svn commit: r184974 - head/sys/dev/mfi

[John Baldwin]

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+.

-- 
John Baldwin