diff --git a/misc/cgo/testcarchive/carchive_test.go b/misc/cgo/testcarchive/carchive_test.go index 8a39c24a6d..5996268018 100644 --- a/misc/cgo/testcarchive/carchive_test.go +++ b/misc/cgo/testcarchive/carchive_test.go @@ -1247,3 +1247,57 @@ func TestPreemption(t *testing.T) { t.Error(err) } } + +// Issue 59294. Test calling Go function from C after using some +// stack space. +func TestDeepStack(t *testing.T) { + t.Parallel() + + if !testWork { + defer func() { + os.Remove("testp9" + exeSuffix) + os.Remove("libgo9.a") + os.Remove("libgo9.h") + }() + } + + cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo9.a", "./libgo9") + out, err := cmd.CombinedOutput() + t.Logf("%v\n%s", cmd.Args, out) + if err != nil { + t.Fatal(err) + } + checkLineComments(t, "libgo9.h") + checkArchive(t, "libgo9.a") + + // build with -O0 so the C compiler won't optimize out the large stack frame + ccArgs := append(cc, "-O0", "-o", "testp9"+exeSuffix, "main9.c", "libgo9.a") + out, err = exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput() + t.Logf("%v\n%s", ccArgs, out) + if err != nil { + t.Fatal(err) + } + + argv := cmdToRun("./testp9") + cmd = exec.Command(argv[0], argv[1:]...) + sb := new(strings.Builder) + cmd.Stdout = sb + cmd.Stderr = sb + if err := cmd.Start(); err != nil { + t.Fatal(err) + } + + timer := time.AfterFunc(time.Minute, + func() { + t.Error("test program timed out") + cmd.Process.Kill() + }, + ) + defer timer.Stop() + + err = cmd.Wait() + t.Logf("%v\n%s", cmd.Args, sb) + if err != nil { + t.Error(err) + } +} diff --git a/misc/cgo/testcarchive/testdata/libgo9/a.go b/misc/cgo/testcarchive/testdata/libgo9/a.go new file mode 100644 index 0000000000..acb08d90ec --- /dev/null +++ b/misc/cgo/testcarchive/testdata/libgo9/a.go @@ -0,0 +1,14 @@ +// Copyright 2023 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 "runtime" + +import "C" + +func main() {} + +//export GoF +func GoF() { runtime.GC() } diff --git a/misc/cgo/testcarchive/testdata/main9.c b/misc/cgo/testcarchive/testdata/main9.c new file mode 100644 index 0000000000..95ad4dea49 --- /dev/null +++ b/misc/cgo/testcarchive/testdata/main9.c @@ -0,0 +1,24 @@ +// Copyright 2023 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. + +#include "libgo9.h" + +void use(int *x) { (*x)++; } + +void callGoFWithDeepStack() { + int x[10000]; + + use(&x[0]); + use(&x[9999]); + + GoF(); + + use(&x[0]); + use(&x[9999]); +} + +int main() { + GoF(); // call GoF without using much stack + callGoFWithDeepStack(); // call GoF with a deep stack +} diff --git a/src/runtime/cgo.go b/src/runtime/cgo.go index 6a3eeb5822..395303552c 100644 --- a/src/runtime/cgo.go +++ b/src/runtime/cgo.go @@ -19,6 +19,7 @@ import "unsafe" //go:linkname _cgo_yield _cgo_yield //go:linkname _cgo_pthread_key_created _cgo_pthread_key_created //go:linkname _cgo_bindm _cgo_bindm +//go:linkname _cgo_getstackbound _cgo_getstackbound var ( _cgo_init unsafe.Pointer @@ -30,6 +31,7 @@ var ( _cgo_yield unsafe.Pointer _cgo_pthread_key_created unsafe.Pointer _cgo_bindm unsafe.Pointer + _cgo_getstackbound unsafe.Pointer ) // iscgo is set to true by the runtime/cgo package diff --git a/src/runtime/cgo/callbacks.go b/src/runtime/cgo/callbacks.go index 792dd7d086..3c246a88b6 100644 --- a/src/runtime/cgo/callbacks.go +++ b/src/runtime/cgo/callbacks.go @@ -141,3 +141,12 @@ var _cgo_yield unsafe.Pointer //go:cgo_export_static _cgo_topofstack //go:cgo_export_dynamic _cgo_topofstack + +// x_cgo_getstackbound gets the thread's C stack size and +// set the G's stack bound based on the stack size. + +//go:cgo_import_static x_cgo_getstackbound +//go:linkname x_cgo_getstackbound x_cgo_getstackbound +//go:linkname _cgo_getstackbound _cgo_getstackbound +var x_cgo_getstackbound byte +var _cgo_getstackbound = &x_cgo_getstackbound diff --git a/src/runtime/cgo/gcc_stack_darwin.c b/src/runtime/cgo/gcc_stack_darwin.c new file mode 100644 index 0000000000..2cc9b76196 --- /dev/null +++ b/src/runtime/cgo/gcc_stack_darwin.c @@ -0,0 +1,21 @@ +// Copyright 2023 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. + +#include +#include "libcgo.h" + +void +x_cgo_getstackbound(G *g) +{ + void* addr; + size_t size; + pthread_t p; + + p = pthread_self(); + addr = pthread_get_stackaddr_np(p); // high address (!) + size = pthread_get_stacksize_np(p); + g->stacklo = (uintptr)addr - size; + // NOTE: don't change g->stackhi. We are called from asmcgocall + // which saves the stack depth based on g->stackhi. +} diff --git a/src/runtime/cgo/gcc_stack_unix.c b/src/runtime/cgo/gcc_stack_unix.c new file mode 100644 index 0000000000..3826322661 --- /dev/null +++ b/src/runtime/cgo/gcc_stack_unix.c @@ -0,0 +1,32 @@ +// Copyright 2023 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. + +//go:build unix && !darwin + +#ifndef _GNU_SOURCE // pthread_getattr_np +#define _GNU_SOURCE +#endif + +#include +#include "libcgo.h" + +void +x_cgo_getstackbound(G *g) +{ + pthread_attr_t attr; + void *addr; + size_t size; + + pthread_attr_init(&attr); +#if defined(__GLIBC__) || defined(__sun) + pthread_getattr_np(pthread_self(), &attr); // GNU extension + pthread_attr_getstack(&attr, &addr, &size); // low address +#else + pthread_attr_getstacksize(&attr, &size); + addr = __builtin_frame_address(0) + 4096 - size; +#endif + g->stacklo = (uintptr)addr; + // NOTE: don't change g->stackhi. We are called from asmcgocall + // which saves the stack depth based on g->stackhi. +} diff --git a/src/runtime/cgo/gcc_stack_windows.c b/src/runtime/cgo/gcc_stack_windows.c new file mode 100644 index 0000000000..9fcb59cf1a --- /dev/null +++ b/src/runtime/cgo/gcc_stack_windows.c @@ -0,0 +1,7 @@ +// Copyright 2023 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. + +#include "libcgo.h" + +void x_cgo_getstackbound(G *g) {} // no-op for now diff --git a/src/runtime/proc.go b/src/runtime/proc.go index fd7760a571..4152aa4852 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -1889,8 +1889,11 @@ func allocm(pp *p, fn func(), id int64) *m { // 1. when the callback is done with the m in non-pthread platforms, // 2. or when the C thread exiting on pthread platforms. // +// The signal argument indicates whether we're called from a signal +// handler. +// //go:nosplit -func needm() { +func needm(signal bool) { if (iscgo || GOOS == "windows") && !cgoHasExtraM { // Can happen if C/C++ code calls Go from a global ctor. // Can also happen on Windows if a global ctor uses a @@ -1939,14 +1942,23 @@ func needm() { osSetupTLS(mp) // Install g (= m->g0) and set the stack bounds - // to match the current stack. We don't actually know + // to match the current stack. If we don't actually know // how big the stack is, like we don't know how big any - // scheduling stack is, but we assume there's at least 32 kB, - // which is more than enough for us. + // scheduling stack is, but we assume there's at least 32 kB. + // If we can get a more accurate stack bound from pthread, + // use that. setg(mp.g0) gp := getg() gp.stack.hi = getcallersp() + 1024 gp.stack.lo = getcallersp() - 32*1024 + if !signal && _cgo_getstackbound != nil { + // Don't adjust if called from the signal handler. + // We are on the signal stack, not the pthread stack. + // (We could get the stack bounds from sigaltstack, but + // we're getting out of the signal handler very soon + // anyway. Not worth it.) + asmcgocall(_cgo_getstackbound, unsafe.Pointer(gp)) + } gp.stackguard0 = gp.stack.lo + _StackGuard // Should mark we are already in Go now. @@ -1967,7 +1979,7 @@ func needm() { // //go:nosplit func needAndBindM() { - needm() + needm(false) if _cgo_pthread_key_created != nil && *(*uintptr)(_cgo_pthread_key_created) != 0 { cgoBindM() diff --git a/src/runtime/signal_unix.go b/src/runtime/signal_unix.go index d1719b22ff..c7edbcd239 100644 --- a/src/runtime/signal_unix.go +++ b/src/runtime/signal_unix.go @@ -585,7 +585,7 @@ func adjustSignalStack(sig uint32, mp *m, gsigStack *gsignalStack) bool { // sp is not within gsignal stack, g0 stack, or sigaltstack. Bad. setg(nil) - needm() + needm(true) if st.ss_flags&_SS_DISABLE != 0 { noSignalStack(sig) } else { @@ -1068,7 +1068,7 @@ func badsignal(sig uintptr, c *sigctxt) { exit(2) *(*uintptr)(unsafe.Pointer(uintptr(123))) = 2 } - needm() + needm(true) if !sigsend(uint32(sig)) { // A foreign thread received the signal sig, and the // Go code does not want to handle it.