From: "Paul E. McKenney" <paulmck@kernel.org>
To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
kernel-team@fb.com, mingo@kernel.org
Cc: stern@rowland.harvard.edu, parri.andrea@gmail.com,
will@kernel.org, peterz@infradead.org, boqun.feng@gmail.com,
npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk,
luc.maranget@inria.fr, akiyks@gmail.com,
"Paul E. McKenney" <paulmck@kernel.org>,
Manfred Spraul <manfred@colorfullife.com>
Subject: [PATCH memory-model 1/4] tools/memory-model: Make read_foo_diagnostic() more clearly diagnostic
Date: Wed, 21 Jul 2021 14:10:00 -0700 [thread overview]
Message-ID: <20210721211003.869892-1-paulmck@kernel.org> (raw)
In-Reply-To: <20210721210726.GA828672@paulmck-ThinkPad-P17-Gen-1>
The current definition of read_foo_diagnostic() in the "Lock Protection
With Lockless Diagnostic Access" section returns a value, which could
be use for any purpose. This could mislead people into incorrectly
using data_race() in cases where READ_ONCE() is required. This commit
therefore makes read_foo_diagnostic() simply print the value read.
Reported-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
tools/memory-model/Documentation/access-marking.txt | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/memory-model/Documentation/access-marking.txt b/tools/memory-model/Documentation/access-marking.txt
index 1ab189f51f55d..58bff26198767 100644
--- a/tools/memory-model/Documentation/access-marking.txt
+++ b/tools/memory-model/Documentation/access-marking.txt
@@ -259,9 +259,9 @@ diagnostic purposes. The code might look as follows:
return ret;
}
- int read_foo_diagnostic(void)
+ void read_foo_diagnostic(void)
{
- return data_race(foo);
+ pr_info("Current value of foo: %d\n", data_race(foo));
}
The reader-writer lock prevents the compiler from introducing concurrency
--
2.31.1.189.g2e36527f23
next prev parent reply other threads:[~2021-07-21 21:10 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-21 21:07 [PATCH kcsan 0/8] KCSAN updates for v5.15 Paul E. McKenney
2021-07-21 21:08 ` [PATCH kcsan 1/8] kcsan: Improve some Kconfig comments Paul E. McKenney
2021-07-21 21:08 ` [PATCH kcsan 2/8] kcsan: Remove CONFIG_KCSAN_DEBUG Paul E. McKenney
2021-07-21 21:08 ` [PATCH kcsan 3/8] kcsan: Introduce CONFIG_KCSAN_STRICT Paul E. McKenney
2021-07-21 21:08 ` [PATCH kcsan 4/8] kcsan: Reduce get_ctx() uses in kcsan_found_watchpoint() Paul E. McKenney
2021-07-21 21:08 ` [PATCH kcsan 5/8] kcsan: Rework atomic.h into permissive.h Paul E. McKenney
2021-07-21 21:08 ` [PATCH kcsan 6/8] kcsan: Print if strict or non-strict during init Paul E. McKenney
2021-07-21 21:08 ` [PATCH kcsan 7/8] kcsan: permissive: Ignore data-racy 1-bit value changes Paul E. McKenney
2021-07-21 21:08 ` [PATCH kcsan 8/8] kcsan: Make strict mode imply interruptible watchers Paul E. McKenney
2021-07-21 21:10 ` Paul E. McKenney [this message]
2021-07-21 21:10 ` [PATCH memory-model 2/4] tools/memory-model: Add example for heuristic lockless reads Paul E. McKenney
2021-07-23 2:08 ` Alan Stern
2021-07-23 6:52 ` Manfred Spraul
2021-07-23 13:05 ` Alan Stern
2021-07-23 13:57 ` Manfred Spraul
2021-07-23 16:30 ` Paul E. McKenney
2021-07-23 17:08 ` Alan Stern
2021-07-23 20:32 ` Paul E. McKenney
2021-07-23 21:03 ` Alan Stern
2021-07-23 22:29 ` Paul E. McKenney
2021-07-23 16:24 ` Paul E. McKenney
2021-07-23 16:59 ` Alan Stern
2021-07-23 17:30 ` Paul E. McKenney
2021-07-23 18:11 ` Alan Stern
2021-07-23 20:28 ` Paul E. McKenney
2021-07-28 17:40 ` [PATCH v2 " Paul E. McKenney
2021-07-21 21:10 ` [PATCH memory-model 3/4] tools/memory-model: Heuristics using data_race() must handle all values Paul E. McKenney
2021-07-21 21:10 ` [PATCH memory-model 4/4] tools/memory-model: Document data_race(READ_ONCE()) Paul E. McKenney
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