[binutils-gdb] gdbserver: When attaching, add process before lwps
Alan Hayward
alahay01@sourceware.org
Thu Feb 7 14:38:00 GMT 2019
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=df0da8a2b80315485330c03c18b704b8d7b3e9c2
commit df0da8a2b80315485330c03c18b704b8d7b3e9c2
Author: Alan Hayward <alan.hayward@arm.com>
Date: Thu Feb 7 14:36:34 2019 +0000
gdbserver: When attaching, add process before lwps
The recent BP/WP changes for AArch64 swapping the order in add_lwp()
so that the process was added before the lwp. This was due to the lwp
creation requiring the process data.
This also needs changing in linux_attach().
Also add additional checks to make sure cannot attach to the same
process twice. Add test case for this - do this by splitting
attach.exp into distinct pass and error case sections.
Fixes gdb.server/ext-attach.exp on Aarch64.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_attach): Add process before lwp.
* server.c (attach_inferior): Check if already attached.
gdb/testsuite/ChangeLog:
* gdb.base/attach.exp: Add double attach test.
Diff:
---
gdb/gdbserver/ChangeLog | 5 ++
gdb/gdbserver/linux-low.c | 7 +--
gdb/gdbserver/server.c | 3 ++
gdb/testsuite/ChangeLog | 4 ++
gdb/testsuite/gdb.base/attach.exp | 105 ++++++++++++++++++++++++++++++--------
5 files changed, 100 insertions(+), 24 deletions(-)
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 17593cb..e9fe5ab 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,8 @@
+2019-02-07 Alan Hayward <alan.hayward@arm.com>
+
+ * linux-low.c (linux_attach): Add process before lwp.
+ * server.c (attach_inferior): Check if already attached.
+
2019-02-07 Tom Tromey <tom@tromey.com>
* x86-tdesc.h: Rename include guard.
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 44016d2..8c5a51f 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -1188,18 +1188,19 @@ linux_attach (unsigned long pid)
ptid_t ptid = ptid_t (pid, pid, 0);
int err;
+ proc = linux_add_process (pid, 1);
+
/* Attach to PID. We will check for other threads
soon. */
err = linux_attach_lwp (ptid);
if (err != 0)
{
- std::string reason = linux_ptrace_attach_fail_reason_string (ptid, err);
+ remove_process (proc);
+ std::string reason = linux_ptrace_attach_fail_reason_string (ptid, err);
error ("Cannot attach to process %ld: %s", pid, reason.c_str ());
}
- proc = linux_add_process (pid, 1);
-
/* Don't ignore the initial SIGSTOP if we just attached to this
process. It will be collected by wait shortly. */
initial_thread = find_thread_ptid (ptid_t (pid, pid, 0));
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index f9bfdd7..e960c10 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -295,6 +295,9 @@ attach_inferior (int pid)
/* myattach should return -1 if attaching is unsupported,
0 if it succeeded, and call error() otherwise. */
+ if (find_process_pid (pid) != nullptr)
+ error ("Already attached to process %d\n", pid);
+
if (myattach (pid) != 0)
return -1;
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index d4ab609..1369b5a 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2019-02-07 Alan Hayward <alan.hayward@arm.com>
+
+ * gdb.base/attach.exp: Add double attach test.
+
2019-02-07 Simon Marchi <simon.marchi@polymtl.ca>
* lib/gdb.exp (default_gdb_start): Don't match pagination
diff --git a/gdb/testsuite/gdb.base/attach.exp b/gdb/testsuite/gdb.base/attach.exp
index 2343354..ec6e457 100644
--- a/gdb/testsuite/gdb.base/attach.exp
+++ b/gdb/testsuite/gdb.base/attach.exp
@@ -45,7 +45,10 @@ if [get_compiler_info] {
return -1
}
-proc do_attach_tests {} {
+# This is a test of the error cases for gdb's ability to attach to a
+# running process.
+
+proc_with_prefix do_attach_failure_tests {} {
global gdb_prompt
global binfile
global escapedbinfile
@@ -54,7 +57,9 @@ proc do_attach_tests {} {
global subdir
global timeout
global decimal
-
+
+ clean_restart $binfile
+
# Figure out a regular expression that will match the sysroot,
# noting that the default sysroot is "target:", and also noting
# that GDB will strip "target:" from the start of filenames when
@@ -154,6 +159,75 @@ proc do_attach_tests {} {
}
}
+ # Verify that we can't double attach to the process.
+
+ set test "first attach"
+ gdb_test_multiple "attach $testpid" "$test" {
+ -re "Attaching to program.*`?$escapedbinfile'?, process $testpid.*main.*at .*$srcfile:.*$gdb_prompt $" {
+ pass "$test"
+ }
+ -re "Attaching to program.*`?$escapedbinfile\.exe'?, process $testpid.*\[Switching to thread $testpid\..*\].*$gdb_prompt $" {
+ # Response expected on Cygwin.
+ pass "$test"
+ }
+ }
+
+ gdb_test "add-inferior" "Added inferior 2.*" "add empty inferior 2"
+ gdb_test "inferior 2" "Switching to inferior 2.*" "switch to inferior 2"
+
+ set test "fail to attach again"
+ gdb_test_multiple "attach $testpid" "$test" {
+ -re "Attaching to process $testpid.*warning: process .* is already traced by process .*$gdb_prompt $" {
+ pass "$test"
+ }
+ -re "Attaching to process .* failed.*$gdb_prompt $" {
+ # Response expected when using gdbserver.
+ pass "$test"
+ }
+ }
+
+ gdb_test "inferior 1" "Switching to inferior 1.*" "switch to inferior 1"
+ set test "exit after attach failures"
+ gdb_test "kill" \
+ "" \
+ "$test" \
+ "Kill the program being debugged.*y or n. $" \
+ "y"
+
+ # Another "don't leave a process around"
+ kill_wait_spawned_process $test_spawn_id
+}
+
+# This is a test of gdb's ability to attach to a running process.
+
+proc_with_prefix do_attach_tests {} {
+ global gdb_prompt
+ global binfile
+ global escapedbinfile
+ global srcfile
+ global testfile
+ global subdir
+ global timeout
+ global decimal
+
+ clean_restart $binfile
+
+ # Figure out a regular expression that will match the sysroot,
+ # noting that the default sysroot is "target:", and also noting
+ # that GDB will strip "target:" from the start of filenames when
+ # operating on the local filesystem. However the default sysroot
+ # can be set via configure option --with-sysroot, which can be "/".
+ # If $binfile is a absolute path, so pattern
+ # "$sysroot$escapedbinfile" below is wrong. Use [^\r\n]* to make
+ # $sysroot simple.
+ set sysroot "\[^\r\n\]*"
+
+ # Start the program running and then wait for a bit, to be sure
+ # that it can be attached to.
+
+ set test_spawn_id [spawn_wait_for_attach $binfile]
+ set testpid [spawn_id_get_pid $test_spawn_id]
+
# Verify that we can attach to the process by first giving its
# executable name via the file command, and using attach with the
# process ID.
@@ -313,10 +387,14 @@ proc do_attach_tests {} {
kill_wait_spawned_process $test_spawn_id
}
-proc do_call_attach_tests {} {
+# Test attaching when the target is inside a system call.
+
+proc_with_prefix do_call_attach_tests {} {
global gdb_prompt
global binfile2
-
+
+ clean_restart
+
set test_spawn_id [spawn_wait_for_attach $binfile2]
set testpid [spawn_id_get_pid $test_spawn_id]
@@ -358,7 +436,7 @@ proc do_call_attach_tests {} {
kill_wait_spawned_process $test_spawn_id
}
-proc do_command_attach_tests {} {
+proc_with_prefix do_command_attach_tests {} {
global gdb_prompt
global binfile
global verbose
@@ -435,23 +513,8 @@ proc test_command_line_attach_run {} {
}
}
-# Start with a fresh gdb
-
-gdb_exit
-gdb_start
-gdb_reinitialize_dir $srcdir/$subdir
-gdb_load ${binfile}
-
-# This is a test of gdb's ability to attach to a running process.
-
do_attach_tests
-
-# Test attaching when the target is inside a system call
-
-gdb_exit
-gdb_start
-
-gdb_reinitialize_dir $srcdir/$subdir
+do_attach_failure_tests
do_call_attach_tests
# Test "gdb --pid"
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