1 files changed, 48 insertions, 4 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b581e388a9d9..d3459e715fbc 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -120,6 +120,7 @@ static int tracing_disabled = 1;
 
 cpumask_var_t __read_mostly	tracing_buffer_mask;
 
+#define MAX_TRACER_SIZE		100
 /*
  * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
  *
@@ -142,7 +143,40 @@ cpumask_var_t __read_mostly	tracing_buffer_mask;
 char ftrace_dump_on_oops[MAX_TRACER_SIZE] = "0";
 
 /* When set, tracing will stop when a WARN*() is hit */
-int __disable_trace_on_warning;
+static int __disable_trace_on_warning;
+
+int tracepoint_printk_sysctl(const struct ctl_table *table, int write,
+			     void *buffer, size_t *lenp, loff_t *ppos);
+static const struct ctl_table trace_sysctl_table[] = {
+	{
+		.procname	= "ftrace_dump_on_oops",
+		.data		= &ftrace_dump_on_oops,
+		.maxlen		= MAX_TRACER_SIZE,
+		.mode		= 0644,
+		.proc_handler	= proc_dostring,
+	},
+	{
+		.procname	= "traceoff_on_warning",
+		.data		= &__disable_trace_on_warning,
+		.maxlen		= sizeof(__disable_trace_on_warning),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "tracepoint_printk",
+		.data		= &tracepoint_printk,
+		.maxlen		= sizeof(tracepoint_printk),
+		.mode		= 0644,
+		.proc_handler	= tracepoint_printk_sysctl,
+	},
+};
+
+static int __init init_trace_sysctls(void)
+{
+	register_sysctl_init("kernel", trace_sysctl_table);
+	return 0;
+}
+subsys_initcall(init_trace_sysctls);
 
 #ifdef CONFIG_TRACE_EVAL_MAP_FILE
 /* Map of enums to their values, for "eval_map" file */
@@ -6043,8 +6077,10 @@ unsigned long trace_adjust_address(struct trace_array *tr, unsigned long addr)
 	tscratch = tr->scratch;
 	/* if there is no tscrach, module_delta must be NULL. */
 	module_delta = READ_ONCE(tr->module_delta);
-	if (!module_delta || tscratch->entries[0].mod_addr > addr)
+	if (!module_delta || !tscratch->nr_entries ||
+	    tscratch->entries[0].mod_addr > addr) {
 		return addr + tr->text_delta;
+	}
 
 	/* Note that entries must be sorted. */
 	nr_entries = tscratch->nr_entries;
@@ -6821,13 +6857,14 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
 		/* Copy the data into the page, so we can start over. */
 		ret = trace_seq_to_buffer(&iter->seq,
 					  page_address(spd.pages[i]),
-					  trace_seq_used(&iter->seq));
+					  min((size_t)trace_seq_used(&iter->seq),
+						  PAGE_SIZE));
 		if (ret < 0) {
 			__free_page(spd.pages[i]);
 			break;
 		}
 		spd.partial[i].offset = 0;
-		spd.partial[i].len = trace_seq_used(&iter->seq);
+		spd.partial[i].len = ret;
 
 		trace_seq_init(&iter->seq);
 	}
@@ -9806,6 +9843,7 @@ static int instance_mkdir(const char *name)
 	return ret;
 }
 
+#ifdef CONFIG_MMU
 static u64 map_pages(unsigned long start, unsigned long size)
 {
 	unsigned long vmap_start, vmap_end;
@@ -9828,6 +9866,12 @@ static u64 map_pages(unsigned long start, unsigned long size)
 
 	return (u64)vmap_start;
 }
+#else
+static inline u64 map_pages(unsigned long start, unsigned long size)
+{
+	return 0;
+}
+#endif
 
 /**
  * trace_array_get_by_name - Create/Lookup a trace array, given its name.