Index: sandbox/linux/seccomp-bpf/kernel_return_value_helpers.cc |
diff --git a/sandbox/linux/seccomp-bpf/kernel_return_value_helpers.cc b/sandbox/linux/seccomp-bpf/kernel_return_value_helpers.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..888bec58b5f169f35efa419bf18c8e66c1c48680 |
--- /dev/null |
+++ b/sandbox/linux/seccomp-bpf/kernel_return_value_helpers.cc |
@@ -0,0 +1,39 @@ |
+// Copyright 2014 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/kernel_return_value_helpers.h" |
+#include "sandbox/linux/seccomp-bpf/linux_seccomp.h" |
+ |
+namespace sandbox { |
+ |
+// In order for errno to be converted to the value that kernel returns to |
+// indicate an error in syscall, errno needs to be negated on Intel/Arm. On |
+// Mips this is not the case since Mips has different mechanism for indicating |
+// error. |
+int ErrnoToKernelRet(int kernel_ret) { |
+#if defined(__mips__) |
+ return kernel_ret; |
+#else |
+ return -kernel_ret; |
+#endif |
+} |
+ |
+void PutValueInUcontext(intptr_t ret_val, ucontext_t* ctx) { |
+#if defined(__mips__) |
+ // Mips ABI states that on error a3 CPU register has non zero value and if |
+ // there is no error, it should be zero. |
+ if (ret_val < 0) { |
jln (very slow on Chromium)
2014/06/13 02:47:36
This should be if (retval <= -1 && ret_val >= -409
nedeljko
2014/06/18 13:41:00
Done.
|
+ // The sign of errno that is returned from the kernel was changed in |
+ // SandboxSyscall() in case of Mips in order for SandboxSyscall() to |
jln (very slow on Chromium)
2014/06/13 02:47:36
This code must not have knowledge of the codepath
nedeljko
2014/06/18 13:41:00
Done.
|
+ // behave the same for all supported architectures. In order to write |
+ // correct value to return register this sign needs to be changed back. |
+ ret_val = -ret_val; |
+ SECCOMP_PARM4(ctx) = 1; |
+ } else |
+ SECCOMP_PARM4(ctx) = 0; |
+#endif |
+ SECCOMP_RESULT(ctx) = static_cast<greg_t>(ret_val); |
+} |
+ |
+} // namespace sandbox |