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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-13 13:17:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-13 13:17:19 -0700
commitbc0f51d35994bc14ae9bebadc9523399711fedf8 (patch)
tree2b53f27c0fc9dc62f9913b6ab57527b8e7631aff /kernel
parentad51271afc21a72479974713abb40ca4b96d1f6b (diff)
parent2e028c4fe12907f226b8221815f16c2486ad3aa7 (diff)
downloadlwn-bc0f51d35994bc14ae9bebadc9523399711fedf8.tar.gz
lwn-bc0f51d35994bc14ae9bebadc9523399711fedf8.zip
Merge tag 'trace-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull more tracing updates from Steven Rostedt: "A few more minor updates: - Show the tgid mappings for user space trace tools to use - Fix and optimize the comm and tgid cache recording - Sanitize derived kprobe names - Ftrace selftest updates - trace file header fix - Update of Documentation/trace/ftrace.txt - Compiler warning fixes - Fix possible uninitialized variable" * tag 'trace-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Fix uninitialized variable in match_records() ftrace: Remove an unneeded NULL check ftrace: Hide cached module code for !CONFIG_MODULES tracing: Do note expose stack_trace_filter without DYNAMIC_FTRACE tracing: Update Documentation/trace/ftrace.txt tracing: Fixup trace file header alignment selftests/ftrace: Add a testcase for kprobe event naming selftests/ftrace: Add a test to probe module functions selftests/ftrace: Update multiple kprobes test for powerpc trace/kprobes: Sanitize derived event names tracing: Attempt to record other information even if some fail tracing: Treat recording tgid for idle task as a success tracing: Treat recording comm for idle task as a success tracing: Add saved_tgids file to show cached pid to tgid mappings
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/ftrace.c6
-rw-r--r--kernel/trace/trace.c142
-rw-r--r--kernel/trace/trace_kprobe.c9
-rw-r--r--kernel/trace/trace_stack.c6
4 files changed, 143 insertions, 20 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2953d558bbee..53f6b6401cf0 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3816,7 +3816,7 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
int exclude_mod = 0;
int found = 0;
int ret;
- int clear_filter;
+ int clear_filter = 0;
if (func) {
func_g.type = filter_parse_regex(func, len, &func_g.search,
@@ -3950,7 +3950,7 @@ static int cache_mod(struct trace_array *tr,
continue;
/* no func matches all */
- if (!func || strcmp(func, "*") == 0 ||
+ if (strcmp(func, "*") == 0 ||
(ftrace_mod->func &&
strcmp(ftrace_mod->func, func) == 0)) {
ret = 0;
@@ -3978,6 +3978,7 @@ static int
ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
int reset, int enable);
+#ifdef CONFIG_MODULES
static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
char *mod, bool enable)
{
@@ -4068,6 +4069,7 @@ static void process_cached_mods(const char *mod_name)
kfree(mod);
}
+#endif
/*
* We register the module command as a template to show others how
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 948ec32e0c27..2d0ffcc49dba 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1916,7 +1916,11 @@ static int trace_save_cmdline(struct task_struct *tsk)
{
unsigned pid, idx;
- if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
+ /* treat recording of idle task as a success */
+ if (!tsk->pid)
+ return 1;
+
+ if (unlikely(tsk->pid > PID_MAX_DEFAULT))
return 0;
/*
@@ -2002,7 +2006,11 @@ int trace_find_tgid(int pid)
static int trace_save_tgid(struct task_struct *tsk)
{
- if (unlikely(!tgid_map || !tsk->pid || tsk->pid > PID_MAX_DEFAULT))
+ /* treat recording of idle task as a success */
+ if (!tsk->pid)
+ return 1;
+
+ if (unlikely(!tgid_map || tsk->pid > PID_MAX_DEFAULT))
return 0;
tgid_map[tsk->pid] = tsk->tgid;
@@ -2029,11 +2037,20 @@ static bool tracing_record_taskinfo_skip(int flags)
*/
void tracing_record_taskinfo(struct task_struct *task, int flags)
{
+ bool done;
+
if (tracing_record_taskinfo_skip(flags))
return;
- if ((flags & TRACE_RECORD_CMDLINE) && !trace_save_cmdline(task))
- return;
- if ((flags & TRACE_RECORD_TGID) && !trace_save_tgid(task))
+
+ /*
+ * Record as much task information as possible. If some fail, continue
+ * to try to record the others.
+ */
+ done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(task);
+ done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(task);
+
+ /* If recording any information failed, retry again soon. */
+ if (!done)
return;
__this_cpu_write(trace_taskinfo_save, false);
@@ -2050,15 +2067,22 @@ void tracing_record_taskinfo(struct task_struct *task, int flags)
void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
struct task_struct *next, int flags)
{
+ bool done;
+
if (tracing_record_taskinfo_skip(flags))
return;
- if ((flags & TRACE_RECORD_CMDLINE) &&
- (!trace_save_cmdline(prev) || !trace_save_cmdline(next)))
- return;
+ /*
+ * Record as much task information as possible. If some fail, continue
+ * to try to record the others.
+ */
+ done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(prev);
+ done &= !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(next);
+ done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(prev);
+ done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(next);
- if ((flags & TRACE_RECORD_TGID) &&
- (!trace_save_tgid(prev) || !trace_save_tgid(next)))
+ /* If recording any information failed, retry again soon. */
+ if (!done)
return;
__this_cpu_write(trace_taskinfo_save, false);
@@ -3334,14 +3358,23 @@ static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file
unsigned int flags)
{
bool tgid = flags & TRACE_ITER_RECORD_TGID;
-
- seq_printf(m, "# %s _-----=> irqs-off\n", tgid ? " " : "");
- seq_printf(m, "# %s / _----=> need-resched\n", tgid ? " " : "");
- seq_printf(m, "# %s| / _---=> hardirq/softirq\n", tgid ? " " : "");
- seq_printf(m, "# %s|| / _--=> preempt-depth\n", tgid ? " " : "");
- seq_printf(m, "# %s||| / delay\n", tgid ? " " : "");
- seq_printf(m, "# TASK-PID CPU#%s|||| TIMESTAMP FUNCTION\n", tgid ? " TGID " : "");
- seq_printf(m, "# | | | %s|||| | |\n", tgid ? " | " : "");
+ const char tgid_space[] = " ";
+ const char space[] = " ";
+
+ seq_printf(m, "# %s _-----=> irqs-off\n",
+ tgid ? tgid_space : space);
+ seq_printf(m, "# %s / _----=> need-resched\n",
+ tgid ? tgid_space : space);
+ seq_printf(m, "# %s| / _---=> hardirq/softirq\n",
+ tgid ? tgid_space : space);
+ seq_printf(m, "# %s|| / _--=> preempt-depth\n",
+ tgid ? tgid_space : space);
+ seq_printf(m, "# %s||| / delay\n",
+ tgid ? tgid_space : space);
+ seq_printf(m, "# TASK-PID CPU#%s|||| TIMESTAMP FUNCTION\n",
+ tgid ? " TGID " : space);
+ seq_printf(m, "# | | | %s|||| | |\n",
+ tgid ? " | " : space);
}
void
@@ -4689,6 +4722,76 @@ static const struct file_operations tracing_readme_fops = {
.llseek = generic_file_llseek,
};
+static void *saved_tgids_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ int *ptr = v;
+
+ if (*pos || m->count)
+ ptr++;
+
+ (*pos)++;
+
+ for (; ptr <= &tgid_map[PID_MAX_DEFAULT]; ptr++) {
+ if (trace_find_tgid(*ptr))
+ return ptr;
+ }
+
+ return NULL;
+}
+
+static void *saved_tgids_start(struct seq_file *m, loff_t *pos)
+{
+ void *v;
+ loff_t l = 0;
+
+ if (!tgid_map)
+ return NULL;
+
+ v = &tgid_map[0];
+ while (l <= *pos) {
+ v = saved_tgids_next(m, v, &l);
+ if (!v)
+ return NULL;
+ }
+
+ return v;
+}
+
+static void saved_tgids_stop(struct seq_file *m, void *v)
+{
+}
+
+static int saved_tgids_show(struct seq_file *m, void *v)
+{
+ int pid = (int *)v - tgid_map;
+
+ seq_printf(m, "%d %d\n", pid, trace_find_tgid(pid));
+ return 0;
+}
+
+static const struct seq_operations tracing_saved_tgids_seq_ops = {
+ .start = saved_tgids_start,
+ .stop = saved_tgids_stop,
+ .next = saved_tgids_next,
+ .show = saved_tgids_show,
+};
+
+static int tracing_saved_tgids_open(struct inode *inode, struct file *filp)
+{
+ if (tracing_disabled)
+ return -ENODEV;
+
+ return seq_open(filp, &tracing_saved_tgids_seq_ops);
+}
+
+
+static const struct file_operations tracing_saved_tgids_fops = {
+ .open = tracing_saved_tgids_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos)
{
unsigned int *ptr = v;
@@ -7921,6 +8024,9 @@ static __init int tracer_init_tracefs(void)
trace_create_file("saved_cmdlines_size", 0644, d_tracer,
NULL, &tracing_saved_cmdlines_size_fops);
+ trace_create_file("saved_tgids", 0444, d_tracer,
+ NULL, &tracing_saved_tgids_fops);
+
trace_eval_init();
trace_create_eval_file(d_tracer);
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 2c5221819be5..c9b5aa10fbf9 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -598,6 +598,14 @@ static struct notifier_block trace_kprobe_module_nb = {
.priority = 1 /* Invoked after kprobe module callback */
};
+/* Convert certain expected symbols into '_' when generating event names */
+static inline void sanitize_event_name(char *name)
+{
+ while (*name++ != '\0')
+ if (*name == ':' || *name == '.')
+ *name = '_';
+}
+
static int create_trace_kprobe(int argc, char **argv)
{
/*
@@ -736,6 +744,7 @@ static int create_trace_kprobe(int argc, char **argv)
else
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
is_return ? 'r' : 'p', addr);
+ sanitize_event_name(buf);
event = buf;
}
tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index b4a751e8f9d6..a4df67cbc711 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -406,6 +406,8 @@ static const struct file_operations stack_trace_fops = {
.release = seq_release,
};
+#ifdef CONFIG_DYNAMIC_FTRACE
+
static int
stack_trace_filter_open(struct inode *inode, struct file *file)
{
@@ -423,6 +425,8 @@ static const struct file_operations stack_trace_filter_fops = {
.release = ftrace_regex_release,
};
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
int
stack_trace_sysctl(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
@@ -477,8 +481,10 @@ static __init int stack_trace_init(void)
trace_create_file("stack_trace", 0444, d_tracer,
NULL, &stack_trace_fops);
+#ifdef CONFIG_DYNAMIC_FTRACE
trace_create_file("stack_trace_filter", 0444, d_tracer,
&trace_ops, &stack_trace_filter_fops);
+#endif
if (stack_trace_filter_buf[0])
ftrace_set_early_filter(&trace_ops, stack_trace_filter_buf, 1);