From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from outpost1.zedat.fu-berlin.de (outpost1.zedat.fu-berlin.de [130.133.4.66]) (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 E5B4616B3B9; Fri, 21 Jun 2024 08:44:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=130.133.4.66 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718959497; cv=none; b=AqPgWN8KafgjtFv3wU3+JZzjpFfnG8Q1dhGyAhsM1vq6p6+dgzcIYX40slwBouBAnFn3DxlX9kFuU3LxgwUbPS3ptwncfVhPn+xe/0PyszANCwqYY7FMzmmwrhyvX3t9Uf015bs2z63jhBpEmk5HK77o5ucoLtP7fYn7PzPE/oc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718959497; c=relaxed/simple; bh=RpckdAUHxpE3PguMTPlZMv4GmZLmasBaPDXDoZBRkPE=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=B1CA3F0EUmzrmjwx0mYeSNp8SThqYBKpd8gGnmqgacQInj3O1sksbnhDllZUiXysFcC+FfY5m7UjlfZYMs92o5oiZuyfIzarZeny55pch6+xHNKAx0gED8jzCl8uQmT7PvafQxl7Y+T7EggEubYlpDGZagSoqms3nZqTXF9UjQs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=physik.fu-berlin.de; spf=pass smtp.mailfrom=zedat.fu-berlin.de; dkim=pass (2048-bit key) header.d=fu-berlin.de header.i=@fu-berlin.de header.b=nYaDaquc; arc=none smtp.client-ip=130.133.4.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=physik.fu-berlin.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zedat.fu-berlin.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=fu-berlin.de header.i=@fu-berlin.de header.b="nYaDaquc" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=fu-berlin.de; s=fub01; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=vnRm0j85otx50gSN5LqFcKunoR/H3ua98B1Wub0g2Lg=; t=1718959493; x=1719564293; b=nYaDaqucSyVb876NSrVRp8vKQ8Gio7rL52u3C9JteReAhHge663w9C8FI4MJy4UhSTZEgQoeOrC /v3OwEkDDyvtTF3QzkgVojyEUsorci95sFQz63qlvqh7eAsB8RKpNLS28/BIgdkjCQi+HJkSriKyE 2AYMwbo5n+vOqE/hzI85JKoBbUu+W6Grt6xd1SQsLisACSVSJUIYIa9tk2OgTwnbI/wOy81FMKQum 0uo24gEar31ZBfMSX6ZvJhN6ddbfnzk2Cap/eOYzwJrPXmBFicXRoWiHvrXhRN/UlEHbPOKVbiZTq ILs1NWlCWp/Gsu707DGha15ifXAoq9eXjdsQ==; Received: from inpost2.zedat.fu-berlin.de ([130.133.4.69]) by outpost.zedat.fu-berlin.de (Exim 4.97) with esmtps (TLS1.3) tls TLS_AES_256_GCM_SHA384 (envelope-from ) id 1sKZsu-00000001rSo-3cOK; Fri, 21 Jun 2024 10:44:41 +0200 Received: from p5b13a475.dip0.t-ipconnect.de ([91.19.164.117] helo=suse-laptop-2.fritz.box) by inpost2.zedat.fu-berlin.de (Exim 4.97) with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (envelope-from ) id 1sKZsv-00000001cr3-0HzV; Fri, 21 Jun 2024 10:44:41 +0200 Message-ID: <366548c1a0d9749e42c0d0c993414a353c9b0b02.camel@physik.fu-berlin.de> Subject: Re: [PATCH 09/15] sh: rework sync_file_range ABI From: John Paul Adrian Glaubitz To: Arnd Bergmann , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Arnd Bergmann , Thomas Bogendoerfer , linux-mips@vger.kernel.org, Helge Deller , linux-parisc@vger.kernel.org, "David S. Miller" , Andreas Larsson , sparclinux@vger.kernel.org, Michael Ellerman , Nicholas Piggin , Christophe Leroy , "Naveen N . Rao" , linuxppc-dev@lists.ozlabs.org, Brian Cain , linux-hexagon@vger.kernel.org, Guo Ren , linux-csky@vger.kernel.org, Heiko Carstens , linux-s390@vger.kernel.org, Rich Felker , linux-sh@vger.kernel.org, "H. Peter Anvin" , Alexander Viro , Christian Brauner , linux-fsdevel@vger.kernel.org, libc-alpha@sourceware.org, musl@lists.openwall.com, ltp@lists.linux.it, stable@vger.kernel.org Date: Fri, 21 Jun 2024 10:44:39 +0200 In-Reply-To: <20240620162316.3674955-10-arnd@kernel.org> References: <20240620162316.3674955-1-arnd@kernel.org> <20240620162316.3674955-10-arnd@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.52.2 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Original-Sender: glaubitz@physik.fu-berlin.de X-ZEDAT-Hint: PO Hi Arnd, thanks for your patch! On Thu, 2024-06-20 at 18:23 +0200, Arnd Bergmann wrote: > From: Arnd Bergmann >=20 > The unusual function calling conventions on superh ended up causing ^^^^^^ It's spelled SuperH > sync_file_range to have the wrong argument order, with the 'flags' > argument getting sorted before 'nbytes' by the compiler. >=20 > In userspace, I found that musl, glibc, uclibc and strace all expect the > normal calling conventions with 'nbytes' last, so changing the kernel > to match them should make all of those work. >=20 > In order to be able to also fix libc implementations to work with existin= g > kernels, they need to be able to tell which ABI is used. An easy way > to do this is to add yet another system call using the sync_file_range2 > ABI that works the same on all architectures. >=20 > Old user binaries can now work on new kernels, and new binaries can > try the new sync_file_range2() to work with new kernels or fall back > to the old sync_file_range() version if that doesn't exist. >=20 > Cc: stable@vger.kernel.org > Fixes: 75c92acdd5b1 ("sh: Wire up new syscalls.") > Signed-off-by: Arnd Bergmann > --- > arch/sh/kernel/sys_sh32.c | 11 +++++++++++ > arch/sh/kernel/syscalls/syscall.tbl | 3 ++- > 2 files changed, 13 insertions(+), 1 deletion(-) >=20 > diff --git a/arch/sh/kernel/sys_sh32.c b/arch/sh/kernel/sys_sh32.c > index 9dca568509a5..d5a4f7c697d8 100644 > --- a/arch/sh/kernel/sys_sh32.c > +++ b/arch/sh/kernel/sys_sh32.c > @@ -59,3 +59,14 @@ asmlinkage int sys_fadvise64_64_wrapper(int fd, u32 of= fset0, u32 offset1, > (u64)len0 << 32 | len1, advice); > #endif > } > + > +/* > + * swap the arguments the way that libc wants it instead of I think "swap the arguments to the order that libc wants them" would be easier to understand here. > + * moving flags ahead of the 64-bit nbytes argument > + */ > +SYSCALL_DEFINE6(sh_sync_file_range6, int, fd, SC_ARG64(offset), > + SC_ARG64(nbytes), unsigned int, flags) > +{ > + return ksys_sync_file_range(fd, SC_VAL64(loff_t, offset), > + SC_VAL64(loff_t, nbytes), flags); > +} > diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscall= s/syscall.tbl > index bbf83a2db986..c55fd7696d40 100644 > --- a/arch/sh/kernel/syscalls/syscall.tbl > +++ b/arch/sh/kernel/syscalls/syscall.tbl > @@ -321,7 +321,7 @@ > 311 common set_robust_list sys_set_robust_list > 312 common get_robust_list sys_get_robust_list > 313 common splice sys_splice > -314 common sync_file_range sys_sync_file_range > +314 common sync_file_range sys_sh_sync_file_range6 ^^^^^^ Why= the suffix 6 here? > 315 common tee sys_tee > 316 common vmsplice sys_vmsplice > 317 common move_pages sys_move_pages > @@ -395,6 +395,7 @@ > 385 common pkey_alloc sys_pkey_alloc > 386 common pkey_free sys_pkey_free > 387 common rseq sys_rseq > +388 common sync_file_range2 sys_sync_file_range2 > # room for arch specific syscalls > 393 common semget sys_semget > 394 common semctl sys_semctl I wonder how you discovered this bug. Did you look up the calling conventio= n on SuperH and compare the argument order for the sys_sync_file_range system call docu= mented there with the order in the kernel? Did you also check what order libc uses? I would expect libc on SuperH miso= rdering the arguments as well unless I am missing something. Or do we know that the cod= e is actually currently broken? Thanks, Adrian --=20 .''`. John Paul Adrian Glaubitz : :' : Debian Developer `. `' Physicist `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913