[PATCH 0/3] dynamic-debug fixups for 5.9

[PATCH 0/3] dynamic-debug fixups for 5.9

[Jim Cromie]

 - fix new export name, with a wrapper for more utility.
 - parse format="foo bar" like "format" "foo bar"
 - pretty-print
 
Jim Cromie (3):
  dyndbg: give %3u width in pr-format, cosmetic only
  dyndbg: refine export, rename to dynamic_debug_exec_queries()
  dyndbg: fix problem parsing format="foo bar"

 include/linux/dynamic_debug.h | 20 +++++++++---
 lib/dynamic_debug.c           | 59 ++++++++++++++++++++++-------------
 2 files changed, 53 insertions(+), 26 deletions(-)

-- 
2.26.2

[PATCH 1/3] dyndbg: give %3u width in pr-format, cosmetic only

[Jim Cromie]

Specify the print-width so log entries line up nicely.

no functional changes.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 1d012e597cc3..01b7d0210412 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -947,7 +947,7 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
 	list_add(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
-	v2pr_info("%u debug prints in module %s\n", n, dt->mod_name);
+	v2pr_info("%3u debug prints in module %s\n", n, dt->mod_name);
 	return 0;
 }
 
-- 
2.26.2

[PATCH 2/3] dyndbg: refine export, rename to dynamic_debug_exec_queries()

[Jim Cromie]

commit 59cf47e7df31 dyndbg: export ddebug_exec_queries
left a few configs broken, fix them with ifdef-stubs.

Rename the export to dynamic_debug_exec_queries().  This is a more
canonical function name, instead of exposing the 'ddebug' internal
name prefix.  Do this now, before export hits v5.9.0

Implement as new function wrapping ddebug_exec_queries(now static
again), which copies the query-string, preserving ddebug_exec_queries'
in-place parsing, while allowing users to pass "const strings".

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h | 20 ++++++++++++++++----
 lib/dynamic_debug.c           | 24 ++++++++++++++++++++++--
 2 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index aa9ff9e1c0b3..b0191d3aff26 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)
+{
+	printk(KERN_WARNING "kernel not built w 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..b6ab2c643116 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 +557,27 @@ int ddebug_exec_queries(char *query, const char *modname)
 		return exitcode;
 	return nfound;
 }
-EXPORT_SYMBOL_GPL(ddebug_exec_queries);
+
+/**
+ * dynamic_debug_exec_queries - apply changes to selected dynamic-debug prints
+ * @query: string with callsite-selectors +enablement+decorations
+ * @modname: string containing module name
+ *
+ * This implements 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)
+{
+	char *qry = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	int rc;
+	strncpy(qry, query, PAGE_SIZE);
+	rc = ddebug_exec_queries(qry, modname);
+	kfree(qry);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(dynamic_debug_exec_queries);
 
 #define PREFIX_SIZE 64
 
-- 
2.26.2

[PATCH 3/3] dyndbg: fix problem parsing format="foo bar"

[Jim Cromie]

 14775b049642 dyndbg: accept query terms like file=bar and module=foo

That commit broke on a tokenization modality where a word could start
with a quote, but couldnt continue with one.  So the above would
tokenize as 'format="foo' and 'bar"', and fail hard.

This commit fixes the tokenizer by terminating an unquoted token on
the '=', avoiding that problem.  And since ddebug-parse-query will
never see a combined 'keyword=value', revert those parts of the
previous commit.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 33 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index b6ab2c643116..4af686e6ef59 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -237,6 +237,7 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 {
 	int nwords = 0;
 
+	vpr_info("entry, buf:'%s'\n", buf);
 	while (*buf) {
 		char *end;
 
@@ -247,6 +248,8 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 		if (*buf == '#')
 			break;	/* token starts comment, skip rest of line */
 
+		vpr_info("start-of-word:%d '%s'\n", nwords, buf);
+
 		/* find `end' of word, whitespace separated or quoted */
 		if (*buf == '"' || *buf == '\'') {
 			int quote = *buf++;
@@ -257,7 +260,9 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 				return -EINVAL;	/* unclosed quote */
 			}
 		} else {
-			for (end = buf; *end && !isspace(*end); end++)
+			for (end = buf;
+			     *end && *end != '=' && !isspace(*end);
+			     end++)
 				;
 			BUG_ON(end == buf);
 		}
@@ -373,30 +378,20 @@ static int ddebug_parse_query(char *words[], int nwords,
 	unsigned int i;
 	int rc = 0;
 	char *fline;
-	char *keyword, *arg;
 
+	if (nwords % 2 != 0) {
+		pr_err("expecting pairs of match-spec <value>\n");
+		return -EINVAL;
+	}
 	if (modname)
 		/* support $modname.dyndbg=<multiple queries> */
 		query->module = modname;
 
-	for (i = 0; i < nwords; i++) {
-		/* accept keyword=arg */
-		vpr_info("%d w:%s\n", i, words[i]);
-
-		keyword = words[i];
-		arg = strchr(keyword, '=');
-		if (arg) {
-			*arg++ = '\0';
-		} else {
-			i++; /* next word is arg */
-			if (!(i < nwords)) {
-				pr_err("missing arg to keyword: %s\n", keyword);
-				return -EINVAL;
-			}
-			arg = words[i];
-		}
-		vpr_info("%d key:%s arg:%s\n", i, keyword, arg);
+	for (i = 0; i < nwords; i+=2) {
+		char *keyword = words[i];
+		char *arg = words[i+1];
 
+		vpr_info("key:'%s' arg:'%s'\n", keyword, arg);
 		if (!strcmp(keyword, "func")) {
 			rc = check_set(&query->function, arg, "func");
 		} else if (!strcmp(keyword, "file")) {
-- 
2.26.2

Re: [PATCH 2/3] dyndbg: refine export, rename to dynamic_debug_exec_queries()

[Joe Perches]

On Mon, 2020-08-24 at 12:54 -0600, Jim Cromie wrote:
> commit 59cf47e7df31 dyndbg: export ddebug_exec_queries
> left a few configs broken, fix them with ifdef-stubs.
> 
> Rename the export to dynamic_debug_exec_queries().  This is a more
> canonical function name, instead of exposing the 'ddebug' internal
> name prefix.  Do this now, before export hits v5.9.0
> 
> Implement as new function wrapping ddebug_exec_queries(now static
> again), which copies the query-string, preserving ddebug_exec_queries'
> in-place parsing, while allowing users to pass "const strings".
[]
> diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
[]
> @@ -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)
> +{
> +	printk(KERN_WARNING "kernel not built w CONFIG_DYNAMIC_DEBUG_CORE\n");

pr_warn and w should be with

> diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
[]
> @@ -557,7 +557,27 @@ int ddebug_exec_queries(char *query, const char *modname)
>  		return exitcode;
>  	return nfound;
>  }
> -EXPORT_SYMBOL_GPL(ddebug_exec_queries);
> +
> +/**
> + * dynamic_debug_exec_queries - apply changes to selected dynamic-debug prints
> + * @query: string with callsite-selectors +enablement+decorations
> + * @modname: string containing module name
> + *
> + * This implements 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)
> +{
> +	char *qry = kmalloc(PAGE_SIZE, GFP_KERNEL);
> +	int rc;
> +	strncpy(qry, query, PAGE_SIZE);

kstrndup?