On Fri, Nov 29, 2024 at 03:11:43AM -0800, Andrew Morton wrote: > > The patch titled > Subject: minmax.h: simplify the variants of clamp() > has been added to the -mm mm-nonmm-unstable branch. Its filename is > minmaxh-simplify-the-variants-of-clamp.patch Hmm, this was generating kernel test bot reports, should we be taking it without that being fixed? > > This patch will shortly appear at > https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/minmaxh-simplify-the-variants-of-clamp.patch > > This patch will later appear in the mm-nonmm-unstable branch at > git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > > Before you just go and hit "reply", please: > a) Consider who else should be cc'ed > b) Prefer to cc a suitable mailing list as well > c) Ideally: find the original patch on the mailing list and do a > reply-to-all to that, adding suitable additional cc's > > *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** > > The -mm tree is included into linux-next via the mm-everything > branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > and is updated there every 2-3 working days > > ------------------------------------------------------ > From: David Laight <David.Laight@xxxxxxxxxx> > Subject: minmax.h: simplify the variants of clamp() > Date: Mon, 18 Nov 2024 19:15:05 +0000 > > Always pass a 'type' through to __clamp_once(), pass '__auto_type' from > clamp() itself. > > The expansion of __types_ok3() is reasonable so it isn't worth the added > complexity of avoiding it when a fixed type is used for all three values. > > Link: https://lkml.kernel.org/r/8f69f4deac014f558bab186444bac2e8@xxxxxxxxxxxxxxxx > Signed-off-by: David Laight <david.laight@xxxxxxxxxx> > Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > Cc: Arnd Bergmann <arnd@xxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> > Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > Cc: Jason A. Donenfeld <Jason@xxxxxxxxx> > Cc: Jens Axboe <axboe@xxxxxxxxx> > Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx> > Cc: Mateusz Guzik <mjguzik@xxxxxxxxx> > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> > Cc: Pedro Falcato <pedro.falcato@xxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > include/linux/minmax.h | 24 ++++++++++++------------ > 1 file changed, 12 insertions(+), 12 deletions(-) > > --- a/include/linux/minmax.h~minmaxh-simplify-the-variants-of-clamp > +++ a/include/linux/minmax.h > @@ -183,29 +183,29 @@ > #define __clamp(val, lo, hi) \ > ((val) >= (hi) ? (hi) : ((val) <= (lo) ? (lo) : (val))) > > -#define __clamp_once(val, lo, hi, uval, ulo, uhi) ({ \ > - __auto_type uval = (val); \ > - __auto_type ulo = (lo); \ > - __auto_type uhi = (hi); \ > +#define __clamp_once(type, val, lo, hi, uval, ulo, uhi) ({ \ > + type uval = (val); \ > + type ulo = (lo); \ > + type uhi = (hi); \ > BUILD_BUG_ON_MSG(statically_true(ulo > uhi), \ > "clamp() low limit " #lo " greater than high limit " #hi); \ > BUILD_BUG_ON_MSG(!__types_ok3(uval, ulo, uhi), \ > "clamp("#val", "#lo", "#hi") signedness error"); \ > __clamp(uval, ulo, uhi); }) > > -#define __careful_clamp(val, lo, hi) \ > - __clamp_once(val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_)) > +#define __careful_clamp(type, val, lo, hi) \ > + __clamp_once(type, val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_)) > > /** > - * clamp - return a value clamped to a given range with strict typechecking > + * clamp - return a value clamped to a given range with typechecking > * @val: current value > * @lo: lowest allowable value > * @hi: highest allowable value > * > - * This macro does strict typechecking of @lo/@hi to make sure they are of the > - * same type as @val. See the unnecessary pointer comparisons. > + * This macro checks @val/@lo/@hi to make sure they have compatible > + * signedness. > */ > -#define clamp(val, lo, hi) __careful_clamp(val, lo, hi) > +#define clamp(val, lo, hi) __careful_clamp(__auto_type, val, lo, hi) > > /** > * clamp_t - return a value clamped to a given range using a given type > @@ -217,7 +217,7 @@ > * This macro does no typechecking and uses temporary variables of type > * @type to make all the comparisons. > */ > -#define clamp_t(type, val, lo, hi) __careful_clamp((type)(val), (type)(lo), (type)(hi)) > +#define clamp_t(type, val, lo, hi) __careful_clamp(type, val, lo, hi) > > /** > * clamp_val - return a value clamped to a given range using val's type > @@ -230,7 +230,7 @@ > * type and @lo and @hi are literals that will otherwise be assigned a signed > * integer type. > */ > -#define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) > +#define clamp_val(val, lo, hi) __careful_clamp(typeof(val), val, lo, hi) > > /* > * Do not check the array parameter using __must_be_array(). > _ > > Patches currently in -mm which might be from David.Laight@xxxxxxxxxx are > > minmaxh-add-whitespace-around-operators-and-after-commas.patch > minmaxh-update-some-comments.patch > minmaxh-reduce-the-define-expansion-of-min-max-and-clamp.patch > minmaxh-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch > minmaxh-move-all-the-clamp-definitions-after-the-min-max-ones.patch > minmaxh-simplify-the-variants-of-clamp.patch > minmaxh-remove-some-defines-that-are-only-expanded-once.patch >
