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dyndbg: add ddebug_attach_module_classes 

Add ddebug_attach_module_classes(), call it from ddebug_add_module().
It scans the classes/section its given, finds records where the
module-name matches the module being added, and adds them to the
module's maps list.  No locking here, since the record
isn't yet linked into the ddebug_tables list.

It is called indirectly from 2 sources:

 - from load_module(), where it scans the module's __dyndbg_classes
   section, which contains DYNAMIC_DEBUG_CLASSES definitions from just
   the module.

 - from dynamic_debug_init(), where all DYNAMIC_DEBUG_CLASSES
   definitions of each builtin module have been packed together.
   This is why ddebug_attach_module_classes() checks module-name.

NOTES

Its (highly) likely that builtin classes will be ordered by module
name (just like prdbg descriptors are in the __dyndbg section).  So
the list can be replaced by a vector (ptr + length), which will work
for loaded modules too.  This would imitate whats currently done for
the _ddebug descriptors.

That said, converting to vector,len is close to pointless; a small
minority of modules will ever define a class-map, and almost all of
them will have only 1 or 2 class-maps, so theres only a couple dozen
pointers to save.  TODO: re-evaluate for lines removable.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20220904214134.408619-17-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jim Cromie 2022-09-04 15:40:53 -06:00 committed by Greg Kroah-Hartman
parent 66f4006b6a
commit c45f67ace8
1 changed files with 31 additions and 1 deletions
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32
lib/dynamic_debug.c
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@ -45,7 +45,7 @@ extern struct ddebug_class_map __start___dyndbg_classes[];
extern struct ddebug_class_map __stop___dyndbg_classes[];
struct ddebug_table {
struct list_head link;
struct list_head link, maps;
const char *mod_name;
unsigned int num_ddebugs;
struct _ddebug *ddebugs;
@ -921,6 +921,32 @@ static const struct proc_ops proc_fops = {
.proc_write = ddebug_proc_write
};
static void ddebug_attach_module_classes(struct ddebug_table *dt,
struct ddebug_class_map *classes,
int num_classes)
{
struct ddebug_class_map *cm;
int i, j, ct = 0;
for (cm = classes, i = 0; i < num_classes; i++, cm++) {
if (!strcmp(cm->mod_name, dt->mod_name)) {
v2pr_info("class[%d]: module:%s base:%d len:%d ty:%d\n", i,
cm->mod_name, cm->base, cm->length, cm->map_type);
for (j = 0; j < cm->length; j++)
v3pr_info(" %d: %d %s\n", j + cm->base, j,
cm->class_names[j]);
list_add(&cm->link, &dt->maps);
ct++;
}
}
if (ct)
vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
}
/*
* Allocate a new ddebug_table for the given module
* and add it to the global list.
@ -952,6 +978,10 @@ static int __ddebug_add_module(struct _ddebug_info *di, unsigned int base,
dt->num_ddebugs = di->num_descs;
INIT_LIST_HEAD(&dt->link);
INIT_LIST_HEAD(&dt->maps);
if (di->classes && di->num_classes)
ddebug_attach_module_classes(dt, di->classes, di->num_classes);
mutex_lock(&ddebug_lock);
list_add_tail(&dt->link, &ddebug_tables);