On Sat, 18 Jan 2025 08:13:06 -0800 Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > Hi, > > On Mon, Nov 18, 2024 at 07:13:31PM +0000, David Laight wrote: > > Use BUILD_BUG_ON_MSG(statically_true(ulo > uhi), ...) for the sanity > > check of the bounds in clamp(). > > Gives better error coverage and one less expansion of the arguments. > > > > Signed-off-by: David Laight <david.laight@xxxxxxxxxx> > > This patch triggers a build error when trying to build parisc:allmodconfig. > See error message and bisect log below. > > I don't think there is anything wrong with the patch. The underlying > problem seems to be that parisc:allmodconfig enables CONFIG_DRM_XE which > tries to build the affected file even though CONFIG_DRM_I915 is not > enabled/supported on parisc. This has appeared before. Any idea which inlined copy of scale() is causing the problem. On the face of it they all look ok. If you can reproduce it maybe try commenting out some of the calls. David > > Copying XE maintainers for feedback/advice. > > Thanks, > Guenter > > --- > Building parisc:allmodconfig ... failed > -------------- > Error log: > In file included from <command-line>: > drivers/gpu/drm/i915/display/intel_backlight.c: In function 'scale': > include/linux/compiler_types.h:542:45: error: call to '__compiletime_assert_415' declared with attribute error: clamp() low limit source_min greater than high limit source_max > 542 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) > | ^ > include/linux/compiler_types.h:523:25: note: in definition of macro '__compiletime_assert' > 523 | prefix ## suffix(); \ > | ^~~~~~ > include/linux/compiler_types.h:542:9: note: in expansion of macro '_compiletime_assert' > 542 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) > | ^~~~~~~~~~~~~~~~~~~ > include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert' > 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) > | ^~~~~~~~~~~~~~~~~~ > include/linux/minmax.h:188:9: note: in expansion of macro 'BUILD_BUG_ON_MSG' > 188 | BUILD_BUG_ON_MSG(statically_true(ulo > uhi), \ > | ^~~~~~~~~~~~~~~~ > include/linux/minmax.h:195:9: note: in expansion of macro '__clamp_once' > 195 | __clamp_once(type, val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_)) > | ^~~~~~~~~~~~ > include/linux/minmax.h:206:28: note: in expansion of macro '__careful_clamp' > 206 | #define clamp(val, lo, hi) __careful_clamp(__auto_type, val, lo, hi) > | ^~~~~~~~~~~~~~~ > drivers/gpu/drm/i915/display/intel_backlight.c:48:22: note: in expansion of macro 'clamp' > 48 | source_val = clamp(source_val, source_min, source_max); > | ^~~~~ > > --- > # bad: [0907e7fb35756464aa34c35d6abb02998418164b] Add linux-next specific files for 20250117 > # good: [5bc55a333a2f7316b58edc7573e8e893f7acb532] Linux 6.13-rc7 > git bisect start 'HEAD' 'v6.13-rc7' > # bad: [195cedf4deacf84167c32b866ceac1cf4a16df15] Merge branch 'main' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git > git bisect bad 195cedf4deacf84167c32b866ceac1cf4a16df15 > # bad: [e8c0711b153b0db806410d8b31ed23b590f4eab4] Merge branch 'xtensa-for-next' of git://github.com/jcmvbkbc/linux-xtensa.git > git bisect bad e8c0711b153b0db806410d8b31ed23b590f4eab4 > # bad: [81d45722d699e594c66c150c8f7a0ec2e2bc9be6] Merge branch 'for-next/perf' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git > git bisect bad 81d45722d699e594c66c150c8f7a0ec2e2bc9be6 > # bad: [7acb844a672defb15cf202a501815ec22c68c800] foo > git bisect bad 7acb844a672defb15cf202a501815ec22c68c800 > # good: [fb2368075b135f174264071b851330649d55f9d0] mm/damon/core: add damos_filter->allow field > git bisect good fb2368075b135f174264071b851330649d55f9d0 > # bad: [fc83c501e385753c90db7316faf9fd4158caaa96] minmax.h: remove some #defines that are only expanded once > git bisect bad fc83c501e385753c90db7316faf9fd4158caaa96 > # good: [b04d305df1171448df5e87802c4d1f1022cc5784] ocfs2: use a folio in ocfs2_map_and_dirty_page() > git bisect good b04d305df1171448df5e87802c4d1f1022cc5784 > # good: [7e01619507058f90ab603acec482951f3c452aaa] kthread: correct comments before kthread_queue_work() > git bisect good 7e01619507058f90ab603acec482951f3c452aaa > # good: [21b510a64c223707caa6db6176128779f0806a73] nilfs2: correct return value kernel-doc descriptions for ioctl functions > git bisect good 21b510a64c223707caa6db6176128779f0806a73 > # good: [6afb87f23458f2d4e4334ee5a4efb8b0d07af68b] nilfs2: handle errors that nilfs_prepare_chunk() may return > git bisect good 6afb87f23458f2d4e4334ee5a4efb8b0d07af68b > # good: [8f6d46fed0bad163e5146fea1fdff150039235b2] minmax.h: reduce the #define expansion of min(), max() and clamp() > git bisect good 8f6d46fed0bad163e5146fea1fdff150039235b2 > # bad: [7a70c678548d71e609b95dbddf2d411a02d13b54] minmax.h: move all the clamp() definitions after the min/max() ones > git bisect bad 7a70c678548d71e609b95dbddf2d411a02d13b54 > # bad: [37f375aab0c585388b90d1af6968454fc2769cb9] minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp() > git bisect bad 37f375aab0c585388b90d1af6968454fc2769cb9 > # first bad commit: [37f375aab0c585388b90d1af6968454fc2769cb9] minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp() > >
