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 18532161; Thu, 13 Jun 2024 12:38:50 +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=1718282331; cv=none; b=SG0S/6mk5MpFRvgkmTxi96spRgrUDVJQyzaStHitan0K4Es3y4oN6OvNLE+fPq02Ba+f9v9hvxNa8kHuAb8czEyNImZl5lwgJQ0jl0sNvCtfn0cDaYl4hy/g/uLgjVV/pB2kv9dcRWSEaGNhvjpwnQK5TgC8WXe8R9C5VQWJdRI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718282331; c=relaxed/simple; bh=wT01WIPyJIwBsz4THtRKuk9NL4XnR6/RSb48D/sHQNk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OY9t4HLymoikmKw/tgZf+iqk0gxdeCqnxIhnw2MJnQqFmMMPzsKYfEDKu+sAjCy3eAZCm2Z4AiZqzSzFikcOWyYFvlUbukd+pKrqqaEOTYI24yctV91syQOgJmoOD4Thhf9wZkHmL4Z+Ea5P6ddngh1lpsEL6AfGhAeSuIfaUps= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=koyByUoU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="koyByUoU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36D53C2BBFC; Thu, 13 Jun 2024 12:38:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718282330; bh=wT01WIPyJIwBsz4THtRKuk9NL4XnR6/RSb48D/sHQNk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=koyByUoURfW0GlNp8CZvl5e1yM4J/d5Cxkw8maGILa8SG/4Bzyc9GTpuDnq/5Vjig m06cgGU6x+cOb2rRGtpYWvnWbCTSu0rvfSkOg53U5Q8+WGVcoHQmJYZeBNGf1yhcoH 4lplLYPOsd9D43UCAtBfDTtrzSYbf2pRU/mEHf5I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vasily Gorbik , Sumanth Korikkar , Heiko Carstens , Sasha Levin Subject: [PATCH 5.15 240/402] s390/vdso64: filter out munaligned-symbols flag for vdso Date: Thu, 13 Jun 2024 13:33:17 +0200 Message-ID: <20240613113311.508164231@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240613113302.116811394@linuxfoundation.org> References: <20240613113302.116811394@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sumanth Korikkar [ Upstream commit 8192a1b3807510d0ed5be1f8988c08f8d41cced9 ] Gcc recently implemented an optimization [1] for loading symbols without explicit alignment, aligning with the IBM Z ELF ABI. This ABI mandates symbols to reside on a 2-byte boundary, enabling the use of the larl instruction. However, kernel linker scripts may still generate unaligned symbols. To address this, a new -munaligned-symbols option has been introduced [2] in recent gcc versions. [1] https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622872.html [2] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625986.html However, when -munaligned-symbols is used in vdso code, it leads to the following compilation error: `.data.rel.ro.local' referenced in section `.text' of arch/s390/kernel/vdso64/vdso64_generic.o: defined in discarded section `.data.rel.ro.local' of arch/s390/kernel/vdso64/vdso64_generic.o vdso linker script discards .data section to make it lightweight. However, -munaligned-symbols in vdso object files references literal pool and accesses _vdso_data. Hence, compile vdso code without -munaligned-symbols. This means in the future, vdso code should deal with alignment of newly introduced unaligned linker symbols. Acked-by: Vasily Gorbik Signed-off-by: Sumanth Korikkar Link: https://lore.kernel.org/r/20240219132734.22881-2-sumanthk@linux.ibm.com Signed-off-by: Heiko Carstens Stable-dep-of: 10f705253651 ("s390/vdso: Generate unwind information for C modules") Signed-off-by: Sasha Levin --- arch/s390/kernel/vdso64/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile index 08e87b083647c..e2e031e4d9243 100644 --- a/arch/s390/kernel/vdso64/Makefile +++ b/arch/s390/kernel/vdso64/Makefile @@ -26,6 +26,7 @@ KBUILD_AFLAGS_64 += -m64 -s KBUILD_CFLAGS_64 := $(filter-out -m64,$(KBUILD_CFLAGS)) KBUILD_CFLAGS_64 := $(filter-out -mno-pic-data-is-text-relative,$(KBUILD_CFLAGS_64)) +KBUILD_CFLAGS_64 := $(filter-out -munaligned-symbols,$(KBUILD_CFLAGS_64)) KBUILD_CFLAGS_64 += -m64 -fPIC -fno-common -fno-builtin ldflags-y := -shared -soname=linux-vdso64.so.1 \ --hash-style=both --build-id=sha1 -T -- 2.43.0