diff options
Diffstat (limited to 'src/runtime/proc.go')
| -rw-r--r-- | src/runtime/proc.go | 22 |
1 files changed, 17 insertions, 5 deletions
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() |