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 BBB4428E5 for ; Fri, 18 Feb 2022 16:34:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 005E3C340E9; Fri, 18 Feb 2022 16:34:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645202066; bh=3mfSjeFg5UvPQyM+d6QjT4buHJvJkQj1rCBa6ArkwLs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZuRn1OerTeB+bGjnhGoQE/AGo69mdoiz0E94CWlv2O8qyXt8tljx3FyIj8RrliyvM WGRoGjBmzmAvbayY/2fINCHlio9C9JYdxFIpqVQcRbhxfyj+EWFZgDIB/645q83692 ZcePfNUtvxSL+MD8fic+EX/SikK+JkWHZBPBjvj1V2YEswppYXOCxRdcjhPnYx8U1r d0/ViUsO9e0tFx6SuBL9yhMRwlJwPPRCFMxcQRDikG1o69g2DygDes4CUt66T+xAtt g1wjcbQ3cLNEJEbcsYE97yvpt8ezTQO6pjTQRdDdiAJkdvjWpRDNAFsqB3MoF1yoHq YjXANXrPgSL0A== Date: Fri, 18 Feb 2022 09:34:22 -0700 From: Nathan Chancellor To: Fangrui Song Cc: Ard Biesheuvel , Catalin Marinas , Will Deacon , Linux ARM , Linux Kernel Mailing List , llvm@lists.linux.dev Subject: Re: [PATCH] arm64 module: remove (NOLOAD) Message-ID: References: <20220218081209.354383-1-maskray@google.com> <20220218085016.jv4qcfaxav5fxhrs@google.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220218085016.jv4qcfaxav5fxhrs@google.com> On Fri, Feb 18, 2022 at 12:50:16AM -0800, Fangrui Song wrote: > On 2022-02-18, Ard Biesheuvel wrote: > > On Fri, 18 Feb 2022 at 09:12, Fangrui Song wrote: > > > > > > On ELF, (NOLOAD) sets the section type to SHT_NOBITS[1]. It is conceptually > > > inappropriate for .plt and .text.* sections which are always > > > SHT_PROGBITS. > > > > > > In GNU ld, if PLT entries are needed, .plt will be SHT_PROGBITS anyway > > > and (NOLOAD) will be essentially ignored. In ld.lld, since > > > https://reviews.llvm.org/D118840 ("[ELF] Support (TYPE=) to > > > customize the output section type"), ld.lld will report a `section type > > > mismatch` error. Just remove (NOLOAD) to fix the error. > > > > > > [1] https://lld.llvm.org/ELF/linker_script.html As of today, "The > > > section should be marked as not loadable" on > > > https://sourceware.org/binutils/docs/ld/Output-Section-Type.html is > > > outdated for ELF. > > > > This patch lacks a SOB line. > > > > With one added, > > > > Acked-by: Ard Biesheuvel > > Ah, yes. Sorry, I haven't sent a kernel patch for a while... > > Reported-by: Nathan Chancellor > Signed-off-by: Fangrui Song > Acked-by: Ard Biesheuvel I am assuming this patch is the solution we want, as opposed to Ard's suggestion of renaming these sections at https://reviews.llvm.org/D118840 (unless that was a tangential suggestion). I have verified that modules still load. Additionally, this needs to go to stable so that groups who upgrade their toolchain to a revision that include the LLD patch don't get broken as well. Cc: stable@vger.kernel.org Tested-by: Nathan Chancellor > > > --- > > > arch/arm64/include/asm/module.lds.h | 6 +++--- > > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > > > diff --git a/arch/arm64/include/asm/module.lds.h b/arch/arm64/include/asm/module.lds.h > > > index a11ccadd47d2..094701ec5500 100644 > > > --- a/arch/arm64/include/asm/module.lds.h > > > +++ b/arch/arm64/include/asm/module.lds.h > > > @@ -1,8 +1,8 @@ > > > SECTIONS { > > > #ifdef CONFIG_ARM64_MODULE_PLTS > > > - .plt 0 (NOLOAD) : { BYTE(0) } > > > - .init.plt 0 (NOLOAD) : { BYTE(0) } > > > - .text.ftrace_trampoline 0 (NOLOAD) : { BYTE(0) } > > > + .plt 0 : { BYTE(0) } > > > + .init.plt 0 : { BYTE(0) } > > > + .text.ftrace_trampoline 0 : { BYTE(0) } > > > #endif > > > > > > #ifdef CONFIG_KASAN_SW_TAGS > > > -- > > > 2.35.1.265.g69c8d7142f-goog > > > >