ANDROID: ftrace: add more vendor hook for ftrace dump on oops

The aosp/1562075 add the following vendor hooks in ftrace oops path
to allow vendor modules to get ftrace buffer data.

1) android_vh_ftrace_oops_enter
2) android_vh_ftrace_size_check
3) android_vh_ftrace_format_check
4) android_vh_ftrace_dump_buffer
5) android_vh_ftrace_oops_exit

Ftrace dump on oops can be controlled with kernel command
line parameter ftrace_dump_on_oops.

However the commit b8e1f899fc6b ("ANDROID: ftrace: vendor hook for ftrace dump on oops")
only cherry-pick android_vh_ftrace_format_check vh.

But following vendor hooks in ftrace oops path was not added.

1) android_vh_ftrace_oops_enter
2) android_vh_ftrace_size_check
3) android_vh_ftrace_dump_buffer
4) android_vh_ftrace_oops_exit

So add these to allow vendor modules to get ftrace buffer data.

Bug: 177387994
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
[xuewen: minor conflicts fixups]
Change-Id: I00328101bc7e1092ce7a0b50c2d47ab8288e0067
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
(cherry picked from commit fbbc48ef18)

drivers/android/vendor_hooks.c

@@ -123,7 +123,11 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_is_fpsimd_save);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_sched_show_task);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_check_uninterruptible_tasks);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_check_uninterruptible_tasks_dn);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ftrace_oops_enter);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ftrace_oops_exit);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ftrace_size_check);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ftrace_format_check);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ftrace_dump_buffer);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mem_cgroup_free);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mem_cgroup_alloc);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_cma_alloc_bypass);

include/trace/hooks/ftrace_dump.h

@@ -9,10 +9,26 @@
 
 #include <trace/hooks/vendor_hooks.h>
 
+DECLARE_HOOK(android_vh_ftrace_oops_enter,
+	TP_PROTO(bool *ftrace_check),
+	TP_ARGS(ftrace_check));
+
+DECLARE_HOOK(android_vh_ftrace_oops_exit,
+	TP_PROTO(bool *ftrace_check),
+	TP_ARGS(ftrace_check));
+
+DECLARE_HOOK(android_vh_ftrace_size_check,
+	TP_PROTO(unsigned long size, bool *ftrace_check),
+	TP_ARGS(size, ftrace_check));
+
 DECLARE_HOOK(android_vh_ftrace_format_check,
 	TP_PROTO(bool *ftrace_check),
 	TP_ARGS(ftrace_check));
 
+DECLARE_HOOK(android_vh_ftrace_dump_buffer,
+	TP_PROTO(struct trace_seq *trace_buf, bool *dump_printk),
+	TP_ARGS(trace_buf, dump_printk));
+
 #endif /* _TRACE_HOOK_FTRACE_DUMP_H */
 /* This part must be outside protection */
 #include <trace/define_trace.h>

kernel/trace/trace.c

@@ -10166,7 +10166,11 @@ static struct notifier_block trace_die_notifier = {
 static int trace_die_panic_handler(struct notifier_block *self,
 				unsigned long ev, void *unused)
 {
-	if (!ftrace_dump_on_oops_enabled())
+	bool ftrace_check = false;
+
+	trace_android_vh_ftrace_oops_enter(&ftrace_check);
+
+	if (!ftrace_dump_on_oops_enabled() || ftrace_check)
 		return NOTIFY_DONE;
 
 	/* The die notifier requires DIE_OOPS to trigger */
@@ -10175,6 +10179,7 @@ static int trace_die_panic_handler(struct notifier_block *self,
 
 	ftrace_dump(DUMP_PARAM);
 
+	trace_android_vh_ftrace_oops_exit(&ftrace_check);
 	return NOTIFY_DONE;
 }
 
@@ -10194,6 +10199,8 @@ static int trace_die_panic_handler(struct notifier_block *self,
 void
 trace_printk_seq(struct trace_seq *s)
 {
+	bool dump_printk = true;
+
 	/* Probably should print a warning here. */
 	if (s->seq.len >= TRACE_MAX_PRINT)
 		s->seq.len = TRACE_MAX_PRINT;
@@ -10209,7 +10216,9 @@ trace_printk_seq(struct trace_seq *s)
 	/* should be zero ended, but we are paranoid. */
 	s->buffer[s->seq.len] = 0;
 
-	printk(KERN_TRACE "%s", s->buffer);
+	trace_android_vh_ftrace_dump_buffer(s, &dump_printk);
+	if (dump_printk)
+		printk(KERN_TRACE "%s", s->buffer);
 
 	trace_seq_init(s);
 }
@@ -10252,6 +10261,8 @@ static void ftrace_dump_one(struct trace_array *tr, enum ftrace_dump_mode dump_m
 	unsigned long flags;
 	int cnt = 0, cpu;
 	bool ftrace_check = true;
+	bool ftrace_size_check = false;
+	unsigned long size;
 
 	/*
 	 * Always turn off tracing when we dump.
@@ -10270,6 +10281,8 @@ static void ftrace_dump_one(struct trace_array *tr, enum ftrace_dump_mode dump_m
 
 	for_each_tracing_cpu(cpu) {
 		atomic_inc(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
+		size = ring_buffer_size(iter.array_buffer->buffer, cpu);
+		trace_android_vh_ftrace_size_check(size, &ftrace_size_check);
 	}
 
 	old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ;
@@ -10277,6 +10290,9 @@ static void ftrace_dump_one(struct trace_array *tr, enum ftrace_dump_mode dump_m
 	/* don't look at user memory in panic mode */
 	tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
 
+	if (ftrace_size_check)
+		goto out_enable;
+
 	if (dump_mode == DUMP_ORIG)
 		iter.cpu_file = raw_smp_processor_id();
 	else
@@ -10335,6 +10351,7 @@ static void ftrace_dump_one(struct trace_array *tr, enum ftrace_dump_mode dump_m
 	else
 		printk(KERN_TRACE "---------------------------------\n");
 
+out_enable:
 	tr->trace_flags |= old_userobj;
 
 	for_each_tracing_cpu(cpu) {