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Re: [patch 2/2] Displaced stepping across fork/vfork : test case
On 09/15/2011 11:52 PM, Pedro Alves wrote:
>> > + set syscall_insn_bp 0
>> > + gdb_test_multiple "break \*$syscall_insn_addr" "break on syscall insn" {
>> > + -re "Breakpoint (\[0-9\]*) at .*$gdb_prompt $" {
>> > + set syscall_insn_bp $expect_out(1,string)
>> > + pass "break on syscall insns"
>> > + }
>> > + -re "Cannot insert breakpoint .*${gdb_prompt} $" {
>> > + # This syscall insn may be in vsyscall page, and we can't set a breakpoint
>> > + # there on some systems.
>> > + fail "break on syscall insns"
> Please don't make this is a fail. It is not GDB's fault. "unsupported"
> or "xfail" would be better.
>
"unsupported" is used here.
>> > + set pf_prefix $old_pf_prefix
>> > + return -1
>> > + }
>> > + }
> But this won't work as is. Breakpoints will only be inserted on the
> next resume, not immediately. Unless you enable always-inserted mode,
> that is.
I can set breakpoint on vsyscall page of my system, so I have to imagine
what will happen if I can't set breakpoint. As you said, breakpoints
will be inserted on the next resume, so I check the "Cannot insert
breakpoint" in next "continue" operation, like this,
gdb_test_multiple "continue" "continue to syscall insn $syscall" {
-re "Cannot insert breakpoint .*${gdb_prompt} $" {
# This syscall insn may be in vsyscall page, and we can't set a
breakpoint
# there on some systems.
unsupported "break on syscall insns"
set pf_prefix $old_pf_prefix
return -1
}
-re "Continuing\\..*Breakpoint \[0-9\]+, .*${gdb_prompt} $" {
pass "break on syscall insns"
}
}
--
Yao (éå)
gdb/testsuite/
* gdb.base/disp-step-fork.c: New.
* gdb.base/disp-step-syscall.exp: New.
* gdb.base/disp-step-vfork.c: New.
---
gdb/testsuite/gdb.base/disp-step-fork.c | 57 ++++++++++
gdb/testsuite/gdb.base/disp-step-syscall.exp | 148
++++++++++++++++++++++++++
gdb/testsuite/gdb.base/disp-step-vfork.c | 70 ++++++++++++
3 files changed, 275 insertions(+), 0 deletions(-)
create mode 100644 gdb/testsuite/gdb.base/disp-step-fork.c
create mode 100644 gdb/testsuite/gdb.base/disp-step-syscall.exp
create mode 100644 gdb/testsuite/gdb.base/disp-step-vfork.c
diff --git a/gdb/testsuite/gdb.base/disp-step-fork.c
b/gdb/testsuite/gdb.base/disp-step-fork.c
new file mode 100644
index 0000000..ab4f3b4
--- /dev/null
+++ b/gdb/testsuite/gdb.base/disp-step-fork.c
@@ -0,0 +1,57 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2011 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/>. */
+
+#include <stdlib.h>
+
+static void
+marker () {}
+
+int
+main (void)
+{
+ int pid;
+
+ pid = fork ();
+ if (pid == 0) /* child */
+ {
+ exit (0); /* at exit */
+ }
+ else
+ {
+ }
+
+ pid = fork ();
+ if (pid == 0) /* child */
+ {
+ exit (0); /* at exit */
+ }
+ else
+ {
+ }
+
+ pid = fork ();
+ if (pid == 0) /* child */
+ {
+ exit (0); /* at exit */
+ }
+ else
+ {
+ }
+
+ marker ();
+
+}
diff --git a/gdb/testsuite/gdb.base/disp-step-syscall.exp
b/gdb/testsuite/gdb.base/disp-step-syscall.exp
new file mode 100644
index 0000000..4860c48
--- /dev/null
+++ b/gdb/testsuite/gdb.base/disp-step-syscall.exp
@@ -0,0 +1,148 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2011 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/>.
+
+if { ![support_displaced_stepping] } {
+ unsupported "displaced stepping"
+ return -1
+}
+
+set syscall_insn ""
+
+# Define the syscall instruction for each target.
+
+if { [istarget "i\[34567\]86-*-linux*"] || [istarget "x86_64-*-linux*"] } {
+ set syscall_insn "(int|syscall|sysenter)"
+} else {
+ return -1
+}
+
+proc disp_step_cross_syscall { syscall } {
+ global syscall_insn
+ global gdb_prompt
+ global pf_prefix
+
+ set testfile "disp-step-$syscall"
+
+ if [prepare_for_testing ${testfile}.exp ${testfile} ${testfile}.c
{debug}] {
+ untested ${testfile}.exp
+ return -1
+ }
+
+ if { ![runto main] } then {
+ fail "run to main ($syscall)"
+ return
+ }
+
+ set old_pf_prefix $pf_prefix
+ lappend pf_prefix "$syscall:"
+
+ # Delete the breakpoint on main.
+ gdb_test_no_output "delete break 1"
+
+ gdb_test "break marker" "Breakpoint.*at.* file .*${testfile}.c, line.*"
+ gdb_test_no_output "set displaced-stepping off"
+
+ set syscall_bp 0
+ gdb_test_multiple "break $syscall" "break $syscall" {
+ -re "Breakpoint (\[0-9\]*) at .*$gdb_prompt $" {
+ set syscall_bp $expect_out(1,string)
+ pass "break $syscall"
+ }
+ }
+
+ gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, .* in
$syscall ().*" \
+ "continue to $syscall (1st time)"
+ # Hit the breakpoint on $syscall for the first time. In this time,
we will let PLT
+ # resolution done, and the number single steps we will do later will be
+ # reduced.
+
+ gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, .* in
$syscall ().*" \
+ "continue to $syscall (2nd time)"
+ # Hit the breakpoint on $syscall for the second time. In this
time, the address
+ # of syscall insn and next insn of syscall are recorded.
+
+ gdb_test "display/i \$pc" ".*"
+
+
+ # Single step until we see sysall insn or we reach the upper bound
of loop
+ # iterations.
+ set see_syscall_insn 0
+
+ for {set i 0} {$i < 1000 && $see_syscall_insn == 0} {incr i} {
+ send_gdb "stepi\n"
+ gdb_expect {
+ -re ".*$syscall_insn.*$gdb_prompt $" {
+ set see_syscall_insn 1
+ }
+ -re ".*$gdb_prompt $" {}
+ }
+ }
+
+ if {$see_syscall_insn == 0} then {
+ fail "find syscall insn in $syscall"
+ set pf_prefix $old_pf_prefix
+ return -1
+ }
+
+ set syscall_insn_addr [get_hexadecimal_valueof "\$pc" "0"]
+ gdb_test "stepi" ".*" "stepi $syscall insn"
+ set syscall_insn_next_addr [get_hexadecimal_valueof "\$pc" "0"]
+
+ gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, .* in
$syscall ().*" \
+ "continue to $syscall (3rd time)"
+
+ # Hit the breakpoint on $syscall for the third time. In this time,
we'll set
+ # breakpoint on the syscall insn we recorded previously, and single
step over it.
+
+ set syscall_insn_bp 0
+ gdb_test_multiple "break \*$syscall_insn_addr" "break on syscall
insn" {
+ -re "Breakpoint (\[0-9\]*) at .*$gdb_prompt $" {
+ set syscall_insn_bp $expect_out(1,string)
+ pass "break on syscall insns"
+ }
+ }
+ gdb_test_no_output "delete $syscall_bp" "delete break $syscall"
+
+ gdb_test_multiple "continue" "continue to syscall insn $syscall" {
+ -re "Cannot insert breakpoint .*${gdb_prompt} $" {
+ # This syscall insn may be in vsyscall page, and we can't set a
breakpoint
+ # there on some systems.
+ unsupported "break on syscall insns"
+ set pf_prefix $old_pf_prefix
+ return -1
+ }
+ -re "Continuing\\..*Breakpoint \[0-9\]+, .*${gdb_prompt} $" {
+ pass "break on syscall insns"
+ }
+ }
+
+ gdb_test_no_output "set displaced-stepping on"
+
+ # Check the address of next instruction of syscall.
+ gdb_test "stepi" ".*$syscall_insn_next_addr.*" "single step over
$syscall"
+
+ # Delete breakpoint syscall insns to avoid interference to other
syscalls.
+ gdb_test_no_output "delete $syscall_insn_bp" "delete break $syscall
insn"
+
+ gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, marker
\\(\\) at.*" \
+ "continue to marker ($syscall)"
+
+ set pf_prefix $old_pf_prefix
+}
+
+disp_step_cross_syscall "fork"
+disp_step_cross_syscall "vfork"
diff --git a/gdb/testsuite/gdb.base/disp-step-vfork.c
b/gdb/testsuite/gdb.base/disp-step-vfork.c
new file mode 100644
index 0000000..fdc7914
--- /dev/null
+++ b/gdb/testsuite/gdb.base/disp-step-vfork.c
@@ -0,0 +1,70 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2011 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/>. */
+
+#include <unistd.h>
+
+static void
+marker () {}
+
+int
+main (void)
+{
+ int pid;
+
+ pid = vfork ();
+ if (pid == -1)
+ {
+ return 1;
+ }
+ else if (pid != 0)
+ {
+ }
+ else
+ {
+ _exit (0);
+ }
+
+ pid = vfork ();
+ if (pid == -1)
+ {
+ return 1;
+ }
+ else if (pid != 0)
+ {
+ }
+ else
+ {
+ _exit (0);
+ }
+
+ pid = vfork ();
+ if (pid == -1)
+ {
+ return 1;
+ }
+ else if (pid != 0)
+ {
+ }
+ else
+ {
+ _exit (0);
+ }
+
+ marker ();
+ return 0;
+
+}
--
1.7.0.4