From patchwork Wed Nov 6 16:14:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13865173 X-Patchwork-Delegate: kuba@kernel.org 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 2DE781E0084; Wed, 6 Nov 2024 16:15:05 +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=1730909706; cv=none; b=bcDXmsA4LsZlx3Ohxi2tA0g+b0iY2jnIb/gK2Pv5fsCfa/m8hDIDDGJEH6k7DkM5IiuLoJC/KaQyNZxGV6PYdIirgdfPOVlnBl1dUt9fAhsKdkCXwxo3SAtgunEW3Is7pBf3NX1OkI8W/qvjF+7y4xIPXTllopJGv7XRofkAV6U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730909706; c=relaxed/simple; bh=L1fz5ifwL7RtYFeEDpd0ry1pl5RXPpuE7qAe8htztHs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nqLvCwsp2aCU0yMzlpUFKORYjuiqz2DjI09/1JgV5Z8Ds2zjthsmzHKrDicvYj3vK/VPCOl6MWris5ij45cC5APdsysZ8X4Twb3HeB1FP6SwGXG1z0bbx+HKmahwxv0YLkFhn5x4tDAUEr4tTTqe0NhMz+0elYrukCRZzs0TI9M= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Rg69Z4SE; 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="Rg69Z4SE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C388C4CECC; Wed, 6 Nov 2024 16:15:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730909705; bh=L1fz5ifwL7RtYFeEDpd0ry1pl5RXPpuE7qAe8htztHs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Rg69Z4SEgjr14uUSm8raG4/pBqR96KcGJKeZyT1jCty/ybLeUUY9kVlJ9WxpuGvY2 JVRAz0Ve5o8Nq/tPBv1cQl0geGUfCQuoUOrwYQBrrNuZb0yIgNnSKolkr54p0mp8U+ 8Mmk58lGjlXIssQ9vVRy2gYIkG7r+951nC1RDlfMVEwKE46+OyDmI+qoghj4KnyykC zTcOfB2jVEA1HfGxTCRhm04xEmDuh9sRBn+M0XWXlOGjF2L8iBNtGtUmNqjwO8cEd3 QW5s5t+fzIbVXEELqgNo2T/VLiwWgZAOeO2smOMhC90WaFISTshS7lhTEl5JJ6KPW0 imFjIcT+ySYeA== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Nicholas Piggin , Masahiro Yamada , Andi Kleen , Andrew Morton , Arnd Bergmann , Bill Wendling , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Justin Stitt , Kees Cook , Nathan Chancellor , Nick Desaulniers , Paolo Abeni , Sami Tolvanen , Simon Horman , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, llvm@lists.linux.dev, netdev@vger.kernel.org Subject: [PATCH 2/2] Rename .data.once to .data..once to fix resetting WARN*_ONCE Date: Thu, 7 Nov 2024 01:14:41 +0900 Message-ID: <20241106161445.189399-2-masahiroy@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241106161445.189399-1-masahiroy@kernel.org> References: <20241106161445.189399-1-masahiroy@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Commit b1fca27d384e ("kernel debug: support resetting WARN*_ONCE") added support for clearing the state of once warnings. However, it is not functional 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. Meanwhile, commit b1fca27d384e introduced the .data.once section, and commit dc5723b02e52 ("kbuild: add support for Clang LTO") extended the #ifdef. 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: b1fca27d384e ("kernel debug: support resetting WARN*_ONCE") Fixes: dc5723b02e52 ("kbuild: add support for Clang LTO") Signed-off-by: Masahiro Yamada --- include/asm-generic/vmlinux.lds.h | 2 +- include/linux/mmdebug.h | 6 +++--- include/linux/once.h | 4 ++-- include/linux/once_lite.h | 2 +- include/net/net_debug.h | 2 +- mm/internal.h | 2 +- 6 files changed, 9 insertions(+), 9 deletions(-) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 3c9dc1fd094d..54504013c749 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -359,7 +359,7 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) *(.data..shared_aligned) /* percpu related */ \ *(.data..unlikely) \ __start_once = .; \ - *(.data.once) \ + *(.data..once) \ __end_once = .; \ STRUCT_ALIGN(); \ *(__tracepoints) \ diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h index 39a7714605a7..d7cb1e5ecbda 100644 --- a/include/linux/mmdebug.h +++ b/include/linux/mmdebug.h @@ -46,7 +46,7 @@ void vma_iter_dump_tree(const struct vma_iterator *vmi); } \ } while (0) #define VM_WARN_ON_ONCE_PAGE(cond, page) ({ \ - static bool __section(".data.once") __warned; \ + static bool __section(".data..once") __warned; \ int __ret_warn_once = !!(cond); \ \ if (unlikely(__ret_warn_once && !__warned)) { \ @@ -66,7 +66,7 @@ void vma_iter_dump_tree(const struct vma_iterator *vmi); unlikely(__ret_warn); \ }) #define VM_WARN_ON_ONCE_FOLIO(cond, folio) ({ \ - static bool __section(".data.once") __warned; \ + static bool __section(".data..once") __warned; \ int __ret_warn_once = !!(cond); \ \ if (unlikely(__ret_warn_once && !__warned)) { \ @@ -77,7 +77,7 @@ void vma_iter_dump_tree(const struct vma_iterator *vmi); unlikely(__ret_warn_once); \ }) #define VM_WARN_ON_ONCE_MM(cond, mm) ({ \ - static bool __section(".data.once") __warned; \ + static bool __section(".data..once") __warned; \ int __ret_warn_once = !!(cond); \ \ if (unlikely(__ret_warn_once && !__warned)) { \ diff --git a/include/linux/once.h b/include/linux/once.h index bc714d414448..30346fcdc799 100644 --- a/include/linux/once.h +++ b/include/linux/once.h @@ -46,7 +46,7 @@ void __do_once_sleepable_done(bool *done, struct static_key_true *once_key, #define DO_ONCE(func, ...) \ ({ \ bool ___ret = false; \ - static bool __section(".data.once") ___done = false; \ + static bool __section(".data..once") ___done = false; \ static DEFINE_STATIC_KEY_TRUE(___once_key); \ if (static_branch_unlikely(&___once_key)) { \ unsigned long ___flags; \ @@ -64,7 +64,7 @@ void __do_once_sleepable_done(bool *done, struct static_key_true *once_key, #define DO_ONCE_SLEEPABLE(func, ...) \ ({ \ bool ___ret = false; \ - static bool __section(".data.once") ___done = false; \ + static bool __section(".data..once") ___done = false; \ static DEFINE_STATIC_KEY_TRUE(___once_key); \ if (static_branch_unlikely(&___once_key)) { \ ___ret = __do_once_sleepable_start(&___done); \ diff --git a/include/linux/once_lite.h b/include/linux/once_lite.h index b7bce4983638..27de7bc32a06 100644 --- a/include/linux/once_lite.h +++ b/include/linux/once_lite.h @@ -12,7 +12,7 @@ #define __ONCE_LITE_IF(condition) \ ({ \ - static bool __section(".data.once") __already_done; \ + static bool __section(".data..once") __already_done; \ bool __ret_cond = !!(condition); \ bool __ret_once = false; \ \ diff --git a/include/net/net_debug.h b/include/net/net_debug.h index 1e74684cbbdb..4a79204c8d30 100644 --- a/include/net/net_debug.h +++ b/include/net/net_debug.h @@ -27,7 +27,7 @@ void netdev_info(const struct net_device *dev, const char *format, ...); #define netdev_level_once(level, dev, fmt, ...) \ do { \ - static bool __section(".data.once") __print_once; \ + static bool __section(".data..once") __print_once; \ \ if (!__print_once) { \ __print_once = true; \ diff --git a/mm/internal.h b/mm/internal.h index 93083bbeeefa..a23f7b11b760 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -48,7 +48,7 @@ struct folio_batch; * when we specify __GFP_NOWARN. */ #define WARN_ON_ONCE_GFP(cond, gfp) ({ \ - static bool __section(".data.once") __warned; \ + static bool __section(".data..once") __warned; \ int __ret_warn_once = !!(cond); \ \ if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \