Add module-to-class validation, in
#> echo class DRM_UT_KMS +p > /proc/dynamic_debug/control
If a query has "class FOO", ddebug_validate_classname (called from ddebug_change) requires that FOO is known to module X, otherwize X is skipped entirely.
The choice of FOO is highly selective, giving isolation and/or coordinated sharing of FOOs. For example, only DRM modules should know and respond to DRM_UT_KMS.
So this, combined with module's opt-in declaration of known classes, effectively privatizes the .class_id space for each module (or coordinated set of modules).
Ignoring a bad query, with dynamic_debug.verbose=3: (lots of modules will not know other module's classes)
bash-5.1# echo module drm class FOO +p > /proc/dynamic_debug/control [ 54.507983] dyndbg: read 24 bytes from userspace [ 54.509549] dyndbg: query 0: "module drm class FOO +p" mod:* [ 54.511502] dyndbg: split into words: "module" "drm" "class" "FOO" "+p" [ 54.513672] dyndbg: op='+' [ 54.514575] dyndbg: flags=0x1 [ 54.515547] dyndbg: *flagsp=0x1 *maskp=0xffffffff [ 54.517112] dyndbg: parsed: func="" file="" module="drm" format="" lineno=0-0 class=FOO [ 54.519707] dyndbg: class: drm.FOO unknown [ 54.521302] dyndbg: no matches for query [ 54.522581] dyndbg: no-match: func="" file="" module="drm" format="" lineno=0-0 class=FOO [ 54.525236] dyndbg: processed 1 queries, with 0 matches, 0 errs
Also add a new column to control-file output, displaying the class-name when its not default. If a module has pr_debugs with non-default .class_id's, and has not registered them, "<unregistered>" is issued.
Signed-off-by: Jim Cromie jim.cromie@gmail.com --- . split out validate_classnames() --- lib/dynamic_debug.c | 70 +++++++++++++++++++++++++++++++++++++++------ 1 file changed, 62 insertions(+), 8 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 8f600c13048a..b1aaf8893cdf 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -56,6 +56,7 @@ struct ddebug_query { const char *module; const char *function; const char *format; + const char *class_string; unsigned int first_lineno, last_lineno; };
@@ -136,13 +137,40 @@ 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=%s\n", + msg, + query->function ?: "", + query->filename ?: "", + query->module ?: "", + fmtlen, query->format ?: "", + query->first_lineno, query->last_lineno, query->class_string); +} + +/* return <0 if class-name is unknown/invalid, 0..CLASS_DFLT otherwise */ +static int ddebug_validate_classname(struct ddebug_table *dt, const char *class_string) +{ + int query_class = -ENOENT; + int idx; + + if (!class_string) + /* all queries w/o class given work only on default class */ + return _DPRINTK_CLASS_DFLT; + + /* + * XXX single list will need to be a for-list + * so that modules can have 2 sets of class-decls + */ + if (!dt->map) + return -ENOENT; + + idx = match_string(dt->map->classes, dt->map->length, class_string); + if (idx < 0) { + v3pr_info("class: %s.%s unknown\n", dt->mod_name, class_string); + return -ENOENT; + } + query_class = idx + dt->map->base; + + return query_class; }
/* @@ -159,6 +187,7 @@ static int ddebug_change(const struct ddebug_query *query, unsigned int newflags; unsigned int nfound = 0; struct flagsbuf fbuf, nbuf; + int query_class;
/* search for matching ddebugs */ mutex_lock(&ddebug_lock); @@ -169,9 +198,18 @@ static int ddebug_change(const struct ddebug_query *query, !match_wildcard(query->module, dt->mod_name)) continue;
+ /* validate class-string against module's known classes */ + query_class = ddebug_validate_classname(dt, query->class_string); + if (query_class < 0) + continue; + for (i = 0; i < dt->num_ddebugs; i++) { struct _ddebug *dp = &dt->ddebugs[i];
+ /* match against query-class, either valid input or default */ + if (query_class != dp->class_id) + continue; + /* match against the source filename */ if (query->filename && !match_wildcard(query->filename, dp->filename) && @@ -424,6 +462,8 @@ 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")) { + rc = check_set(&query->class_string, arg, "class"); } else { pr_err("unknown keyword "%s"\n", keyword); return -EINVAL; @@ -851,6 +891,13 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) return dp; }
+static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp) +{ + if (iter->table->map) + return iter->table->map->classes[dp->class_id]; + return NULL; +} + /* * Seq_ops show method. Called several times within a read() * call from userspace, with ddebug_lock held. Formats the @@ -862,6 +909,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p) struct ddebug_iter *iter = m->private; struct _ddebug *dp = p; struct flagsbuf flags; + char const *class;
if (p == SEQ_START_TOKEN) { seq_puts(m, @@ -874,7 +922,13 @@ 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_CLASS_DFLT) { + class = ddebug_class_name(iter, dp); + seq_printf(m, " class:%s", class ?: "<unregistered>"); + } + seq_puts(m, "\n");
return 0; }