Source file src/runtime/runtime-gdb_test.go

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package runtime_test
     6  
     7  import (
     8  	"bytes"
     9  	"flag"
    10  	"fmt"
    11  	"internal/testenv"
    12  	"os"
    13  	"os/exec"
    14  	"path/filepath"
    15  	"regexp"
    16  	"runtime"
    17  	"strconv"
    18  	"strings"
    19  	"testing"
    20  	"time"
    21  )
    22  
    23  // NOTE: In some configurations, GDB will segfault when sent a SIGWINCH signal.
    24  // Some runtime tests send SIGWINCH to the entire process group, so those tests
    25  // must never run in parallel with GDB tests.
    26  //
    27  // See issue 39021 and https://sourceware.org/bugzilla/show_bug.cgi?id=26056.
    28  
    29  func checkGdbEnvironment(t *testing.T) {
    30  	testenv.MustHaveGoBuild(t)
    31  	switch runtime.GOOS {
    32  	case "darwin":
    33  		t.Skip("gdb does not work on darwin")
    34  	case "netbsd":
    35  		t.Skip("gdb does not work with threads on NetBSD; see https://golang.org/issue/22893 and https://gnats.netbsd.org/52548")
    36  	case "linux":
    37  		if runtime.GOARCH == "ppc64" {
    38  			t.Skip("skipping gdb tests on linux/ppc64; see https://golang.org/issue/17366")
    39  		}
    40  		if runtime.GOARCH == "mips" {
    41  			t.Skip("skipping gdb tests on linux/mips; see https://golang.org/issue/25939")
    42  		}
    43  		// Disable GDB tests on alpine until issue #54352 resolved.
    44  		if strings.HasSuffix(testenv.Builder(), "-alpine") {
    45  			t.Skip("skipping gdb tests on alpine; see https://golang.org/issue/54352")
    46  		}
    47  	case "freebsd":
    48  		t.Skip("skipping gdb tests on FreeBSD; see https://golang.org/issue/29508")
    49  	case "aix":
    50  		if testing.Short() {
    51  			t.Skip("skipping gdb tests on AIX; see https://golang.org/issue/35710")
    52  		}
    53  	case "plan9":
    54  		t.Skip("there is no gdb on Plan 9")
    55  	}
    56  }
    57  
    58  func checkGdbVersion(t *testing.T) {
    59  	// Issue 11214 reports various failures with older versions of gdb.
    60  	out, err := exec.Command("gdb", "--version").CombinedOutput()
    61  	if err != nil {
    62  		t.Skipf("skipping: error executing gdb: %v", err)
    63  	}
    64  	re := regexp.MustCompile(`([0-9]+)\.([0-9]+)`)
    65  	matches := re.FindSubmatch(out)
    66  	if len(matches) < 3 {
    67  		t.Skipf("skipping: can't determine gdb version from\n%s\n", out)
    68  	}
    69  	major, err1 := strconv.Atoi(string(matches[1]))
    70  	minor, err2 := strconv.Atoi(string(matches[2]))
    71  	if err1 != nil || err2 != nil {
    72  		t.Skipf("skipping: can't determine gdb version: %v, %v", err1, err2)
    73  	}
    74  	// The Go toolchain now generates DWARF 5 by default, which needs
    75  	// a GDB version of 10 or above.
    76  	if major < 10 {
    77  		t.Skipf("skipping: gdb version %d.%d too old", major, minor)
    78  	}
    79  	if major < 12 || (major == 12 && minor < 1) {
    80  		t.Logf("gdb version <12.1 is known to crash due to a SIGWINCH recieved in non-interactive mode; if you see a crash, some test may be sending SIGWINCH to the whole process group. See go.dev/issue/58932.")
    81  	}
    82  	t.Logf("gdb version %d.%d", major, minor)
    83  }
    84  
    85  func checkGdbPython(t *testing.T) {
    86  	if runtime.GOOS == "solaris" || runtime.GOOS == "illumos" {
    87  		t.Skip("skipping gdb python tests on illumos and solaris; see golang.org/issue/20821")
    88  	}
    89  	args := []string{"-nx", "-q", "--batch", "-iex", "python import sys; print('go gdb python support')"}
    90  	gdbArgsFixup(args)
    91  	cmd := exec.Command("gdb", args...)
    92  	out, err := cmd.CombinedOutput()
    93  
    94  	if err != nil {
    95  		t.Skipf("skipping due to issue running gdb: %v", err)
    96  	}
    97  	if strings.TrimSpace(string(out)) != "go gdb python support" {
    98  		t.Skipf("skipping due to lack of python gdb support: %s", out)
    99  	}
   100  }
   101  
   102  // checkCleanBacktrace checks that the given backtrace is well formed and does
   103  // not contain any error messages from GDB.
   104  func checkCleanBacktrace(t *testing.T, backtrace string) {
   105  	backtrace = strings.TrimSpace(backtrace)
   106  	lines := strings.Split(backtrace, "\n")
   107  	if len(lines) == 0 {
   108  		t.Fatalf("empty backtrace")
   109  	}
   110  	for i, l := range lines {
   111  		if !strings.HasPrefix(l, fmt.Sprintf("#%v  ", i)) {
   112  			t.Fatalf("malformed backtrace at line %v: %v", i, l)
   113  		}
   114  	}
   115  	// TODO(mundaym): check for unknown frames (e.g. "??").
   116  }
   117  
   118  // checkPtraceScope checks the value of the kernel parameter ptrace_scope,
   119  // skips the test when gdb cannot attach to the target process via ptrace.
   120  // See issue 69932
   121  //
   122  // 0 - Default attach security permissions.
   123  // 1 - Restricted attach. Only child processes plus normal permissions.
   124  // 2 - Admin-only attach. Only executables with CAP_SYS_PTRACE.
   125  // 3 - No attach. No process may call ptrace at all. Irrevocable.
   126  func checkPtraceScope(t *testing.T) {
   127  	if runtime.GOOS != "linux" {
   128  		return
   129  	}
   130  
   131  	// If the Linux kernel does not have the YAMA module enabled,
   132  	// there will be no ptrace_scope file, which does not affect the tests.
   133  	path := "/proc/sys/kernel/yama/ptrace_scope"
   134  	if _, err := os.Stat(path); os.IsNotExist(err) {
   135  		return
   136  	}
   137  
   138  	data, err := os.ReadFile(path)
   139  	if err != nil {
   140  		t.Fatalf("failed to read file: %v", err)
   141  	}
   142  	value, err := strconv.Atoi(strings.TrimSpace(string(data)))
   143  	if err != nil {
   144  		t.Fatalf("failed converting value to int: %v", err)
   145  	}
   146  	switch value {
   147  	case 3:
   148  		t.Skip("skipping ptrace: Operation not permitted")
   149  	case 2:
   150  		if os.Geteuid() != 0 {
   151  			t.Skip("skipping ptrace: Operation not permitted with non-root user")
   152  		}
   153  	}
   154  }
   155  
   156  var helloSource = `
   157  import "fmt"
   158  import "runtime"
   159  var gslice []string
   160  // TODO(prattmic): Stack allocated maps initialized inline appear "optimized out" in GDB.
   161  var smallmapvar map[string]string
   162  func main() {
   163  	smallmapvar = make(map[string]string)
   164  	// NOTE: the maps below are allocated large to ensure that they are not
   165  	// "optimized out".
   166  	mapvar := make(map[string]string, 10)
   167  	slicemap := make(map[string][]string, 10)
   168  	chanint := make(chan int, 10)
   169  	chanstr := make(chan string, 10)
   170  	chanint <- 99
   171  	chanint <- 11
   172  	chanstr <- "spongepants"
   173  	chanstr <- "squarebob"
   174  	smallmapvar["abc"] = "def"
   175  	mapvar["abc"] = "def"
   176  	mapvar["ghi"] = "jkl"
   177  	slicemap["a"] = []string{"b","c","d"}
   178  	slicemap["e"] = []string{"f","g","h"}
   179  	strvar := "abc"
   180  	ptrvar := &strvar
   181  	slicevar := make([]string, 0, 16)
   182  	slicevar = append(slicevar, mapvar["abc"])
   183  	fmt.Println("hi")
   184  	runtime.KeepAlive(ptrvar)
   185  	_ = ptrvar // set breakpoint here
   186  	gslice = slicevar
   187  	fmt.Printf("%v, %v, %v\n", slicemap, <-chanint, <-chanstr)
   188  	runtime.KeepAlive(smallmapvar)
   189  	runtime.KeepAlive(mapvar)
   190  }  // END_OF_PROGRAM
   191  `
   192  
   193  func lastLine(src []byte) int {
   194  	eop := []byte("END_OF_PROGRAM")
   195  	for i, l := range bytes.Split(src, []byte("\n")) {
   196  		if bytes.Contains(l, eop) {
   197  			return i
   198  		}
   199  	}
   200  	return 0
   201  }
   202  
   203  func gdbArgsFixup(args []string) {
   204  	if runtime.GOOS != "windows" {
   205  		return
   206  	}
   207  	// On Windows, some gdb flavors expect -ex and -iex arguments
   208  	// containing spaces to be double quoted.
   209  	var quote bool
   210  	for i, arg := range args {
   211  		if arg == "-iex" || arg == "-ex" {
   212  			quote = true
   213  		} else if quote {
   214  			if strings.ContainsRune(arg, ' ') {
   215  				args[i] = `"` + arg + `"`
   216  			}
   217  			quote = false
   218  		}
   219  	}
   220  }
   221  
   222  func TestGdbPython(t *testing.T) {
   223  	testGdbPython(t, false)
   224  }
   225  
   226  func TestGdbPythonCgo(t *testing.T) {
   227  	if strings.HasPrefix(runtime.GOARCH, "mips") {
   228  		testenv.SkipFlaky(t, 37794)
   229  	}
   230  	testGdbPython(t, true)
   231  }
   232  
   233  func testGdbPython(t *testing.T, cgo bool) {
   234  	if cgo {
   235  		testenv.MustHaveCGO(t)
   236  	}
   237  
   238  	checkGdbEnvironment(t)
   239  	t.Parallel()
   240  	checkGdbVersion(t)
   241  	checkGdbPython(t)
   242  	checkPtraceScope(t)
   243  
   244  	dir := t.TempDir()
   245  
   246  	var buf bytes.Buffer
   247  	buf.WriteString("package main\n")
   248  	if cgo {
   249  		buf.WriteString(`import "C"` + "\n")
   250  	}
   251  	buf.WriteString(helloSource)
   252  
   253  	src := buf.Bytes()
   254  
   255  	// Locate breakpoint line
   256  	var bp int
   257  	lines := bytes.Split(src, []byte("\n"))
   258  	for i, line := range lines {
   259  		if bytes.Contains(line, []byte("breakpoint")) {
   260  			bp = i
   261  			break
   262  		}
   263  	}
   264  
   265  	err := os.WriteFile(filepath.Join(dir, "main.go"), src, 0644)
   266  	if err != nil {
   267  		t.Fatalf("failed to create file: %v", err)
   268  	}
   269  	nLines := lastLine(src)
   270  
   271  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
   272  	cmd.Dir = dir
   273  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   274  	if err != nil {
   275  		t.Fatalf("building source %v\n%s", err, out)
   276  	}
   277  
   278  	args := []string{"-nx", "-q", "--batch",
   279  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   280  		"-ex", "set startup-with-shell off",
   281  		"-ex", "set print thread-events off",
   282  	}
   283  	if cgo {
   284  		// When we build the cgo version of the program, the system's
   285  		// linker is used. Some external linkers, like GNU gold,
   286  		// compress the .debug_gdb_scripts into .zdebug_gdb_scripts.
   287  		// Until gold and gdb can work together, temporarily load the
   288  		// python script directly.
   289  		args = append(args,
   290  			"-ex", "source "+filepath.Join(testenv.GOROOT(t), "src", "runtime", "runtime-gdb.py"),
   291  		)
   292  	} else {
   293  		args = append(args,
   294  			"-ex", "info auto-load python-scripts",
   295  		)
   296  	}
   297  	args = append(args,
   298  		"-ex", "set python print-stack full",
   299  		"-ex", fmt.Sprintf("br main.go:%d", bp),
   300  		"-ex", "run",
   301  		"-ex", "echo BEGIN info goroutines\n",
   302  		"-ex", "info goroutines",
   303  		"-ex", "echo END\n",
   304  		"-ex", "echo BEGIN print smallmapvar\n",
   305  		"-ex", "print smallmapvar",
   306  		"-ex", "echo END\n",
   307  		"-ex", "echo BEGIN print mapvar\n",
   308  		"-ex", "print mapvar",
   309  		"-ex", "echo END\n",
   310  		"-ex", "echo BEGIN print slicemap\n",
   311  		"-ex", "print slicemap",
   312  		"-ex", "echo END\n",
   313  		"-ex", "echo BEGIN print strvar\n",
   314  		"-ex", "print strvar",
   315  		"-ex", "echo END\n",
   316  		"-ex", "echo BEGIN print chanint\n",
   317  		"-ex", "print chanint",
   318  		"-ex", "echo END\n",
   319  		"-ex", "echo BEGIN print chanstr\n",
   320  		"-ex", "print chanstr",
   321  		"-ex", "echo END\n",
   322  		"-ex", "echo BEGIN info locals\n",
   323  		"-ex", "info locals",
   324  		"-ex", "echo END\n",
   325  		"-ex", "echo BEGIN goroutine 1 bt\n",
   326  		"-ex", "goroutine 1 bt",
   327  		"-ex", "echo END\n",
   328  		"-ex", "echo BEGIN goroutine all bt\n",
   329  		"-ex", "goroutine all bt",
   330  		"-ex", "echo END\n",
   331  		"-ex", "clear main.go:15", // clear the previous break point
   332  		"-ex", fmt.Sprintf("br main.go:%d", nLines), // new break point at the end of main
   333  		"-ex", "c",
   334  		"-ex", "echo BEGIN goroutine 1 bt at the end\n",
   335  		"-ex", "goroutine 1 bt",
   336  		"-ex", "echo END\n",
   337  		filepath.Join(dir, "a.exe"),
   338  	)
   339  	gdbArgsFixup(args)
   340  	got, err := exec.Command("gdb", args...).CombinedOutput()
   341  	t.Logf("gdb output:\n%s", got)
   342  	if err != nil {
   343  		t.Fatalf("gdb exited with error: %v", err)
   344  	}
   345  
   346  	got = bytes.ReplaceAll(got, []byte("\r\n"), []byte("\n")) // normalize line endings
   347  	// Extract named BEGIN...END blocks from output
   348  	partRe := regexp.MustCompile(`(?ms)^BEGIN ([^\n]*)\n(.*?)\nEND`)
   349  	blocks := map[string]string{}
   350  	for _, subs := range partRe.FindAllSubmatch(got, -1) {
   351  		blocks[string(subs[1])] = string(subs[2])
   352  	}
   353  
   354  	infoGoroutinesRe := regexp.MustCompile(`\*\s+\d+\s+running\s+`)
   355  	if bl := blocks["info goroutines"]; !infoGoroutinesRe.MatchString(bl) {
   356  		t.Fatalf("info goroutines failed: %s", bl)
   357  	}
   358  
   359  	printSmallMapvarRe := regexp.MustCompile(`^\$[0-9]+ = map\[string\]string = {\[(0x[0-9a-f]+\s+)?"abc"\] = (0x[0-9a-f]+\s+)?"def"}$`)
   360  	if bl := blocks["print smallmapvar"]; !printSmallMapvarRe.MatchString(bl) {
   361  		t.Fatalf("print smallmapvar failed: %s", bl)
   362  	}
   363  
   364  	printMapvarRe1 := regexp.MustCompile(`^\$[0-9]+ = map\[string\]string = {\[(0x[0-9a-f]+\s+)?"abc"\] = (0x[0-9a-f]+\s+)?"def", \[(0x[0-9a-f]+\s+)?"ghi"\] = (0x[0-9a-f]+\s+)?"jkl"}$`)
   365  	printMapvarRe2 := regexp.MustCompile(`^\$[0-9]+ = map\[string\]string = {\[(0x[0-9a-f]+\s+)?"ghi"\] = (0x[0-9a-f]+\s+)?"jkl", \[(0x[0-9a-f]+\s+)?"abc"\] = (0x[0-9a-f]+\s+)?"def"}$`)
   366  	if bl := blocks["print mapvar"]; !printMapvarRe1.MatchString(bl) &&
   367  		!printMapvarRe2.MatchString(bl) {
   368  		t.Fatalf("print mapvar failed: %s", bl)
   369  	}
   370  
   371  	// 2 orders, and possible differences in spacing.
   372  	sliceMapSfx1 := `map[string][]string = {["e"] = []string = {"f", "g", "h"}, ["a"] = []string = {"b", "c", "d"}}`
   373  	sliceMapSfx2 := `map[string][]string = {["a"] = []string = {"b", "c", "d"}, ["e"] = []string = {"f", "g", "h"}}`
   374  	if bl := strings.ReplaceAll(blocks["print slicemap"], "  ", " "); !strings.HasSuffix(bl, sliceMapSfx1) && !strings.HasSuffix(bl, sliceMapSfx2) {
   375  		t.Fatalf("print slicemap failed: %s", bl)
   376  	}
   377  
   378  	chanIntSfx := `chan int = {99, 11}`
   379  	if bl := strings.ReplaceAll(blocks["print chanint"], "  ", " "); !strings.HasSuffix(bl, chanIntSfx) {
   380  		t.Fatalf("print chanint failed: %s", bl)
   381  	}
   382  
   383  	chanStrSfx := `chan string = {"spongepants", "squarebob"}`
   384  	if bl := strings.ReplaceAll(blocks["print chanstr"], "  ", " "); !strings.HasSuffix(bl, chanStrSfx) {
   385  		t.Fatalf("print chanstr failed: %s", bl)
   386  	}
   387  
   388  	strVarRe := regexp.MustCompile(`^\$[0-9]+ = (0x[0-9a-f]+\s+)?"abc"$`)
   389  	if bl := blocks["print strvar"]; !strVarRe.MatchString(bl) {
   390  		t.Fatalf("print strvar failed: %s", bl)
   391  	}
   392  
   393  	// The exact format of composite values has changed over time.
   394  	// For issue 16338: ssa decompose phase split a slice into
   395  	// a collection of scalar vars holding its fields. In such cases
   396  	// the DWARF variable location expression should be of the
   397  	// form "var.field" and not just "field".
   398  	// However, the newer dwarf location list code reconstituted
   399  	// aggregates from their fields and reverted their printing
   400  	// back to its original form.
   401  	// Only test that all variables are listed in 'info locals' since
   402  	// different versions of gdb print variables in different
   403  	// order and with differing amount of information and formats.
   404  
   405  	if bl := blocks["info locals"]; !strings.Contains(bl, "slicevar") ||
   406  		!strings.Contains(bl, "mapvar") ||
   407  		!strings.Contains(bl, "strvar") {
   408  		t.Fatalf("info locals failed: %s", bl)
   409  	}
   410  
   411  	// Check that the backtraces are well formed.
   412  	checkCleanBacktrace(t, blocks["goroutine 1 bt"])
   413  	checkCleanBacktrace(t, blocks["goroutine 1 bt at the end"])
   414  
   415  	btGoroutine1Re := regexp.MustCompile(`(?m)^#0\s+(0x[0-9a-f]+\s+in\s+)?main\.main.+at`)
   416  	if bl := blocks["goroutine 1 bt"]; !btGoroutine1Re.MatchString(bl) {
   417  		t.Fatalf("goroutine 1 bt failed: %s", bl)
   418  	}
   419  
   420  	if bl := blocks["goroutine all bt"]; !btGoroutine1Re.MatchString(bl) {
   421  		t.Fatalf("goroutine all bt failed: %s", bl)
   422  	}
   423  
   424  	btGoroutine1AtTheEndRe := regexp.MustCompile(`(?m)^#0\s+(0x[0-9a-f]+\s+in\s+)?main\.main.+at`)
   425  	if bl := blocks["goroutine 1 bt at the end"]; !btGoroutine1AtTheEndRe.MatchString(bl) {
   426  		t.Fatalf("goroutine 1 bt at the end failed: %s", bl)
   427  	}
   428  }
   429  
   430  const backtraceSource = `
   431  package main
   432  
   433  //go:noinline
   434  func aaa() bool { return bbb() }
   435  
   436  //go:noinline
   437  func bbb() bool { return ccc() }
   438  
   439  //go:noinline
   440  func ccc() bool { return ddd() }
   441  
   442  //go:noinline
   443  func ddd() bool { return f() }
   444  
   445  //go:noinline
   446  func eee() bool { return true }
   447  
   448  var f = eee
   449  
   450  func main() {
   451  	_ = aaa()
   452  }
   453  `
   454  
   455  // TestGdbBacktrace tests that gdb can unwind the stack correctly
   456  // using only the DWARF debug info.
   457  func TestGdbBacktrace(t *testing.T) {
   458  	if runtime.GOOS == "netbsd" {
   459  		testenv.SkipFlaky(t, 15603)
   460  	}
   461  	if flag.Lookup("test.parallel").Value.(flag.Getter).Get().(int) < 2 {
   462  		// It is possible that this test will hang for a long time due to an
   463  		// apparent GDB bug reported in https://go.dev/issue/37405.
   464  		// If test parallelism is high enough, that might be ok: the other parallel
   465  		// tests will finish, and then this test will finish right before it would
   466  		// time out. However, if test are running sequentially, a hang in this test
   467  		// would likely cause the remaining tests to run out of time.
   468  		testenv.SkipFlaky(t, 37405)
   469  	}
   470  
   471  	checkGdbEnvironment(t)
   472  	t.Parallel()
   473  	checkGdbVersion(t)
   474  	checkPtraceScope(t)
   475  
   476  	dir := t.TempDir()
   477  
   478  	// Build the source code.
   479  	src := filepath.Join(dir, "main.go")
   480  	err := os.WriteFile(src, []byte(backtraceSource), 0644)
   481  	if err != nil {
   482  		t.Fatalf("failed to create file: %v", err)
   483  	}
   484  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
   485  	cmd.Dir = dir
   486  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   487  	if err != nil {
   488  		t.Fatalf("building source %v\n%s", err, out)
   489  	}
   490  
   491  	// Execute gdb commands.
   492  	start := time.Now()
   493  	args := []string{"-nx", "-batch",
   494  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   495  		"-ex", "set startup-with-shell off",
   496  		"-ex", "break main.eee",
   497  		"-ex", "run",
   498  		"-ex", "backtrace",
   499  		"-ex", "continue",
   500  		filepath.Join(dir, "a.exe"),
   501  	}
   502  	gdbArgsFixup(args)
   503  	cmd = testenv.Command(t, "gdb", args...)
   504  
   505  	// Work around the GDB hang reported in https://go.dev/issue/37405.
   506  	// Sometimes (rarely), the GDB process hangs completely when the Go program
   507  	// exits, and we suspect that the bug is on the GDB side.
   508  	//
   509  	// The default Cancel function added by testenv.Command will mark the test as
   510  	// failed if it is in danger of timing out, but we want to instead mark it as
   511  	// skipped. Change the Cancel function to kill the process and merely log
   512  	// instead of failing the test.
   513  	//
   514  	// (This approach does not scale: if the test parallelism is less than or
   515  	// equal to the number of tests that run right up to the deadline, then the
   516  	// remaining parallel tests are likely to time out. But as long as it's just
   517  	// this one flaky test, it's probably fine..?)
   518  	//
   519  	// If there is no deadline set on the test at all, relying on the timeout set
   520  	// by testenv.Command will cause the test to hang indefinitely, but that's
   521  	// what “no deadline” means, after all — and it's probably the right behavior
   522  	// anyway if someone is trying to investigate and fix the GDB bug.
   523  	cmd.Cancel = func() error {
   524  		t.Logf("GDB command timed out after %v: %v", time.Since(start), cmd)
   525  		return cmd.Process.Kill()
   526  	}
   527  
   528  	got, err := cmd.CombinedOutput()
   529  	t.Logf("gdb output:\n%s", got)
   530  	if err != nil {
   531  		noProcessRE := regexp.MustCompile(`Couldn't get [a-zA-Z_ -]* ?registers: No such process\.`)
   532  		switch {
   533  		case bytes.Contains(got, []byte("internal-error: wait returned unexpected status 0x0")):
   534  			// GDB bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28551
   535  			testenv.SkipFlaky(t, 43068)
   536  		case noProcessRE.Match(got),
   537  			bytes.Contains(got, []byte("Unable to fetch general registers.: No such process.")),
   538  			bytes.Contains(got, []byte("reading register pc (#64): No such process.")):
   539  			// GDB bug: https://sourceware.org/bugzilla/show_bug.cgi?id=9086
   540  			testenv.SkipFlaky(t, 50838)
   541  		case bytes.Contains(got, []byte("waiting for new child: No child processes.")):
   542  			// GDB bug: Sometimes it fails to wait for a clone child.
   543  			testenv.SkipFlaky(t, 60553)
   544  		case bytes.Contains(got, []byte(" exited normally]\n")):
   545  			// GDB bug: Sometimes the inferior exits fine,
   546  			// but then GDB hangs.
   547  			testenv.SkipFlaky(t, 37405)
   548  		}
   549  		t.Fatalf("gdb exited with error: %v", err)
   550  	}
   551  
   552  	// Check that the backtrace matches the source code.
   553  	bt := []string{
   554  		"eee",
   555  		"ddd",
   556  		"ccc",
   557  		"bbb",
   558  		"aaa",
   559  		"main",
   560  	}
   561  	for i, name := range bt {
   562  		s := fmt.Sprintf("#%v.*main\\.%v", i, name)
   563  		re := regexp.MustCompile(s)
   564  		if found := re.Find(got) != nil; !found {
   565  			t.Fatalf("could not find '%v' in backtrace", s)
   566  		}
   567  	}
   568  }
   569  
   570  const autotmpTypeSource = `
   571  package main
   572  
   573  type astruct struct {
   574  	a, b int
   575  }
   576  
   577  func main() {
   578  	var iface interface{} = map[string]astruct{}
   579  	var iface2 interface{} = []astruct{}
   580  	println(iface, iface2)
   581  }
   582  `
   583  
   584  // TestGdbAutotmpTypes ensures that types of autotmp variables appear in .debug_info
   585  // See bug #17830.
   586  func TestGdbAutotmpTypes(t *testing.T) {
   587  	checkGdbEnvironment(t)
   588  	t.Parallel()
   589  	checkGdbVersion(t)
   590  	checkPtraceScope(t)
   591  
   592  	if runtime.GOOS == "aix" && testing.Short() {
   593  		t.Skip("TestGdbAutotmpTypes is too slow on aix/ppc64")
   594  	}
   595  
   596  	dir := t.TempDir()
   597  
   598  	// Build the source code.
   599  	src := filepath.Join(dir, "main.go")
   600  	err := os.WriteFile(src, []byte(autotmpTypeSource), 0644)
   601  	if err != nil {
   602  		t.Fatalf("failed to create file: %v", err)
   603  	}
   604  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-gcflags=all=-N -l", "-o", "a.exe", "main.go")
   605  	cmd.Dir = dir
   606  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   607  	if err != nil {
   608  		t.Fatalf("building source %v\n%s", err, out)
   609  	}
   610  
   611  	// Execute gdb commands.
   612  	args := []string{"-nx", "-batch",
   613  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   614  		"-ex", "set startup-with-shell off",
   615  		// Some gdb may set scheduling-locking as "step" by default. This prevents background tasks
   616  		// (e.g GC) from completing which may result in a hang when executing the step command.
   617  		// See #49852.
   618  		"-ex", "set scheduler-locking off",
   619  		"-ex", "break main.main",
   620  		"-ex", "run",
   621  		"-ex", "step",
   622  		"-ex", "info types astruct",
   623  		filepath.Join(dir, "a.exe"),
   624  	}
   625  	gdbArgsFixup(args)
   626  	got, err := exec.Command("gdb", args...).CombinedOutput()
   627  	t.Logf("gdb output:\n%s", got)
   628  	if err != nil {
   629  		t.Fatalf("gdb exited with error: %v", err)
   630  	}
   631  
   632  	sgot := string(got)
   633  
   634  	// Check that the backtrace matches the source code.
   635  	types := []string{
   636  		"[]main.astruct",
   637  		"main.astruct",
   638  		"groupReference<string,main.astruct>",
   639  		"table<string,main.astruct>",
   640  		"map<string,main.astruct>",
   641  		"map<string,main.astruct> * map[string]main.astruct",
   642  	}
   643  	for _, name := range types {
   644  		if !strings.Contains(sgot, name) {
   645  			t.Fatalf("could not find %q in 'info typrs astruct' output", name)
   646  		}
   647  	}
   648  }
   649  
   650  const constsSource = `
   651  package main
   652  
   653  const aConstant int = 42
   654  const largeConstant uint64 = ^uint64(0)
   655  const minusOne int64 = -1
   656  
   657  func main() {
   658  	println("hello world")
   659  }
   660  `
   661  
   662  func TestGdbConst(t *testing.T) {
   663  	checkGdbEnvironment(t)
   664  	t.Parallel()
   665  	checkGdbVersion(t)
   666  	checkPtraceScope(t)
   667  
   668  	dir := t.TempDir()
   669  
   670  	// Build the source code.
   671  	src := filepath.Join(dir, "main.go")
   672  	err := os.WriteFile(src, []byte(constsSource), 0644)
   673  	if err != nil {
   674  		t.Fatalf("failed to create file: %v", err)
   675  	}
   676  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-gcflags=all=-N -l", "-o", "a.exe", "main.go")
   677  	cmd.Dir = dir
   678  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   679  	if err != nil {
   680  		t.Fatalf("building source %v\n%s", err, out)
   681  	}
   682  
   683  	// Execute gdb commands.
   684  	args := []string{"-nx", "-batch",
   685  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   686  		"-ex", "set startup-with-shell off",
   687  		"-ex", "break main.main",
   688  		"-ex", "run",
   689  		"-ex", "print main.aConstant",
   690  		"-ex", "print main.largeConstant",
   691  		"-ex", "print main.minusOne",
   692  		"-ex", "print 'runtime.mSpanInUse'",
   693  		"-ex", "print 'runtime._PageSize'",
   694  		filepath.Join(dir, "a.exe"),
   695  	}
   696  	gdbArgsFixup(args)
   697  	got, err := exec.Command("gdb", args...).CombinedOutput()
   698  	t.Logf("gdb output:\n%s", got)
   699  	if err != nil {
   700  		t.Fatalf("gdb exited with error: %v", err)
   701  	}
   702  
   703  	sgot := strings.ReplaceAll(string(got), "\r\n", "\n")
   704  
   705  	if !strings.Contains(sgot, "\n$1 = 42\n$2 = 18446744073709551615\n$3 = -1\n$4 = 1 '\\001'\n$5 = 8192") {
   706  		t.Fatalf("output mismatch")
   707  	}
   708  }
   709  
   710  const panicSource = `
   711  package main
   712  
   713  import "runtime/debug"
   714  
   715  func main() {
   716  	debug.SetTraceback("crash")
   717  	crash()
   718  }
   719  
   720  func crash() {
   721  	panic("panic!")
   722  }
   723  `
   724  
   725  // TestGdbPanic tests that gdb can unwind the stack correctly
   726  // from SIGABRTs from Go panics.
   727  func TestGdbPanic(t *testing.T) {
   728  	checkGdbEnvironment(t)
   729  	t.Parallel()
   730  	checkGdbVersion(t)
   731  	checkPtraceScope(t)
   732  
   733  	if runtime.GOOS == "windows" {
   734  		t.Skip("no signals on windows")
   735  	}
   736  
   737  	dir := t.TempDir()
   738  
   739  	// Build the source code.
   740  	src := filepath.Join(dir, "main.go")
   741  	err := os.WriteFile(src, []byte(panicSource), 0644)
   742  	if err != nil {
   743  		t.Fatalf("failed to create file: %v", err)
   744  	}
   745  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
   746  	cmd.Dir = dir
   747  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   748  	if err != nil {
   749  		t.Fatalf("building source %v\n%s", err, out)
   750  	}
   751  
   752  	// Execute gdb commands.
   753  	args := []string{"-nx", "-batch",
   754  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   755  		"-ex", "set startup-with-shell off",
   756  		"-ex", "run",
   757  		"-ex", "backtrace",
   758  		filepath.Join(dir, "a.exe"),
   759  	}
   760  	gdbArgsFixup(args)
   761  	got, err := exec.Command("gdb", args...).CombinedOutput()
   762  	t.Logf("gdb output:\n%s", got)
   763  	if err != nil {
   764  		t.Fatalf("gdb exited with error: %v", err)
   765  	}
   766  
   767  	// Check that the backtrace matches the source code.
   768  	bt := []string{
   769  		`crash`,
   770  		`main`,
   771  	}
   772  	for _, name := range bt {
   773  		s := fmt.Sprintf("(#.* .* in )?main\\.%v", name)
   774  		re := regexp.MustCompile(s)
   775  		if found := re.Find(got) != nil; !found {
   776  			t.Fatalf("could not find '%v' in backtrace", s)
   777  		}
   778  	}
   779  }
   780  
   781  const InfCallstackSource = `
   782  package main
   783  import "C"
   784  import "time"
   785  
   786  func loop() {
   787          for i := 0; i < 1000; i++ {
   788                  time.Sleep(time.Millisecond*5)
   789          }
   790  }
   791  
   792  func main() {
   793          go loop()
   794          time.Sleep(time.Second * 1)
   795  }
   796  `
   797  
   798  // TestGdbInfCallstack tests that gdb can unwind the callstack of cgo programs
   799  // on arm64 platforms without endless frames of function 'crossfunc1'.
   800  // https://golang.org/issue/37238
   801  func TestGdbInfCallstack(t *testing.T) {
   802  	checkGdbEnvironment(t)
   803  
   804  	testenv.MustHaveCGO(t)
   805  	if runtime.GOARCH != "arm64" {
   806  		t.Skip("skipping infinite callstack test on non-arm64 arches")
   807  	}
   808  
   809  	t.Parallel()
   810  	checkGdbVersion(t)
   811  	checkPtraceScope(t)
   812  
   813  	dir := t.TempDir()
   814  
   815  	// Build the source code.
   816  	src := filepath.Join(dir, "main.go")
   817  	err := os.WriteFile(src, []byte(InfCallstackSource), 0644)
   818  	if err != nil {
   819  		t.Fatalf("failed to create file: %v", err)
   820  	}
   821  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
   822  	cmd.Dir = dir
   823  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   824  	if err != nil {
   825  		t.Fatalf("building source %v\n%s", err, out)
   826  	}
   827  
   828  	// Execute gdb commands.
   829  	// 'setg_gcc' is the first point where we can reproduce the issue with just one 'run' command.
   830  	args := []string{"-nx", "-batch",
   831  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   832  		"-ex", "set startup-with-shell off",
   833  		"-ex", "break setg_gcc",
   834  		"-ex", "run",
   835  		"-ex", "backtrace 3",
   836  		"-ex", "disable 1",
   837  		"-ex", "continue",
   838  		filepath.Join(dir, "a.exe"),
   839  	}
   840  	gdbArgsFixup(args)
   841  	got, err := exec.Command("gdb", args...).CombinedOutput()
   842  	t.Logf("gdb output:\n%s", got)
   843  	if err != nil {
   844  		t.Fatalf("gdb exited with error: %v", err)
   845  	}
   846  
   847  	// Check that the backtrace matches
   848  	// We check the 3 inner most frames only as they are present certainly, according to gcc_<OS>_arm64.c
   849  	bt := []string{
   850  		`setg_gcc`,
   851  		`crosscall1`,
   852  		`threadentry`,
   853  	}
   854  	for i, name := range bt {
   855  		s := fmt.Sprintf("#%v.*%v", i, name)
   856  		re := regexp.MustCompile(s)
   857  		if found := re.Find(got) != nil; !found {
   858  			t.Fatalf("could not find '%v' in backtrace", s)
   859  		}
   860  	}
   861  }
   862  

View as plain text