[PATCH v7c 05/24] dyndbg: ddebug_apply_class_bitmap - add module arg, select on it

Jim Cromie
2023-10-18T17:06:35Z

Add query_module param to ddebug_apply_class_bitmap(). This allows
its caller to update just one module, or all (as currently). We'll
use this later to propagate drm.debug to each USEr as they're
modprobed.

No functional change.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---

after `modprobe i915`, heres the module dependencies,
though not all on drm.debug.

bash-5.2# lsmod
Module Size Used by
i915 3133440 0
drm_buddy 20480 1 i915
ttm 90112 1 i915
i2c_algo_bit 16384 1 i915
video 61440 1 i915
wmi 32768 1 video
drm_display_helper 200704 1 i915
drm_kms_helper 208896 2 drm_display_helper,i915
drm 606208 5 drm_kms_helper,drm_display_helper,drm_buddy,i915,ttm
cec 57344 2 drm_display_helper,i915
---
lib/dynamic_debug.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index a3be2e7c8c84..ba41fdeaaf98 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -601,7 +601,8 @@ static int ddebug_exec_queries(char *query, const char *modname)

/* apply a new bitmap to the sys-knob's current bit-state */
static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
- unsigned long *new_bits, unsigned long *old_bits)
+ unsigned long *new_bits, unsigned long *old_bits,
+ const char *query_modname)
{
#define QUERY_SIZE 128
char query[QUERY_SIZE];
@@ -609,7 +610,8 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
int matches = 0;
int bi, ct;

- v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
+ v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, *old_bits,
+ query_modname ?: "");

for (bi = 0; bi < map->length; bi++) {
if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
@@ -618,12 +620,15 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
test_bit(bi, new_bits) ? '+' : '-', dcp->flags);

- ct = ddebug_exec_queries(query, NULL);
+ ct = ddebug_exec_queries(query, query_modname);
matches += ct;

v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
ct, map->class_names[bi], *new_bits);
}
+ v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, *old_bits,
+ query_modname ?: "");
+
return matches;
}

@@ -679,7 +684,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
continue;
}
curr_bits ^= BIT(cls_id);
- totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
+ totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits, NULL);
*dcp->bits = curr_bits;
v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
map->class_names[cls_id]);
@@ -689,7 +694,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
old_bits = CLASSMAP_BITMASK(*dcp->lvl);
curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));

- totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
+ totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits, NULL);
*dcp->lvl = (cls_id + (wanted ? 1 : 0));
v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
map->class_names[cls_id], old_bits, curr_bits);
@@ -752,7 +757,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
inrep &= CLASSMAP_BITMASK(map->length);
}
v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
- totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
+ totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, NULL);
*dcp->bits = inrep;
break;
case DD_CLASS_TYPE_LEVEL_NUM:
@@ -765,7 +770,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
old_bits = CLASSMAP_BITMASK(*dcp->lvl);
new_bits = CLASSMAP_BITMASK(inrep);
v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
- totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
+ totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, NULL);
*dcp->lvl = inrep;
break;
default:
--
2.41.0