  // namespace
+