From 15140d6df667a71e660dc9da9ca9071fa3c5dbbd Mon Sep 17 00:00:00 2001 From: Jon Turney Date: Tue, 16 Jan 2024 16:12:51 +0000 Subject: Cygwin: Don't terminate via dumper A process which is exiting due to a core dumping signal doesn't propagate the correct exist status after dumping core, because 'dumper' itself forcibly terminates the process. Use 'dumper -n' to avoid killing the dumped process, so we continue to the end of signal_exit(), to exit with the 128+signal exit status. Busy-wait in exec_prepared_command() in an attempt to reliably notice the dumper attaching, so we don't get stuck there. Also: document these important facts for custom uses of error_start. --- winsup/cygwin/exceptions.cc | 7 +++---- winsup/doc/cygwinenv.xml | 6 ++++++ 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc index 8b1c5493e..0e1a804ca 100644 --- a/winsup/cygwin/exceptions.cc +++ b/winsup/cygwin/exceptions.cc @@ -149,7 +149,7 @@ dumper_init (void) /* Calculate the length of the command, allowing for an appended DWORD PID and terminating null */ - int cmd_len = 1 + wcslen(dll_dir) + 11 + 2 + 1 + wcslen(global_progname) + 1 + 10 + 1; + int cmd_len = 1 + wcslen(dll_dir) + 11 + 5 + 1 + wcslen(global_progname) + 1 + 10 + 1; if (cmd_len > 32767) { /* If this comes to more than the 32,767 characters CreateProcess() can @@ -163,7 +163,7 @@ dumper_init (void) cp = wcpcpy (cp, L"\""); cp = wcpcpy (cp, dll_dir); cp = wcpcpy (cp, L"\\dumper.exe"); - cp = wcpcpy (cp, L"\" "); + cp = wcpcpy (cp, L"\" -n "); cp = wcpcpy (cp, L"\""); cp = wcpcpy (cp, global_progname); wcscat (cp, L"\""); @@ -570,9 +570,8 @@ int exec_prepared_command (PWCHAR command) system_printf ("Failed to start, %E"); else { - SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_IDLE); while (!being_debugged ()) - Sleep (1); + Sleep (0); Sleep (2000); } diff --git a/winsup/doc/cygwinenv.xml b/winsup/doc/cygwinenv.xml index d97f2b77d..05672c404 100644 --- a/winsup/doc/cygwinenv.xml +++ b/winsup/doc/cygwinenv.xml @@ -46,6 +46,12 @@ to the command as arguments. Note: This has no effect if a debugger is already attached when the fatal error occurs. + + Note: The command invoked must either (i) attach to the errored process with + DebugActiveProcess(), or (ii) forcibly terminate the + errored process (with TerminateProcess() or similar), as + otherwise the errored process will wait forever for a debugger to attach. + -- cgit v1.2.3