gdb/gdb-6.8-attach-signalled-detach-stopped.patch
Sergio Durigan Junior 6f7202ecff Rebase to FSF GDB 8.1.
2018-01-31 17:47:02 -05:00

200 lines
6.2 KiB
Diff

From FEDORA_PATCHES Mon Sep 17 00:00:00 2001
From: Fedora GDB patches <invalid@email.com>
Date: Fri, 27 Oct 2017 21:07:50 +0200
Subject: gdb-6.8-attach-signalled-detach-stopped.patch
FileName: gdb-6.8-attach-signalled-detach-stopped.patch
;; [RHEL5,RHEL6] Fix attaching to stopped processes.
;; [RHEL5] Workaround kernel for detaching SIGSTOPped processes (BZ 809382).
;;=fedora
---
gdb/infrun.c | 7 ++++
gdb/linux-nat.c | 45 +++++++++++++++++++++
gdb/testsuite/gdb.threads/attach-stopped.exp | 60 +++++++++++++++++++++++++++-
3 files changed, 111 insertions(+), 1 deletion(-)
diff --git a/gdb/infrun.c b/gdb/infrun.c
index b468d02fd6..16561dd119 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -606,6 +606,13 @@ holding the child stopped. Try \"set detach-on-fork\" or \
target_pid_to_str (process_ptid));
}
+#ifdef NEED_DETACH_SIGSTOP
+ /* We should check PID_WAS_STOPPED and detach it stopped accordingly.
+ In this point of code it cannot be 1 as we would not get FORK
+ executed without CONTINUE first which resets PID_WAS_STOPPED.
+ We would have to first TARGET_STOP and WAITPID it as with running
+ inferior PTRACE_DETACH, SIGSTOP will ignore the signal. */
+#endif
target_detach (NULL, 0);
}
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index 1570a2bcb6..a101fbbe33 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -194,6 +194,11 @@ enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN;
static struct target_ops *linux_ops;
static struct target_ops linux_ops_saved;
+#ifdef NEED_DETACH_SIGSTOP
+/* PID of the inferior stopped by SIGSTOP before attaching (or zero). */
+static pid_t pid_was_stopped;
+
+#endif
/* The method to call, if any, when a new thread is attached. */
static void (*linux_nat_new_thread) (struct lwp_info *);
@@ -1065,6 +1070,9 @@ linux_nat_post_attach_wait (ptid_t ptid, int *signalled)
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
"LNPAW: Attaching to a stopped process\n");
+#ifdef NEED_DETACH_SIGSTOP
+ pid_was_stopped = ptid_get_pid (ptid);
+#endif
/* The process is definitely stopped. It is in a job control
stop, unless the kernel predates the TASK_STOPPED /
@@ -1420,6 +1428,25 @@ get_detach_signal (struct lwp_info *lp)
return gdb_signal_to_host (signo);
}
+#ifdef NEED_DETACH_SIGSTOP
+ /* Workaround RHEL-5 kernel which has unreliable PTRACE_DETACH, SIGSTOP (that
+ many TIDs are left unstopped). See RH Bug 496732. */
+ if (ptid_get_pid (lp->ptid) == pid_was_stopped)
+ {
+ int err;
+
+ errno = 0;
+ err = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
+ if (debug_linux_nat)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "SC: lwp kill %d %s\n",
+ err,
+ errno ? safe_strerror (errno) : "ERRNO-OK");
+ }
+ }
+
+#endif
return 0;
}
@@ -1578,6 +1605,10 @@ linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
detach_one_lwp (main_lwp, &signo);
inf_ptrace_detach_success (ops);
+
+#ifdef NEED_DETACH_SIGSTOP
+ pid_was_stopped = 0;
+#endif
}
}
@@ -1838,6 +1869,16 @@ linux_nat_resume (struct target_ops *ops,
return;
}
+#ifdef NEED_DETACH_SIGSTOP
+ /* At this point, we are going to resume the inferior and if we
+ have attached to a stopped process, we no longer should leave
+ it as stopped if the user detaches. PTID variable has PID set to LWP
+ while we need to check the real PID here. */
+
+ if (!step && lp && pid_was_stopped == ptid_get_pid (lp->ptid))
+ pid_was_stopped = 0;
+
+#endif
if (resume_many)
iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
@@ -3830,6 +3871,10 @@ linux_nat_mourn_inferior (struct target_ops *ops)
/* Let the arch-specific native code know this process is gone. */
linux_nat_forget_process (pid);
+#ifdef NEED_DETACH_SIGSTOP
+
+ pid_was_stopped = 0;
+#endif
}
/* Convert a native/host siginfo object, into/from the siginfo in the
diff --git a/gdb/testsuite/gdb.threads/attach-stopped.exp b/gdb/testsuite/gdb.threads/attach-stopped.exp
index 6c8c8bf10e..c953a9c60d 100644
--- a/gdb/testsuite/gdb.threads/attach-stopped.exp
+++ b/gdb/testsuite/gdb.threads/attach-stopped.exp
@@ -56,7 +56,65 @@ proc corefunc { threadtype } {
gdb_reinitialize_dir $srcdir/$subdir
gdb_load ${binfile}
- # Verify that we can attach to the stopped process.
+ # Verify that we can attach to the process by first giving its
+ # executable name via the file command, and using attach with the
+ # process ID.
+
+ set test "$threadtype: set file, before attach1 to stopped process"
+ gdb_test_multiple "file $binfile" "$test" {
+ -re "Load new symbol table from.*y or n. $" {
+ gdb_test "y" "Reading symbols from $escapedbinfile\.\.\.*done." \
+ "$test (re-read)"
+ }
+ -re "Reading symbols from $escapedbinfile\.\.\.*done.*$gdb_prompt $" {
+ pass "$test"
+ }
+ }
+
+ set test "$threadtype: attach1 to stopped, after setting file"
+ gdb_test_multiple "attach $testpid" "$test" {
+ -re "Attaching to program.*`?$escapedbinfile'?, process $testpid.*$gdb_prompt $" {
+ pass "$test"
+ }
+ }
+
+ # ".*sleep.*clone.*" would fail on s390x as bt stops at START_THREAD there.
+ if {[string equal $threadtype threaded]} {
+ gdb_test "thread apply all bt" ".*sleep.*start_thread.*" "$threadtype: attach1 to stopped bt"
+ } else {
+ gdb_test "bt" ".*sleep.*main.*" "$threadtype: attach1 to stopped bt"
+ }
+
+ # Exit and detach the process.
+
+ gdb_exit
+
+ # Avoid some race:
+ sleep 2
+
+ if [catch {open /proc/${testpid}/status r} fileid] {
+ set line2 "NOTFOUND"
+ } else {
+ gets $fileid line1;
+ gets $fileid line2;
+ close $fileid;
+ }
+
+ set test "$threadtype: attach1, exit leaves process stopped"
+ if {[string match "*(stopped)*" $line2]} {
+ pass $test
+ } else {
+ fail $test
+ }
+
+ # At this point, the process should still be stopped
+
+ gdb_start
+ gdb_reinitialize_dir $srcdir/$subdir
+ gdb_load ${binfile}
+
+ # Verify that we can attach to the process just by giving the
+ # process ID.
set test "$threadtype: attach2 to stopped, after setting file"
gdb_test_multiple "attach $testpid" "$test" {
--
2.14.3