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Code Issues Releases Wiki Activity

dyndbg: refine export, rename to dynamic_debug_exec_queries()

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commit 4c0d77828d ("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: 4c0d77828d ("dyndbg: export ddebug_exec_queries")
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20200831182210.850852-3-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jim Cromie 2020-08-31 12:22:09 -06:00 committed by Greg Kroah-Hartman
parent b52a95eac1
commit a2d375eda7
2 changed files with 41 additions and 6 deletions
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20
include/linux/dynamic_debug.h
View file

@ -49,6 +49,10 @@ struct _ddebug {
#if defined(CONFIG_DYNAMIC_DEBUG_CORE) #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, int ddebug_add_module(struct _ddebug *tab, unsigned int n,
const char *modname); const char *modname);
extern int ddebug_remove_module(const char *mod_name); 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) static_branch_unlikely(&descriptor.key.dd_key_false)
#endif #endif
#else /* !HAVE_JUMP_LABEL */ #else /* !CONFIG_JUMP_LABEL */
#define _DPRINTK_KEY_INIT #define _DPRINTK_KEY_INIT
@ -117,7 +121,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
#endif #endif
#endif #endif /* CONFIG_JUMP_LABEL */
#define __dynamic_func_call(id, fmt, func, ...) do { \ #define __dynamic_func_call(id, fmt, func, ...) do { \
DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \ DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
@ -172,10 +176,11 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
KERN_DEBUG, prefix_str, prefix_type, \ KERN_DEBUG, prefix_str, prefix_type, \
rowsize, groupsize, buf, len, ascii) rowsize, groupsize, buf, len, ascii)
#else #else /* !CONFIG_DYNAMIC_DEBUG_CORE */
#include <linux/string.h> #include <linux/string.h>
#include <linux/errno.h> #include <linux/errno.h>
#include <linux/printk.h>
static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n, static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n,
const char *modname) 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, \ print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \
rowsize, groupsize, buf, len, ascii); \ rowsize, groupsize, buf, len, ascii); \
} while (0) } 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 #endif

27
lib/dynamic_debug.c
View file

@ -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 last error or number of matching callsites. Module name is either
in param (for boot arg) or perhaps in query string. 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; char *split;
int i, errs = 0, exitcode = 0, rc, nfound = 0; 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 exitcode;
return nfound; 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 #define PREFIX_SIZE 64