From: Pedro Alves Date: Tue, 5 Mar 2024 16:03:15 +0000 (+0000) Subject: Cygwin/testsuite: Avoid infinite hang X-Git-Tag: gdb-15-branchpoint~420 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9c25a9d0f7542113e995fdc967e522fc5aabd936;p=thirdparty%2Fbinutils-gdb.git Cygwin/testsuite: Avoid infinite hang On Cygwin, the gdb.base/fork-no-detach-follow-child-dlopen.exp testcase hits a sequence of cascading FAILs: (gdb) run Starting program: ..../gdb.base/fork-no-detach-follow-child-dlopen/fork-no-detach-follow-child-dlopen [New Thread 12672.0x318c] [New Thread 12672.0x2844] [New Thread 12672.0x714] FAIL: gdb.base/fork-no-detach-follow-child-dlopen.exp: runto: run to add (timeout) frame FAIL: gdb.base/fork-no-detach-follow-child-dlopen.exp: frame (timeout) list FAIL: gdb.base/fork-no-detach-follow-child-dlopen.exp: list (timeout) And the test program never makes progress. ... and at this point, Cygwin is completely stuck. I can't run any other Cygwin program. However, if we run the test program outside DejaGnu, we see something different: (gdb) b add Function "add" not defined. Make breakpoint pending on future shared library load? (y or [n]) y Breakpoint 1 (add) pending. (gdb) r Starting program: ..../gdb.base/fork-no-detach-follow-child-dlopen/fork-no-detach-follow-child-dlopen [New Thread 10968.0x834] [New Thread 10968.0x29a4] [New Thread 10968.0x16b8] [New Thread 10968.0xf9c] [Switching to Thread 10968.0x16b8] Thread 4 "sig" hit Breakpoint 1.2, pending_signals::add (pack=..., this=0x7ffa1e748a40 ) at /usr/src/debug/cygwin-3.4.9-1/winsup/cygwin/sigproc.cc:1304 1304 se = sigs + pack.si.si_signo; (gdb) Ah, the test wanted to run to a global "add" function, but managed to stop at an internal Cygwin method called "add". And stopping there deadlocks everything Cygwin in the system. (I believe some cygwin1.dll mechanisms use cross-process synchronization or communication, we're probably blocking something like that.) Fix this by using "break -q". The tests FAIL because we don't support follow-fork for Cygwin, but at least we no longer deadlock the machine. Approved-by: Kevin Buettner Change-Id: I7181d8481c2ae1024b0d73e3bb194f9a4f0a7eb9 --- diff --git a/gdb/testsuite/gdb.base/fork-no-detach-follow-child-dlopen.exp b/gdb/testsuite/gdb.base/fork-no-detach-follow-child-dlopen.exp index d56148d79e8..de339c531bd 100644 --- a/gdb/testsuite/gdb.base/fork-no-detach-follow-child-dlopen.exp +++ b/gdb/testsuite/gdb.base/fork-no-detach-follow-child-dlopen.exp @@ -45,7 +45,7 @@ proc do_test {} { gdb_test_no_output "set follow-fork-mode child" gdb_test_no_output "set detach-on-fork off" - runto "add" allow-pending + runto "add" qualified allow-pending # Since we have debug info in the shlib, we should have the file name available. gdb_test "frame" "add \(.*\) at .*$::srcfile2:\[0-9\]+.*"