DRM defines/uses 10 enum drm_debug_category's to create exclusive
classes of debug messages. To support this directly in dynamic-debug,
add the following:
- struct _ddebug.class_id:4 - 4 bits is enough
- define _DPRINTK_SITE_UNCLASSED 15 - see below
and the query support:
- struct _ddebug_query.class_id
- ddebug_parse_query - looks for "class" keyword, then calls..
- parse_class - accepts uint: 0-15, sets query.class_id and marker
- vpr_info_dq - displays new field
- ddebug_proc_show - append column with "cls:%d" if !UNCLASSED
With the patch, one can enable current/unclassed callsites by:
#> echo drm class 15 +p > /proc/dynamic_debug/control
parse_class() accepts 0 .. _DPRINTK_SITE_UNCLASSED, which allows the
>control interface to explicitly manipulate unclassed callsites.
After parsing keywords, ddebug_parse_query() sets .class_id=15, iff it
wasnt explicitly set. This allows future classed/categorized
callsites to be untouched by legacy (class unaware) queries.
DEFINE_DYNAMIC_DEBUG_METADATA gets _CLS(cls,) suffix and arg, and
initializes the new .class_id=cls field. The old name gets the default.
Then, these _CLS(cls,...) modifications are repeated up through the
stack of *dynamic_func_call* macros that use the METADATA initializer,
so as to actually supply the category into it.
NOTES:
_DPRINTK_SITE_UNCLASSED: this symbol is used to initialize all
existing/unclassed pr-debug callsites. Normally, the default would be
zero, but DRM_UT_CORE "uses" that value, in the sense that 0 is
exposed as a bit position in drm.debug. Using 15 allows identity
mapping from category to class, avoiding fiddly offsets.
Default .class_id = 15 means that ``echo +p > control`` no longer
toggles ALL the callsites, only the unclassed ones. This was only
useful for static-branch toggle load testing anyway.
RFC:
The new _CLS macro flavor gets a warning from DRM/dri-devel's CI,
but not from checkpatch (on this subject).
a8f6c71f283e dyndbg: add class_id field and query support
-:141: CHECK:MACRO_ARG_REUSE: Macro argument reuse 'id' - possible side-effects?
+#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \
+ DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
+ if (DYNAMIC_DEBUG_BRANCH(id)) \
+ func(&id, ##__VA_ARGS__); \
} while (0)
I couldn't fix it with a ``typeof(id) _id = id`` construct. I haven't
seen the warning myself, on the _CLS extended macro, nor the original.
CC: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
.../admin-guide/dynamic-debug-howto.rst | 7 +++
include/linux/dynamic_debug.h | 54 ++++++++++++++-----
lib/dynamic_debug.c | 48 ++++++++++++++---
3 files changed, 88 insertions(+), 21 deletions(-)
diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index a89cfa083155..8ef8d7dcd140 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -35,6 +35,7 @@ Dynamic debug has even more useful features:
- line number (including ranges of line numbers)
- module name
- format string
+ - class number:0-15
* Provides a debugfs control file: ``<debugfs>/dynamic_debug/control``
which can be read to display the complete list of known debug
@@ -143,6 +144,7 @@ against. Possible keywords are:::
'module' string |
'format' string |
'line' line-range
+ 'class' integer:[0-15]
line-range ::= lineno |
'-'lineno |
@@ -217,6 +219,11 @@ line
line -1605 // the 1605 lines from line 1 to line 1605
line 1600- // all lines from line 1600 to the end of the file
+class
+ This expects a single integer in range: 0-15.
+ 15 is used/reserved for existing/unclassed callsites,
+ and is defaulted in unless specified to >control
+
The flags specification comprises a change operation followed
by one or more flag characters. The change operation is one
of the characters::
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index dce631e678dd..d4b48f3cc6e8 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -6,6 +6,8 @@
#include <linux/jump_label.h>
#endif
+#include <linux/build_bug.h>
+
/*
* An instance of this structure is created in a special
* ELF section at every dynamic debug callsite. At runtime,
@@ -21,6 +23,9 @@ struct _ddebug {
const char *filename;
const char *format;
unsigned int lineno:18;
+#define CLS_BITS 4
+ unsigned int class_id:CLS_BITS;
+#define _DPRINTK_SITE_UNCLASSED ((1 << CLS_BITS) - 1)
/*
* The flags field controls the behaviour at the callsite.
* The bits here are changed dynamically when the user
@@ -87,7 +92,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
const struct ib_device *ibdev,
const char *fmt, ...);
-#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
+#define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \
static struct _ddebug __aligned(8) \
__section("__dyndbg") name = { \
.modname = KBUILD_MODNAME, \
@@ -96,8 +101,14 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
.format = (fmt), \
.lineno = __LINE__, \
.flags = _DPRINTK_FLAGS_DEFAULT, \
+ .class_id = cls, \
_DPRINTK_KEY_INIT \
- }
+ }; \
+ BUILD_BUG_ON_MSG(cls > _DPRINTK_SITE_UNCLASSED, \
+ "classid value overflow")
+
+#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
+ DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, _DPRINTK_SITE_UNCLASSED, fmt)
#ifdef CONFIG_JUMP_LABEL
@@ -128,18 +139,26 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
#endif /* CONFIG_JUMP_LABEL */
-#define __dynamic_func_call(id, fmt, func, ...) do { \
- DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
- if (DYNAMIC_DEBUG_BRANCH(id)) \
- func(&id, ##__VA_ARGS__); \
+#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \
+ DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
+ if (DYNAMIC_DEBUG_BRANCH(id)) \
+ func(&id, ##__VA_ARGS__); \
} while (0)
-#define __dynamic_func_call_no_desc(id, fmt, func, ...) do { \
- DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
- if (DYNAMIC_DEBUG_BRANCH(id)) \
- func(__VA_ARGS__); \
+#define __dynamic_func_call_no_desc_cls(id, cls, fmt, func, ...) do { \
+ DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
+ if (DYNAMIC_DEBUG_BRANCH(id)) \
+ func(__VA_ARGS__); \
} while (0)
+#define __dynamic_func_call(id, fmt, func, ...) \
+ __dynamic_func_call_cls(id, _DPRINTK_SITE_UNCLASSED, \
+ fmt, func, ##__VA_ARGS__)
+
+#define __dynamic_func_call_no_desc(id, fmt, func, ...) \
+ __dynamic_func_call_no_desc_cls(id, _DPRINTK_SITE_UNCLASSED, \
+ fmt, func, ##__VA_ARGS__)
+
/*
* "Factory macro" for generating a call to func, guarded by a
* DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be
@@ -148,15 +167,24 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
* the varargs. Note that fmt is repeated in invocations of this
* macro.
*/
+#define _dynamic_func_call_cls(cls, fmt, func, ...) \
+ __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
#define _dynamic_func_call(fmt, func, ...) \
- __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
+ _dynamic_func_call_cls(_DPRINTK_SITE_UNCLASSED, fmt, func, ##__VA_ARGS__)
+
/*
* A variant that does the same, except that the descriptor is not
* passed as the first argument to the function; it is only called
* with precisely the macro's varargs.
*/
-#define _dynamic_func_call_no_desc(fmt, func, ...) \
- __dynamic_func_call_no_desc(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
+#define _dynamic_func_call_no_desc_cls(fmt, cat, func, ...) \
+ __dynamic_func_call_no_desc_cls(__UNIQUE_ID(ddebug), cat, \
+ fmt, func, ##__VA_ARGS__)
+
+#define _dynamic_func_call_no_desc(fmt, func, ...) \
+ __dynamic_func_call_no_desc_cls(__UNIQUE_ID(ddebug), \
+ _DPRINTK_SITE_UNCLASSED, \
+ fmt, func, ##__VA_ARGS__)
#define dynamic_pr_debug(fmt, ...) \
_dynamic_func_call(fmt, __dynamic_pr_debug, \
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index a56c1286ffa4..ee2129becacc 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -55,6 +55,8 @@ struct ddebug_query {
const char *function;
const char *format;
unsigned int first_lineno, last_lineno;
+ unsigned int class_id;
+ unsigned int class_marked:1;
};
struct ddebug_iter {
@@ -134,13 +136,13 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
fmtlen--;
}
- v3pr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n",
- msg,
- query->function ?: "",
- query->filename ?: "",
- query->module ?: "",
- fmtlen, query->format ?: "",
- query->first_lineno, query->last_lineno);
+ v3pr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u class=%u\n",
+ msg,
+ query->function ?: "",
+ query->filename ?: "",
+ query->module ?: "",
+ fmtlen, query->format ?: "",
+ query->first_lineno, query->last_lineno, query->class_id);
}
/*
@@ -170,6 +172,10 @@ static int ddebug_change(const struct ddebug_query *query,
for (i = 0; i < dt->num_ddebugs; i++) {
struct _ddebug *dp = &dt->ddebugs[i];
+ /* match against the class_id, either given or default */
+ if (query->class_id != dp->class_id)
+ continue;
+
/* match against the source filename */
if (query->filename &&
!match_wildcard(query->filename, dp->filename) &&
@@ -308,6 +314,21 @@ static inline int parse_lineno(const char *str, unsigned int *val)
return 0;
}
+static inline int parse_class(struct ddebug_query *query, const char *str)
+{
+ int rc;
+ unsigned int val;
+
+ rc = kstrtouint(str, 10, &val);
+ if (rc < 0 || val > _DPRINTK_SITE_UNCLASSED) {
+ pr_err("expecting class:[0-%d], not %s\n", _DPRINTK_SITE_UNCLASSED, str);
+ return -EINVAL;
+ }
+ query->class_id = val;
+ query->class_marked = 1;
+ return 0;
+}
+
static int parse_linerange(struct ddebug_query *query, const char *first)
{
char *last = strchr(first, '-');
@@ -421,6 +442,9 @@ static int ddebug_parse_query(char *words[], int nwords,
} else if (!strcmp(keyword, "line")) {
if (parse_linerange(query, arg))
return -EINVAL;
+ } else if (!strcmp(keyword, "class")) {
+ if (parse_class(query, arg))
+ return -EINVAL;
} else {
pr_err("unknown keyword \"%s\"\n", keyword);
return -EINVAL;
@@ -428,6 +452,10 @@ static int ddebug_parse_query(char *words[], int nwords,
if (rc)
return rc;
}
+ /* post-validate the query, set default */
+ if (!query->class_marked)
+ query->class_id = _DPRINTK_SITE_UNCLASSED;
+
vpr_info_dq(query, "parsed");
return 0;
}
@@ -900,7 +928,11 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
iter->table->mod_name, dp->function,
ddebug_describe_flags(dp->flags, &flags));
seq_escape(m, dp->format, "\t\r\n\"");
- seq_puts(m, "\"\n");
+ seq_puts(m, "\"");
+
+ if (dp->class_id != _DPRINTK_SITE_UNCLASSED)
+ seq_printf(m, " cls:%u", dp->class_id);
+ seq_puts(m, "\n");
return 0;
}
--
2.35.1
