Add libunwindstack support for Mips and Mips64

This patch requires v3.18 kernel or above, because v3.10 kernel
has a bug (as of 8/1/2017) in the ptrace(GETREGSET) function for mips
and mips64.

Change-Id: I004c1fa190193eebe1c84440b366289122a6bd8a
Signed-off-by: Douglas Leung <douglas.leung@mips.com>
Signed-off-by: Dejan Jovicevic <dejan.jovicevic@mips.com>
diff --git a/libunwindstack/tests/RegsStepIfSignalHandlerTest.cpp b/libunwindstack/tests/RegsStepIfSignalHandlerTest.cpp
index ae57caf..ef9e61c 100644
--- a/libunwindstack/tests/RegsStepIfSignalHandlerTest.cpp
+++ b/libunwindstack/tests/RegsStepIfSignalHandlerTest.cpp
@@ -23,11 +23,15 @@
 #include <unwindstack/RegsArm64.h>
 #include <unwindstack/RegsX86.h>
 #include <unwindstack/RegsX86_64.h>
+#include <unwindstack/RegsMips.h>
+#include <unwindstack/RegsMips64.h>
 
 #include "MachineArm.h"
 #include "MachineArm64.h"
 #include "MachineX86.h"
 #include "MachineX86_64.h"
+#include "MachineMips.h"
+#include "MachineMips64.h"
 
 #include "MemoryFake.h"
 
@@ -204,4 +208,64 @@
   EXPECT_EQ(0x150U, regs.pc());
 }
 
+TEST_F(RegsStepIfSignalHandlerTest, mips_step_if_signal_handler_non_rt) {
+  uint64_t addr = 0x1000;
+  RegsMips regs;
+  regs[MIPS_REG_PC] = 0x8000;
+  regs[MIPS_REG_SP] = addr;
+  regs.SetFromRaw();
+
+  elf_memory_->SetData64(0x8000, 0x0000000c24021017ULL);
+
+  for (uint64_t index = 0; index <= 50; index++) {
+    process_memory_.SetData64(addr + index * 8, index * 0x10);
+  }
+
+  ASSERT_TRUE(regs.StepIfSignalHandler(0x8000, elf_.get(), &process_memory_));
+  EXPECT_EQ(0x220U, regs[MIPS_REG_SP]);
+  EXPECT_EQ(0x040U, regs[MIPS_REG_PC]);
+  EXPECT_EQ(0x220U, regs.sp());
+  EXPECT_EQ(0x040U, regs.pc());
+}
+
+TEST_F(RegsStepIfSignalHandlerTest, mips_step_if_signal_handler_rt) {
+  uint64_t addr = 0x1000;
+  RegsMips regs;
+  regs[MIPS_REG_PC] = 0x8000;
+  regs[MIPS_REG_SP] = addr;
+  regs.SetFromRaw();
+
+  elf_memory_->SetData64(0x8000, 0x0000000c24021061ULL);
+
+  for (uint64_t index = 0; index <= 100; index++) {
+    process_memory_.SetData64(addr + index * 8, index * 0x10);
+  }
+
+  ASSERT_TRUE(regs.StepIfSignalHandler(0x8000, elf_.get(), &process_memory_));
+  EXPECT_EQ(0x350U, regs[MIPS_REG_SP]);
+  EXPECT_EQ(0x170U, regs[MIPS_REG_PC]);
+  EXPECT_EQ(0x350U, regs.sp());
+  EXPECT_EQ(0x170U, regs.pc());
+}
+
+TEST_F(RegsStepIfSignalHandlerTest, mips64_step_if_signal_handler) {
+  uint64_t addr = 0x1000;
+  RegsMips64 regs;
+  regs[MIPS64_REG_PC] = 0x8000;
+  regs[MIPS64_REG_SP] = addr;
+  regs.SetFromRaw();
+
+  elf_memory_->SetData64(0x8000, 0x0000000c2402145bULL);
+
+  for (uint64_t index = 0; index <= 100; index++) {
+    process_memory_.SetData64(addr + index * 8, index * 0x10);
+  }
+
+  ASSERT_TRUE(regs.StepIfSignalHandler(0x8000, elf_.get(), &process_memory_));
+  EXPECT_EQ(0x350U, regs[MIPS64_REG_SP]);
+  EXPECT_EQ(0x600U, regs[MIPS64_REG_PC]);
+  EXPECT_EQ(0x350U, regs.sp());
+  EXPECT_EQ(0x600U, regs.pc());
+}
+
 }  // namespace unwindstack