[GIT PULL] tracing: Various tracing fixes
From: Steven Rostedt
Date: Sat Aug 31 2019 - 07:09:03 EST
Linus,
Small fixes and minor cleanups for Tracing
- Make exported ftrace function not static
- Fix NULL pointer dereference in reading probes as they are created
- Fix NULL pointer dereference in k/uprobe clean up path
- Various documentation fixes
Please pull the latest trace-v5.3-rc6 tree, which can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace-v5.3-rc6
Tag SHA1: b0d99ebe7abd58ab40cd18b4d2ac26ca394909d1
Head SHA1: c68c9ec1c52e5bcd221eb09bc5344ad4f407b204
Denis Efremov (1):
tracing: Make exported ftrace_set_clr_event non-static
Jakub Kicinski (1):
tracing: Correct kdoc formats
Jisheng Zhang (1):
ftrace/x86: Remove mcount() declaration
Naveen N. Rao (2):
ftrace: Fix NULL pointer dereference in t_probe_next()
ftrace: Check for successful allocation of hash
Steven Rostedt (VMware) (1):
ftrace: Check for empty hash and comment the race with registering probes
Xinpeng Liu (1):
tracing/probe: Fix null pointer dereference
----
arch/x86/include/asm/ftrace.h | 1 -
include/linux/trace_events.h | 1 +
kernel/trace/ftrace.c | 17 +++++++++++++++++
kernel/trace/trace.c | 26 ++++++++++++++------------
kernel/trace/trace_events.c | 2 +-
kernel/trace/trace_probe.c | 3 ++-
6 files changed, 35 insertions(+), 15 deletions(-)
---------------------------
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 287f1f7b2e52..c38a66661576 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -16,7 +16,6 @@
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#ifndef __ASSEMBLY__
-extern void mcount(void);
extern atomic_t modifying_ftrace_code;
extern void __fentry__(void);
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 5150436783e8..30a8cdcfd4a4 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -548,6 +548,7 @@ extern int trace_event_get_offsets(struct trace_event_call *call);
#define is_signed_type(type) (((type)(-1)) < (type)1)
+int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
int trace_set_clr_event(const char *system, const char *event, int set);
/*
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index eca34503f178..f9821a3374e9 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3095,6 +3095,14 @@ t_probe_next(struct seq_file *m, loff_t *pos)
hnd = &iter->probe_entry->hlist;
hash = iter->probe->ops.func_hash->filter_hash;
+
+ /*
+ * A probe being registered may temporarily have an empty hash
+ * and it's at the end of the func_probes list.
+ */
+ if (!hash || hash == EMPTY_HASH)
+ return NULL;
+
size = 1 << hash->size_bits;
retry:
@@ -4320,12 +4328,21 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr,
mutex_unlock(&ftrace_lock);
+ /*
+ * Note, there's a small window here that the func_hash->filter_hash
+ * may be NULL or empty. Need to be carefule when reading the loop.
+ */
mutex_lock(&probe->ops.func_hash->regex_lock);
orig_hash = &probe->ops.func_hash->filter_hash;
old_hash = *orig_hash;
hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
+ if (!hash) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
ret = ftrace_match_records(hash, glob, strlen(glob));
/* Nothing found? */
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 525a97fbbc60..563e80f9006a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1567,9 +1567,9 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
/**
* update_max_tr_single - only copy one trace over, and reset the rest
- * @tr - tracer
- * @tsk - task with the latency
- * @cpu - the cpu of the buffer to copy.
+ * @tr: tracer
+ * @tsk: task with the latency
+ * @cpu: the cpu of the buffer to copy.
*
* Flip the trace of a single CPU buffer between the @tr and the max_tr.
*/
@@ -1767,7 +1767,7 @@ static void __init apply_trace_boot_options(void);
/**
* register_tracer - register a tracer with the ftrace system.
- * @type - the plugin for the tracer
+ * @type: the plugin for the tracer
*
* Register a new plugin tracer.
*/
@@ -2230,9 +2230,9 @@ static bool tracing_record_taskinfo_skip(int flags)
/**
* tracing_record_taskinfo - record the task info of a task
*
- * @task - task to record
- * @flags - TRACE_RECORD_CMDLINE for recording comm
- * - TRACE_RECORD_TGID for recording tgid
+ * @task: task to record
+ * @flags: TRACE_RECORD_CMDLINE for recording comm
+ * TRACE_RECORD_TGID for recording tgid
*/
void tracing_record_taskinfo(struct task_struct *task, int flags)
{
@@ -2258,10 +2258,10 @@ void tracing_record_taskinfo(struct task_struct *task, int flags)
/**
* tracing_record_taskinfo_sched_switch - record task info for sched_switch
*
- * @prev - previous task during sched_switch
- * @next - next task during sched_switch
- * @flags - TRACE_RECORD_CMDLINE for recording comm
- * TRACE_RECORD_TGID for recording tgid
+ * @prev: previous task during sched_switch
+ * @next: next task during sched_switch
+ * @flags: TRACE_RECORD_CMDLINE for recording comm
+ * TRACE_RECORD_TGID for recording tgid
*/
void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
struct task_struct *next, int flags)
@@ -3072,7 +3072,9 @@ static void trace_printk_start_stop_comm(int enabled)
/**
* trace_vbprintk - write binary msg to tracing buffer
- *
+ * @ip: The address of the caller
+ * @fmt: The string format to write to the buffer
+ * @args: Arguments for @fmt
*/
int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
{
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index c7506bc81b75..648930823b57 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -787,7 +787,7 @@ static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
return ret;
}
-static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
+int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
{
char *event = NULL, *sub = NULL, *match;
int ret;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index dbef0d135075..fb6bfbc5bf86 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -895,7 +895,8 @@ void trace_probe_cleanup(struct trace_probe *tp)
for (i = 0; i < tp->nr_args; i++)
traceprobe_free_probe_arg(&tp->args[i]);
- kfree(call->class->system);
+ if (call->class)
+ kfree(call->class->system);
kfree(call->name);
kfree(call->print_fmt);
}