From: Dan Carpenter <dan.carpenter@linaro.org>
To: oe-kbuild@lists.linux.dev, Tamir Duberstein <tamird@gmail.com>,
David Gow <davidgow@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>,
Waiman Long <longman@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Shuah Khan <skhan@linuxfoundation.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>
Cc: lkp@intel.com, oe-kbuild-all@lists.linux.dev,
Linux Memory Management List <linux-mm@kvack.org>,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
llvm@lists.linux.dev, Tamir Duberstein <tamird@gmail.com>
Subject: Re: [PATCH] ww_mutex: convert self-test to KUnit
Date: Wed, 12 Feb 2025 14:53:30 +0300 [thread overview]
Message-ID: <3dabe058-2308-4990-8e5d-0af1efd27431@stanley.mountain> (raw)
In-Reply-To: <20250210-ww_mutex-kunit-convert-v1-1-972f0201f71e@gmail.com>
Hi Tamir,
kernel test robot noticed the following build warnings:
url: https://github.com/intel-lab-lkp/linux/commits/Tamir-Duberstein/ww_mutex-convert-self-test-to-KUnit/20250211-000245
base: a64dcfb451e254085a7daee5fe51bf22959d52d3
patch link: https://lore.kernel.org/r/20250210-ww_mutex-kunit-convert-v1-1-972f0201f71e%40gmail.com
patch subject: [PATCH] ww_mutex: convert self-test to KUnit
config: i386-randconfig-141-20250212 (https://download.01.org/0day-ci/archive/20250212/202502121806.CS6r741y-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
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>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202502121806.CS6r741y-lkp@intel.com/
smatch warnings:
kernel/locking/ww_mutex_kunit.c:238 test_abba_gen_params() warn: shift has higher precedence than mask
kernel/locking/ww_mutex_kunit.c:249 test_abba() warn: shift has higher precedence than mask
vim +238 kernel/locking/ww_mutex_kunit.c
70207686e492fb kernel/locking/test-ww_mutex.c Chris Wilson 2016-12-01 231
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 232 static const void *test_abba_gen_params(const void *prev, char *desc)
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 233 {
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 234 static unsigned int storage;
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 235 const unsigned int *next = gen_range(&storage, 0b00, 0b11, prev);
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 236
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 237 if (next != NULL) {
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 @238 const bool trylock = *next & 0b01 >> 0;
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 239 const bool resolve = *next & 0b10 >> 1;
The shifts here are weird... A zero shift is strange but even the 1 shift
is odd. The current code is equivalent to:
const bool resolve = *next & (0b10 >> 1);
But changing it to:
const bool resolve = (*next & 0b10) >> 1;
Doesn't make sense either... Probably that makes less sense actually.
What are you trying to communicate with this code?
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 240
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 241 snprintf(desc, KUNIT_PARAM_DESC_SIZE, "trylock=%d,resolve=%d", trylock, resolve);
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 242 }
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 243 return next;
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 244 }
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 245
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 246 static void test_abba(struct kunit *test)
70207686e492fb kernel/locking/test-ww_mutex.c Chris Wilson 2016-12-01 247 {
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 248 const unsigned int *param = test->param_value;
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 @249 const bool trylock = *param & 0b01 >> 0;
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 250 const bool resolve = *param & 0b10 >> 1;
Same.
70207686e492fb kernel/locking/test-ww_mutex.c Chris Wilson 2016-12-01 251 struct test_abba abba;
70207686e492fb kernel/locking/test-ww_mutex.c Chris Wilson 2016-12-01 252 struct ww_acquire_ctx ctx;
daf92a37bd1117 kernel/locking/ww_mutex_kunit.c Tamir Duberstein 2025-02-10 253 int err;
70207686e492fb kernel/locking/test-ww_mutex.c Chris Wilson 2016-12-01 254
70207686e492fb kernel/locking/test-ww_mutex.c Chris Wilson 2016-12-01 255 ww_mutex_init(&abba.a_mutex, &ww_class);
70207686e492fb kernel/locking/test-ww_mutex.c Chris Wilson 2016-12-01 256 ww_mutex_init(&abba.b_mutex, &ww_class);
70207686e492fb kernel/locking/test-ww_mutex.c Chris Wilson 2016-12-01 257 INIT_WORK_ONSTACK(&abba.work, test_abba_work);
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next parent reply other threads:[~2025-02-12 11:53 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20250210-ww_mutex-kunit-convert-v1-1-972f0201f71e@gmail.com>
2025-02-12 11:53 ` Dan Carpenter [this message]
2025-02-12 14:33 ` Tamir Duberstein
2025-02-12 15:31 ` Dan Carpenter
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