From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3489C223339; Mon, 6 Oct 2025 11:07:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759748870; cv=none; b=VQmiY9O2nZc9T1rSZsYrym+ycivsICCB1nfX7w6QjEHbifb8rIY/kUdlnPQSzXWF+SvOUcrEXEptg2U/cAMSZMjiYf/AptTvSbIEom23Okif96LIItVfIWSAM+6jRVi7PTxSY9kucwj1fFeeSxqTzfMfrg4Yp+oOQ1GpygCDQ7Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759748870; c=relaxed/simple; bh=H/JV3keURjBYWjBPl+P5pFvTDDpr2Zqj0n/evlTqhZg=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=c1DVCRet5674WZIhh1kCGmWKd8q9TsomBc5jDRkcYkT5pfRKzFPFEmYp4qEumRXHTNS60OzMlAgXC3feDMJMBON9VvK8dhDhqAhln7QHF5eM8N+trrrgccDC6x2OJA+D9QCAYP7RLnUW4qqO35q44GPjsuxeHKhZ/Vl3MwWJx1M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bTSvBZNx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bTSvBZNx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFD8AC4CEF5; Mon, 6 Oct 2025 11:07:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759748870; bh=H/JV3keURjBYWjBPl+P5pFvTDDpr2Zqj0n/evlTqhZg=; h=From:To:Cc:Subject:Date:From; b=bTSvBZNxrDEHRl923Elq+0kwdFS8sNKO6Uaa+ZaSwDpY0eAy2fh/0xSHYSonXwVHi 4C1rJIEyb4selbzZe6m6spkGS0OwNxwVAf4ra2PuQH4xs/ufrPqxJ5TggwJCL3H8hf wverrlc7LX5kramgFCZj/KpAWEY5A8j2u9A+j4U8UgQQsuMSYVonbiC/5LNZvrBiSn JhHP6Wgfr1a8G53YsVNJiM/VmwryqdbIQTQ0jAekdTaxe/F1iSZbsg5Dsn/rgJDfFG /Jwnofo4Tn7oybqve5U4Zj6PuLCwO8offhpB+TylknkBIzH8jI9wZ5op/HLp9Z7npV fWJ7kx86cxMBw== From: Arnd Bergmann To: Will Deacon , Peter Zijlstra , Boqun Feng Cc: Geert Uytterhoeven , Linux-Arch , linux-m68k@vger.kernel.org, Arnd Bergmann , Finn Thain , Mark Rutland , Gary Guo , linux-kernel@vger.kernel.org Subject: [PATCH] atomic: skip alignment check for try_cmpxchg() old arg Date: Mon, 6 Oct 2025 13:07:32 +0200 Message-Id: <20251006110740.468309-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-m68k@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnd Bergmann The 'old' argument in atomic_try_cmpxchg() and related functions is a pointer to a normal non-atomic integer number, which does not require to be naturally aligned, unlike the atomic_t/atomic64_t types themselves. In order to add an alignment check with CONFIG_DEBUG_ATOMIC into the normal instrument_atomic_read_write() helper, change this check to use the non-atomic instrument_read_write(), the same way that was done earlier for try_cmpxchg() in commit ec570320b09f ("locking/atomic: Correct (cmp)xchg() instrumentation"). This prevents warnings on m68k calling the 32-bit atomic_try_cmpxchg() with 16-bit aligned arguments as well as several more architectures including x86-32 when calling atomic64_try_cmpxchg() with 32-bit aligned u64 arguments. Reported-by: Finn Thain Link: https://lore.kernel.org/all/cover.1757810729.git.fthain@linux-m68k.org/ Signed-off-by: Arnd Bergmann --- include/linux/atomic/atomic-instrumented.h | 26 +++++++++++----------- scripts/atomic/gen-atomic-instrumented.sh | 11 +++++---- 2 files changed, 20 insertions(+), 17 deletions(-) diff --git a/include/linux/atomic/atomic-instrumented.h b/include/linux/atomic/atomic-instrumented.h index 9409a6ddf3e0..37ab6314a9f7 100644 --- a/include/linux/atomic/atomic-instrumented.h +++ b/include/linux/atomic/atomic-instrumented.h @@ -1276,7 +1276,7 @@ atomic_try_cmpxchg(atomic_t *v, int *old, int new) { kcsan_mb(); instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic_try_cmpxchg(v, old, new); } @@ -1298,7 +1298,7 @@ static __always_inline bool atomic_try_cmpxchg_acquire(atomic_t *v, int *old, int new) { instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic_try_cmpxchg_acquire(v, old, new); } @@ -1321,7 +1321,7 @@ atomic_try_cmpxchg_release(atomic_t *v, int *old, int new) { kcsan_release(); instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic_try_cmpxchg_release(v, old, new); } @@ -1343,7 +1343,7 @@ static __always_inline bool atomic_try_cmpxchg_relaxed(atomic_t *v, int *old, int new) { instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic_try_cmpxchg_relaxed(v, old, new); } @@ -2854,7 +2854,7 @@ atomic64_try_cmpxchg(atomic64_t *v, s64 *old, s64 new) { kcsan_mb(); instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic64_try_cmpxchg(v, old, new); } @@ -2876,7 +2876,7 @@ static __always_inline bool atomic64_try_cmpxchg_acquire(atomic64_t *v, s64 *old, s64 new) { instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic64_try_cmpxchg_acquire(v, old, new); } @@ -2899,7 +2899,7 @@ atomic64_try_cmpxchg_release(atomic64_t *v, s64 *old, s64 new) { kcsan_release(); instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic64_try_cmpxchg_release(v, old, new); } @@ -2921,7 +2921,7 @@ static __always_inline bool atomic64_try_cmpxchg_relaxed(atomic64_t *v, s64 *old, s64 new) { instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic64_try_cmpxchg_relaxed(v, old, new); } @@ -4432,7 +4432,7 @@ atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new) { kcsan_mb(); instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic_long_try_cmpxchg(v, old, new); } @@ -4454,7 +4454,7 @@ static __always_inline bool atomic_long_try_cmpxchg_acquire(atomic_long_t *v, long *old, long new) { instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic_long_try_cmpxchg_acquire(v, old, new); } @@ -4477,7 +4477,7 @@ atomic_long_try_cmpxchg_release(atomic_long_t *v, long *old, long new) { kcsan_release(); instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic_long_try_cmpxchg_release(v, old, new); } @@ -4499,7 +4499,7 @@ static __always_inline bool atomic_long_try_cmpxchg_relaxed(atomic_long_t *v, long *old, long new) { instrument_atomic_read_write(v, sizeof(*v)); - instrument_atomic_read_write(old, sizeof(*old)); + instrument_read_write(old, sizeof(*old)); return raw_atomic_long_try_cmpxchg_relaxed(v, old, new); } @@ -5050,4 +5050,4 @@ atomic_long_dec_if_positive(atomic_long_t *v) #endif /* _LINUX_ATOMIC_INSTRUMENTED_H */ -// 8829b337928e9508259079d32581775ececd415b +// f618ac667f868941a84ce0ab2242f1786e049ed4 diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh index 592f3ec89b5f..9c1d53f81eb2 100755 --- a/scripts/atomic/gen-atomic-instrumented.sh +++ b/scripts/atomic/gen-atomic-instrumented.sh @@ -12,7 +12,7 @@ gen_param_check() local arg="$1"; shift local type="${arg%%:*}" local name="$(gen_param_name "${arg}")" - local rw="write" + local rw="atomic_write" case "${type#c}" in i) return;; @@ -20,14 +20,17 @@ gen_param_check() if [ ${type#c} != ${type} ]; then # We don't write to constant parameters. - rw="read" + rw="atomic_read" + elif [ "${type}" = "p" ] ; then + # The "old" argument in try_cmpxchg() gets accessed non-atomically + rw="read_write" elif [ "${meta}" != "s" ]; then # An atomic RMW: if this parameter is not a constant, and this atomic is # not just a 's'tore, this parameter is both read from and written to. - rw="read_write" + rw="atomic_read_write" fi - printf "\tinstrument_atomic_${rw}(${name}, sizeof(*${name}));\n" + printf "\tinstrument_${rw}(${name}, sizeof(*${name}));\n" } #gen_params_checks(meta, arg...) -- 2.39.5