Hi,
Ping. I just booted with a bsd.rd and saw this issue is still outstanding.
Is the patch that I provided not good enough?
Regards,
-peter
On Thu, Jul 05, 2018 at 02:00:45PM +0200, Peter J. Philipp wrote:
> On Thu, Jul 05, 2018 at 11:20:51AM +0200, Mark Kettenis wrote:
> > > So sorry, it was erroneous... second attempt. The first attempt wasn't
> > > safe
> > > for replies from OFW that were of size 0. Also on my box the dmesg
> > > starts
> > > like so on this:
> >
> > Sorry, but this isn't quite right. What the code should really do is
> > count all memory below the 4G boundary. Since part if the phyical
> > address space is reserved for devices that will be less < 4GB.
> >
> > Yes that means that dmesg will not report the full amount of memory in
> > the machine. But you can't use that memory anyway on a 32-bit OpenBSD
> > system. And if the physmem variable includes a lot of memory that
> > isn't actually usable, the kernel will make bad choices in sizing
> > various things.
> >
> > Cheers,
> >
> > Mark
>
> Hi Mark,
>
> That makes perfect sense. I adjusted my patch and wonder if you like it?
> The patch takes a "pagelimit" which is UINT_MAX >> PAGE_SHIFT and doesn't
> allow page counts over that. This way is guaranteed that there is never
> an overflow. It perhaps isn't the classiest patch out there.
>
> Here is what the dmesg reports from real memory from the last patch and below
> it the real memory from this patch.
>
> iota# dmesg | grep ^real\ mem
> real mem = 4294950912 (4095MB)
> real mem = 4294963200 (4095MB)
>
> Regards,
> -peter
>
>
> Index: ofw_machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/macppc/macppc/ofw_machdep.c,v
> retrieving revision 1.56
> diff -u -p -u -r1.56 ofw_machdep.c
> --- ofw_machdep.c 22 Jul 2017 18:33:38 -0000 1.56
> +++ ofw_machdep.c 5 Jul 2018 11:51:35 -0000
> @@ -131,9 +131,10 @@ ppc_mem_regions(struct mem_region **memp
> void
> ofw_read_mem_regions(int phandle, int address_cells, int size_cells)
> {
> + const uint pagelimit = (UINT_MAX >> PAGE_SHIFT);
> int nreg, navail;
> int i, j;
> - uint physpages;
> + uint physpages, tmp;
>
> switch (address_cells) {
> default:
> @@ -171,16 +172,26 @@ ofw_read_mem_regions(int phandle, int ad
> case 2:
> physpages = 0;
> for (i = 0, j = 0; i < nreg; i++) {
> - if (OFmem64[i].size == 0)
> + if ((tmp = OFmem64[i].size) == 0)
> continue;
> - physpages += atop(OFmem64[i].size);
> +
> + /*
> + * restrict overflows to constant pagelimit,
> + * even if > 4 GB of memory exist in the machine
> + */
> +
> + if (physpages + atop(tmp) > pagelimit)
> + physpages = pagelimit;
> + else
> + physpages += atop(tmp);
> +
> if (OFmem64[i].start >= 1ULL << 32)
> continue;
> OFmem[j].start = OFmem64[i].start;
> - if (OFmem64[i].start + OFmem64[i].size >= 1ULL << 32)
> + if (OFmem64[i].start + tmp >= 1ULL << 32)
> OFmem[j].size = (1ULL << 32) - OFmem64[i].start;
> else
> - OFmem[j].size = OFmem64[i].size;
> + OFmem[j].size = tmp;
> j++;
> }
> physmem = physpages;
