[MIPS] Add seccomp bpf support

sandbox/linux/seccomp-bpf/syscall_iterator_unittest.cc

Index: sandbox/linux/seccomp-bpf/syscall_iterator_unittest.cc
diff --git a/sandbox/linux/seccomp-bpf/syscall_iterator_unittest.cc b/sandbox/linux/seccomp-bpf/syscall_iterator_unittest.cc
index 08a857a2e2933ad03eb29406874f0e48bb99d5ef..5409a63d9b3978f27f37b0d45d7dd0ff5e5b09a4 100644
--- a/sandbox/linux/seccomp-bpf/syscall_iterator_unittest.cc
+++ b/sandbox/linux/seccomp-bpf/syscall_iterator_unittest.cc
@@ -29,7 +29,26 @@ SANDBOX_TEST(SyscallIterator, Monotonous) {
   }
 }
 
-SANDBOX_TEST(SyscallIterator, PublicSyscallRange) {
+#if defined(__mips__)
+SANDBOX_TEST(SyscallIterator, PublicSyscallRangeMIPS) {
+  SyscallIterator iter(false);
+  uint32_t next = iter.Next();
+
+  // The iterator should cover the public syscall range
+  // MIN_SYSCALL..MAX_PUBLIC_SYSCALL, without skipping syscalls.
+  // Since MIN_SYSCALL != 0 we need to move iterator to valid range.
+  while (next < MIN_SYSCALL - 1) {

[jln (very slow on Chromium), 2014/05/28 00:06:57]

Don't perform a while loop here. This test should explicitly show what Next()
does.

It should do 0, then skip to MIN_SYSCALL - 1 immediately (or something similar).

This test should be a great way to know exactly what happens without reading the
code.

[nedeljko, 2014/05/29 14:06:45]

Done.

+    next = iter.Next();
+  }
+  SANDBOX_ASSERT(next == MIN_SYSCALL -1);
+
+  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);
+}
+#else
+SANDBOX_TEST(SyscallIterator, PublicSyscallRangeIntelArm) {
   SyscallIterator iter(false);
   uint32_t next = iter.Next();
 
@@ -44,6 +63,7 @@ SANDBOX_TEST(SyscallIterator, PublicSyscallRange) {
   }
   SANDBOX_ASSERT(next == MAX_PUBLIC_SYSCALL + 1);
 }
+#endif

[jln (very slow on Chromium), 2014/05/28 00:06:57]

Nit: add "// defined(__mips__)"

[nedeljko, 2014/05/29 14:06:45]

Done.

 
 #if defined(__arm__)
 SANDBOX_TEST(SyscallIterator, ARMPrivateSyscallRange) {
@@ -103,7 +123,30 @@ SANDBOX_TEST(SyscallIterator, Invalid) {
   }
 }
 
-SANDBOX_TEST(SyscallIterator, InvalidOnly) {
+#if defined(__mips__)
+SANDBOX_TEST(SyscallIterator, InvalidOnlyMIPS) {
+  bool invalid_only = true;
+  SyscallIterator iter(invalid_only);
+  uint32_t next = iter.Next();

[jln (very slow on Chromium), 2014/05/28 00:06:57]

You should ASSERT the value of iter.Next() here.

[nedeljko, 2014/05/29 14:06:45]

Done.

+  // For Mips O32 ABI we're assuming MIN_SYSCALL == 4000.
+  SANDBOX_ASSERT(MIN_SYSCALL == 4000);
+
+  // Since MIN_SYSCALL != 0, we need to move iterator to valid range
+  next = iter.Next();
+  // The iterator should skip until the last invalid syscall in this range.
+  SANDBOX_ASSERT(next == MIN_SYSCALL - 1);
+  int count = 0;
+  while (next <= MAX_PUBLIC_SYSCALL) {
+    printf("count: %d\n",count++);

[jln (very slow on Chromium), 2014/05/28 00:06:57]

Did you forget to remove this printf?

You should instead assert that the iterator never returns a public syscall.

[nedeljko, 2014/05/28 09:33:43]

Yes, sorry...
But the counter of this loop is going over public syscall range.

On the other hand, I should probably remove this loop and instead do one
iteration.
This way assert after this loop will check iterator correctly,

[nedeljko, 2014/05/29 14:06:45]

Done.

+    next = iter.Next();
+  }
+  // First next invalid syscall should then be |MAX_PUBLIC_SYSCALL + 1|.
+  SANDBOX_ASSERT(next == MAX_PUBLIC_SYSCALL + 1);
+}
+
+#else
+
+SANDBOX_TEST(SyscallIterator, InvalidOnlyIntelArm) {
   bool invalid_only = true;
   SyscallIterator iter(invalid_only);
   uint32_t next = iter.Next();
@@ -130,6 +173,7 @@ SANDBOX_TEST(SyscallIterator, InvalidOnly) {
   SANDBOX_ASSERT(next == MAX_SYSCALL + 1);
 #endif

[jln (very slow on Chromium), 2014/05/28 00:06:57]

Nit: add "// defined(__arm__)"

[nedeljko, 2014/05/29 14:06:45]

Done.

 }
+#endif

[jln (very slow on Chromium), 2014/05/28 00:06:57]

Nit: add "// defined(__mips__)

[nedeljko, 2014/05/29 14:06:45]

Done.

 
 }  // namespace