diff options
Diffstat (limited to 'src/runtime/traceback.go')
| -rw-r--r-- | src/runtime/traceback.go | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/src/runtime/traceback.go b/src/runtime/traceback.go index 834435b40..1c6ce6e64 100644 --- a/src/runtime/traceback.go +++ b/src/runtime/traceback.go @@ -101,6 +101,22 @@ func gentraceback(pc0 uintptr, sp0 uintptr, lr0 uintptr, gp *g, skip int, pcbuf gothrow("gentraceback before goexitPC initialization") } g := getg() + if g == gp && g == g.m.curg { + // The starting sp has been passed in as a uintptr, and the caller may + // have other uintptr-typed stack references as well. + // If during one of the calls that got us here or during one of the + // callbacks below the stack must be grown, all these uintptr references + // to the stack will not be updated, and gentraceback will continue + // to inspect the old stack memory, which may no longer be valid. + // Even if all the variables were updated correctly, it is not clear that + // we want to expose a traceback that begins on one stack and ends + // on another stack. That could confuse callers quite a bit. + // Instead, we require that gentraceback and any other function that + // accepts an sp for the current goroutine (typically obtained by + // calling getcallersp) must not run on that goroutine's stack but + // instead on the g0 stack. + gothrow("gentraceback cannot trace user goroutine on its own stack") + } gotraceback := gotraceback(nil) if pc0 == ^uintptr(0) && sp0 == ^uintptr(0) { // Signal to fetch saved values from gp. if gp.syscallsp != 0 { @@ -511,7 +527,11 @@ func traceback1(pc uintptr, sp uintptr, lr uintptr, gp *g, flags uint) { func callers(skip int, pcbuf *uintptr, m int) int { sp := getcallersp(unsafe.Pointer(&skip)) pc := uintptr(getcallerpc(unsafe.Pointer(&skip))) - return gentraceback(pc, sp, 0, getg(), skip, pcbuf, m, nil, nil, 0) + var n int + onM(func() { + n = gentraceback(pc, sp, 0, getg(), skip, pcbuf, m, nil, nil, 0) + }) + return n } func gcallers(gp *g, skip int, pcbuf *uintptr, m int) int { |