Re: [PATCH 06/63] dyndbg: ddebug_apply_class_bitmap - add module arg, select on it

[Louis Chauvet <louis.chauvet@bootlin.com>]

Le 25/01/2025 à 07:45, Jim Cromie a écrit :
> Add param: query_module to ddebug_apply_class_bitmap(), and pass it
> thru to _ddebug_queries(), replacing NULL with query_module.  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>

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.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 41cbaa96f83d..8adb81e75a16 100644
> --- a/lib/dynamic_debug.c
> +++ b/lib/dynamic_debug.c
> @@ -605,7 +605,8 @@ 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];
> @@ -613,7 +614,8 @@ 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))
> @@ -622,12 +624,15 @@ 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;
>   }
>   
> @@ -682,7 +687,7 @@ 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]);
> @@ -692,7 +697,7 @@ 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);
> @@ -755,7 +760,7 @@ 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:
> @@ -768,7 +773,7 @@ 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:

-- 
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com