aboutsummaryrefslogtreecommitdiff
path: root/kernel/trace
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace.c93
-rw-r--r--kernel/trace/trace.h27
-rw-r--r--kernel/trace/trace_functions_return.c38
-rw-r--r--kernel/trace/trace_nop.c52
-rw-r--r--kernel/trace/trace_stack.c24
5 files changed, 213 insertions, 21 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5653c6b07ba..4ee6f037522 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -43,6 +43,20 @@
unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
unsigned long __read_mostly tracing_thresh;
+/* For tracers that don't implement custom flags */
+static struct tracer_opt dummy_tracer_opt[] = {
+ { }
+};
+
+static struct tracer_flags dummy_tracer_flags = {
+ .val = 0,
+ .opts = dummy_tracer_opt
+};
+
+static int dummy_set_flag(u32 old_flags, u32 bit, int set)
+{
+ return 0;
+}
/*
* Kill all tracing for good (never come back).
@@ -537,6 +551,14 @@ int register_tracer(struct tracer *type)
}
}
+ if (!type->set_flag)
+ type->set_flag = &dummy_set_flag;
+ if (!type->flags)
+ type->flags = &dummy_tracer_flags;
+ else
+ if (!type->flags->opts)
+ type->flags->opts = dummy_tracer_opt;
+
#ifdef CONFIG_FTRACE_STARTUP_TEST
if (type->selftest) {
struct tracer *saved_tracer = current_trace;
@@ -840,6 +862,7 @@ static void __trace_function_return(struct trace_array *tr,
entry->parent_ip = trace->ret;
entry->rettime = trace->rettime;
entry->calltime = trace->calltime;
+ entry->overrun = trace->overrun;
ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
}
#endif
@@ -2436,10 +2459,13 @@ static ssize_t
tracing_trace_options_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
+ int i;
char *buf;
int r = 0;
int len = 0;
- int i;
+ u32 tracer_flags = current_trace->flags->val;
+ struct tracer_opt *trace_opts = current_trace->flags->opts;
+
/* calulate max size */
for (i = 0; trace_options[i]; i++) {
@@ -2447,6 +2473,15 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
len += 3; /* "no" and space */
}
+ /*
+ * Increase the size with names of options specific
+ * of the current tracer.
+ */
+ for (i = 0; trace_opts[i].name; i++) {
+ len += strlen(trace_opts[i].name);
+ len += 3; /* "no" and space */
+ }
+
/* +2 for \n and \0 */
buf = kmalloc(len + 2, GFP_KERNEL);
if (!buf)
@@ -2459,6 +2494,15 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
r += sprintf(buf + r, "no%s ", trace_options[i]);
}
+ for (i = 0; trace_opts[i].name; i++) {
+ if (tracer_flags & trace_opts[i].bit)
+ r += sprintf(buf + r, "%s ",
+ trace_opts[i].name);
+ else
+ r += sprintf(buf + r, "no%s ",
+ trace_opts[i].name);
+ }
+
r += sprintf(buf + r, "\n");
WARN_ON(r >= len + 2);
@@ -2469,6 +2513,40 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
return r;
}
+/* Try to assign a tracer specific option */
+static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
+{
+ struct tracer_flags *trace_flags = trace->flags;
+ struct tracer_opt *opts = NULL;
+ int ret = 0, i = 0;
+ int len;
+
+ for (i = 0; trace_flags->opts[i].name; i++) {
+ opts = &trace_flags->opts[i];
+ len = strlen(opts->name);
+
+ if (strncmp(cmp, opts->name, len) == 0) {
+ ret = trace->set_flag(trace_flags->val,
+ opts->bit, !neg);
+ break;
+ }
+ }
+ /* Not found */
+ if (!trace_flags->opts[i].name)
+ return -EINVAL;
+
+ /* Refused to handle */
+ if (ret)
+ return ret;
+
+ if (neg)
+ trace_flags->val &= ~opts->bit;
+ else
+ trace_flags->val |= opts->bit;
+
+ return 0;
+}
+
static ssize_t
tracing_trace_options_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
@@ -2476,6 +2554,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
char buf[64];
char *cmp = buf;
int neg = 0;
+ int ret;
int i;
if (cnt >= sizeof(buf))
@@ -2502,11 +2581,13 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
break;
}
}
- /*
- * If no option could be set, return an error:
- */
- if (!trace_options[i])
- return -EINVAL;
+
+ /* If no option could be set, test the specific tracer options */
+ if (!trace_options[i]) {
+ ret = set_tracer_option(current_trace, cmp, neg);
+ if (ret)
+ return ret;
+ }
filp->f_pos += cnt;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 37947f6b92b..2cb12fd98f6 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -60,6 +60,7 @@ struct ftrace_ret_entry {
unsigned long parent_ip;
unsigned long long calltime;
unsigned long long rettime;
+ unsigned long overrun;
};
extern struct tracer boot_tracer;
@@ -259,6 +260,29 @@ enum print_line_t {
TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */
};
+
+/*
+ * An option specific to a tracer. This is a boolean value.
+ * The bit is the bit index that sets its value on the
+ * flags value in struct tracer_flags.
+ */
+struct tracer_opt {
+ const char *name; /* Will appear on the trace_options file */
+ u32 bit; /* Mask assigned in val field in tracer_flags */
+};
+
+/*
+ * The set of specific options for a tracer. Your tracer
+ * have to set the initial value of the flags val.
+ */
+struct tracer_flags {
+ u32 val;
+ struct tracer_opt *opts;
+};
+
+/* Makes more easy to define a tracer opt */
+#define TRACER_OPT(s, b) .name = #s, .bit = b
+
/*
* A specific tracer, represented by methods that operate on a trace array:
*/
@@ -280,8 +304,11 @@ struct tracer {
struct trace_array *tr);
#endif
enum print_line_t (*print_line)(struct trace_iterator *iter);
+ /* If you handled the flag setting, return 0 */
+ int (*set_flag)(u32 old_flags, u32 bit, int set);
struct tracer *next;
int print_max;
+ struct tracer_flags *flags;
};
struct trace_seq {
diff --git a/kernel/trace/trace_functions_return.c b/kernel/trace/trace_functions_return.c
index a68564af022..e00d64509c9 100644
--- a/kernel/trace/trace_functions_return.c
+++ b/kernel/trace/trace_functions_return.c
@@ -14,6 +14,19 @@
#include "trace.h"
+#define TRACE_RETURN_PRINT_OVERRUN 0x1
+static struct tracer_opt trace_opts[] = {
+ /* Display overruns or not */
+ { TRACER_OPT(overrun, TRACE_RETURN_PRINT_OVERRUN) },
+ { } /* Empty entry */
+};
+
+static struct tracer_flags tracer_flags = {
+ .val = 0, /* Don't display overruns by default */
+ .opts = trace_opts
+};
+
+
static int return_trace_init(struct trace_array *tr)
{
int cpu;
@@ -42,26 +55,39 @@ print_return_function(struct trace_iterator *iter)
ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
+
ret = seq_print_ip_sym(s, field->ip,
trace_flags & TRACE_ITER_SYM_MASK);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, " (%llu ns)\n",
+
+ ret = trace_seq_printf(s, " (%llu ns)",
field->rettime - field->calltime);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- else
- return TRACE_TYPE_HANDLED;
+
+ if (tracer_flags.val & TRACE_RETURN_PRINT_OVERRUN) {
+ ret = trace_seq_printf(s, " (Overruns: %lu)",
+ field->overrun);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ ret = trace_seq_printf(s, "\n");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ return TRACE_TYPE_HANDLED;
}
return TRACE_TYPE_UNHANDLED;
}
-static struct tracer return_trace __read_mostly =
-{
+static struct tracer return_trace __read_mostly = {
.name = "return",
.init = return_trace_init,
.reset = return_trace_reset,
- .print_line = print_return_function
+ .print_line = print_return_function,
+ .flags = &tracer_flags,
};
static __init int init_return_trace(void)
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 0e77415caed..b9767acd30a 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -12,6 +12,27 @@
#include "trace.h"
+/* Our two options */
+enum {
+ TRACE_NOP_OPT_ACCEPT = 0x1,
+ TRACE_NOP_OPT_REFUSE = 0x2
+};
+
+/* Options for the tracer (see trace_options file) */
+static struct tracer_opt nop_opts[] = {
+ /* Option that will be accepted by set_flag callback */
+ { TRACER_OPT(test_nop_accept, TRACE_NOP_OPT_ACCEPT) },
+ /* Option that will be refused by set_flag callback */
+ { TRACER_OPT(test_nop_refuse, TRACE_NOP_OPT_REFUSE) },
+ { } /* Always set a last empty entry */
+};
+
+static struct tracer_flags nop_flags = {
+ /* You can check your flags value here when you want. */
+ .val = 0, /* By default: all flags disabled */
+ .opts = nop_opts
+};
+
static struct trace_array *ctx_trace;
static void start_nop_trace(struct trace_array *tr)
@@ -41,6 +62,35 @@ static void nop_trace_reset(struct trace_array *tr)
stop_nop_trace(tr);
}
+/* It only serves as a signal handler and a callback to
+ * accept or refuse tthe setting of a flag.
+ * If you don't implement it, then the flag setting will be
+ * automatically accepted.
+ */
+static int nop_set_flag(u32 old_flags, u32 bit, int set)
+{
+ /*
+ * Note that you don't need to update nop_flags.val yourself.
+ * The tracing Api will do it automatically if you return 0
+ */
+ if (bit == TRACE_NOP_OPT_ACCEPT) {
+ printk(KERN_DEBUG "nop_test_accept flag set to %d: we accept."
+ " Now cat trace_options to see the result\n",
+ set);
+ return 0;
+ }
+
+ if (bit == TRACE_NOP_OPT_REFUSE) {
+ printk(KERN_DEBUG "nop_test_refuse flag set to %d: we refuse."
+ "Now cat trace_options to see the result\n",
+ set);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+
struct tracer nop_trace __read_mostly =
{
.name = "nop",
@@ -49,5 +99,7 @@ struct tracer nop_trace __read_mostly =
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_nop,
#endif
+ .flags = &nop_flags,
+ .set_flag = nop_set_flag
};
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index d39e8b7de6a..fde3be15c64 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -180,11 +180,16 @@ static struct file_operations stack_max_size_fops = {
static void *
t_next(struct seq_file *m, void *v, loff_t *pos)
{
- long i = (long)m->private;
+ long i;
(*pos)++;
- i++;
+ if (v == SEQ_START_TOKEN)
+ i = 0;
+ else {
+ i = *(long *)v;
+ i++;
+ }
if (i >= max_stack_trace.nr_entries ||
stack_dump_trace[i] == ULONG_MAX)
@@ -197,12 +202,15 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
static void *t_start(struct seq_file *m, loff_t *pos)
{
- void *t = &m->private;
+ void *t = SEQ_START_TOKEN;
loff_t l = 0;
local_irq_disable();
__raw_spin_lock(&max_stack_lock);
+ if (*pos == 0)
+ return SEQ_START_TOKEN;
+
for (; t && l < *pos; t = t_next(m, t, &l))
;
@@ -231,10 +239,10 @@ static int trace_lookup_stack(struct seq_file *m, long i)
static int t_show(struct seq_file *m, void *v)
{
- long i = *(long *)v;
+ long i;
int size;
- if (i < 0) {
+ if (v == SEQ_START_TOKEN) {
seq_printf(m, " Depth Size Location"
" (%d entries)\n"
" ----- ---- --------\n",
@@ -242,6 +250,8 @@ static int t_show(struct seq_file *m, void *v)
return 0;
}
+ i = *(long *)v;
+
if (i >= max_stack_trace.nr_entries ||
stack_dump_trace[i] == ULONG_MAX)
return 0;
@@ -271,10 +281,6 @@ static int stack_trace_open(struct inode *inode, struct file *file)
int ret;
ret = seq_open(file, &stack_trace_seq_ops);
- if (!ret) {
- struct seq_file *m = file->private_data;
- m->private = (void *)-1;
- }
return ret;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-25 14:06:18 +0000