[binutils-gdb] Fix "run" failure handling with GDBserver

[binutils-gdb] Fix "run" failure handling with GDBserver

[Pedro Alves]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e6dad9621d1f3388dd291af53f8ce264d5107c6b

commit e6dad9621d1f3388dd291af53f8ce264d5107c6b
Author: Pedro Alves <pedro@palves.net>
Date:   Fri Jan 26 18:00:42 2024 +0000

    Fix "run" failure handling with GDBserver
    
    If starting the inferior process with "run" (vRun packet) fails,
    GDBserver throws an error that escapes all the way to the top level.
    When an error escapes all the way like that, GDBserver interprets it
    as a disconnection, and either goes back to waiting for a new GDB
    connection, or exits, if --once was specified.
    
    E.g., with the testcase program added by this commit, we see:
    
    On GDB side:
    
     ...
     (gdb) tar extended-remote :999
     ...
     Remote debugging using :9999
     (gdb) r
     Starting program:
     Running ".../gdb.base/run-fail-twice/run-fail-twice.nox" on the remote target failed
     (gdb)
    
    On GDBserver side:
    
     $ gdbserver --once --multi :9999
     Remote debugging from host 127.0.0.1, port 34344
     bash: line 1: .../gdb.base/run-fail-twice/run-fail-twice.nox: Permission denied
     bash: line 1: exec: .../gdb.base/run-fail-twice/run-fail-twice.nox: cannot execute: Permission denied
     gdbserver: During startup program exited with code 126.
     $   # gdbserver exited
    
    This is wrong, as we've connected with extended-remote/--multi.
    GDBserver should just report an error to vCont, and continue connected
    to GDB, waiting for other commands.
    
    This commit fixes GDBserver by catching the error locally in
    handle_v_run.
    
    Change-Id: Ib386f267522603f554b52a885b15229c9639e870
    Approved-By: Tom Tromey <tom@tromey.com>

Diff:
---
 gdb/testsuite/gdb.base/run-fail-twice.c   | 20 ++++++++++
 gdb/testsuite/gdb.base/run-fail-twice.exp | 63 +++++++++++++++++++++++++++++++
 gdbserver/server.cc                       | 10 ++++-
 3 files changed, 92 insertions(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.base/run-fail-twice.c b/gdb/testsuite/gdb.base/run-fail-twice.c
new file mode 100644
index 00000000000..fddf841eb3e
--- /dev/null
+++ b/gdb/testsuite/gdb.base/run-fail-twice.c
@@ -0,0 +1,20 @@
+/* Copyright 2024 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+int
+main (int argc, char **argv)
+{
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.base/run-fail-twice.exp b/gdb/testsuite/gdb.base/run-fail-twice.exp
new file mode 100644
index 00000000000..676fc486fbf
--- /dev/null
+++ b/gdb/testsuite/gdb.base/run-fail-twice.exp
@@ -0,0 +1,63 @@
+# Copyright 2024 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test doing a "run" that fails, and then another "run".
+
+require target_can_use_run_cmd
+
+standard_testfile
+
+if {[build_executable "failed to build" $testfile $srcfile {debug}]} {
+    return -1
+}
+
+proc test_run {testname} {
+    gdb_test_multiple "run" $testname {
+	-re -wrap "During startup program exited with code 126\\." {
+	    # What we get on GNU/Linux.
+	    pass $gdb_test_name
+	}
+	-re -wrap "Error creating process.*" {
+	    # What we get on Windows.
+	    pass $gdb_test_name
+	}
+	-re -wrap "Running .* on the remote target failed" {
+	    # What we get with remote targets.
+	    pass $gdb_test_name
+	}
+    }
+}
+
+proc_with_prefix test {} {
+    global gdb_prompt binfile
+
+    clean_restart $binfile
+
+    gdb_test_no_output "set confirm off"
+
+    gdb_remote_download host $binfile $binfile.nox
+    remote_exec target "chmod \"a-x\" $binfile.nox"
+    gdb_test_no_output \
+	"exec-file $binfile.nox" \
+	"exec-file \$binfile.nox"
+    gdb_test_no_output \
+	"set remote exec-file $binfile.nox" \
+	"set remote exec-file \$binfile.nox"
+
+    test_run "bad run 1"
+    test_run "bad run 2"
+}
+
+test
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index c7d5cc1c1b0..b170da44f6a 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -3427,7 +3427,15 @@ handle_v_run (char *own_buf)
   free_vector_argv (program_args);
   program_args = new_argv;
 
-  target_create_inferior (program_path.get (), program_args);
+  try
+    {
+      target_create_inferior (program_path.get (), program_args);
+    }
+  catch (const gdb_exception_error &exception)
+    {
+      sprintf (own_buf, "E.%s", exception.what ());
+      return;
+    }
 
   if (cs.last_status.kind () == TARGET_WAITKIND_STOPPED)
     {