[PATCH] ftrace: Add initialization check in trace_printk for *puts paths

From: Jiri Olsa
Date: Mon Aug 12 2013 - 05:34:16 EST


Adding initialization check in trace_printk for *puts
paths, plus unifying the check for all related cases.

Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/trace/trace.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 882ec1d..cb7cf96 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -126,6 +126,9 @@ static char *default_bootup_tracer;

static bool allocate_snapshot;

+#define TRACE_PRINTK_DENIED \
+ unlikely(tracing_selftest_running || tracing_disabled)
+
static int __init set_cmdline_ftrace(char *str)
{
strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
@@ -430,6 +433,9 @@ int __trace_puts(unsigned long ip, const char *str, int size)
unsigned long irq_flags;
int alloc;

+ if (TRACE_PRINTK_DENIED)
+ return 0;
+
alloc = sizeof(*entry) + size + 2; /* possible \n added */

local_save_flags(irq_flags);
@@ -470,6 +476,9 @@ int __trace_bputs(unsigned long ip, const char *str)
unsigned long irq_flags;
int size = sizeof(struct bputs_entry);

+ if (TRACE_PRINTK_DENIED)
+ return 0;
+
local_save_flags(irq_flags);
buffer = global_trace.trace_buffer.buffer;
event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
@@ -1757,7 +1766,7 @@ void trace_dump_stack(int skip)
{
unsigned long flags;

- if (tracing_disabled || tracing_selftest_running)
+ if (TRACE_PRINTK_DENIED)
return;

local_save_flags(flags);
@@ -1976,7 +1985,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
char *tbuffer;
int len = 0, size, pc;

- if (unlikely(tracing_selftest_running || tracing_disabled))
+ if (TRACE_PRINTK_DENIED)
return 0;

/* Don't pollute graph traces with trace_vprintk internals */
@@ -2032,7 +2041,7 @@ __trace_array_vprintk(struct ring_buffer *buffer,
unsigned long flags;
char *tbuffer;

- if (tracing_disabled || tracing_selftest_running)
+ if (TRACE_PRINTK_DENIED)
return 0;

/* Don't pollute graph traces with trace_vprintk internals */
--
1.7.11.7

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