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| author | Michael Anthony Knyszek <mknyszek@google.com> | 2021-11-05 23:35:58 +0000 |
|---|---|---|
| committer | Michael Knyszek <mknyszek@google.com> | 2021-11-08 16:44:14 +0000 |
| commit | 7ee3f1427b079bb363689321b0565ba7b03de03e (patch) | |
| tree | 015a05e87a0d84ff43ffbff2f0131cebbb4ee0d0 /src/runtime/export_debug_test.go | |
| parent | 759eaa22adb0ab883959e4a36c19f2dfe77b5895 (diff) | |
| download | go-7ee3f1427b079bb363689321b0565ba7b03de03e.tar.xz | |
runtime: disable GC during debug call tests
Currently the debug call protocol implementation we use for testing is
riddled with write barriers, and called from a signal handler. This is
not safe, as write barriers need a P to execute.
Ideally this implementation would be rewritten to avoid the write
barriers, but it's not straightforward, and needs some thought. As a
temporary measure, disable GC during the debug call tests to avoid a
write barrier.
Note that this does not indicate a problem with real use of the debug
call protocol. Only our test implementation has this issue, because it
needs to get executed in a signal handler, normally a separate process
is interfacing with the protocol via process signals and ptrace (and the
like).
Fixes #49370.
Change-Id: Ic0fde5d0f4c64f9ecc9789b7dabb3954538fe0a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/361896
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Diffstat (limited to 'src/runtime/export_debug_test.go')
| -rw-r--r-- | src/runtime/export_debug_test.go | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/src/runtime/export_debug_test.go b/src/runtime/export_debug_test.go index 032a9b9725..fffc99d7e5 100644 --- a/src/runtime/export_debug_test.go +++ b/src/runtime/export_debug_test.go @@ -107,6 +107,10 @@ type debugCallHandler struct { } func (h *debugCallHandler) inject(info *siginfo, ctxt *sigctxt, gp2 *g) bool { + // TODO(49370): This code is riddled with write barriers, but called from + // a signal handler. Add the go:nowritebarrierrec annotation and restructure + // this to avoid write barriers. + switch h.gp.atomicstatus { case _Grunning: if getg().m != h.mp { @@ -141,7 +145,11 @@ func (h *debugCallHandler) inject(info *siginfo, ctxt *sigctxt, gp2 *g) bool { } func (h *debugCallHandler) handle(info *siginfo, ctxt *sigctxt, gp2 *g) bool { - // Sanity check. + // TODO(49370): This code is riddled with write barriers, but called from + // a signal handler. Add the go:nowritebarrierrec annotation and restructure + // this to avoid write barriers. + + // Double-check m. if getg().m != h.mp { println("trap on wrong M", getg().m, h.mp) return false |