From patchwork Wed Nov 6 16:14:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13865174 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 303B6189F5C; Wed, 6 Nov 2024 16:15:00 +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=1730909701; cv=none; b=EYm6CDfzJFS0FdcNH9PJiYGev+8aXU0xVRV0Nx8RslrnDS1M29A5XFDjRT6Vz0rLoOIgKrZ5PXQrfb3PZFufHBT/x/kp15GqhVwvfxRlP0VXmvK1H/VcIXui2JTgtyEd7z7j5Pfd12WkGYriDqybzPFvUEsC0Kt/NhCE+ATohdY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730909701; c=relaxed/simple; bh=2L2KPeDDY1cDn036D9Ij9ZGhV0YgRwxwdrhtgK5vbtM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=E2EzPrBW+OKcRC7BLfP/YuGIKOxj2sGEw6XGBftHmdQ+TvbZ9GizveUODvHAhiSV/pPYqK5jGQ+3NBeL/y+RrxzLaBUTZTBTWx6ZR0n7eIhzJRoWvruwhwMDvVX/ixW3fdsQflrrvaEPAOSt5DMbytjRJondyJtyiDUki3p82wM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jPCLy3Cn; 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="jPCLy3Cn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2296C4CEC6; Wed, 6 Nov 2024 16:14:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730909700; bh=2L2KPeDDY1cDn036D9Ij9ZGhV0YgRwxwdrhtgK5vbtM=; h=From:To:Cc:Subject:Date:From; b=jPCLy3Cn1ejfR/Oqs80JkzGiLv3SCxGNZ4ypNsRamXXfgbqqZcaWpxIfGhoQ2gG4T HnSqcDcgtAupIFLbtTx8SgkRdAnqsYYM7b/YWqxQ9Z4Rq0J17D9onjpDG1vxkjPOE8 i279sAap4rqLk6l986/3nDR072mM3wsa4pS3TVdCr6jOKO6OX+Ui+cBA7dbRa7+AeJ G6T9Ewm0aEfd87HNHkpxebzx+MN7PrSlpOFXXAImlq9xzXO3BZB89bk6+EyEHhACHK EXdhit2XeH2rIyfhHM3QlGHCwx2umZ2kQY3Sqb2pWQGquABgQ9aYZKE3aszqbOIsL3 OIhMIeE4XUvjg== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Nicholas Piggin , Masahiro Yamada , Arnd Bergmann , Boqun Feng , Frederic Weisbecker , Joel Fernandes , Josh Triplett , Lai Jiangshan , Masahiro Yamada , Mathieu Desnoyers , Neeraj Upadhyay , "Paul E. McKenney" , Steven Rostedt , Uladzislau Rezki , Zqiang , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, rcu@vger.kernel.org Subject: [PATCH 1/2] Rename .data.unlikely to .data..unlikely Date: Thu, 7 Nov 2024 01:14:40 +0900 Message-ID: <20241106161445.189399-1-masahiroy@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Commit 7ccaba5314ca ("consolidate WARN_...ONCE() static variables") was intended to collect all .data.unlikely sections into one chunk. However, this has not worked when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION or CONFIG_LTO_CLANG is enabled, because .data.unlikely matches the .data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro. Commit cb87481ee89d ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case, providing a minimal fix for stable backporting. We were aware this did not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The plan was to apply correct fixes and then revert cb87481ee89d. [1] Seven years have passed since then, yet the #ifdef workaround remains in place. Using a ".." separator in the section name fixes the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG. [1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/ Fixes: cb87481ee89d ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured") Signed-off-by: Masahiro Yamada --- include/asm-generic/vmlinux.lds.h | 2 +- include/linux/rcupdate.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index c995474e4c64..3c9dc1fd094d 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -357,7 +357,7 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) *(.data..decrypted) \ *(.ref.data) \ *(.data..shared_aligned) /* percpu related */ \ - *(.data.unlikely) \ + *(.data..unlikely) \ __start_once = .; \ *(.data.once) \ __end_once = .; \ diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 58d84c59f3dd..48e5c03df1dd 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -401,7 +401,7 @@ static inline int debug_lockdep_rcu_enabled(void) */ #define RCU_LOCKDEP_WARN(c, s) \ do { \ - static bool __section(".data.unlikely") __warned; \ + static bool __section(".data..unlikely") __warned; \ if (debug_lockdep_rcu_enabled() && (c) && \ debug_lockdep_rcu_enabled() && !__warned) { \ __warned = true; \