From: Jim Cromie <jim.cromie@gmail.com>
To: jbaron@akamai.com, gregkh@linuxfoundation.org,
dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
intel-gvt-dev@lists.freedesktop.org,
intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
Cc: daniel.vetter@ffwll.ch, seanpaul@chromium.org,
robdclark@gmail.com, linux@rasmusvillemoes.dk, joe@perches.com,
Jim Cromie <jim.cromie@gmail.com>
Subject: [PATCH v6 14/57] dyndbg: add DECLARE_DYNDBG_CLASSMAP macro
Date: Sun, 4 Sep 2022 15:40:51 -0600 [thread overview]
Message-ID: <20220904214134.408619-15-jim.cromie@gmail.com> (raw)
In-Reply-To: <20220904214134.408619-1-jim.cromie@gmail.com>
Using DECLARE_DYNDBG_CLASSMAP, modules can declare up to 31 classnames.
By doing so, they authorize dyndbg to manipulate class'd prdbgs (ie:
__pr_debug_cls, and soon drm_*dbg), ala::
:#> echo class DRM_UT_KMS +p > /proc/dynamic_debug/control
The macro declares and initializes a static struct ddebug_class_map::
- maps approved class-names to class_ids used in module,
by array order. forex: DRM_UT_*
- class-name vals allow validation of "class FOO" queries
using macro is opt-in
- enum class_map_type - determines interface, behavior
Each module has its own class-type and class_id space, and only known
class-names will be authorized for a manipulation. Only DRM modules
should know and respont to this:
:#> echo class DRM_UT_CORE +p > control # across all modules
pr_debugs (with default class_id) are still controllable as before.
DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, classes...) is::
_var: name of the static struct var. user passes to module_param_cb()
if they want a sysfs node.
_maptype: this is hard-coded to DD_CLASS_TYPE_DISJOINT_BITS for now.
_base: usually 0, it allows splitting 31 classes into subranges, so
that multiple classes / sysfs-nodes can share the module's
class-id space.
classes: list of class_name strings, these are mapped to class-ids
starting at _base. This class-names list must have a
corresponding ENUM, with SYMBOLS that match the literals,
and 1st enum val = _base.
enum class_map_type has 4 values, on 2 factors::
- classes are disjoint/independent vs relative/x<y/verbosity.
disjoint is basis, verbosity by overlay.
- input NUMBERS vs [+-]CLASS_NAMES
uints, ideally hex. vs +DRM_UT_CORE,-DRM_UT_KMS
DD_CLASS_TYPE_DISJOINT_BITS: classes are separate, one per bit.
expecting hex input. built for drm.debug, basis for other types.
DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
classes are independent, like DISJOINT
DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
0 implies silence. use printk to break that.
relative levels applied on bitmaps.
DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
names like: ERR,WARNING,NOTICE,INFO,DEBUG
avoiding EMERG,ALERT,CRIT,ERR - no point.
NOTES:
The macro places the initialized struct ddebug_class_map into the
__dyndbg_classes section. That draws an 'orphan' warning which we
handle in the next commit. The struct attributes are necessary:
__aligned(8) fixed null-ptr derefs, and __used is needed by drm
drivers, which declare class-maps, but don't also declare a
sysfs-param, and thus dont ref the classmap. The __used insures that
the linkage is made, then the class-map is found at load-time.
While its possible to handle both NAMES and NUMBERS in the same
sys-interface, there is ambiguity to avoid, by disallowing them
together. Later, if ambiguities are resolved, 2 new enums can permit
both inputs, on verbose & independent types separately, and authors
can select the interface style they like.
The plan is to implement LEVELS in the callbacks, outside of
ddebug_exec_query(), which for simplicity will treat the CLASSES in
the map as disjoint. The callbacks can see map-type, and apply ++/--
loops (or bitops) to force the relative meanings across the
class-bitmap.
RFC: That leaves 2 issues:
1. doing LEVELs in callbacks means that the native >control interface
doesn't enforce the LEVELS relationship, so you could confusingly have
V3 enabled, but V1 disabled. OTOH, the control iface already allows
infinite tweaking of the underlying callsites; sysfs node readback can
only tell the user what they previously wrote.
2. All dyndbg >control reduces to a query/command, includes +/-, which
is at-root a kernel patching operation with +/- semantics. And the
_NAMES handling exposes it to the user, making it API-adjacent.
And its not just >control where +/- gets used (which is settled), the
new place is with sysfs-nodes exposing _*_NAMES classes, and here its
subtly different.
_DISJOINT_NAMES: is simple, independent
_LEVEL_NAMES: masks-on bits 0 .. N-1, N..max off
# turn on L3,L2,L1 others off
echo +L3 > /sys/module/test_dynamic_debug/parameters/p_level_names
# turn on L2,L1 others off
echo -L3 > /sys/module/test_dynamic_debug/parameters/p_level_names
IOW, the - changes the threshold-on bitpos by 1.
Alternatively, we could treat the +/- as half-duplex, where -L3 turns
off L>2 (and ignores L1), and +L2 would turn on L<=2 (and ignore others).
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
. revised DD_CLASS_TYPE_{DISJOINT,LEVEL}_* names
. reorder-enum - _NAMES feature is extra.
---
include/linux/dynamic_debug.h | 55 +++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 3c9690da44d9..98dbf1d49984 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -56,6 +56,61 @@ struct _ddebug {
#endif
} __attribute__((aligned(8)));
+enum class_map_type {
+ DD_CLASS_TYPE_DISJOINT_BITS,
+ /**
+ * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit.
+ * expecting hex input. Built for drm.debug, basis for other types.
+ */
+ DD_CLASS_TYPE_LEVEL_NUM,
+ /**
+ * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
+ * N turns on just bits N-1 .. 0, so N=0 turns all bits off.
+ */
+ DD_CLASS_TYPE_DISJOINT_NAMES,
+ /**
+ * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
+ * classes are independent, like _DISJOINT_BITS.
+ */
+ DD_CLASS_TYPE_LEVEL_NAMES,
+ /**
+ * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
+ * intended for names like: INFO,DEBUG,TRACE, with a module prefix
+ * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug
+ */
+};
+
+struct ddebug_class_map {
+ struct list_head link;
+ struct module *mod;
+ const char *mod_name; /* needed for builtins */
+ const char **class_names;
+ const int length;
+ const int base; /* index of 1st .class_id, allows split/shared space */
+ enum class_map_type map_type;
+};
+
+/**
+ * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
+ * @_var: a struct ddebug_class_map, passed to module_param_cb
+ * @_type: enum class_map_type, chooses bits/verbose, numeric/symbolic
+ * @_base: offset of 1st class-name. splits .class_id space
+ * @classes: class-names used to control class'd prdbgs
+ */
+#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \
+ static const char *_var##_classnames[] = { __VA_ARGS__ }; \
+ static struct ddebug_class_map __aligned(8) __used \
+ __section("__dyndbg_classes") _var = { \
+ .mod = THIS_MODULE, \
+ .mod_name = KBUILD_MODNAME, \
+ .base = _base, \
+ .map_type = _maptype, \
+ .length = NUM_TYPE_ARGS(char*, __VA_ARGS__), \
+ .class_names = _var##_classnames, \
+ }
+#define NUM_TYPE_ARGS(eltype, ...) \
+ (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype))
+
/* encapsulate linker provided built-in (or module) dyndbg data */
struct _ddebug_info {
struct _ddebug *descs;
--
2.37.2
next prev parent reply other threads:[~2022-09-04 21:43 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-04 21:40 [PATCH v6 00/57] DYNDBG: opt-in class'd debug for modules, use in drm Jim Cromie
2022-09-04 21:40 ` [PATCH v6 01/57] dyndbg: fix static_branch manipulation Jim Cromie
2022-09-04 21:40 ` [PATCH v6 02/57] dyndbg: fix module.dyndbg handling Jim Cromie
2022-09-04 21:40 ` [PATCH v6 03/57] dyndbg: show both old and new in change-info Jim Cromie
2022-09-04 21:40 ` [PATCH v6 04/57] dyndbg: reverse module walk in cat control Jim Cromie
2022-09-04 21:40 ` [PATCH v6 05/57] dyndbg: reverse module.callsite " Jim Cromie
2022-09-04 21:40 ` [PATCH v6 06/57] dyndbg: use ESCAPE_SPACE for " Jim Cromie
2022-09-04 21:40 ` [PATCH v6 07/57] dyndbg: let query-modname override actual module name Jim Cromie
2022-09-04 21:40 ` [PATCH v6 08/57] dyndbg: add test_dynamic_debug module Jim Cromie
2022-09-04 21:40 ` [PATCH v6 09/57] dyndbg: drop EXPORTed dynamic_debug_exec_queries Jim Cromie
2022-09-04 21:40 ` [PATCH v6 10/57] dyndbg: cleanup auto vars in dynamic_debug_init Jim Cromie
2022-09-07 14:10 ` Jason Baron
2022-09-04 21:40 ` [PATCH v6 11/57] dyndbg: gather __dyndbg[] state into struct _ddebug_info Jim Cromie
2022-09-04 21:40 ` [PATCH v6 12/57] dyndbg: add class_id to pr_debug callsites Jim Cromie
2022-09-04 21:40 ` [PATCH v6 13/57] dyndbg: add __pr_debug_cls for testing Jim Cromie
2022-09-04 21:40 ` Jim Cromie [this message]
2022-09-04 21:40 ` [PATCH v6 15/57] kernel/module: add __dyndbg_classes section Jim Cromie
2022-09-04 21:40 ` [PATCH v6 16/57] dyndbg: add ddebug_attach_module_classes Jim Cromie
2022-09-04 21:40 ` [PATCH v6 17/57] dyndbg: validate class FOO by checking with module Jim Cromie
2022-09-07 18:19 ` Jason Baron
2022-09-09 20:44 ` jim.cromie
2022-09-12 20:17 ` Jason Baron
2022-09-12 22:08 ` jim.cromie
2022-09-04 21:40 ` [PATCH v6 18/57] doc-dyndbg: describe "class CLASS_NAME" query support Jim Cromie
2022-09-04 21:40 ` [PATCH v6 19/57] doc-dyndbg: edit dynamic-debug-howto for brevity, audience Jim Cromie
2022-09-04 21:40 ` [PATCH v6 20/57] dyndbg: add drm.debug style (drm/parameters/debug) bitmap support Jim Cromie
2022-09-04 21:40 ` [PATCH v6 21/57] dyndbg: test DECLARE_DYNDBG_CLASSMAP, sysfs nodes Jim Cromie
2022-09-07 14:54 ` Greg KH
2022-09-07 14:57 ` Greg KH
2022-09-04 21:40 ` [PATCH v6 22/57] drm_print: condense enum drm_debug_category Jim Cromie
2022-09-07 6:09 ` Daniel Vetter
2022-09-04 21:41 ` [PATCH v6 23/57] drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers Jim Cromie
2022-09-07 6:13 ` Daniel Vetter
2022-09-09 19:06 ` jim.cromie
2022-09-04 21:41 ` [PATCH v6 24/57] drm_print: interpose drm_*dbg with forwarding macros Jim Cromie
2022-09-04 21:41 ` [PATCH v6 25/57] drm_print: wrap drm_*_dbg in dyndbg descriptor factory macro Jim Cromie
2022-09-04 21:41 ` [PATCH v6 26/57] drm-print.h: include dyndbg header Jim Cromie
2022-09-04 21:41 ` [PATCH v6 27/57] drm-print: add drm_dbg_driver to improve namespace symmetry Jim Cromie
2022-09-04 21:41 ` [PATCH v6 28/57] drm_print: refine drm_debug_enabled for jump-label Jim Cromie
2022-09-07 6:40 ` Daniel Vetter
2022-09-09 23:42 ` jim.cromie
2022-09-04 21:41 ` [PATCH v6 29/57] drm_print: prefer bare printk KERN_DEBUG on generic fn Jim Cromie
2022-09-04 21:41 ` [PATCH v6 30/57] drm_print: add _ddebug descriptor to drm_*dbg prototypes Jim Cromie
2022-09-04 21:41 ` [PATCH v6 31/57] nouveau: change nvkm_debug/trace to use dev_dbg POC Jim Cromie
2022-09-04 21:41 ` [PATCH v6 32/57] nouveau: adapt NV_DEBUG, NV_ATOMIC to use DRM.debug Jim Cromie
2023-03-06 18:49 ` Timur Tabi
2023-03-07 5:10 ` jim.cromie
2022-09-04 21:41 ` [PATCH v6 33/57] nouveau: WIP add 2 LEVEL_NUM classmaps for CLI, SUBDEV Jim Cromie
2022-09-04 21:41 ` [PATCH v6 34/57] dyndbg: add _DPRINTK_FLAGS_ENABLED Jim Cromie
2022-09-04 21:41 ` [PATCH v6 35/57] dyndbg: add _DPRINTK_FLAGS_TRACE Jim Cromie
2022-09-04 21:41 ` [PATCH v6 36/57] dyndbg: add write-events-to-tracefs code Jim Cromie
2022-09-04 21:41 ` [PATCH v6 37/57] dyndbg: add 2 trace-events: drm_debug, drm_devdbg Jim Cromie
2022-09-04 21:41 ` [PATCH v6 38/57] dyndbg: add 2 more trace-events: pr_debug, dev_dbg Jim Cromie
2022-09-04 21:41 ` [PATCH v6 39/57] dyndbg/drm: POC add tracebits sysfs-knob Jim Cromie
2022-09-07 6:59 ` Daniel Vetter
2022-09-04 21:41 ` [PATCH v6 40/57] dyndbg: abstraction macros for modname,function,filename fields Jim Cromie
2022-09-04 21:41 ` [PATCH v6 41/57] dyndbg: split repeating columns to new struct _ddebug_site Jim Cromie
2022-09-04 21:41 ` [PATCH v6 42/57] dyndbg: shrink lineno field by 2 bits Jim Cromie
2022-09-04 21:41 ` [PATCH v6 43/57] dyndbg: add _index,_map to struct _ddebug Jim Cromie
2022-09-04 21:41 ` [PATCH v6 44/57] dyndbg: extend __ddebug_add_module proto to allow packing sites Jim Cromie
2022-09-04 21:41 ` [PATCH v6 45/57] dyndbg: de-duplicate sites Jim Cromie
2022-09-04 21:41 ` [PATCH v6 46/57] dyndbg: drop site-> in add-module, more needed Jim Cromie
2022-09-04 21:41 ` [PATCH v6 47/57] dyndbg: demote iter->site in _init Jim Cromie
2022-09-04 21:41 ` [PATCH v6 48/57] dyndbg: add .gnu.linkonce slot in vmlinux.lds.h KEEPs Jim Cromie
2022-09-04 21:41 ` [PATCH v6 49/57] dyndbg: add structs _ddebug_hdr, _ddebug_site_hdr Jim Cromie
2022-09-04 21:41 ` [PATCH v6 50/57] dyndbg: count unique callsites Jim Cromie
2022-09-04 21:41 ` [PATCH v6 51/57] dyndbg: prevent build bugs via -DNO_DYNAMIC_DEBUG_TABLE Jim Cromie
2022-09-04 21:41 ` [PATCH v6 52/57] dyndbg: add DEFINE_DYNAMIC_DEBUG_TABLE, use it tacitly RFC Jim Cromie
2022-09-04 21:41 ` [PATCH v6 53/57] dyndbg: add/use is_dyndbg_header then set _uplink Jim Cromie
2022-09-04 21:41 ` [PATCH v6 54/57] dyndbg: add .gnu.linkonce. & __dyndbg* sections in module.lds.h Jim Cromie
2022-09-04 21:41 ` [PATCH v6 55/57] dyndbg: dynamic_debug_sites_reclaim() using free_reserved_page() WAG Jim Cromie
2022-09-04 21:41 ` [PATCH v6 56/57] dyndbg: work ddebug_map_site Jim Cromie
2022-09-04 21:41 ` [PATCH v6 57/57] dyndbg: fiddle with readback value on LEVEL_NAMES types Jim Cromie
2022-09-07 15:08 ` [PATCH v6 00/57] DYNDBG: opt-in class'd debug for modules, use in drm Greg KH
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