Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

cmd/cgo: add hooks for thread sanitizer

Browse source 
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/17421
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
This commit is contained in:
Ian Lance Taylor 2015-12-03 19:17:21 -08:00
parent c86dbbe1b9
commit c8ef0df06c
4 changed files with 228 additions and 36 deletions
Download patch file Download diff file Expand all files Collapse all files

60
src/cmd/cgo/out.go
View file

@ -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{})
`