From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Kent Subject: Re: [PATCH] unbreak automounter support on 64-bit kernel with 32-bit userspace (v2) Date: Wed, 06 Feb 2013 13:58:06 +0800 Message-ID: <1360130286.4186.0.camel@perseus.themaw.net> References: <20130204193952.GA5785@p100.box> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=themaw.net; h= message-id:subject:from:to:cc:date:in-reply-to:references :content-type:content-transfer-encoding:mime-version; s=mesmtp; bh=HWwyJbqbReJZKAtoVoo6biTKHXI=; b=PqWbVTy7V8laNDrWXpGt5yvGvZpj 3xz1IBQJKZiSxWThQ6gpawR4GFx7PK5fDeW7ZCuQxEsgCKw0Ju6RA7Rkc3RimBoR KuRE75U5ltnEp5/W/yjXPmyPWwSsA5ZKNca7ShUBDHjFAV74C+yKvv88ZGlkPBBm DhLraZHHGflb9+c= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=message-id:subject:from:to:cc:date :in-reply-to:references:content-type:content-transfer-encoding :mime-version; s=smtpout; bh=HWwyJbqbReJZKAtoVoo6biTKHXI=; b=cGJ fZatRVcshvmh/5lCHXvVKA78gMuRdB3G9fshxMJTz6WNB89kc6t9JoLbKNkuQHbo JND9gY95ArFQGNjZhMz96qksERB7r/nQMtvVb2HAJShjqzlj8VjG0upAhzpLVObM r1Tr7JGG8UBsAuL3zKhjkxZrOyiU7A4Szw5eOiT8= In-Reply-To: <20130204193952.GA5785@p100.box> Sender: linux-parisc-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Helge Deller Cc: "H. Peter Anvin" , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, James Bottomley , John David Anglin , Catalin Marinas , Rolf Eike Beer , autofs@vger.kernel.org On Mon, 2013-02-04 at 20:39 +0100, Helge Deller wrote: > automount-support is broken on the parisc architecture, because the existing > #if list does not include a check for defined(__hppa__). The HPPA (parisc) > architecture is similiar to other 64bit Linux targets where we have to define > autofs_wqt_t (which is passed back and forth to user space) as int type which > has a size of 32bit across 32 and 64bit kernels. > > During the discussion on the mailing list, H. Peter Anvin suggested to invert > the #if list since only specific platforms (specifically those who do not have > a 32bit userspace, like IA64 and Alpha) should have autofs_wqt_t as unsigned > long type. > > This suggestion is probably the best way to go, since Arm64 (and maybe others?) > seems to have a non-working automounter. So in the long run even for other new > upcoming architectures this inverted check seem to be the best solution, since > it will not require them to change this #if again (unless they are 64bit only). > > Signed-off-by: Helge Deller > CC: James Bottomley > CC: Catalin Marinas > CC: Rolf Eike Beer > CC: H. Peter Anvin > CC: Ian Kent > > > diff --git a/include/uapi/linux/auto_fs.h b/include/uapi/linux/auto_fs.h > index 77cdba9..bb991df 100644 > --- a/include/uapi/linux/auto_fs.h > +++ b/include/uapi/linux/auto_fs.h > @@ -28,25 +28,16 @@ > #define AUTOFS_MIN_PROTO_VERSION AUTOFS_PROTO_VERSION > > /* > - * Architectures where both 32- and 64-bit binaries can be executed > - * on 64-bit kernels need this. This keeps the structure format > - * uniform, and makes sure the wait_queue_token isn't too big to be > - * passed back down to the kernel. > - * > - * This assumes that on these architectures: > - * mode 32 bit 64 bit > - * ------------------------- > - * int 32 bit 32 bit > - * long 32 bit 64 bit > - * > - * If so, 32-bit user-space code should be backwards compatible. > + * The wait_queue_token (autofs_wqt_t) is part of a structure which is passed > + * back to the kernel via ioctl from userspace. On architectures where 32- and > + * 64-bit userspace binaries can be executed it's important that the size of > + * autofs_wqt_t stays constant between 32- and 64-bit Linux kernels so that we > + * do not break the binary ABI interface by changing the structure size. > */ > - > -#if defined(__sparc__) || defined(__mips__) || defined(__x86_64__) \ > - || defined(__powerpc__) || defined(__s390__) > -typedef unsigned int autofs_wqt_t; > -#else > +#if defined(__ia64__) || defined(__alpha__) /* pure 64bit architectures */ > typedef unsigned long autofs_wqt_t; > +#else > +typedef unsigned int autofs_wqt_t; > #endif > > /* Packet types */ Acked-by: Ian Kent