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From:   Jim Cromie <jim.cromie@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     david@redhat.com, Liam.Howlett@Oracle.com, linux-mm@kvack.org,
        Jim Cromie <jim.cromie@gmail.com>
Subject: [RFC PATCH 01/10] dyndbg: prep to isolate 3 repetetive fields
Date:   Thu, 12 Oct 2023 13:47:02 -0600
Message-ID: <20231012194711.3288031-2-jim.cromie@gmail.com>
In-Reply-To: <20231012194711.3288031-1-jim.cromie@gmail.com>
References: <20231012194711.3288031-1-jim.cromie@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Move 3 fields: modname, filename, function into an anonymous struct,
and rename with '_' prefix to catch stale uses.

Add 3 desc_*() macros to abstract the field refs.

Add DYNAMIC_DEBUG_SITE_INIT() to initialize the fields.

no functional change.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h | 22 ++++++++++++++++------
 lib/dynamic_debug.c           | 28 ++++++++++++++--------------
 2 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 2237d454bc19..aacfafc466c0 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -13,14 +13,17 @@
  * ELF section at every dynamic debug callsite.  At runtime,
  * the special section is treated as an array of these.
  */
+
 struct _ddebug {
 	/*
 	 * These fields are used to drive the user interface
 	 * for selecting and displaying debug callsites.
 	 */
-	const char *modname;
-	const char *function;
-	const char *filename;
+	struct /* _ddebug_site */ {
+		const char *_modname;
+		const char *_function;
+		const char *_filename;
+	};
 	const char *format;
 	unsigned int lineno:18;
 #define CLS_BITS 6
@@ -61,6 +64,10 @@ struct _ddebug {
 #endif
 } __attribute__((aligned(8)));
 
+#define desc_modname(d)		(d)->modname
+#define desc_filename(d)	(d)->filename
+#define desc_function(d)	(d)->function
+
 enum ddebug_class_map_type {
 	DD_CLASS_TYPE_DISJOINT_BITS,
 	/**
@@ -213,12 +220,15 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 			 const struct ib_device *ibdev,
 			 const char *fmt, ...);
 
+#define DYNAMIC_DEBUG_SITE_INIT()			\
+	._modname = KBUILD_MODNAME,			\
+	._function = __func__,				\
+	._filename = __FILE__
+
 #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt)	\
 	static struct _ddebug  __aligned(8)			\
 	__section("__dyndbg") name = {				\
-		.modname = KBUILD_MODNAME,			\
-		.function = __func__,				\
-		.filename = __FILE__,				\
+		DYNAMIC_DEBUG_SITE_INIT(),			\
 		.format = (fmt),				\
 		.lineno = __LINE__,				\
 		.flags = _DPRINTK_FLAGS_DEFAULT,		\
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 3dc512fb1d66..c0e595483cb9 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -235,16 +235,16 @@ static int ddebug_change(const struct ddebug_query *query,
 
 			/* match against the source filename */
 			if (query->filename &&
-			    !match_wildcard(query->filename, dp->filename) &&
+			    !match_wildcard(query->filename, desc_filename(dp)) &&
 			    !match_wildcard(query->filename,
-					   kbasename(dp->filename)) &&
+					    kbasename(desc_filename(dp))) &&
 			    !match_wildcard(query->filename,
-					   trim_prefix(dp->filename)))
+					    trim_prefix(desc_filename(dp))))
 				continue;
 
 			/* match against the function */
 			if (query->function &&
-			    !match_wildcard(query->function, dp->function))
+			    !match_wildcard(query->function, desc_function(dp)))
 				continue;
 
 			/* match against the format */
@@ -281,8 +281,8 @@ static int ddebug_change(const struct ddebug_query *query,
 			}
 #endif
 			v4pr_info("changed %s:%d [%s]%s %s => %s\n",
-				  trim_prefix(dp->filename), dp->lineno,
-				  dt->mod_name, dp->function,
+				  trim_prefix(desc_filename(dp)), dp->lineno,
+				  dt->mod_name, desc_function(dp),
 				  ddebug_describe_flags(dp->flags, &fbuf),
 				  ddebug_describe_flags(newflags, &nbuf));
 			dp->flags = newflags;
@@ -781,13 +781,13 @@ static int __dynamic_emit_prefix(const struct _ddebug *desc, char *buf, int pos)
 {
 	if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
 		pos += snprintf(buf + pos, remaining(pos), "%s:",
-				desc->modname);
+				desc_modname(desc));
 	if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
 		pos += snprintf(buf + pos, remaining(pos), "%s:",
-				desc->function);
+				desc_function(desc));
 	if (desc->flags & _DPRINTK_FLAGS_INCL_SOURCENAME)
 		pos += snprintf(buf + pos, remaining(pos), "%s:",
-				trim_prefix(desc->filename));
+				trim_prefix(desc_filename(desc)));
 	return pos;
 }
 
@@ -1110,8 +1110,8 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 	}
 
 	seq_printf(m, "%s:%u [%s]%s =%s \"",
-		   trim_prefix(dp->filename), dp->lineno,
-		   iter->table->mod_name, dp->function,
+		   trim_prefix(desc_filename(dp)), dp->lineno,
+		   iter->table->mod_name, desc_function(dp),
 		   ddebug_describe_flags(dp->flags, &flags));
 	seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
 	seq_puts(m, "\"");
@@ -1528,12 +1528,12 @@ static int __init dynamic_debug_init(void)
 	}
 
 	iter = iter_mod_start = __start___dyndbg;
-	modname = iter->modname;
+	modname = desc_modname(iter);
 	i = mod_sites = mod_ct = 0;
 
 	for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
 
-		if (strcmp(modname, iter->modname)) {
+		if (strcmp(modname, desc_modname(iter))) {
 			mod_ct++;
 			di.num_descs = mod_sites;
 			di.descs = iter_mod_start;
@@ -1542,7 +1542,7 @@ static int __init dynamic_debug_init(void)
 				goto out_err;
 
 			mod_sites = 0;
-			modname = iter->modname;
+			modname = desc_modname(iter);
 			iter_mod_start = iter;
 		}
 	}
-- 
2.41.0