From: kernel test robot <lkp@intel.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org,
linux-snps-arc@lists.infradead.org,
Vineet Gupta <vgupta@kernel.org>
Subject: include/linux/atomic/atomic-arch-fallback.h:4152:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe)
Date: Wed, 23 Jul 2025 00:11:37 +0800 [thread overview]
Message-ID: <202507230016.wIB7yFIo-lkp@intel.com> (raw)
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 89be9a83ccf1f88522317ce02f854f30d6115c41
commit: ea7caffedd011f7d40abe93a884ffbe46f122535 ARC: atomics: Implement arch_atomic64_cmpxchg using _relaxed
date: 6 weeks ago
config: arc-randconfig-r111-20250722 (https://download.01.org/0day-ci/archive/20250723/202507230016.wIB7yFIo-lkp@intel.com/config)
compiler: arc-linux-gcc (GCC) 8.5.0
reproduce: (https://download.01.org/0day-ci/archive/20250723/202507230016.wIB7yFIo-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202507230016.wIB7yFIo-lkp@intel.com/
sparse warnings: (new ones prefixed by >>)
lib/atomic64_test.c: note: in included file (through include/linux/atomic.h, include/asm-generic/bitops/lock.h, arch/arc/include/asm/bitops.h, ...):
include/linux/atomic/atomic-arch-fallback.h:4152:16: sparse: sparse: cast truncates bits from constant value (aaa31337c001d00d becomes c001d00d)
>> include/linux/atomic/atomic-arch-fallback.h:4152:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe)
include/linux/atomic/atomic-arch-fallback.h:4181:16: sparse: sparse: cast truncates bits from constant value (aaa31337c001d00d becomes c001d00d)
include/linux/atomic/atomic-arch-fallback.h:4181:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe)
include/linux/atomic/atomic-arch-fallback.h:4209:16: sparse: sparse: cast truncates bits from constant value (aaa31337c001d00d becomes c001d00d)
include/linux/atomic/atomic-arch-fallback.h:4209:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe)
include/linux/atomic/atomic-arch-fallback.h:4234:16: sparse: sparse: cast truncates bits from constant value (aaa31337c001d00d becomes c001d00d)
include/linux/atomic/atomic-arch-fallback.h:4234:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe)
include/linux/atomic/atomic-arch-fallback.h:4152:16: sparse: sparse: cast truncates bits from constant value (faceabadf00df001 becomes f00df001)
>> include/linux/atomic/atomic-arch-fallback.h:4152:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe)
include/linux/atomic/atomic-arch-fallback.h:4181:16: sparse: sparse: cast truncates bits from constant value (faceabadf00df001 becomes f00df001)
include/linux/atomic/atomic-arch-fallback.h:4181:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe)
include/linux/atomic/atomic-arch-fallback.h:4209:16: sparse: sparse: cast truncates bits from constant value (faceabadf00df001 becomes f00df001)
include/linux/atomic/atomic-arch-fallback.h:4209:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe)
include/linux/atomic/atomic-arch-fallback.h:4234:16: sparse: sparse: cast truncates bits from constant value (faceabadf00df001 becomes f00df001)
include/linux/atomic/atomic-arch-fallback.h:4234:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe)
vim +4152 include/linux/atomic/atomic-arch-fallback.h
37f8173dd84936 include/linux/atomic-arch-fallback.h Peter Zijlstra 2020-01-24 4126
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4127 /**
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4128 * raw_atomic64_cmpxchg() - atomic compare and exchange with full ordering
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4129 * @v: pointer to atomic64_t
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4130 * @old: s64 value to compare with
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4131 * @new: s64 value to assign
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4132 *
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4133 * If (@v == @old), atomically updates @v to @new with full ordering.
6dfee110c6cc7a include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2024-02-09 4134 * Otherwise, @v is not modified and relaxed ordering is provided.
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4135 *
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4136 * Safe to use in noinstr code; prefer atomic64_cmpxchg() elsewhere.
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4137 *
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4138 * Return: The original value of @v.
ad8110706f3811 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4139 */
37f8173dd84936 include/linux/atomic-arch-fallback.h Peter Zijlstra 2020-01-24 4140 static __always_inline s64
9257959a6e5b4f include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4141 raw_atomic64_cmpxchg(atomic64_t *v, s64 old, s64 new)
37f8173dd84936 include/linux/atomic-arch-fallback.h Peter Zijlstra 2020-01-24 4142 {
1d78814d41701c include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4143 #if defined(arch_atomic64_cmpxchg)
1d78814d41701c include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4144 return arch_atomic64_cmpxchg(v, old, new);
1d78814d41701c include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4145 #elif defined(arch_atomic64_cmpxchg_relaxed)
37f8173dd84936 include/linux/atomic-arch-fallback.h Peter Zijlstra 2020-01-24 4146 s64 ret;
37f8173dd84936 include/linux/atomic-arch-fallback.h Peter Zijlstra 2020-01-24 4147 __atomic_pre_full_fence();
9257959a6e5b4f include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4148 ret = arch_atomic64_cmpxchg_relaxed(v, old, new);
37f8173dd84936 include/linux/atomic-arch-fallback.h Peter Zijlstra 2020-01-24 4149 __atomic_post_full_fence();
37f8173dd84936 include/linux/atomic-arch-fallback.h Peter Zijlstra 2020-01-24 4150 return ret;
9257959a6e5b4f include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4151 #else
9257959a6e5b4f include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 @4152 return raw_cmpxchg(&v->counter, old, new);
d12157efc8e083 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4153 #endif
1d78814d41701c include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4154 }
d12157efc8e083 include/linux/atomic/atomic-arch-fallback.h Mark Rutland 2023-06-05 4155
:::::: The code at line 4152 was first introduced by commit
:::::: 9257959a6e5b4fca6fc8e985790bff62c2046f20 locking/atomic: scripts: restructure fallback ifdeffery
:::::: TO: Mark Rutland <mark.rutland@arm.com>
:::::: CC: Peter Zijlstra <peterz@infradead.org>
--
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https://github.com/intel/lkp-tests/wiki
next reply other threads:[~2025-07-22 16:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-22 16:11 kernel test robot [this message]
-- strict thread matches above, loose matches on Subject: below --
2025-09-15 0:21 include/linux/atomic/atomic-arch-fallback.h:4152:16: sparse: sparse: cast truncates bits from constant value (deadbeefdeafcafe becomes deafcafe) kernel test robot
2025-10-28 14:43 kernel test robot
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