@@ -110,6 +110,7 @@ config DYNAMIC_DEBUG
default n
depends on PRINTK
depends on (DEBUG_FS || PROC_FS)
+ depends on TRACING
select DYNAMIC_DEBUG_CORE
help
@@ -181,6 +182,7 @@ config DYNAMIC_DEBUG_CORE
bool "Enable core function of dynamic debug support"
depends on PRINTK
depends on (DEBUG_FS || PROC_FS)
+ depends on TRACING
help
Enable core functional support of dynamic debug. It is useful
when you want to tie dynamic debug to your kernel modules with
@@ -36,6 +36,7 @@
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/netdevice.h>
+#include <linux/trace.h>
#define CREATE_TRACE_POINTS
#include <trace/events/dyndbg.h>
@@ -73,6 +74,27 @@ struct flag_settings {
unsigned int mask;
};
+#define DD_OPEN_CMD "open"
+#define DD_CLOSE_CMD "close"
+#define DD_TR_EVENT "0"
+
+struct dd_private_tracebuf {
+ const char *name;
+ struct trace_array *arr;
+};
+
+/*
+ * Trace destination value 0 is reserved for writing
+ * debug logs to trace events (prdbg, devdbg), that
+ * is why buf[0] is not used and we traverse bitmap
+ * starting from bit 1 (bit 0 is also not used).
+ */
+struct dd_tracebuf_tbl_info {
+ struct dd_private_tracebuf buf[TRACE_DST_LAST];
+ DECLARE_BITMAP(bmap, TRACE_DST_LAST);
+ int bmap_size;
+};
+
static DEFINE_MUTEX(ddebug_lock);
static LIST_HEAD(ddebug_tables);
static int verbose;
@@ -80,6 +102,9 @@ module_param(verbose, int, 0644);
MODULE_PARM_DESC(verbose, " dynamic_debug/control processing "
"( 0 = off (default), 1 = module add/rm, 2 = >control summary, 3 = parsing, 4 = per-site changes)");
+static struct
+dd_tracebuf_tbl_info trc_tbl = { .bmap_size = TRACE_DST_LAST };
+
static inline struct dd_ctrl *get_ctrl(struct _ddebug *desc)
{
return &desc->ctrl;
@@ -171,6 +196,145 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
query->first_lineno, query->last_lineno, query->class_string);
}
+static bool is_dd_trace_cmd(const char *str)
+{
+ if (!strcmp(str, DD_OPEN_CMD) || !strcmp(str, DD_CLOSE_CMD))
+ return true;
+
+ return false;
+}
+
+static bool dd_good_trace_name(const char *str)
+{
+ /* "0" is reserved for writing debug logs to trace events (prdbg, devdbg) */
+ if (!strcmp(str, DD_TR_EVENT))
+ return false;
+
+ /* we allow trace instance names to include ^\w+ and underscore */
+ while (*str != '\0') {
+ if (!isalnum(*str) && *str != '_')
+ return false;
+ str++;
+ }
+
+ return true;
+}
+
+static int find_tr_instance(const char *name)
+{
+ int idx = 1;
+
+ for_each_set_bit_from(idx, trc_tbl.bmap, trc_tbl.bmap_size)
+ if (!strcmp(trc_tbl.buf[idx].name, name))
+ return idx;
+
+ return -ENOENT;
+}
+
+static int handle_trace_open_cmd(const char *arg)
+{
+ struct dd_private_tracebuf *buf;
+ int idx, ret = 0;
+
+ mutex_lock(&ddebug_lock);
+
+ /* bit 0 is not used, reserved for trace prdbg and devdbg events */
+ idx = find_next_zero_bit(trc_tbl.bmap, trc_tbl.bmap_size, 1);
+ if (idx == trc_tbl.bmap_size) {
+ ret = -ENOSPC;
+ goto end;
+ }
+
+ if (!dd_good_trace_name(arg)) {
+ pr_err("invalid instance name:%s\n", arg);
+ ret = -EINVAL;
+ goto end;
+ }
+
+ if (find_tr_instance(arg) >= 0) {
+ pr_err("instance is already opened name:%s\n", arg);
+ ret = -EEXIST;
+ goto end;
+ }
+
+ buf = &trc_tbl.buf[idx];
+ buf->name = kstrdup(arg, GFP_KERNEL);
+ if (!buf->name) {
+ ret = -ENOMEM;
+ goto end;
+ }
+
+ buf->arr = trace_array_get_by_name(buf->name, NULL);
+ if (!buf->arr) {
+ pr_err("failed to get trace array name:%s", buf->name);
+ ret = -EINVAL;
+ goto end;
+ }
+
+ ret = trace_array_init_printk(buf->arr);
+ if (ret) {
+ pr_err("failed to init trace array name:%s", buf->name);
+ trace_array_put(buf->arr);
+ trace_array_destroy(buf->arr);
+ goto end;
+ }
+
+ set_bit(idx, trc_tbl.bmap);
+ v3pr_info("opened trace instance idx=%d, name=%s\n", idx, arg);
+end:
+ mutex_unlock(&ddebug_lock);
+ return ret;
+}
+
+static int handle_trace_close_cmd(const char *arg)
+{
+ struct dd_private_tracebuf *buf;
+ int idx, ret = 0;
+
+ mutex_lock(&ddebug_lock);
+
+ idx = find_tr_instance(arg);
+ if (idx < 0) {
+ ret = idx;
+ goto end;
+ }
+
+ buf = &trc_tbl.buf[idx];
+
+ trace_array_put(buf->arr);
+ /*
+ * don't destroy trace instance but let user do it manually
+ * with rmdir command at a convenient time later, if it is
+ * destroyed here all debug logs will be lost
+ *
+ * trace_array_destroy(inst->arr);
+ */
+ buf->arr = NULL;
+
+ kfree(buf->name);
+ buf->name = NULL;
+
+ clear_bit(idx, trc_tbl.bmap);
+ v3pr_info("closed trace instance idx=%d, name=%s\n", idx, arg);
+end:
+ mutex_unlock(&ddebug_lock);
+ return ret;
+}
+
+static int ddebug_parse_cmd(char *words[], int nwords)
+{
+ if (nwords != 1)
+ return -EINVAL;
+
+ if (!strcmp(words[0], DD_OPEN_CMD))
+ return handle_trace_open_cmd(words[1]);
+ if (!strcmp(words[0], DD_CLOSE_CMD))
+ return handle_trace_close_cmd(words[1]);
+
+ pr_err("invalid command %s\n", words[0]);
+ return -EINVAL;
+}
+
static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
const char *class_string, int *class_id)
{
@@ -567,6 +731,11 @@ static int ddebug_exec_query(char *query_string, const char *modname)
pr_err("tokenize failed\n");
return -EINVAL;
}
+
+ /* check for open, close commands */
+ if (is_dd_trace_cmd(words[0]))
+ return ddebug_parse_cmd(words, nwords-1);
+
/* check flags 1st (last arg) so query is pairs of spec,val */
if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
pr_err("flags parse failed\n");
@@ -1191,6 +1360,20 @@ static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
return &iter->table->ddebugs[iter->idx];
}
+/*
+ * Check if the iterator points to the last _ddebug object
+ * to traverse.
+ */
+static bool ddebug_iter_is_last(struct ddebug_iter *iter)
+{
+ if (iter->table == NULL)
+ return false;
+ if (iter->idx-1 < 0 &&
+ list_is_last(&iter->table->link, &ddebug_tables))
+ return true;
+ return false;
+}
+
/*
* Seq_ops start method. Called at the start of every
* read() call from userspace. Takes the ddebug_lock and
@@ -1281,6 +1464,17 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
}
seq_puts(m, "\n");
+ if (ddebug_iter_is_last(iter) &&
+ !bitmap_empty(trc_tbl.bmap, trc_tbl.bmap_size)) {
+ int idx = 1;
+
+ seq_puts(m, "\n");
+ seq_puts(m, "#: Opened trace instances:");
+ for_each_set_bit_from(idx, trc_tbl.bmap, trc_tbl.bmap_size)
+ seq_printf(m, " %s", trc_tbl.buf[idx].name);
+ seq_puts(m, "\n");
+ }
+
return 0;
}