commit 4c0d77828d4f ("dyndbg: export ddebug_exec_queries")
had a few problems:
- broken non DYNAMIC_DEBUG_CORE configs, sparse warning
- the exported function modifies query string, breaks on RO strings.
- func name follows internal convention, shouldn't be exposed as is.
1st is fixed in header with ifdefd function prototype or stub defn.
Also remove an obsolete HAVE-symbol ifdef-comment, and add others.
Fix others by wrapping existing internal function with a new one,
named in accordance with module-prefix naming convention, before
export hits v5.9.0. In new function, copy query string to a local
buffer, so users can pass hard-coded/RO queries, and internal function
can be used unchanged.
Fixes: 4c0d77828d4f ("dyndbg: export ddebug_exec_queries")
---
v2- code improvements, per Joe Perches
v3- commit message fixups
Signed-off-by: Jim Cromie <jim.cro...@gmail.com>
---
include/linux/dynamic_debug.h | 20 ++++++++++++++++----
lib/dynamic_debug.c | 27 +++++++++++++++++++++++++--
2 files changed, 41 insertions(+), 6 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index aa9ff9e1c0b3..8aa0c7c2608c 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -49,6 +49,10 @@ struct _ddebug {
#if defined(CONFIG_DYNAMIC_DEBUG_CORE)
+
+/* exported for module authors to exercise >control */
+int dynamic_debug_exec_queries(const char *query, const char *modname);
+
int ddebug_add_module(struct _ddebug *tab, unsigned int n,
const char *modname);
extern int ddebug_remove_module(const char *mod_name);
@@ -105,7 +109,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
static_branch_unlikely(&descriptor.key.dd_key_false)
#endif
-#else /* !HAVE_JUMP_LABEL */
+#else /* !CONFIG_JUMP_LABEL */
#define _DPRINTK_KEY_INIT
@@ -117,7 +121,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
#endif
-#endif
+#endif /* CONFIG_JUMP_LABEL */
#define __dynamic_func_call(id, fmt, func, ...) do { \
DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
@@ -172,10 +176,11 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
KERN_DEBUG, prefix_str, prefix_type, \
rowsize, groupsize, buf, len, ascii)
-#else
+#else /* !CONFIG_DYNAMIC_DEBUG_CORE */
#include <linux/string.h>
#include <linux/errno.h>
+#include <linux/printk.h>
static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n,
const char *modname)
@@ -210,6 +215,13 @@ static inline int ddebug_dyndbg_module_param_cb(char
*param, char *val,
print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \
rowsize, groupsize, buf, len, ascii); \
} while (0)
-#endif
+
+static inline int dynamic_debug_exec_queries(const char *query, const char
*modname)
+{
+ pr_warn("kernel not built with CONFIG_DYNAMIC_DEBUG_CORE\n");
+ return 0;
+}
+
+#endif /* !CONFIG_DYNAMIC_DEBUG_CORE */
#endif
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 01b7d0210412..08e4b057514c 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -525,7 +525,7 @@ static int ddebug_exec_query(char *query_string, const char
*modname)
last error or number of matching callsites. Module name is either
in param (for boot arg) or perhaps in query string.
*/
-int ddebug_exec_queries(char *query, const char *modname)
+static int ddebug_exec_queries(char *query, const char *modname)
{
char *split;
int i, errs = 0, exitcode = 0, rc, nfound = 0;
@@ -557,7 +557,30 @@ int ddebug_exec_queries(char *query, const char *modname)
return exitcode;
return nfound;
}
-EXPORT_SYMBOL_GPL(ddebug_exec_queries);
+
+/**
+ * dynamic_debug_exec_queries - select and change dynamic-debug prints
+ * @query: query-string described in admin-guide/dynamic-debug-howto
+ * @modname: string containing module name, usually &module.mod_name
+ *
+ * This uses the >/proc/dynamic_debug/control reader, allowing module
+ * authors to modify their dynamic-debug callsites. The modname is
+ * canonically struct module.mod_name, but can also be null or a
+ * module-wildcard, for example: "drm*".
+ */
+int dynamic_debug_exec_queries(const char *query, const char *modname)
+{
+ int rc;
+ char *qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
+
+ if (!query)
+ return -ENOMEM;
+
+ rc = ddebug_exec_queries(qry, modname);
+ kfree(qry);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(dynamic_debug_exec_queries);
#define PREFIX_SIZE 64
--
2.26.2
