[release-branch.go1.2] runtime: fix crash in runtime.GoroutineProfile

This CL is not exactly a copy of the original quoted below.
This CL omits the changes made to mgc0.c in the original.
Those changes do not apply cleanly to the Go 1.2 tree,
and they were cosmetic, simplifying code that was already
doing the right thing.

To double-check that omitting the mgc0.c change has not
invalidated the fix, I have verified by hand that the test program
in issue 6946 fails without this CL and passes with this CL.

««« CL 41640043 / e4c381446b48
runtime: fix crash in runtime.GoroutineProfile

This is a possible Go 1.2.1 candidate.

Fixes #6946.

R=iant, r
CC=golang-dev
https://golang.org/cl/41640043
»»»

LGTM=adg
R=adg
CC=golang-codereviews, golang-dev, iant, r
https://golang.org/cl/68820045

diff --git a/src/pkg/runtime/mprof.goc b/src/pkg/runtime/mprof.goc
index 5b92cec95c72856053f84bf785cf8875db084dae..4ae74f0c288377de607d5d63ad3f01b5125ec786 100644 (file)
--- a/src/pkg/runtime/mprof.goc
+++ b/src/pkg/runtime/mprof.goc
@@ -477,7 +477,7 @@ saveg(uintptr pc, uintptr sp, G *gp, TRecord *r)
 {
        int32 n;
        
-       n = runtime·gentraceback((uintptr)pc, (uintptr)sp, 0, gp, 0, r->stk, nelem(r->stk), nil, nil, false);
+       n = runtime·gentraceback(pc, sp, 0, gp, 0, r->stk, nelem(r->stk), nil, nil, false);
        if(n < nelem(r->stk))
                r->stk[n] = 0;
 }
@@ -505,7 +505,7 @@ func GoroutineProfile(b Slice) (n int, ok bool) {
                        for(gp = runtime·allg; gp != nil; gp = gp->alllink) {
                                if(gp == g || gp->status == Gdead)
                                        continue;
-                               saveg(gp->sched.pc, gp->sched.sp, gp, r++);
+                               saveg(~(uintptr)0, ~(uintptr)0, gp, r++);
                        }
                }
        

diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c
index de26c72d3d7553243dd79c7e6ffcef95fb5ef8a4..ed3e1e73eebdd1ba7a5556cce834b74b56632647 100644 (file)
--- a/src/pkg/runtime/proc.c
+++ b/src/pkg/runtime/proc.c
@@ -276,7 +276,7 @@ runtime·tracebackothers(G *me)
        if((gp = m->curg) != nil && gp != me) {
                runtime·printf("\n");
                runtime·goroutineheader(gp);
-               runtime·traceback(gp->sched.pc, gp->sched.sp, gp->sched.lr, gp);
+               runtime·traceback(~(uintptr)0, ~(uintptr)0, 0, gp);
        }
 
        for(gp = runtime·allg; gp != nil; gp = gp->alllink) {
@@ -290,7 +290,7 @@ runtime·tracebackothers(G *me)
                        runtime·printf("\tgoroutine running on other thread; stack unavailable\n");
                        runtime·printcreatedby(gp);
                } else
-                       runtime·traceback(gp->sched.pc, gp->sched.sp, gp->sched.lr, gp);
+                       runtime·traceback(~(uintptr)0, ~(uintptr)0, 0, gp);
        }
 }
 

diff --git a/src/pkg/runtime/traceback_arm.c b/src/pkg/runtime/traceback_arm.c
index 341aa20588010d7a3a0574dce69732a431084e7b..8a3685e76c508ee3d0ffa251bfdba5a88aaf3eee 100644 (file)
--- a/src/pkg/runtime/traceback_arm.c
+++ b/src/pkg/runtime/traceback_arm.c
@@ -20,6 +20,18 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
        Stktop *stk;
        String file;
 
+       if(pc0 == ~(uintptr)0 && sp0 == ~(uintptr)0) { // Signal to fetch saved values from gp.
+               if(gp->syscallstack != (uintptr)nil) {
+                       pc0 = gp->syscallpc;
+                       sp0 = gp->syscallsp;
+                       lr0 = 0;
+               } else {
+                       pc0 = gp->sched.pc;
+                       sp0 = gp->sched.sp;
+                       lr0 = gp->sched.lr;
+               }
+       }
+
        nprint = 0;
        runtime·memclr((byte*)&frame, sizeof frame);
        frame.pc = pc0;

diff --git a/src/pkg/runtime/traceback_x86.c b/src/pkg/runtime/traceback_x86.c
index d658e8f11a94d32184833e38179d9ea5be4795a2..8e3063f43a64a89fe23f064d95059ef89795b4a3 100644 (file)
--- a/src/pkg/runtime/traceback_x86.c
+++ b/src/pkg/runtime/traceback_x86.c
@@ -30,6 +30,16 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
        String file;
 
        USED(lr0);
+       
+       if(pc0 == ~(uintptr)0 && sp0 == ~(uintptr)0) { // Signal to fetch saved values from gp.
+               if(gp->syscallstack != (uintptr)nil) {
+                       pc0 = gp->syscallpc;
+                       sp0 = gp->syscallsp;
+               } else {
+                       pc0 = gp->sched.pc;
+                       sp0 = gp->sched.sp;
+               }
+       }
 
        nprint = 0;
        runtime·memclr((byte*)&frame, sizeof frame);