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

[Doug Ambrisko]

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.

Doug A.