[GIT PULL] tracing: Fixes for 5.5-rc5

From: Steven Rostedt
Date: Mon Jan 06 2020 - 16:25:33 EST



Linus,

Various tracing fixes:

- kbuild found missing define of MCOUNT_INSN_SIZE for various build configs
- Initialize variable to zero as gcc thinks it is used undefined
(it really isn't but the code is subtle enough that this doesn't hurt)
- Convert from do_div() to div64_ull() to prevent potential divide by zero
- Unregister a trace point on error path in sched_wakeup tracer
- Use signed offset for archs that can have stext not be first
- A simple indentation fix (whitespace error)


Please pull the latest trace-v5.5-rc5 tree, which can be found at:


git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace-v5.5-rc5

Tag SHA1: f648cd56e3506f76f81703a43545729147a7c80f
Head SHA1: 72879ee0c53e2fc17f443f7b1adcc0d5130cd934


Colin Ian King (1):
tracing: Fix indentation issue

Joel Fernandes (Google) (1):
tracing: Change offset type to s32 in preempt/irq tracepoints

Kaitao Cheng (1):
kernel/trace: Fix do not unregister tracepoints when register sched_migrate_task fail

Steven Rostedt (VMware) (3):
tracing: Initialize val to zero in parse_entry of inject code
tracing: Define MCOUNT_INSN_SIZE when not defined without direct calls
tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined

Wen Yang (1):
ftrace: Avoid potential division by zero in function profiler

----
include/trace/events/preemptirq.h | 8 ++++----
kernel/trace/fgraph.c | 14 ++++++++++++++
kernel/trace/ftrace.c | 6 +++---
kernel/trace/trace_events_inject.c | 2 +-
kernel/trace/trace_sched_wakeup.c | 4 +++-
kernel/trace/trace_seq.c | 2 +-
kernel/trace/trace_stack.c | 5 +++++
7 files changed, 31 insertions(+), 10 deletions(-)
---------------------------
diff --git a/include/trace/events/preemptirq.h b/include/trace/events/preemptirq.h
index 95fba0471e5b..3f249e150c0c 100644
--- a/include/trace/events/preemptirq.h
+++ b/include/trace/events/preemptirq.h
@@ -18,13 +18,13 @@ DECLARE_EVENT_CLASS(preemptirq_template,
TP_ARGS(ip, parent_ip),

TP_STRUCT__entry(
- __field(u32, caller_offs)
- __field(u32, parent_offs)
+ __field(s32, caller_offs)
+ __field(s32, parent_offs)
),

TP_fast_assign(
- __entry->caller_offs = (u32)(ip - (unsigned long)_stext);
- __entry->parent_offs = (u32)(parent_ip - (unsigned long)_stext);
+ __entry->caller_offs = (s32)(ip - (unsigned long)_stext);
+ __entry->parent_offs = (s32)(parent_ip - (unsigned long)_stext);
),

TP_printk("caller=%pS parent=%pS",
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index a2659735db73..1af321dec0f1 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -96,6 +96,20 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func,
return 0;
}

+/*
+ * Not all archs define MCOUNT_INSN_SIZE which is used to look for direct
+ * functions. But those archs currently don't support direct functions
+ * anyway, and ftrace_find_rec_direct() is just a stub for them.
+ * Define MCOUNT_INSN_SIZE to keep those archs compiling.
+ */
+#ifndef MCOUNT_INSN_SIZE
+/* Make sure this only works without direct calls */
+# ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+# error MCOUNT_INSN_SIZE not defined with direct calls enabled
+# endif
+# define MCOUNT_INSN_SIZE 0
+#endif
+
int function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index ac99a3500076..9bf1f2cd515e 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -526,8 +526,7 @@ static int function_stat_show(struct seq_file *m, void *v)
}

#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- avg = rec->time;
- do_div(avg, rec->counter);
+ avg = div64_ul(rec->time, rec->counter);
if (tracing_thresh && (avg < tracing_thresh))
goto out;
#endif
@@ -553,7 +552,8 @@ static int function_stat_show(struct seq_file *m, void *v)
* Divide only 1000 for ns^2 -> us^2 conversion.
* trace_print_graph_duration will divide 1000 again.
*/
- do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
+ stddev = div64_ul(stddev,
+ rec->counter * (rec->counter - 1) * 1000);
}

trace_seq_init(&s);
diff --git a/kernel/trace/trace_events_inject.c b/kernel/trace/trace_events_inject.c
index d45079ee62f8..22bcf7c51d1e 100644
--- a/kernel/trace/trace_events_inject.c
+++ b/kernel/trace/trace_events_inject.c
@@ -195,7 +195,7 @@ static int parse_entry(char *str, struct trace_event_call *call, void **pentry)
unsigned long irq_flags;
void *entry = NULL;
int entry_size;
- u64 val;
+ u64 val = 0;
int len;

entry = trace_alloc_entry(call, &entry_size);
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 5e43b9664eca..617e297f46dc 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -630,7 +630,7 @@ static void start_wakeup_tracer(struct trace_array *tr)
if (ret) {
pr_info("wakeup trace: Couldn't activate tracepoint"
" probe to kernel_sched_migrate_task\n");
- return;
+ goto fail_deprobe_sched_switch;
}

wakeup_reset(tr);
@@ -648,6 +648,8 @@ static void start_wakeup_tracer(struct trace_array *tr)
printk(KERN_ERR "failed to start wakeup tracer\n");

return;
+fail_deprobe_sched_switch:
+ unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL);
fail_deprobe_wake_new:
unregister_trace_sched_wakeup_new(probe_wakeup, NULL);
fail_deprobe:
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index 344e4c1aa09c..87de6edafd14 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -381,7 +381,7 @@ int trace_seq_hex_dump(struct trace_seq *s, const char *prefix_str,
int prefix_type, int rowsize, int groupsize,
const void *buf, size_t len, bool ascii)
{
- unsigned int save_len = s->seq.len;
+ unsigned int save_len = s->seq.len;

if (s->full)
return 0;
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 4df9a209f7ca..c557f42a9397 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -283,6 +283,11 @@ static void check_stack(unsigned long ip, unsigned long *stack)
local_irq_restore(flags);
}

+/* Some archs may not define MCOUNT_INSN_SIZE */
+#ifndef MCOUNT_INSN_SIZE
+# define MCOUNT_INSN_SIZE 0
+#endif
+
static void
stack_trace_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs)