diff --git a/lib/std/debug.zig b/lib/std/debug.zig index 942c21212c..5c6043c8c3 100644 --- a/lib/std/debug.zig +++ b/lib/std/debug.zig @@ -1438,6 +1438,22 @@ fn handleSegfaultPosix(sig: i32, info: *const posix.siginfo_t, ctx_ptr: ?*anyopa break :info .{ addr, name }; }; const opt_cpu_context: ?cpu_context.Native = cpu_context.fromPosixSignalContext(ctx_ptr); + + if (native_arch.isSPARC()) { + // It's unclear to me whether this is a QEMU bug or also real kernel behavior, but in the + // former, I observed that the most recent register window wasn't getting spilled on the + // stack as expected when a signal arrived. A `flushw` from the signal handler does not + // appear to be sufficient either. On the other hand, when doing a synchronous stack trace + // and using `flushw`, this all appears to work as expected. So, *probably* a QEMU bug, but + // someone with real SPARC hardware should verify. + // + // In any case, the register save area exists specifically so that register windows can be + // spilled asynchronously. This means that it should be perfectly fine for us to manually do + // so here. + const ctx = opt_cpu_context.?; + @as(*[16]usize, @ptrFromInt(ctx.o[6] + StackIterator.stack_bias)).* = ctx.l ++ ctx.i; + } + handleSegfault(addr, name, if (opt_cpu_context) |*ctx| ctx else null); }