x86/Linux: disable all-stop on top of non-stop

Markus reported that ASNS breaks target record-btrace.  In particular,
the gdb.btrace/multi-thread-step.exp test fails (both with BTS and PT
tracing) with a crash in py-inferior.c:

 Program received signal SIGSEGV, Segmentation fault.

 0x00000000006aa40d in add_thread_object (tp=0x27d32d0)

     at /users/mmetzger/team/gdb/git/gdb/python/py-inferior.c:337

 337       entry->next = inf_obj->threads;

My machine doesn't support BTS nor PT, so I missed this...

Disabling ASNS temporarily on x86 until this is addressed.

Tested on x86_64 Fedora 20.

gdb/ChangeLog:
2015-08-18  Pedro Alves  <palves@redhat.com>

	* linux-nat.c (linux_nat_always_non_stop_p): If the linux_ops
	target implements to_always_non_stop_p, call it.
	* x86-linux-nat.c (x86_linux_always_non_stop_p): New function.
	(x86_linux_create_target): Install it as to_always_non_stop_p
	method.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index be2ed47..38872b1 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2015-08-18  Pedro Alves  <palves@redhat.com>
+
+       * linux-nat.c (linux_nat_always_non_stop_p): If the linux_ops
+       target implements to_always_non_stop_p, call it.
+       * x86-linux-nat.c (x86_linux_always_non_stop_p): New function.
+       (x86_linux_create_target): Install it as to_always_non_stop_p
+       method.
+
 2015-08-17  Doug Evans  <dje@google.com>
 
        * ui-out.c (default_ui_out_impl): Add comment.

diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index be7a915..a13fb9e 100644 (file)
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -4594,6 +4594,8 @@ linux_nat_supports_non_stop (struct target_ops *self)
 static int
 linux_nat_always_non_stop_p (struct target_ops *self)
 {
+  if (linux_ops->to_always_non_stop_p != NULL)
+    return linux_ops->to_always_non_stop_p (linux_ops);
   return 1;
 }
 

diff --git a/gdb/x86-linux-nat.c b/gdb/x86-linux-nat.c
index 34a9257..fe52c1f 100644 (file)
--- a/gdb/x86-linux-nat.c
+++ b/gdb/x86-linux-nat.c
@@ -357,6 +357,15 @@ x86_linux_get_thread_area (pid_t pid, void *addr, unsigned int *base_addr)
 }
 \f
 
+/* to_always_non_stop_p implementation.  */
+
+static int
+x86_linux_always_non_stop_p (struct target_ops *self)
+{
+  /* Enabling this breaks the btrace target.  */
+  return 0;
+}
+
 /* Create an x86 GNU/Linux target.  */
 
 struct target_ops *
@@ -389,6 +398,8 @@ x86_linux_create_target (void)
   t->to_read_btrace = x86_linux_read_btrace;
   t->to_btrace_conf = x86_linux_btrace_conf;
 
+  t->to_always_non_stop_p = x86_linux_always_non_stop_p;
+
   return t;
 }