cfi_frame_info_unittest.cc

// Copyright (c) 2010, Google Inc.
// All rights reserved.
//
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// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
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// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>

// cfi_frame_info_unittest.cc: Unit tests for CFIFrameInfo,
// CFIRuleParser, CFIFrameInfoParseHandler, and SimpleCFIWalker.

#include <string.h>

#include "breakpad_googletest_includes.h"
#include "common/using_std_string.h"
#include "processor/cfi_frame_info.h"
#include "google_breakpad/processor/memory_region.h"

using google_breakpad::CFIFrameInfo;
using google_breakpad::CFIFrameInfoParseHandler;
using google_breakpad::CFIRuleParser;
using google_breakpad::MemoryRegion;
using google_breakpad::SimpleCFIWalker;
using testing::_;
using testing::A;
using testing::AtMost;
using testing::DoAll;
using testing::Return;
using testing::SetArgumentPointee;
using testing::Test;

class MockMemoryRegion: public MemoryRegion {
 public:
  MOCK_CONST_METHOD0(GetBase, uint64_t());
  MOCK_CONST_METHOD0(GetSize, uint32_t());
  MOCK_CONST_METHOD2(GetMemoryAtAddress, bool(uint64_t, uint8_t *));
  MOCK_CONST_METHOD2(GetMemoryAtAddress, bool(uint64_t, uint16_t *));
  MOCK_CONST_METHOD2(GetMemoryAtAddress, bool(uint64_t, uint32_t *));
  MOCK_CONST_METHOD2(GetMemoryAtAddress, bool(uint64_t, uint64_t *));
  MOCK_CONST_METHOD0(Print, void());
};

// Handy definitions for all tests.
struct CFIFixture {

  // Set up the mock memory object to expect no references.
  void ExpectNoMemoryReferences() {
    EXPECT_CALL(memory, GetBase()).Times(0);
    EXPECT_CALL(memory, GetSize()).Times(0);
    EXPECT_CALL(memory, GetMemoryAtAddress(_, A<uint8_t *>())).Times(0);
    EXPECT_CALL(memory, GetMemoryAtAddress(_, A<uint16_t *>())).Times(0);
    EXPECT_CALL(memory, GetMemoryAtAddress(_, A<uint32_t *>())).Times(0);
    EXPECT_CALL(memory, GetMemoryAtAddress(_, A<uint64_t *>())).Times(0);
  }

  CFIFrameInfo cfi;
  MockMemoryRegion memory;
  CFIFrameInfo::RegisterValueMap<uint64_t> registers, caller_registers;
};

class Simple: public CFIFixture, public Test { };

// FindCallerRegs should fail if no .cfa rule is provided.
TEST_F(Simple, NoCFA) {
  ExpectNoMemoryReferences();

  cfi.SetRARule("0");
  ASSERT_FALSE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                             &caller_registers));
  ASSERT_EQ(".ra: 0", cfi.Serialize());
}

// FindCallerRegs should fail if no .ra rule is provided.
TEST_F(Simple, NoRA) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule("0");
  ASSERT_FALSE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                             &caller_registers));
  ASSERT_EQ(".cfa: 0", cfi.Serialize());
}

TEST_F(Simple, SetCFAAndRARule) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule("330903416631436410");
  cfi.SetRARule("5870666104170902211");
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(2U, caller_registers.size());
  ASSERT_EQ(330903416631436410ULL, caller_registers[".cfa"]);
  ASSERT_EQ(5870666104170902211ULL, caller_registers[".ra"]);

  ASSERT_EQ(".cfa: 330903416631436410 .ra: 5870666104170902211",
            cfi.Serialize());
}

TEST_F(Simple, SetManyRules) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule("$temp1 68737028 = $temp2 61072337 = $temp1 $temp2 -");
  cfi.SetRARule(".cfa 99804755 +");
  cfi.SetRegisterRule("register1", ".cfa 54370437 *");
  cfi.SetRegisterRule("vodkathumbscrewingly", "24076308 .cfa +");
  cfi.SetRegisterRule("pubvexingfjordschmaltzy", ".cfa 29801007 -");
  cfi.SetRegisterRule("uncopyrightables", "92642917 .cfa /");
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(6U, caller_registers.size());
  ASSERT_EQ(7664691U,           caller_registers[".cfa"]);
  ASSERT_EQ(107469446U,         caller_registers[".ra"]);
  ASSERT_EQ(416732599139967ULL, caller_registers["register1"]);
  ASSERT_EQ(31740999U,          caller_registers["vodkathumbscrewingly"]);
  ASSERT_EQ(-22136316ULL,       caller_registers["pubvexingfjordschmaltzy"]);
  ASSERT_EQ(12U,                caller_registers["uncopyrightables"]);
  ASSERT_EQ(".cfa: $temp1 68737028 = $temp2 61072337 = $temp1 $temp2 - "
            ".ra: .cfa 99804755 + "
            "pubvexingfjordschmaltzy: .cfa 29801007 - "
            "register1: .cfa 54370437 * "
            "uncopyrightables: 92642917 .cfa / "
            "vodkathumbscrewingly: 24076308 .cfa +",
            cfi.Serialize());
}

TEST_F(Simple, RulesOverride) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule("330903416631436410");
  cfi.SetRARule("5870666104170902211");
  cfi.SetCFARule("2828089117179001");
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(2U, caller_registers.size());
  ASSERT_EQ(2828089117179001ULL, caller_registers[".cfa"]);
  ASSERT_EQ(5870666104170902211ULL, caller_registers[".ra"]);
  ASSERT_EQ(".cfa: 2828089117179001 .ra: 5870666104170902211",
            cfi.Serialize());
}

class Scope: public CFIFixture, public Test { };

// There should be no value for .cfa in scope when evaluating the CFA rule.
TEST_F(Scope, CFALacksCFA) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule(".cfa");
  cfi.SetRARule("0");
  ASSERT_FALSE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                             &caller_registers));
}

// There should be no value for .ra in scope when evaluating the CFA rule.
TEST_F(Scope, CFALacksRA) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule(".ra");
  cfi.SetRARule("0");
  ASSERT_FALSE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                             &caller_registers));
}

// The current frame's registers should be in scope when evaluating
// the CFA rule.
TEST_F(Scope, CFASeesCurrentRegs) {
  ExpectNoMemoryReferences();

  registers[".baraminology"] = 0x06a7bc63e4f13893ULL;
  registers[".ornithorhynchus"] = 0x5e0bf850bafce9d2ULL;
  cfi.SetCFARule(".baraminology .ornithorhynchus +");
  cfi.SetRARule("0");
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(2U, caller_registers.size());
  ASSERT_EQ(0x06a7bc63e4f13893ULL + 0x5e0bf850bafce9d2ULL,
            caller_registers[".cfa"]);
}

// .cfa should be in scope in the return address expression.
TEST_F(Scope, RASeesCFA) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule("48364076");
  cfi.SetRARule(".cfa");
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(2U, caller_registers.size());
  ASSERT_EQ(48364076U, caller_registers[".ra"]);
}

// There should be no value for .ra in scope when evaluating the CFA rule.
TEST_F(Scope, RALacksRA) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule("0");
  cfi.SetRARule(".ra");
  ASSERT_FALSE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                             &caller_registers));
}

// The current frame's registers should be in scope in the return
// address expression.
TEST_F(Scope, RASeesCurrentRegs) {
  ExpectNoMemoryReferences();

  registers["noachian"] = 0x54dc4a5d8e5eb503ULL;
  cfi.SetCFARule("10359370");
  cfi.SetRARule("noachian");
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(2U, caller_registers.size());
  ASSERT_EQ(0x54dc4a5d8e5eb503ULL, caller_registers[".ra"]);
}

// .cfa should be in scope for register rules.
TEST_F(Scope, RegistersSeeCFA) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule("6515179");
  cfi.SetRARule(".cfa");
  cfi.SetRegisterRule("rogerian", ".cfa");
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(3U, caller_registers.size());
  ASSERT_EQ(6515179U, caller_registers["rogerian"]);
}

// The return address should not be in scope for register rules.
TEST_F(Scope, RegsLackRA) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule("42740329");
  cfi.SetRARule("27045204");
  cfi.SetRegisterRule("$r1", ".ra");
  ASSERT_FALSE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                             &caller_registers));
}

// Register rules can see the current frame's register values.
TEST_F(Scope, RegsSeeRegs) {
  ExpectNoMemoryReferences();

  registers["$r1"] = 0x6ed3582c4bedb9adULL;
  registers["$r2"] = 0xd27d9e742b8df6d0ULL;
  cfi.SetCFARule("88239303");
  cfi.SetRARule("30503835");
  cfi.SetRegisterRule("$r1", "$r1 42175211 = $r2");
  cfi.SetRegisterRule("$r2", "$r2 21357221 = $r1");
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(4U, caller_registers.size());
  ASSERT_EQ(0xd27d9e742b8df6d0ULL, caller_registers["$r1"]);
  ASSERT_EQ(0x6ed3582c4bedb9adULL, caller_registers["$r2"]);
}

// Each rule's temporaries are separate.
TEST_F(Scope, SeparateTempsRA) {
  ExpectNoMemoryReferences();

  cfi.SetCFARule("$temp1 76569129 = $temp1");
  cfi.SetRARule("0");
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));

  cfi.SetCFARule("$temp1 76569129 = $temp1");
  cfi.SetRARule("$temp1");
  ASSERT_FALSE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                             &caller_registers));
}

class MockCFIRuleParserHandler: public CFIRuleParser::Handler {
 public:
  MOCK_METHOD1(CFARule, void(const string &));
  MOCK_METHOD1(RARule,  void(const string &));
  MOCK_METHOD2(RegisterRule, void(const string &, const string &));
};

// A fixture class for testing CFIRuleParser.
class CFIParserFixture {
 public:
  CFIParserFixture() : parser(&mock_handler) {
    // Expect no parsing results to be reported to mock_handler. Individual
    // tests can override this.
    EXPECT_CALL(mock_handler, CFARule(_)).Times(0);
    EXPECT_CALL(mock_handler, RARule(_)).Times(0);
    EXPECT_CALL(mock_handler, RegisterRule(_, _)).Times(0);
  }

  MockCFIRuleParserHandler mock_handler;
  CFIRuleParser parser;
};

class Parser: public CFIParserFixture, public Test { };

TEST_F(Parser, Empty) {
  EXPECT_FALSE(parser.Parse(""));
}

TEST_F(Parser, LoneColon) {
  EXPECT_FALSE(parser.Parse(":"));
}

TEST_F(Parser, CFANoExpr) {
  EXPECT_FALSE(parser.Parse(".cfa:"));
}

TEST_F(Parser, CFANoColonNoExpr) {
  EXPECT_FALSE(parser.Parse(".cfa"));
}

TEST_F(Parser, RANoExpr) {
  EXPECT_FALSE(parser.Parse(".ra:"));
}

TEST_F(Parser, RANoColonNoExpr) {
  EXPECT_FALSE(parser.Parse(".ra"));
}

TEST_F(Parser, RegNoExpr) {
  EXPECT_FALSE(parser.Parse("reg:"));
}

TEST_F(Parser, NoName) {
  EXPECT_FALSE(parser.Parse("expr"));
}

TEST_F(Parser, NoNameTwo) {
  EXPECT_FALSE(parser.Parse("expr1 expr2"));
}

TEST_F(Parser, StartsWithExpr) {
  EXPECT_FALSE(parser.Parse("expr1 reg: expr2"));
}

TEST_F(Parser, CFA) {
  EXPECT_CALL(mock_handler, CFARule("spleen")).WillOnce(Return());
  EXPECT_TRUE(parser.Parse(".cfa: spleen"));
}

TEST_F(Parser, RA) {
  EXPECT_CALL(mock_handler, RARule("notoriety")).WillOnce(Return());
  EXPECT_TRUE(parser.Parse(".ra: notoriety"));
}

TEST_F(Parser, Reg) {
  EXPECT_CALL(mock_handler, RegisterRule("nemo", "mellifluous"))
      .WillOnce(Return());
  EXPECT_TRUE(parser.Parse("nemo: mellifluous"));
}

TEST_F(Parser, CFARARegs) {
  EXPECT_CALL(mock_handler, CFARule("cfa expression")).WillOnce(Return());
  EXPECT_CALL(mock_handler, RARule("ra expression")).WillOnce(Return());
  EXPECT_CALL(mock_handler, RegisterRule("galba", "praetorian"))
      .WillOnce(Return());
  EXPECT_CALL(mock_handler, RegisterRule("otho", "vitellius"))
      .WillOnce(Return());
  EXPECT_TRUE(parser.Parse(".cfa: cfa expression .ra: ra expression "
                    "galba: praetorian otho: vitellius"));
}

TEST_F(Parser, Whitespace) {
  EXPECT_CALL(mock_handler, RegisterRule("r1", "r1 expression"))
      .WillOnce(Return());
  EXPECT_CALL(mock_handler, RegisterRule("r2", "r2 expression"))
      .WillOnce(Return());
  EXPECT_TRUE(parser.Parse(" r1:\tr1\nexpression \tr2:\t\rr2\r\n "
                           "expression  \n"));
}

TEST_F(Parser, WhitespaceLoneColon) {
  EXPECT_FALSE(parser.Parse("  \n:\t  "));
}

TEST_F(Parser, EmptyName) {
  EXPECT_CALL(mock_handler, RegisterRule("reg", _))
      .Times(AtMost(1))
      .WillRepeatedly(Return());
  EXPECT_FALSE(parser.Parse("reg: expr1 : expr2"));
}

TEST_F(Parser, RuleLoneColon) {
  EXPECT_CALL(mock_handler, RegisterRule("r1", "expr"))
      .Times(AtMost(1))
      .WillRepeatedly(Return());
  EXPECT_FALSE(parser.Parse(" r1:   expr   :"));
}

TEST_F(Parser, RegNoExprRule) {
  EXPECT_CALL(mock_handler, RegisterRule("r1", "expr"))
      .Times(AtMost(1))
      .WillRepeatedly(Return());
  EXPECT_FALSE(parser.Parse("r0: r1:   expr"));
}

class ParseHandlerFixture: public CFIFixture {
 public:
  ParseHandlerFixture() : CFIFixture(), handler(&cfi) { }
  CFIFrameInfoParseHandler handler;
};

class ParseHandler: public ParseHandlerFixture, public Test { };

TEST_F(ParseHandler, CFARARule) {
  handler.CFARule("reg-for-cfa");
  handler.RARule("reg-for-ra");
  registers["reg-for-cfa"] = 0x268a9a4a3821a797ULL;
  registers["reg-for-ra"] = 0x6301b475b8b91c02ULL;
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(0x268a9a4a3821a797ULL, caller_registers[".cfa"]);
  ASSERT_EQ(0x6301b475b8b91c02ULL, caller_registers[".ra"]);
}

TEST_F(ParseHandler, RegisterRules) {
  handler.CFARule("reg-for-cfa");
  handler.RARule("reg-for-ra");
  handler.RegisterRule("reg1", "reg-for-reg1");
  handler.RegisterRule("reg2", "reg-for-reg2");
  registers["reg-for-cfa"] = 0x268a9a4a3821a797ULL;
  registers["reg-for-ra"] = 0x6301b475b8b91c02ULL;
  registers["reg-for-reg1"] = 0x06cde8e2ff062481ULL;
  registers["reg-for-reg2"] = 0xff0c4f76403173e2ULL;
  ASSERT_TRUE(cfi.FindCallerRegs<uint64_t>(registers, memory,
                                            &caller_registers));
  ASSERT_EQ(0x268a9a4a3821a797ULL, caller_registers[".cfa"]);
  ASSERT_EQ(0x6301b475b8b91c02ULL, caller_registers[".ra"]);
  ASSERT_EQ(0x06cde8e2ff062481ULL, caller_registers["reg1"]);
  ASSERT_EQ(0xff0c4f76403173e2ULL, caller_registers["reg2"]);
}

struct SimpleCFIWalkerFixture {
  struct RawContext {
    uint64_t r0, r1, r2, r3, r4, sp, pc;
  };
  enum Validity {
    R0_VALID = 0x01,
    R1_VALID = 0x02,
    R2_VALID = 0x04,
    R3_VALID = 0x08,
    R4_VALID = 0x10,
    SP_VALID = 0x20,
    PC_VALID = 0x40
  };
  typedef SimpleCFIWalker<uint64_t, RawContext> CFIWalker;

  SimpleCFIWalkerFixture()
      : walker(register_map,
               sizeof(register_map) / sizeof(register_map[0])) { }

  static CFIWalker::RegisterSet register_map[7];
  CFIFrameInfo call_frame_info;
  CFIWalker walker;
  MockMemoryRegion memory;
  RawContext callee_context, caller_context;
};

SimpleCFIWalkerFixture::CFIWalker::RegisterSet
SimpleCFIWalkerFixture::register_map[7] = {
  { "r0", NULL,   true,  R0_VALID, &RawContext::r0 },
  { "r1", NULL,   true,  R1_VALID, &RawContext::r1 },
  { "r2", NULL,   false, R2_VALID, &RawContext::r2 },
  { "r3", NULL,   false, R3_VALID, &RawContext::r3 },
  { "r4", NULL,   true,  R4_VALID, &RawContext::r4 },
  { "sp", ".cfa", true,  SP_VALID, &RawContext::sp },
  { "pc", ".ra",  true,  PC_VALID, &RawContext::pc },
};

class SimpleWalker: public SimpleCFIWalkerFixture, public Test { };

TEST_F(SimpleWalker, Walk) {
  // Stack_top is the current stack pointer, pointing to the lowest
  // address of a frame that looks like this (all 64-bit words):
  //
  // sp ->  saved r0
  //        garbage
  //        return address
  // cfa -> 
  //
  // r0 has been saved on the stack.
  // r1 has been saved in r2.
  // r2 and r3 are not recoverable.
  // r4 is not recoverable, even though it is a callee-saves register.
  //    Some earlier frame's unwinder must have failed to recover it.

  uint64_t stack_top = 0x83254944b20d5512ULL;

  // Saved r0.
  EXPECT_CALL(memory,
              GetMemoryAtAddress(stack_top, A<uint64_t *>()))
      .WillRepeatedly(DoAll(SetArgumentPointee<1>(0xdc1975eba8602302ULL),
                            Return(true)));
  // Saved return address.
  EXPECT_CALL(memory,
              GetMemoryAtAddress(stack_top + 16, A<uint64_t *>()))
      .WillRepeatedly(DoAll(SetArgumentPointee<1>(0xba5ad6d9acce28deULL),
                            Return(true)));

  call_frame_info.SetCFARule("sp 24 +");
  call_frame_info.SetRARule(".cfa 8 - ^");
  call_frame_info.SetRegisterRule("r0", ".cfa 24 - ^");
  call_frame_info.SetRegisterRule("r1", "r2");

  callee_context.r0 = 0x94e030ca79edd119ULL;
  callee_context.r1 = 0x937b4d7e95ce52d9ULL;
  callee_context.r2 = 0x5fe0027416b8b62aULL; // caller's r1
  // callee_context.r3 is not valid in callee.
  // callee_context.r4 is not valid in callee.
  callee_context.sp = stack_top;
  callee_context.pc = 0x25b21b224311d280ULL;
  int callee_validity = R0_VALID | R1_VALID | R2_VALID | SP_VALID | PC_VALID;

  memset(&caller_context, 0, sizeof(caller_context));

  int caller_validity;
  EXPECT_TRUE(walker.FindCallerRegisters(memory, call_frame_info,
                                         callee_context, callee_validity,
                                         &caller_context, &caller_validity));
  EXPECT_EQ(R0_VALID | R1_VALID | SP_VALID | PC_VALID, caller_validity);
  EXPECT_EQ(0xdc1975eba8602302ULL, caller_context.r0);
  EXPECT_EQ(0x5fe0027416b8b62aULL, caller_context.r1);
  EXPECT_EQ(stack_top + 24,        caller_context.sp);
  EXPECT_EQ(0xba5ad6d9acce28deULL, caller_context.pc);
}