| Message ID | 20250320185238.447458-21-jim.cromie@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix CONFIG_DRM_USE_DYNAMIC_DEBUG=y | expand |
Le 20/03/2025 à 19:51, Jim Cromie a écrit : > Add __DYNDBG_CLASSMAP_CHECK to implement these arg-checks at compile: > 0 <= _base < 63 > class_names is not empty > class_names[0] is a string > (class_names.length + _base) < 63 > > These compile-time checks will prevent several misuses; 4 such > examples are added to test_dynamic_debug_submod.ko, and will fail > compilation if -DDD_MACRO_ARGCHECK is added to cflags. This wouldn't > be useful CONFIG_ item, since it breaks the build. > > NB: > > checkpatch complains incorrectly about do-while-0 here; its a strictly > file-scope macro, and do-whiles break there. > > It should soften ERR to WARN and qualify advice wrt file-vs-fn scope, > & new-scope-declaratives exception (forex: _METADATA_) > > The known exceptions by name/pattern works well (_METADATA_ is covered > by "struct"), this patch just wants static_assert added. On my list, > with above. > > Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Nice addition to avoid issues! Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com> > --- > - split static-asserts to __DYNDBG_CLASSMAP_CHECK > - move __DYNDBG_CLASSMAP_CHECK above kdoc for DYNDBG_CLASSMAP_DEFINE > silences kernel-doc warnings > --- > include/linux/dynamic_debug.h | 9 +++++++++ > lib/test_dynamic_debug.c | 11 +++++++++++ > 2 files changed, 20 insertions(+) > > diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h > index 0e3e14ca4765..da2d677947ee 100644 > --- a/include/linux/dynamic_debug.h > +++ b/include/linux/dynamic_debug.h > @@ -101,6 +101,14 @@ struct _ddebug_class_map { > enum ddebug_class_map_type map_type; > }; > > +#define __DYNDBG_CLASSMAP_CHECK(_clnames, _base) \ > + static_assert(((_base) >= 0 && (_base) < _DPRINTK_CLASS_DFLT), \ > + "_base must be in 0..62"); \ > + static_assert(ARRAY_SIZE(_clnames) > 0, \ > + "classnames array size must be > 0"); \ > + static_assert((ARRAY_SIZE(_clnames) + (_base)) < _DPRINTK_CLASS_DFLT, \ > + "_base + classnames.length exceeds range") > + > /** > * DYNAMIC_DEBUG_CLASSMAP_DEFINE - define debug classes used by a module. > * @_var: name of the classmap, exported for other modules coordinated use. > @@ -114,6 +122,7 @@ struct _ddebug_class_map { > */ > #define DYNAMIC_DEBUG_CLASSMAP_DEFINE(_var, _mapty, _base, ...) \ > static const char *_var##_classnames[] = { __VA_ARGS__ }; \ > + __DYNDBG_CLASSMAP_CHECK(_var##_classnames, (_base)); \ > extern struct _ddebug_class_map _var; \ > struct _ddebug_class_map __aligned(8) __used \ > __section("__dyndbg_class_maps") _var = { \ > diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c > index e42916b08fd4..9f9e3fddd7e6 100644 > --- a/lib/test_dynamic_debug.c > +++ b/lib/test_dynamic_debug.c > @@ -146,8 +146,19 @@ DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE"); > DYNAMIC_DEBUG_CLASSMAP_USE(map_disjoint_bits); > DYNAMIC_DEBUG_CLASSMAP_USE(map_level_num); > > +#if defined(DD_MACRO_ARGCHECK) > +/* > + * Exersize compile-time arg-checks in DYNDBG_CLASSMAP_DEFINE. > + * These will break compilation. > + */ > +DYNDBG_CLASSMAP_DEFINE(fail_base_neg, 0, -1, "NEGATIVE_BASE_ARG"); > +DYNDBG_CLASSMAP_DEFINE(fail_base_big, 0, 100, "TOOBIG_BASE_ARG"); > +DYNDBG_CLASSMAP_DEFINE(fail_str_type, 0, 0, 1 /* not a string */); > +DYNDBG_CLASSMAP_DEFINE(fail_emptyclass, 0, 0 /* ,empty */); > #endif > > +#endif /* TEST_DYNAMIC_DEBUG_SUBMOD */ > + > /* stand-in for all pr_debug etc */ > #define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n") >
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 0e3e14ca4765..da2d677947ee 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -101,6 +101,14 @@ struct _ddebug_class_map { enum ddebug_class_map_type map_type; }; +#define __DYNDBG_CLASSMAP_CHECK(_clnames, _base) \ + static_assert(((_base) >= 0 && (_base) < _DPRINTK_CLASS_DFLT), \ + "_base must be in 0..62"); \ + static_assert(ARRAY_SIZE(_clnames) > 0, \ + "classnames array size must be > 0"); \ + static_assert((ARRAY_SIZE(_clnames) + (_base)) < _DPRINTK_CLASS_DFLT, \ + "_base + classnames.length exceeds range") + /** * DYNAMIC_DEBUG_CLASSMAP_DEFINE - define debug classes used by a module. * @_var: name of the classmap, exported for other modules coordinated use. @@ -114,6 +122,7 @@ struct _ddebug_class_map { */ #define DYNAMIC_DEBUG_CLASSMAP_DEFINE(_var, _mapty, _base, ...) \ static const char *_var##_classnames[] = { __VA_ARGS__ }; \ + __DYNDBG_CLASSMAP_CHECK(_var##_classnames, (_base)); \ extern struct _ddebug_class_map _var; \ struct _ddebug_class_map __aligned(8) __used \ __section("__dyndbg_class_maps") _var = { \ diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c index e42916b08fd4..9f9e3fddd7e6 100644 --- a/lib/test_dynamic_debug.c +++ b/lib/test_dynamic_debug.c @@ -146,8 +146,19 @@ DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE"); DYNAMIC_DEBUG_CLASSMAP_USE(map_disjoint_bits); DYNAMIC_DEBUG_CLASSMAP_USE(map_level_num); +#if defined(DD_MACRO_ARGCHECK) +/* + * Exersize compile-time arg-checks in DYNDBG_CLASSMAP_DEFINE. + * These will break compilation. + */ +DYNDBG_CLASSMAP_DEFINE(fail_base_neg, 0, -1, "NEGATIVE_BASE_ARG"); +DYNDBG_CLASSMAP_DEFINE(fail_base_big, 0, 100, "TOOBIG_BASE_ARG"); +DYNDBG_CLASSMAP_DEFINE(fail_str_type, 0, 0, 1 /* not a string */); +DYNDBG_CLASSMAP_DEFINE(fail_emptyclass, 0, 0 /* ,empty */); #endif +#endif /* TEST_DYNAMIC_DEBUG_SUBMOD */ + /* stand-in for all pr_debug etc */ #define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
Add __DYNDBG_CLASSMAP_CHECK to implement these arg-checks at compile: 0 <= _base < 63 class_names is not empty class_names[0] is a string (class_names.length + _base) < 63 These compile-time checks will prevent several misuses; 4 such examples are added to test_dynamic_debug_submod.ko, and will fail compilation if -DDD_MACRO_ARGCHECK is added to cflags. This wouldn't be useful CONFIG_ item, since it breaks the build. NB: checkpatch complains incorrectly about do-while-0 here; its a strictly file-scope macro, and do-whiles break there. It should soften ERR to WARN and qualify advice wrt file-vs-fn scope, & new-scope-declaratives exception (forex: _METADATA_) The known exceptions by name/pattern works well (_METADATA_ is covered by "struct"), this patch just wants static_assert added. On my list, with above. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> --- - split static-asserts to __DYNDBG_CLASSMAP_CHECK - move __DYNDBG_CLASSMAP_CHECK above kdoc for DYNDBG_CLASSMAP_DEFINE silences kernel-doc warnings --- include/linux/dynamic_debug.h | 9 +++++++++ lib/test_dynamic_debug.c | 11 +++++++++++ 2 files changed, 20 insertions(+)