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Re: [PATCH v2] gdbserver: Fix crash when QTinit is handled with no inferior process attached
- From: Pedro Alves <palves at redhat dot com>
- To: Antoine Tremblay <antoine dot tremblay at ericsson dot com>, gdb-patches at sourceware dot org
- Date: Fri, 06 Feb 2015 15:50:24 +0000
- Subject: Re: [PATCH v2] gdbserver: Fix crash when QTinit is handled with no inferior process attached
- Authentication-results: sourceware.org; auth=none
- References: <54D3A9FB dot 2050305 at redhat dot com> <1423166768-24921-1-git-send-email-antoine dot tremblay at ericsson dot com>
On 02/05/2015 08:06 PM, Antoine Tremblay wrote:
> When gdbserver is called with --multi and attach has not been called yet
> and tstart is called on the gdb client, gdbserver would crash.
> This patch fixes gdbserver so that it returns E01 to the gdb client.
>
> Also this patch adds a testcase to verify this bug named no-attach-trace.exp
Thanks! Pretty good. Just a few minor nits. Just the usual formatting
details that are easy to miss the first time around.
> gdb/ChangeLog:
> PR gdb/15956
> * gdb/gdbserver/tracepoint.c (cmd_qtinit): Added check for
> current_thread.
gdbserver has it's own ChangeLog file, gdb/gdbserver/ChangeLog.
Then adjust the entry to read "* gdbserver/tracepoint.c", as entries
are relative to the ChangeLog file's path.
Also, s/Added/Add/.
>
> gdb/testsuite/ChangeLog:
> * gdb.trace/no-attach-trace.c: New file.
> * gdb.trace/no-attach-trace.exp: New file.
> ---
> gdb/gdbserver/tracepoint.c | 7 +++++
> gdb/testsuite/gdb.trace/Makefile.in | 4 +--
> gdb/testsuite/gdb.trace/no-attach-trace.c | 25 ++++++++++++++++
> gdb/testsuite/gdb.trace/no-attach-trace.exp | 43 +++++++++++++++++++++++++++
> 4 files changed, 77 insertions(+), 2 deletions(-)
> create mode 100644 gdb/testsuite/gdb.trace/no-attach-trace.c
> create mode 100644 gdb/testsuite/gdb.trace/no-attach-trace.exp
>
> diff --git a/gdb/gdbserver/tracepoint.c b/gdb/gdbserver/tracepoint.c
> index 82d6ce5..0518530 100644
> --- a/gdb/gdbserver/tracepoint.c
> +++ b/gdb/gdbserver/tracepoint.c
> @@ -2377,6 +2377,13 @@ cmd_qtinit (char *packet)
> {
> struct trace_state_variable *tsv, *prev, *next;
>
> + /* Can't do this command without a pid attached */
Period and double-space at end of all sentences:
/* Can't do this command without a pid attached. */
> + if (current_thread == NULL)
> + {
> + write_enn(packet);
Space before parens:
write_enn (packet);
> + return;
> + }
> +
> /* Make sure we don't try to read from a trace frame. */
> current_traceframe = -1;
>
> diff --git a/gdb/testsuite/gdb.trace/Makefile.in b/gdb/testsuite/gdb.trace/Makefile.in
> index 2e23223..514beab 100644
> --- a/gdb/testsuite/gdb.trace/Makefile.in
> +++ b/gdb/testsuite/gdb.trace/Makefile.in
> @@ -4,8 +4,8 @@ srcdir = @srcdir@
> .PHONY: all clean mostlyclean distclean realclean
>
> PROGS = actions-changed ax backtrace deltrace disconnected-tracing \
> - infotrace packetlen passc-dyn passcount report save-trace tfile \
> - tfind tracecmd tsv unavailable while-dyn while-stepping
> + infotrace no-attach-trace packetlen passc-dyn passcount report \
> + save-trace tfile tfind tracecmd tsv unavailable while-dyn while-stepping
>
> all info install-info dvi install uninstall installcheck check:
> @echo "Nothing to be done for $@..."
> diff --git a/gdb/testsuite/gdb.trace/no-attach-trace.c b/gdb/testsuite/gdb.trace/no-attach-trace.c
> new file mode 100644
> index 0000000..383e6d0
> --- /dev/null
> +++ b/gdb/testsuite/gdb.trace/no-attach-trace.c
> @@ -0,0 +1,25 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + Copyright 2015 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/>. */
> +
> +/* This program is intended to be a simple dummy program for gdb to read */
Period, double-space.
> +
> +#include <unistd.h>
> +
> +int main ()
Break before function name, and "(void)":
int
main (void)
> +{
> + return 0;
> +}
> diff --git a/gdb/testsuite/gdb.trace/no-attach-trace.exp b/gdb/testsuite/gdb.trace/no-attach-trace.exp
> new file mode 100644
> index 0000000..2470347
> --- /dev/null
> +++ b/gdb/testsuite/gdb.trace/no-attach-trace.exp
> @@ -0,0 +1,43 @@
> +# This testcase is part of GDB, the GNU debugger.
> +
> +# Copyright 2015 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 that trying to trace without a program attached fails properly.
> +
> +load_lib trace-support.exp
> +
> +standard_testfile
> +
> +if {[prepare_for_testing $testfile.exp $testfile $srcfile debug]} {
> + return -1
> +}
> +
> +if ![runto_main] {
> + fail "Can't run to main to check for trace support"
> + return -1
> +}
> +
> +if { ![gdb_target_supports_trace] } then {
> + unsupported "Current target does not support trace"
> + return 1
> +
> +}
> +
> +#clean test state so that we have no process attached
Space after #, Uppercase, period at end:
# Clean test state so that we have no process attached.
> +clean_restart $testfile
> +
> +gdb_test "trace main" "Tracepoint.*"
Let's expand this a bit more, like in other tests:
gdb_test "trace main" \
"Tracepoint \[0-9\] at.* file .*$srcfile, line.*" \
"set tracepoint on main"
Basically, reasonably avoid false positives.
> +gdb_test "tstart" "Target returns error code '01'\."
Targets can send other error codes, so I think it'd be
prudent to .* the '01' part, like:
gdb_test "tstart" "Target returns error code.*\."
Can you also after this run to main? That'd make sure that the
target didn't crash or get wedged. If you decide to use
runto_main, wrap it in
with_test_prefix "after tstart" {
...
}
to make its potential FAIL test message distinguishable from
the runto_main at the top.
Thanks,
Pedro Alves