From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-176.mta1.migadu.com (out-176.mta1.migadu.com [95.215.58.176]) (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 0F4D014AA9 for ; Sat, 8 Mar 2025 02:22:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741400569; cv=none; b=JghqQbEw5Q0gaA+YrVh3T2p5feAst1VPQA4Crn4dAzewI62AcHjaRrEIO1x1ztRjvWm7d5X4doJndZmzrhUDxusSy6UVAEQl6BlkPIL20IrV5KUs3GyX8m67ScjVbhVM7aWIIuOQgg09P/TnaZyKilIsgKXBIXOCkFUCgYQ+lRA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741400569; c=relaxed/simple; bh=L/7jaKoLREh8m9RJKqR0YdJUC506zG80lLbEZM3Eaw0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=V9nH7W6y4PLVSvGutmbKB9xpc+ySFeQ+BdhvrB+N4ZMdEi3HlTY4PkYrti/jDmFCwIMAeNGusTOsiPdbq2MFfT7k9ftyrBO4g7/2IqjVPI8jckfItNx5fIdnJ2NkYjFvTUq7+50O2+SM+m+RB9M9APUryGDqCvcaaA2iagNjX3M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=WyslvGXS; arc=none smtp.client-ip=95.215.58.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="WyslvGXS" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1741400555; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jjhDoAzUW/5FGOnDp5v3OzlWQhpu3YvcufnBv3JkkCM=; b=WyslvGXSkVSfE45H250Oc8xhGdfep6CJ03v8xSTm1NlBuuoYFOJekXiQapFNHzVBr0sFgf aPVdC/D1z9yTXMwG76VmJNwp7EOEunCUVEeachPWaLqL6QiP4oU1vXiRusZzj9OS5F2cdi rBVZHezXAvweCUq6RmimulD3iMtv+Gw= Date: Sat, 8 Mar 2025 10:21:37 +0800 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH] fs: binfmt_elf_efpic: fix variable set but not used warning Content-Language: en-US To: Kees Cook , Jan Kara Cc: viro@zeniv.linux.org.uk, brauner@kernel.org, ebiederm@xmission.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, sunliming@kylinos.cn, kernel test robot References: <20250307061128.2999222-1-sunliming@linux.dev> <202503071227.578545FF9@keescook> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Sunliming In-Reply-To: <202503071227.578545FF9@keescook> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 2025/3/8 04:30, Kees Cook wrote: > On Fri, Mar 07, 2025 at 03:47:28PM +0100, Jan Kara wrote: >> On Fri 07-03-25 14:11:28, sunliming@linux.dev wrote: >>> From: sunliming >>> >>> Fix below kernel warning: >>> fs/binfmt_elf_fdpic.c:1024:52: warning: variable 'excess1' set but not >>> used [-Wunused-but-set-variable] >>> >>> Reported-by: kernel test robot >>> Signed-off-by: sunliming >> The extra ifdef is not pretty but I guess it's better. Feel free to add: >> >> Reviewed-by: Jan Kara > Since we allow loop-scope variable definitions now, perhaps this is a > case for defining the variable later within the #ifdef, like this? > > > diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c > index e3cf2801cd64..b0ef71238328 100644 > --- a/fs/binfmt_elf_fdpic.c > +++ b/fs/binfmt_elf_fdpic.c > @@ -1024,7 +1024,7 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, > /* deal with each load segment separately */ > phdr = params->phdrs; > for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { > - unsigned long maddr, disp, excess, excess1; > + unsigned long maddr, disp, excess; > int prot = 0, flags; > > if (phdr->p_type != PT_LOAD) > @@ -1120,9 +1120,10 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, > * extant in the file > */ > excess = phdr->p_memsz - phdr->p_filesz; > - excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); > > #ifdef CONFIG_MMU > + const unsigned long excess1 = > + PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); > if (excess > excess1) { > unsigned long xaddr = maddr + phdr->p_filesz + excess1; > unsigned long xmaddr; I think this is a good idea. I will resend this patch in this way，thanks. >> Honza >> >>> --- >>> fs/binfmt_elf_fdpic.c | 7 +++++-- >>> 1 file changed, 5 insertions(+), 2 deletions(-) >>> >>> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c >>> index e3cf2801cd64..bed13ee8bfec 100644 >>> --- a/fs/binfmt_elf_fdpic.c >>> +++ b/fs/binfmt_elf_fdpic.c >>> @@ -1024,8 +1024,11 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, >>> /* deal with each load segment separately */ >>> phdr = params->phdrs; >>> for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { >>> - unsigned long maddr, disp, excess, excess1; >>> + unsigned long maddr, disp, excess; >>> int prot = 0, flags; >>> +#ifdef CONFIG_MMU >>> + unsigned long excess1; >>> +#endif >>> >>> if (phdr->p_type != PT_LOAD) >>> continue; >>> @@ -1120,9 +1123,9 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, >>> * extant in the file >>> */ >>> excess = phdr->p_memsz - phdr->p_filesz; >>> - excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); >>> >>> #ifdef CONFIG_MMU >>> + excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); >>> if (excess > excess1) { >>> unsigned long xaddr = maddr + phdr->p_filesz + excess1; >>> unsigned long xmaddr; >>> -- >>> 2.25.1 >>> >> -- >> Jan Kara >> SUSE Labs, CR