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Commit c8ef0df0 authored by Ian Lance Taylor's avatar Ian Lance Taylor
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cmd/cgo: add hooks for thread sanitizer 

When Go code is used with C code compiled with -fsanitize=thread, adds
thread sanitizer calls so that correctly synchronized Go code does not
cause spurious failure reports from the thread sanitizer.  This may
cause some false negatives, but for the thread sanitizer what is most
important is avoiding false positives.

Change-Id: If670e4a6f2874c7a2be2ff7db8728c6036340a52
Reviewed-on: https://go-review.googlesource.com/17421Reviewed-by: default avatarDmitry Vyukov <dvyukov@google.com>
parent c86dbbe1
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Showing with 228 additions and 36 deletions
misc/cgo/testsanitizers/test.bash
View file @ c8ef0df0
......@@ -15,35 +15,36 @@ if test -x "$(type -p clang)"; then
fi
export CC
msan=yes
TMPDIR=${TMPDIR:-/tmp}
echo > ${TMPDIR}/testsanitizers$$.c
if $CC -fsanitize=memory -c ${TMPDIR}/testsanitizers$$.c -o ${TMPDIR}/testsanitizers$$.o 2>&1 | grep "unrecognized" >& /dev/null; then
echo "skipping msan test: -fsanitize=memory not supported"
rm -f ${TMPDIR}/testsanitizers$$.*
exit 0
echo "skipping msan tests: -fsanitize=memory not supported"
msan=no
fi
rm -f ${TMPDIR}/testsanitizers$$.*
# The memory sanitizer in versions of clang before 3.6 don't work with Go.
if $CC --version | grep clang >& /dev/null; then
if test "$msan" = "yes" && $CC --version | grep clang >& /dev/null; then
ver=$($CC --version | sed -e 's/.* version \([0-9.-]*\).*/\1/')
major=$(echo $ver | sed -e 's/\([0-9]*\).*/\1/')
minor=$(echo $ver | sed -e 's/[0-9]*\.\([0-9]*\).*/\1/')
if test "$major" -lt 3 || test "$major" -eq 3 -a "$minor" -lt 6; then
echo "skipping msan test; clang version $major.$minor (older than 3.6)"
exit 0
echo "skipping msan tests: clang version $major.$minor (older than 3.6)"
msan=no
fi
# Clang before 3.8 does not work with Linux at or after 4.1.
# golang.org/issue/12898.
if test "$major" -lt 3 || test "$major" -eq 3 -a "$minor" -lt 8; then
if test "$msan" = "yes" -a "$major" -lt 3 || test "$major" -eq 3 -a "$minor" -lt 8; then
if test "$(uname)" = Linux; then
linuxver=$(uname -r)
linuxmajor=$(echo $linuxver | sed -e 's/\([0-9]*\).*/\1/')
linuxminor=$(echo $linuxver | sed -e 's/[0-9]*\.\([0-9]*\).*/\1/')
if test "$linuxmajor" -gt 4 || test "$linuxmajor" -eq 4 -a "$linuxminor" -ge 1; then
echo "skipping msan test; clang version $major.$minor (older than 3.8) incompatible with linux version $linuxmajor.$linuxminor (4.1 or newer)"
exit 0
echo "skipping msan tests: clang version $major.$minor (older than 3.8) incompatible with linux version $linuxmajor.$linuxminor (4.1 or newer)"
msan=no
fi
fi
fi
......@@ -51,39 +52,75 @@ fi
status=0
if ! go build -msan std; then
echo "FAIL: build -msan std"
status=1
fi
if test "$msan" = "yes"; then
if ! go build -msan std; then
echo "FAIL: build -msan std"
status=1
fi
if ! go run -msan msan.go; then
echo "FAIL: msan"
status=1
fi
if ! go run -msan msan.go; then
echo "FAIL: msan"
status=1
fi
if ! CGO_LDFLAGS="-fsanitize=memory" CGO_CPPFLAGS="-fsanitize=memory" go run -msan -a msan2.go; then
echo "FAIL: msan2 with -fsanitize=memory"
status=1
fi
if ! CGO_LDFLAGS="-fsanitize=memory" CGO_CPPFLAGS="-fsanitize=memory" go run -msan -a msan2.go; then
echo "FAIL: msan2 with -fsanitize=memory"
status=1
fi
if ! go run -msan -a msan2.go; then
echo "FAIL: msan2"
status=1
fi
if ! go run -msan -a msan2.go; then
echo "FAIL: msan2"
status=1
fi
if ! go run -msan msan3.go; then
echo "FAIL: msan3"
status=1
if ! go run -msan msan3.go; then
echo "FAIL: msan3"
status=1
fi
if ! go run -msan msan4.go; then
echo "FAIL: msan4"
status=1
fi
if go run -msan msan_fail.go 2>/dev/null; then
echo "FAIL: msan_fail"
status=1
fi
fi
if ! go run -msan msan4.go; then
echo "FAIL: msan4"
status=1
tsan=yes
TMPDIR=${TMPDIR:-/tmp}
echo > ${TMPDIR}/testsanitizers$$.c
if $CC -fsanitize=thread -c ${TMPDIR}/testsanitizers$$.c -o ${TMPDIR}/testsanitizers$$.o 2>&1 | grep "unrecognized" >& /dev/null; then
echo "skipping tsan tests: -fsanitize=thread not supported"
tsan=no
fi
rm -f ${TMPDIR}/testsanitizers$$.*
if test "$tsan" = "yes"; then
err=${TMPDIR}/tsanerr$$.out
if ! go run tsan.go 2>$err; then
echo "FAIL: tsan"
status=1
elif grep -i warning $err >/dev/null 2>&1; then
cat $err
echo "FAIL: tsan"
status=1
fi
if ! go run tsan2.go 2>$err; then
echo "FAIL: tsan2"
status=1
elif grep -i warning $err >/dev/null 2>&1; then
cat $err
echo "FAIL: tsan2"
status=1
fi
if go run -msan msan_fail.go 2>/dev/null; then
echo "FAIL: msan_fail"
status=1
rm -f $err
fi
exit $status
misc/cgo/testsanitizers/tsan.go 0 → 100644
View file @ c8ef0df0
// Copyright 2015 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
// This program produced false race reports when run under the C/C++
// ThreadSanitizer, as it did not understand the synchronization in
// the Go code.
/*
#cgo CFLAGS: -fsanitize=thread
#cgo LDFLAGS: -fsanitize=thread
int val;
int getVal() {
return val;
}
void setVal(int i) {
val = i;
}
*/
import "C"
import (
"runtime"
)
func main() {
runtime.LockOSThread()
C.setVal(1)
c := make(chan bool)
go func() {
runtime.LockOSThread()
C.setVal(2)
c <- true
}()
<-c
if v := C.getVal(); v != 2 {
panic(v)
}
}
misc/cgo/testsanitizers/tsan2.go 0 → 100644
View file @ c8ef0df0
// Copyright 2015 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
// This program produced false race reports when run under the C/C++
// ThreadSanitizer, as it did not understand the synchronization in
// the Go code.
/*
#cgo CFLAGS: -fsanitize=thread
#cgo LDFLAGS: -fsanitize=thread
extern void GoRun(void);
// Yes, you can have definitions if you use //export, as long as they are weak.
int val __attribute__ ((weak));
int run(void) __attribute__ ((weak));
int run() {
val = 1;
GoRun();
return val;
}
void setVal(int) __attribute__ ((weak));
void setVal(int i) {
val = i;
}
*/
import "C"
import "runtime"
//export GoRun
func GoRun() {
runtime.LockOSThread()
c := make(chan bool)
go func() {
runtime.LockOSThread()
C.setVal(2)
c <- true
}()
<-c
}
func main() {
if v := C.run(); v != 2 {
panic(v)
}
}
src/cmd/cgo/out.go
View file @ c8ef0df0
......@@ -507,6 +507,7 @@ func (p *Package) writeOutput(f *File, srcfile string) {
// Gcc output starts with the preamble.
fmt.Fprintf(fgcc, "%s\n", f.Preamble)
fmt.Fprintf(fgcc, "%s\n", gccProlog)
fmt.Fprintf(fgcc, "%s\n", tsanProlog)
for _, key := range nameKeys(f.Name) {
n := f.Name[key]
......@@ -573,6 +574,7 @@ func (p *Package) writeOutputFunc(fgcc *os.File, n *Name) {
// Save the stack top for use below.
fmt.Fprintf(fgcc, "\tchar *stktop = _cgo_topofstack();\n")
}
fmt.Fprintf(fgcc, "\t_cgo_tsan_acquire();\n")
fmt.Fprintf(fgcc, "\t")
if t := n.FuncType.Result; t != nil {
fmt.Fprintf(fgcc, "__typeof__(a->r) r = ")
......@@ -598,6 +600,7 @@ func (p *Package) writeOutputFunc(fgcc *os.File, n *Name) {
fmt.Fprintf(fgcc, "a->p%d", i)
}
fmt.Fprintf(fgcc, ");\n")
fmt.Fprintf(fgcc, "\t_cgo_tsan_release();\n")
if n.FuncType.Result != nil {
// The cgo call may have caused a stack copy (via a callback).
// Adjust the return value pointer appropriately.
......@@ -636,9 +639,13 @@ func (p *Package) writeGccgoOutputFunc(fgcc *os.File, n *Name) {
}
fmt.Fprintf(fgcc, ")\n")
fmt.Fprintf(fgcc, "{\n")
if t := n.FuncType.Result; t != nil {
fmt.Fprintf(fgcc, "\t%s r;\n", t.C.String())
}
fmt.Fprintf(fgcc, "\t_cgo_tsan_acquire();\n")
fmt.Fprintf(fgcc, "\t")
if t := n.FuncType.Result; t != nil {
fmt.Fprintf(fgcc, "return ")
fmt.Fprintf(fgcc, "r = ")
// Cast to void* to avoid warnings due to omitted qualifiers.
if c := t.C.String(); c[len(c)-1] == '*' {
fmt.Fprintf(fgcc, "(void*)")
......@@ -656,6 +663,16 @@ func (p *Package) writeGccgoOutputFunc(fgcc *os.File, n *Name) {
fmt.Fprintf(fgcc, "p%d", i)
}
fmt.Fprintf(fgcc, ");\n")
fmt.Fprintf(fgcc, "\t_cgo_tsan_release();\n")
if t := n.FuncType.Result; t != nil {
fmt.Fprintf(fgcc, "\treturn ")
// Cast to void* to avoid warnings due to omitted qualifiers
// and explicit incompatible struct types.
if c := t.C.String(); c[len(c)-1] == '*' {
fmt.Fprintf(fgcc, "(void*)")
}
fmt.Fprintf(fgcc, "r;\n")
}
fmt.Fprintf(fgcc, "}\n")
fmt.Fprintf(fgcc, "\n")
}
......@@ -683,6 +700,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) {
fmt.Fprintf(fgcc, "extern void crosscall2(void (*fn)(void *, int), void *, int);\n")
fmt.Fprintf(fgcc, "extern void _cgo_wait_runtime_init_done();\n\n")
fmt.Fprintf(fgcc, "%s\n", tsanProlog)
for _, exp := range p.ExpFunc {
fn := exp.Func
......@@ -798,7 +816,9 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) {
func(i int, aname string, atype ast.Expr) {
fmt.Fprintf(fgcc, "\ta.p%d = p%d;\n", i, i)
})
fmt.Fprintf(fgcc, "\t_cgo_tsan_release();\n")
fmt.Fprintf(fgcc, "\tcrosscall2(_cgoexp%s_%s, &a, %d);\n", cPrefix, exp.ExpName, off)
fmt.Fprintf(fgcc, "\t_cgo_tsan_acquire();\n")
if gccResult != "void" {
if len(fntype.Results.List) == 1 && len(fntype.Results.List[0].Names) <= 1 {
fmt.Fprintf(fgcc, "\treturn a.r0;\n")
......@@ -915,6 +935,7 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) {
fmt.Fprintf(fgcc, "#include \"_cgo_export.h\"\n")
fmt.Fprintf(fgcc, "%s\n", gccgoExportFileProlog)
fmt.Fprintf(fgcc, "%s\n", tsanProlog)
for _, exp := range p.ExpFunc {
fn := exp.Func
......@@ -985,11 +1006,15 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) {
fmt.Fprint(fgcc, "\n")
fmt.Fprintf(fgcc, "%s %s %s {\n", cRet, exp.ExpName, cParams)
if resultCount > 0 {
fmt.Fprintf(fgcc, "\t%s r;\n", cRet)
}
fmt.Fprintf(fgcc, "\tif(_cgo_wait_runtime_init_done)\n")
fmt.Fprintf(fgcc, "\t\t_cgo_wait_runtime_init_done();\n")
fmt.Fprintf(fgcc, "\t_cgo_tsan_release();\n")
fmt.Fprint(fgcc, "\t")
if resultCount > 0 {
fmt.Fprint(fgcc, "return ")
fmt.Fprint(fgcc, "r = ")
}
fmt.Fprintf(fgcc, "%s(", goName)
if fn.Recv != nil {
......@@ -1003,6 +1028,10 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) {
fmt.Fprintf(fgcc, "p%d", i)
})
fmt.Fprint(fgcc, ");\n")
fmt.Fprintf(fgcc, "\t_cgo_tsan_acquire();\n")
if resultCount > 0 {
fmt.Fprint(fgcc, "\treturn r;\n")
}
fmt.Fprint(fgcc, "}\n")
// Dummy declaration for _cgo_main.c
......@@ -1257,6 +1286,31 @@ extern char* _cgo_topofstack(void);
#include <string.h>
`
// Prologue defining TSAN functions in C.
const tsanProlog = `
#define _cgo_tsan_acquire()
#define _cgo_tsan_release()
#if defined(__has_feature)
#if __has_feature(thread_sanitizer)
#undef _cgo_tsan_acquire
#undef _cgo_tsan_release
long long _cgo_sync __attribute__ ((common));
extern void __tsan_acquire(void*);
extern void __tsan_release(void*);
static void _cgo_tsan_acquire() {
__tsan_acquire(&_cgo_sync);
}
static void _cgo_tsan_release() {
__tsan_release(&_cgo_sync);
}
#endif
#endif
`
const builtinProlog = `
#include <stddef.h> /* for ptrdiff_t and size_t below */
......@@ -1290,8 +1344,10 @@ func _cgoCheckResult(interface{})
`
const gccgoGoProlog = `
//extern runtime.cgoCheckPointer
func _cgoCheckPointer(interface{}, ...interface{}) interface{}
//extern runtime.cgoCheckResult
func _cgoCheckResult(interface{})
`
......
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