r267658 - in /trunk: gcc/go/gofrontend/MERGE li...

[ian@gcc.gnu.org]

Author: ian
Date: Mon Jan  7 20:12:39 2019
New Revision: 267658

URL: https://gcc.gnu.org/viewcvs?rev=267658&root=gcc&view=rev
Log:
    runtime: in getTraceback, set gp->m before gogo
    
    Currently, when collecting a traceback for another goroutine,
    getTraceback calls gogo(gp) switching to gp, which will resume in
    mcall, which will call gtraceback, which will set up gp->m. There
    is a gap between setting the current running g to gp and setting
    gp->m. If a profiling signal arrives in between, sigtramp will
    see a non-nil gp with a nil m, and will seg fault. Fix this by
    setting up gp->m first.
    
    Fixes golang/go#29448.
    
    Reviewed-on: https://go-review.googlesource.com/c/156038

Modified:
    trunk/gcc/go/gofrontend/MERGE
    trunk/libgo/go/runtime/pprof/pprof_test.go
    trunk/libgo/runtime/proc.c