runtime: handle async fatal signals in VDSO
If we receive an async signal while running in the VDSO, such as a
SIGABRT or SIGSEGV sent from another process, we fail to print the
stacktrace with "runtime: unknown pc <vdso PC>".
We already have machinery to handle SIGPROF in the VDSO, but it isn't
hooked up for other signals. Add it to the general signal traceback
path.
This case is covered by TestSegv by making the test more strict w.r.t.
accepted output.
Fixes #47537
Change-Id: I755585f70e0c23e207e135bc6bd2aa68298e5d24
Reviewed-on: https://go-review.googlesource.com/c/go/+/339990
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
diff --git a/src/runtime/crash_cgo_test.go b/src/runtime/crash_cgo_test.go
index 9df6fcd..0ccfe85 100644
--- a/src/runtime/crash_cgo_test.go
+++ b/src/runtime/crash_cgo_test.go
@@ -526,13 +526,15 @@
}
t.Parallel()
got := runTestProg(t, "testprogcgo", "TracebackSigpanic")
+ t.Log(got)
want := "runtime.sigpanic"
if !strings.Contains(got, want) {
- t.Fatalf("want failure containing %q. output:\n%s\n", want, got)
+ t.Errorf("did not see %q in output", want)
}
- nowant := "unexpected return pc"
+ // No runtime errors like "runtime: unexpected return pc".
+ nowant := "runtime: "
if strings.Contains(got, nowant) {
- t.Fatalf("failure incorrectly contains %q. output:\n%s\n", nowant, got)
+ t.Errorf("unexpectedly saw %q in output", want)
}
}
@@ -619,8 +621,14 @@
t.Parallel()
got := runTestProg(t, "testprogcgo", test)
t.Log(got)
- if !strings.Contains(got, "SIGSEGV") {
- t.Errorf("expected crash from signal")
+ want := "SIGSEGV"
+ if !strings.Contains(got, want) {
+ t.Errorf("did not see %q in output", want)
+ }
+ // No runtime errors like "runtime: unknown pc".
+ nowant := "runtime: "
+ if strings.Contains(got, nowant) {
+ t.Errorf("unexpectedly saw %q in output", want)
}
})
}
diff --git a/src/runtime/traceback.go b/src/runtime/traceback.go
index 530d572..7e1b14c 100644
--- a/src/runtime/traceback.go
+++ b/src/runtime/traceback.go
@@ -777,16 +777,23 @@
printCgoTraceback(&cgoCallers)
}
- var n int
if readgstatus(gp)&^_Gscan == _Gsyscall {
// Override registers if blocked in system call.
pc = gp.syscallpc
sp = gp.syscallsp
flags &^= _TraceTrap
}
+ if gp.m != nil && gp.m.vdsoSP != 0 {
+ // Override registers if running in VDSO. This comes after the
+ // _Gsyscall check to cover VDSO calls after entersyscall.
+ pc = gp.m.vdsoPC
+ sp = gp.m.vdsoSP
+ flags &^= _TraceTrap
+ }
+
// Print traceback. By default, omits runtime frames.
// If that means we print nothing at all, repeat forcing all frames printed.
- n = gentraceback(pc, sp, lr, gp, 0, nil, _TracebackMaxFrames, nil, nil, flags)
+ n := gentraceback(pc, sp, lr, gp, 0, nil, _TracebackMaxFrames, nil, nil, flags)
if n == 0 && (flags&_TraceRuntimeFrames) == 0 {
n = gentraceback(pc, sp, lr, gp, 0, nil, _TracebackMaxFrames, nil, nil, flags|_TraceRuntimeFrames)
}
