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-rw-r--r--test/nosplit.go425
1 files changed, 425 insertions, 0 deletions
diff --git a/test/nosplit.go b/test/nosplit.go
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index 0000000..218eb73
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+++ b/test/nosplit.go
@@ -0,0 +1,425 @@
+// +build !nacl,!js,!aix,!gcflags_noopt,gc
+// run
+
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+ "bytes"
+ "fmt"
+ "io/ioutil"
+ "log"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "regexp"
+ "runtime"
+ "strconv"
+ "strings"
+)
+
+const debug = false
+
+var tests = `
+# These are test cases for the linker analysis that detects chains of
+# nosplit functions that would cause a stack overflow.
+#
+# Lines beginning with # are comments.
+#
+# Each test case describes a sequence of functions, one per line.
+# Each function definition is the function name, then the frame size,
+# then optionally the keyword 'nosplit', then the body of the function.
+# The body is assembly code, with some shorthands.
+# The shorthand 'call x' stands for CALL x(SB).
+# The shorthand 'callind' stands for 'CALL R0', where R0 is a register.
+# Each test case must define a function named start, and it must be first.
+# That is, a line beginning "start " indicates the start of a new test case.
+# Within a stanza, ; can be used instead of \n to separate lines.
+#
+# After the function definition, the test case ends with an optional
+# REJECT line, specifying the architectures on which the case should
+# be rejected. "REJECT" without any architectures means reject on all architectures.
+# The linker should accept the test case on systems not explicitly rejected.
+#
+# 64-bit systems do not attempt to execute test cases with frame sizes
+# that are only 32-bit aligned.
+
+# Ordinary function should work
+start 0
+
+# Large frame marked nosplit is always wrong.
+# Frame is so large it overflows cmd/link's int16.
+start 100000 nosplit
+REJECT
+
+# Calling a large frame is okay.
+start 0 call big
+big 10000
+
+# But not if the frame is nosplit.
+start 0 call big
+big 10000 nosplit
+REJECT
+
+# Recursion is okay.
+start 0 call start
+
+# Recursive nosplit runs out of space.
+start 0 nosplit call start
+REJECT
+
+# Non-trivial recursion runs out of space.
+start 0 call f1
+f1 0 nosplit call f2
+f2 0 nosplit call f1
+REJECT
+# Same but cycle starts below nosplit entry.
+start 0 call f1
+f1 0 nosplit call f2
+f2 0 nosplit call f3
+f3 0 nosplit call f2
+REJECT
+
+# Chains of ordinary functions okay.
+start 0 call f1
+f1 80 call f2
+f2 80
+
+# Chains of nosplit must fit in the stack limit, 128 bytes.
+start 0 call f1
+f1 80 nosplit call f2
+f2 80 nosplit
+REJECT
+
+# Larger chains.
+start 0 call f1
+f1 16 call f2
+f2 16 call f3
+f3 16 call f4
+f4 16 call f5
+f5 16 call f6
+f6 16 call f7
+f7 16 call f8
+f8 16 call end
+end 1000
+
+start 0 call f1
+f1 16 nosplit call f2
+f2 16 nosplit call f3
+f3 16 nosplit call f4
+f4 16 nosplit call f5
+f5 16 nosplit call f6
+f6 16 nosplit call f7
+f7 16 nosplit call f8
+f8 16 nosplit call end
+end 1000
+REJECT
+
+# Two paths both go over the stack limit.
+start 0 call f1
+f1 80 nosplit call f2 call f3
+f2 40 nosplit call f4
+f3 96 nosplit
+f4 40 nosplit
+REJECT
+
+# Test cases near the 128-byte limit.
+
+# Ordinary stack split frame is always okay.
+start 112
+start 116
+start 120
+start 124
+start 128
+start 132
+start 136
+
+# A nosplit leaf can use the whole 128-CallSize bytes available on entry.
+# (CallSize is 32 on ppc64, 8 on amd64 for frame pointer.)
+start 96 nosplit
+start 100 nosplit; REJECT ppc64 ppc64le
+start 104 nosplit; REJECT ppc64 ppc64le arm64
+start 108 nosplit; REJECT ppc64 ppc64le
+start 112 nosplit; REJECT ppc64 ppc64le arm64
+start 116 nosplit; REJECT ppc64 ppc64le
+start 120 nosplit; REJECT ppc64 ppc64le amd64 arm64
+start 124 nosplit; REJECT ppc64 ppc64le amd64
+start 128 nosplit; REJECT
+start 132 nosplit; REJECT
+start 136 nosplit; REJECT
+
+# Calling a nosplit function from a nosplit function requires
+# having room for the saved caller PC and the called frame.
+# Because ARM doesn't save LR in the leaf, it gets an extra 4 bytes.
+# Because arm64 doesn't save LR in the leaf, it gets an extra 8 bytes.
+# ppc64 doesn't save LR in the leaf, but CallSize is 32, so it gets 24 bytes.
+# Because AMD64 uses frame pointer, it has 8 fewer bytes.
+start 96 nosplit call f; f 0 nosplit
+start 100 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le
+start 104 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le arm64
+start 108 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le
+start 112 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le amd64 arm64
+start 116 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le amd64
+start 120 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le amd64 arm64
+start 124 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le amd64 386
+start 128 nosplit call f; f 0 nosplit; REJECT
+start 132 nosplit call f; f 0 nosplit; REJECT
+start 136 nosplit call f; f 0 nosplit; REJECT
+
+# Calling a splitting function from a nosplit function requires
+# having room for the saved caller PC of the call but also the
+# saved caller PC for the call to morestack.
+# Architectures differ in the same way as before.
+start 96 nosplit call f; f 0 call f
+start 100 nosplit call f; f 0 call f; REJECT ppc64 ppc64le
+start 104 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64 arm64
+start 108 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64
+start 112 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64 arm64
+start 116 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64
+start 120 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64 386 arm64
+start 124 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64 386
+start 128 nosplit call f; f 0 call f; REJECT
+start 132 nosplit call f; f 0 call f; REJECT
+start 136 nosplit call f; f 0 call f; REJECT
+
+# Indirect calls are assumed to be splitting functions.
+start 96 nosplit callind
+start 100 nosplit callind; REJECT ppc64 ppc64le
+start 104 nosplit callind; REJECT ppc64 ppc64le amd64 arm64
+start 108 nosplit callind; REJECT ppc64 ppc64le amd64
+start 112 nosplit callind; REJECT ppc64 ppc64le amd64 arm64
+start 116 nosplit callind; REJECT ppc64 ppc64le amd64
+start 120 nosplit callind; REJECT ppc64 ppc64le amd64 386 arm64
+start 124 nosplit callind; REJECT ppc64 ppc64le amd64 386
+start 128 nosplit callind; REJECT
+start 132 nosplit callind; REJECT
+start 136 nosplit callind; REJECT
+
+# Issue 7623
+start 0 call f; f 112
+start 0 call f; f 116
+start 0 call f; f 120
+start 0 call f; f 124
+start 0 call f; f 128
+start 0 call f; f 132
+start 0 call f; f 136
+`
+
+var (
+ commentRE = regexp.MustCompile(`(?m)^#.*`)
+ rejectRE = regexp.MustCompile(`(?s)\A(.+?)((\n|; *)REJECT(.*))?\z`)
+ lineRE = regexp.MustCompile(`(\w+) (\d+)( nosplit)?(.*)`)
+ callRE = regexp.MustCompile(`\bcall (\w+)\b`)
+ callindRE = regexp.MustCompile(`\bcallind\b`)
+)
+
+func main() {
+ goarch := os.Getenv("GOARCH")
+ if goarch == "" {
+ goarch = runtime.GOARCH
+ }
+
+ dir, err := ioutil.TempDir("", "go-test-nosplit")
+ if err != nil {
+ bug()
+ fmt.Printf("creating temp dir: %v\n", err)
+ return
+ }
+ defer os.RemoveAll(dir)
+ os.Setenv("GOPATH", filepath.Join(dir, "_gopath"))
+
+ if err := ioutil.WriteFile(filepath.Join(dir, "go.mod"), []byte("module go-test-nosplit\n"), 0666); err != nil {
+ log.Panic(err)
+ }
+
+ tests = strings.Replace(tests, "\t", " ", -1)
+ tests = commentRE.ReplaceAllString(tests, "")
+
+ nok := 0
+ nfail := 0
+TestCases:
+ for len(tests) > 0 {
+ var stanza string
+ i := strings.Index(tests, "\nstart ")
+ if i < 0 {
+ stanza, tests = tests, ""
+ } else {
+ stanza, tests = tests[:i], tests[i+1:]
+ }
+
+ m := rejectRE.FindStringSubmatch(stanza)
+ if m == nil {
+ bug()
+ fmt.Printf("invalid stanza:\n\t%s\n", indent(stanza))
+ continue
+ }
+ lines := strings.TrimSpace(m[1])
+ reject := false
+ if m[2] != "" {
+ if strings.TrimSpace(m[4]) == "" {
+ reject = true
+ } else {
+ for _, rej := range strings.Fields(m[4]) {
+ if rej == goarch {
+ reject = true
+ }
+ }
+ }
+ }
+ if lines == "" && !reject {
+ continue
+ }
+
+ var gobuf bytes.Buffer
+ fmt.Fprintf(&gobuf, "package main\n")
+
+ var buf bytes.Buffer
+ ptrSize := 4
+ switch goarch {
+ case "mips", "mipsle":
+ fmt.Fprintf(&buf, "#define REGISTER (R0)\n")
+ case "mips64", "mips64le":
+ ptrSize = 8
+ fmt.Fprintf(&buf, "#define REGISTER (R0)\n")
+ case "loong64":
+ ptrSize = 8
+ fmt.Fprintf(&buf, "#define REGISTER (R0)\n")
+ case "ppc64", "ppc64le":
+ ptrSize = 8
+ fmt.Fprintf(&buf, "#define REGISTER (CTR)\n")
+ case "arm":
+ fmt.Fprintf(&buf, "#define REGISTER (R0)\n")
+ case "arm64":
+ ptrSize = 8
+ fmt.Fprintf(&buf, "#define REGISTER (R0)\n")
+ case "amd64":
+ ptrSize = 8
+ fmt.Fprintf(&buf, "#define REGISTER AX\n")
+ case "riscv64":
+ ptrSize = 8
+ fmt.Fprintf(&buf, "#define REGISTER A0\n")
+ case "s390x":
+ ptrSize = 8
+ fmt.Fprintf(&buf, "#define REGISTER R10\n")
+ default:
+ fmt.Fprintf(&buf, "#define REGISTER AX\n")
+ }
+
+ // Since all of the functions we're generating are
+ // ABI0, first enter ABI0 via a splittable function
+ // and then go to the chain we're testing. This way we
+ // don't have to account for ABI wrappers in the chain.
+ fmt.Fprintf(&gobuf, "func main0()\n")
+ fmt.Fprintf(&gobuf, "func main() { main0() }\n")
+ fmt.Fprintf(&buf, "TEXT ·main0(SB),0,$0-0\n\tCALL ·start(SB)\n")
+
+ adjusted := false
+ for _, line := range strings.Split(lines, "\n") {
+ line = strings.TrimSpace(line)
+ if line == "" {
+ continue
+ }
+ for _, subline := range strings.Split(line, ";") {
+ subline = strings.TrimSpace(subline)
+ if subline == "" {
+ continue
+ }
+ m := lineRE.FindStringSubmatch(subline)
+ if m == nil {
+ bug()
+ fmt.Printf("invalid function line: %s\n", subline)
+ continue TestCases
+ }
+ name := m[1]
+ size, _ := strconv.Atoi(m[2])
+
+ if size%ptrSize == 4 {
+ continue TestCases
+ }
+ nosplit := m[3]
+ body := m[4]
+
+ // The limit was originally 128 but is now 800 (928-128).
+ // Instead of rewriting the test cases above, adjust
+ // the first nosplit frame to use up the extra bytes.
+ // This isn't exactly right because we could have
+ // nosplit -> split -> nosplit, but it's good enough.
+ if !adjusted && nosplit != "" {
+ adjusted = true
+ size += (928 - 128) - 128
+ // Noopt builds have a larger stackguard.
+ // See ../src/cmd/dist/buildruntime.go:stackGuardMultiplier
+ // This increase is included in objabi.StackGuard
+ for _, s := range strings.Split(os.Getenv("GO_GCFLAGS"), " ") {
+ if s == "-N" {
+ size += 928
+ }
+ }
+ }
+
+ if nosplit != "" {
+ nosplit = ",7"
+ } else {
+ nosplit = ",0"
+ }
+ body = callRE.ReplaceAllString(body, "CALL ·$1(SB);")
+ body = callindRE.ReplaceAllString(body, "CALL REGISTER;")
+
+ fmt.Fprintf(&gobuf, "func %s()\n", name)
+ fmt.Fprintf(&buf, "TEXT ·%s(SB)%s,$%d-0\n\t%s\n\tRET\n\n", name, nosplit, size, body)
+ }
+ }
+
+ if debug {
+ fmt.Printf("===\n%s\n", strings.TrimSpace(stanza))
+ fmt.Printf("-- main.go --\n%s", gobuf.String())
+ fmt.Printf("-- asm.s --\n%s", buf.String())
+ }
+
+ if err := ioutil.WriteFile(filepath.Join(dir, "asm.s"), buf.Bytes(), 0666); err != nil {
+ log.Fatal(err)
+ }
+ if err := ioutil.WriteFile(filepath.Join(dir, "main.go"), gobuf.Bytes(), 0666); err != nil {
+ log.Fatal(err)
+ }
+
+ cmd := exec.Command("go", "build")
+ cmd.Dir = dir
+ output, err := cmd.CombinedOutput()
+ if err == nil {
+ nok++
+ if reject {
+ bug()
+ fmt.Printf("accepted incorrectly:\n\t%s\n", indent(strings.TrimSpace(stanza)))
+ }
+ } else {
+ nfail++
+ if !reject {
+ bug()
+ fmt.Printf("rejected incorrectly:\n\t%s\n", indent(strings.TrimSpace(stanza)))
+ fmt.Printf("\n\tlinker output:\n\t%s\n", indent(string(output)))
+ }
+ }
+ }
+
+ if !bugged && (nok == 0 || nfail == 0) {
+ bug()
+ fmt.Printf("not enough test cases run\n")
+ }
+}
+
+func indent(s string) string {
+ return strings.Replace(s, "\n", "\n\t", -1)
+}
+
+var bugged = false
+
+func bug() {
+ if !bugged {
+ bugged = true
+ fmt.Printf("BUG\n")
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-29 06:43:46 +0000