Date: Mon, 17 Nov 2008 18:02:17 -0500 From: John Baldwin <jhb@freebsd.org> To: Kostik Belousov <kostikbel@gmail.com> Cc: Doug Ambrisko <ambrisko@freebsd.org>, src-committers@freebsd.org, Doug Ambrisko <ambrisko@ambrisko.com>, Peter Wemm <peter@wemm.org>, svn-src-all@freebsd.org, dchagin@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r184974 - head/sys/dev/mfi Message-ID: <200811171802.17674.jhb@freebsd.org> In-Reply-To: <20081117224048.GN90129@deviant.kiev.zoral.com.ua> References: <200811170237.mAH2bjY5088186@ambrisko.com> <e7db6d980811171321n217adff0gc6213c2779a0f94@mail.gmail.com> <20081117224048.GN90129@deviant.kiev.zoral.com.ua>
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On Monday 17 November 2008 05:40:48 pm Kostik Belousov wrote: > On Mon, Nov 17, 2008 at 01:21:53PM -0800, Peter Wemm wrote: > > On Mon, Nov 17, 2008 at 1:13 PM, John Baldwin <jhb@freebsd.org> wrote: > > > On Monday 17 November 2008 02:35:41 pm Kostik Belousov wrote: > > >> On Mon, Nov 17, 2008 at 12:11:41PM -0500, John Baldwin wrote: > > >> > On Sunday 16 November 2008 09:37:45 pm Doug Ambrisko wrote: > > >> > > Kostik Belousov writes: > > >> > > | On Fri, Nov 14, 2008 at 09:05:45PM +0000, Doug Ambrisko wrote: > > >> > > | > Author: ambrisko > > >> > > | > Date: Fri Nov 14 21:05:45 2008 > > >> > > | > New Revision: 184974 > > >> > > | > URL: http://svn.freebsd.org/changeset/base/184974 > > >> > > | > > > >> > > | > Log: > > >> > > | > When running a 32bit app. on amd64, ensure the bits above 32bit > > >> > > | > are zero for the copyout. Confirmed by LSI. > > >> > > | > > > >> > > | > Modified: > > >> > > | > head/sys/dev/mfi/mfi.c > > >> > > | > > > >> > > | > Modified: head/sys/dev/mfi/mfi.c > > >> > > | > > > >> > > > > ============================================================================== > > >> > > | > --- head/sys/dev/mfi/mfi.c Fri Nov 14 18:09:19 2008 (r184973) > > >> > > | > +++ head/sys/dev/mfi/mfi.c Fri Nov 14 21:05:45 2008 (r184974) > > >> > > | > @@ -2130,6 +2130,14 @@ mfi_ioctl(struct cdev *dev, u_long cmd, > > >> > > | > ->mfi_frame.raw[ioc->mfi_sense_off], > > >> > > | > &sense_ptr.sense_ptr_data[0], > > >> > > | > sizeof(sense_ptr.sense_ptr_data)); > > >> > > | > +#ifdef __amd64__ > > >> > > | > + if (cmd != MFI_CMD) { > > >> > > | > + /* > > >> > > | > + * not 64bit native so zero out any address > > >> > > | > + * over 32bit */ > > >> > > | > + sense_ptr.high = 0; > > >> > > | > + } > > >> > > | > +#endif > > >> > > | > error = copyout(cm->cm_sense, sense_ptr.user_space, > > >> > > | > ioc->mfi_sense_len); > > >> > > | > if (error != 0) { > > >> > > | > @@ -2353,6 +2361,13 @@ mfi_linux_ioctl_int(struct cdev *dev, u_ > > >> > > | > ->lioc_frame.raw[l_ioc.lioc_sense_off], > > >> > > | > &sense_ptr.sense_ptr_data[0], > > >> > > | > sizeof(sense_ptr.sense_ptr_data)); > > >> > > | > +#ifdef __amd64__ > > >> > > | > + /* > > >> > > | > + * only 32bit Linux support so zero out any > > >> > > | > + * address over 32bit > > >> > > | > + */ > > >> > > | > + sense_ptr.high = 0; > > >> > > | > +#endif > > >> > > | > error = copyout(cm->cm_sense, sense_ptr.user_space, > > >> > > | > l_ioc.lioc_sense_len); > > >> > > | > if (error != 0) { > > >> > > | > > >> > > | Would it make sense to perform this cut slightly more generically, by > > >> > > | checking whether the current process is 32bit ? > > >> > > | > > >> > > | We still have not grew the easy to check flag or attribute of the > > > image, > > >> > > | but usual practice is to compare p_sysent with corresponding sysvec, > > >> > > | like > > >> > > | if (td->td_proc->p_sysent == &ia32_freebsd_sysvec) > > >> > > | or > > >> > > | if (td->td_proc->p_sysent == &elf_linux_sysvec) > > >> > > > > >> > > So far we do it based on the ioctl since the 32bit or 64bit ioctl > > >> > > value is different. I put in that comment for Linux since there > > >> > > is talk/work for Linux amd64 emulation. For 64bit Linux ioctl > > >> > > support we need a 64bit structure defined. When the ioctl can't > > >> > > be figured out then I've used the p_sysent. Eventually, something > > >> > > that is more generic then the #ifdef __amd64__ should be done > > >> > > in all the drivers that do this emulation. > > >> > > > >> > I prefer depending on things like ioctl values and the 32-bit sysctl flag > > > when > > >> > possible. If we do have to directly check for the ABI, I'd much rather > > > have > > >> > a flags field in sysent rather than trying to compare against global > > > symbols, > > >> > as you can't compare against a global symbol unless it is present in the > > >> > kernel. Something like: > > >> > > > >> > if (td->td_proc->p_sysent->sy_flags & SY_32) > > >> > > > >> > or some such. I've wanted to have a COMPAT_FREEBSD32 that gets > > > auto-enabled > > >> > when you turn on COMPAT_IA32 on amd64 and ia64. It would also potentially > > > be > > >> > enabled by a COMPAT_SPARC8 or some such on sparc64 if we ever had that. > > >> > > >> Ok, what about the following. I only compiled it on i386/amd64. And, > > >> there are more places to convert to such checks, for sure. > > >> > > >> [yummy patch] > > > > > > Commit! Note that this is not MFC'able due to ABI breakage for older linux.ko > > > modules, but this is the proper solution for 8.0+. > I do not think that sysent KBI shall be preserved on the stable branch, > it is too core functionality. Our KBI guarantee mostly center around > drivers and less so for filesystem modules. Well, I didn't MFC the .sv_maxssiz fix to 6.x due to ABI concerns. -- John Baldwin
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