Commit a2d375ed authored by Jim Cromie's avatar Jim Cromie Committed by Greg Kroah-Hartman
Browse files

dyndbg: refine export, rename to dynamic_debug_exec_queries() 



commit 4c0d7782 ("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: 4c0d7782 ("dyndbg: export ddebug_exec_queries")
Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20200831182210.850852-3-jim.cromie@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b52a95ea

include/linux/dynamic_debug.h

+16 −4
Original line number Diff line number Diff line
@@ -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

lib/dynamic_debug.c

+25 −2
Original line number Diff line number Diff line
@@ -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

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