From acebfba75570d3039720d603774dd72d51275c31 Mon Sep 17 00:00:00 2001 From: Heschi Kreinick Date: Wed, 18 Apr 2018 13:03:35 -0400 Subject: [PATCH] runtime: use saved state in SIGPROF handler for vDSO calls VDSO calls do manual stack alignment, which doesn't get tracked in the pcsp table. Without accurate pcsp information, backtracing them is dangerous, and causes a crash in the SIGPROF handler. Fortunately, https://golang.org/cl/97315 saves a clean state in m.vdsoPC/SP. Change to use those if they're present, without attempting a normal backtrace. Fixes #24925 Change-Id: I4b8501ae73a9d18209e22f839773c4fe6102a509 Reviewed-on: https://go-review.googlesource.com/107778 Run-TryBot: Heschi Kreinick Run-TryBot: Ian Lance Taylor Reviewed-by: Ian Lance Taylor Reviewed-by: Austin Clements TryBot-Result: Gobot Gobot --- src/runtime/proc.go | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/runtime/proc.go b/src/runtime/proc.go index d99c8be1abe..b67d67a6f79 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -3716,7 +3716,7 @@ func sigprof(pc, sp, lr uintptr, gp *g, mp *m) { // transition. We simply require that g and SP match and that the PC is not // in gogo. traceback := true - if gp == nil || sp < gp.stack.lo || gp.stack.hi < sp || setsSP(pc) { + if gp == nil || sp < gp.stack.lo || gp.stack.hi < sp || setsSP(pc) || (mp != nil && mp.vdsoSP != 0) { traceback = false } var stk [maxCPUProfStack]uintptr