Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kerne…

…l/git/tip/linux-2.6-tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqs kprobes/trace: Fix kprobe selftest for gcc 4.6 ftrace: Fix possible undefined return code oprofile, dcookies: Fix possible circular locking dependency oprofile: Fix locking dependency in sync_start() oprofile: Free potentially owned tasks in case of errors oprofile, x86: Add comments to IBS LVT offset initialization

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kerne…
…l/git/tip/linux-2.6-tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqs kprobes/trace: Fix kprobe selftest for gcc 4.6 ftrace: Fix possible undefined return code oprofile, dcookies: Fix possible circular locking dependency oprofile: Fix locking dependency in sync_start() oprofile: Free potentially owned tasks in case of errors oprofile, x86: Add comments to IBS LVT offset initialization
Linus Torvalds
2 parents 842c895d14 5f127133ee
Showing 6 changed files Side-by-side Diff
arch/x86/kernel/apic/apic.c
arch/x86/oprofile/op_model_amd.c
drivers/oprofile/buffer_sync.c
fs/dcookies.c
kernel/trace/ftrace.c
kernel/trace/trace_kprobe.c
@@ -390,7 +390,8 @@
  
 /*
  * If mask=1, the LVT entry does not generate interrupts while mask=0
- * enables the vector. See also the BKDGs.
+ * enables the vector. See also the BKDGs. Must be called with
+ * preemption disabled.
  */
  
 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
@@ -609,16 +609,21 @@
 	return 0;
 }
  
+/*
+ * This runs only on the current cpu. We try to find an LVT offset and
+ * setup the local APIC. For this we must disable preemption. On
+ * success we initialize all nodes with this offset. This updates then
+ * the offset in the IBS_CTL per-node msr. The per-core APIC setup of
+ * the IBS interrupt vector is called from op_amd_setup_ctrs()/op_-
+ * amd_cpu_shutdown() using the new offset.
+ */
 static int force_ibs_eilvt_setup(void)
 {
 	int offset;
 	int ret;
  
-	/*
-	 * find the next free available EILVT entry, skip offset 0,
-	 * pin search to this cpu
-	 */
 	preempt_disable();
+	/* find the next free available EILVT entry, skip offset 0 */
 	for (offset = 1; offset < APIC_EILVT_NR_MAX; offset++) {
 		if (get_eilvt(offset))
 			break;
@@ -141,6 +141,13 @@
 	.notifier_call = module_load_notify,
 };
  
+static void free_all_tasks(void)
+{
+	/* make sure we don't leak task structs */
+	process_task_mortuary();
+	process_task_mortuary();
+}
+
 int sync_start(void)
 {
 	int err;
@@ -148,8 +155,6 @@
 	if (!zalloc_cpumask_var(&marked_cpus, GFP_KERNEL))
 		return -ENOMEM;
  
-	mutex_lock(&buffer_mutex);
-
 	err = task_handoff_register(&task_free_nb);
 	if (err)
 		goto out1;
@@ -166,7 +171,6 @@
 	start_cpu_work();
  
 out:
-	mutex_unlock(&buffer_mutex);
 	return err;
 out4:
 	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
@@ -174,6 +178,7 @@
 	profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
 out2:
 	task_handoff_unregister(&task_free_nb);
+	free_all_tasks();
 out1:
 	free_cpumask_var(marked_cpus);
 	goto out;
  
  
@@ -182,20 +187,16 @@
  
 void sync_stop(void)
 {
-	/* flush buffers */
-	mutex_lock(&buffer_mutex);
 	end_cpu_work();
 	unregister_module_notifier(&module_load_nb);
 	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
 	profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
 	task_handoff_unregister(&task_free_nb);
-	mutex_unlock(&buffer_mutex);
+	barrier();			/* do all of the above first */
+
 	flush_cpu_work();
  
-	/* make sure we don't leak task structs */
-	process_task_mortuary();
-	process_task_mortuary();
-
+	free_all_tasks();
 	free_cpumask_var(marked_cpus);
 }
  
@@ -178,6 +178,8 @@
 	/* FIXME: (deleted) ? */
 	path = d_path(&dcs->path, kbuf, PAGE_SIZE);
  
+	mutex_unlock(&dcookie_mutex);
+
 	if (IS_ERR(path)) {
 		err = PTR_ERR(path);
 		goto out_free;
@@ -194,6 +196,7 @@
  
 out_free:
 	kfree(kbuf);
+	return err;
 out:
 	mutex_unlock(&dcookie_mutex);
 	return err;
@@ -2740,7 +2740,7 @@
 {
 	char *func, *command, *next = buff;
 	struct ftrace_func_command *p;
-	int ret;
+	int ret = -EINVAL;
  
 	func = strsep(&next, ":");
  
@@ -3330,6 +3330,7 @@
 {
 	unsigned long *p;
 	unsigned long addr;
+	unsigned long flags;
  
 	mutex_lock(&ftrace_lock);
 	p = start;
  
@@ -3346,7 +3347,13 @@
 		ftrace_record_ip(addr);
 	}
  
+	/*
+	 * Disable interrupts to prevent interrupts from executing
+	 * code that is being modified.
+	 */
+	local_irq_save(flags);
 	ftrace_update_code(mod);
+	local_irq_restore(flags);
 	mutex_unlock(&ftrace_lock);
  
 	return 0;
@@ -1870,8 +1870,12 @@
  
 #ifdef CONFIG_FTRACE_STARTUP_TEST
  
-static int kprobe_trace_selftest_target(int a1, int a2, int a3,
-					int a4, int a5, int a6)
+/*
+ * The "__used" keeps gcc from removing the function symbol
+ * from the kallsyms table.
+ */
+static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
+					       int a4, int a5, int a6)
 {
 	return a1 + a2 + a3 + a4 + a5 + a6;
 }
...	...	@@ -390,7 +390,8 @@
390	390
391	391	/*
392	392	* If mask=1, the LVT entry does not generate interrupts while mask=0
393		- * enables the vector. See also the BKDGs.
	393	+ * enables the vector. See also the BKDGs. Must be called with
	394	+ * preemption disabled.
394	395	*/
395	396
396	397	int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
...	...	@@ -609,16 +609,21 @@
609	609	return 0;
610	610	}
611	611
	612	+/*
	613	+ * This runs only on the current cpu. We try to find an LVT offset and
	614	+ * setup the local APIC. For this we must disable preemption. On
	615	+ * success we initialize all nodes with this offset. This updates then
	616	+ * the offset in the IBS_CTL per-node msr. The per-core APIC setup of
	617	+ * the IBS interrupt vector is called from op_amd_setup_ctrs()/op_-
	618	+ * amd_cpu_shutdown() using the new offset.
	619	+ */
612	620	static int force_ibs_eilvt_setup(void)
613	621	{
614	622	int offset;
615	623	int ret;
616	624
617		- /*
618		- * find the next free available EILVT entry, skip offset 0,
619		- * pin search to this cpu
620		- */
621	625	preempt_disable();
	626	+ /* find the next free available EILVT entry, skip offset 0 */
622	627	for (offset = 1; offset < APIC_EILVT_NR_MAX; offset++) {
623	628	if (get_eilvt(offset))
624	629	break;
...	...	@@ -141,6 +141,13 @@
141	141	.notifier_call = module_load_notify,
142	142	};
143	143
	144	+static void free_all_tasks(void)
	145	+{
	146	+ /* make sure we don't leak task structs */
	147	+ process_task_mortuary();
	148	+ process_task_mortuary();
	149	+}
	150	+
144	151	int sync_start(void)
145	152	{
146	153	int err;
...	...	@@ -148,8 +155,6 @@
148	155	if (!zalloc_cpumask_var(&marked_cpus, GFP_KERNEL))
149	156	return -ENOMEM;
150	157
151		- mutex_lock(&buffer_mutex);
152		-
153	158	err = task_handoff_register(&task_free_nb);
154	159	if (err)
155	160	goto out1;
...	...	@@ -166,7 +171,6 @@
166	171	start_cpu_work();
167	172
168	173	out:
169		- mutex_unlock(&buffer_mutex);
170	174	return err;
171	175	out4:
172	176	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
...	...	@@ -174,6 +178,7 @@
174	178	profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
175	179	out2:
176	180	task_handoff_unregister(&task_free_nb);
	181	+ free_all_tasks();
177	182	out1:
178	183	free_cpumask_var(marked_cpus);
179	184	goto out;
180	185
181	186
...	...	@@ -182,20 +187,16 @@
182	187
183	188	void sync_stop(void)
184	189	{
185		- /* flush buffers */
186		- mutex_lock(&buffer_mutex);
187	190	end_cpu_work();
188	191	unregister_module_notifier(&module_load_nb);
189	192	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
190	193	profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
191	194	task_handoff_unregister(&task_free_nb);
192		- mutex_unlock(&buffer_mutex);
	195	+ barrier(); /* do all of the above first */
	196	+
193	197	flush_cpu_work();
194	198
195		- /* make sure we don't leak task structs */
196		- process_task_mortuary();
197		- process_task_mortuary();
198		-
	199	+ free_all_tasks();
199	200	free_cpumask_var(marked_cpus);
200	201	}
201	202
...	...	@@ -178,6 +178,8 @@
178	178	/* FIXME: (deleted) ? */
179	179	path = d_path(&dcs->path, kbuf, PAGE_SIZE);
180	180
	181	+ mutex_unlock(&dcookie_mutex);
	182	+
181	183	if (IS_ERR(path)) {
182	184	err = PTR_ERR(path);
183	185	goto out_free;
...	...	@@ -194,6 +196,7 @@
194	196
195	197	out_free:
196	198	kfree(kbuf);
	199	+ return err;
197	200	out:
198	201	mutex_unlock(&dcookie_mutex);
199	202	return err;
...	...	@@ -2740,7 +2740,7 @@
2740	2740	{
2741	2741	char func, command, *next = buff;
2742	2742	struct ftrace_func_command *p;
2743		- int ret;
	2743	+ int ret = -EINVAL;
2744	2744
2745	2745	func = strsep(&next, ":");
2746	2746
...	...	@@ -3330,6 +3330,7 @@
3330	3330	{
3331	3331	unsigned long *p;
3332	3332	unsigned long addr;
	3333	+ unsigned long flags;
3333	3334
3334	3335	mutex_lock(&ftrace_lock);
3335	3336	p = start;
3336	3337
...	...	@@ -3346,7 +3347,13 @@
3346	3347	ftrace_record_ip(addr);
3347	3348	}
3348	3349
	3350	+ /*
	3351	+ * Disable interrupts to prevent interrupts from executing
	3352	+ * code that is being modified.
	3353	+ */
	3354	+ local_irq_save(flags);
3349	3355	ftrace_update_code(mod);
	3356	+ local_irq_restore(flags);
3350	3357	mutex_unlock(&ftrace_lock);
3351	3358
3352	3359	return 0;
...	...	@@ -1870,8 +1870,12 @@
1870	1870
1871	1871	#ifdef CONFIG_FTRACE_STARTUP_TEST
1872	1872
1873		-static int kprobe_trace_selftest_target(int a1, int a2, int a3,
1874		- int a4, int a5, int a6)
	1873	+/*
	1874	+ * The "__used" keeps gcc from removing the function symbol
	1875	+ * from the kallsyms table.
	1876	+ */
	1877	+static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
	1878	+ int a4, int a5, int a6)
1875	1879	{
1876	1880	return a1 + a2 + a3 + a4 + a5 + a6;
1877	1881	}