Re: [patch, v2] x86/pat: pass valid address to sanitize_phys()

[Dan Williams]

On Wed, Aug 11, 2021 at 2:06 PM Jeff Moyer <jmoyer@xxxxxxxxxx> wrote:
>
> The end address passed to memtype_reserve() is handed directly to
> sanitize_phys().  However, end is exclusive and sanitize_phys() expects
> an inclusive address.  If end falls at the end of the physical address
> space, sanitize_phys() will return 0.  This can result in drivers
> failing to load, and the following warning:
>
> [    9.999440] mpt3sas version 29.100.01.00 loaded
> [    9.999817] mpt3sas_cm0: 64 BIT PCI BUS DMA ADDRESSING SUPPORTED, total mem (65413664 kB)
> [    9.999819] ------------[ cut here ]------------
> [    9.999826] WARNING: CPU: 26 PID: 749 at arch/x86/mm/pat.c:354 reserve_memtype+0x262/0x450
> [    9.999828] reserve_memtype failed: [mem 0x3ffffff00000-0xffffffffffffffff], req uncached-minus
> [    9.999828] Modules linked in: mpt3sas(+) bnxt_en(+) ahci(+) crct10dif_pclmul crct10dif_common nvme crc32c_intel libahci nvme_core libata raid_class scsi_transport_sas devlink drm_panel_orientation_quirks nfit libnvdimm dm_mirror dm_region_hash dm_log dm_mod
> [    9.999840] CPU: 26 PID: 749 Comm: systemd-udevd Not tainted 3.10.0-1077.el7_7.mpt3sas_test008.x86_64 #1
> [    9.999842] Hardware name: Inspur SA5112M5/SA5112M5, BIOS 4.1.12 02/24/2021
> [    9.999843] Call Trace:
> [    9.999851]  [<ffffffffa497c4e4>] dump_stack+0x19/0x1b
> [    9.999857]  [<ffffffffa429bc08>] __warn+0xd8/0x100
> [    9.999859]  [<ffffffffa429bc8f>] warn_slowpath_fmt+0x5f/0x80
> [    9.999861]  [<ffffffffa427b1f2>] reserve_memtype+0x262/0x450
> [    9.999867]  [<ffffffffa4276254>] __ioremap_caller+0xf4/0x330
> [    9.999872]  [<ffffffffc04620a1>] ? mpt3sas_base_map_resources+0x151/0xa60 [mpt3sas]
> [    9.999875]  [<ffffffffa42764aa>] ioremap_nocache+0x1a/0x20
> [    9.999879]  [<ffffffffc04620a1>] mpt3sas_base_map_resources+0x151/0xa60 [mpt3sas]
> [    9.999884]  [<ffffffffa442656b>] ? __kmalloc+0x1eb/0x230
> [    9.999889]  [<ffffffffc0465555>] mpt3sas_base_attach+0xf5/0xa50 [mpt3sas]
> [    9.999894]  [<ffffffffc046af3c>] _scsih_probe+0x4ec/0xb00 [mpt3sas]
> [    9.999901]  [<ffffffffa45d297a>] local_pci_probe+0x4a/0xb0
> [    9.999903]  [<ffffffffa45d40c9>] pci_device_probe+0x109/0x160
> [    9.999909]  [<ffffffffa46b7225>] driver_probe_device+0xc5/0x3e0
> [    9.999910]  [<ffffffffa46b7623>] __driver_attach+0x93/0xa0
> [    9.999912]  [<ffffffffa46b7590>] ? __device_attach+0x50/0x50
> [    9.999914]  [<ffffffffa46b4dc5>] bus_for_each_dev+0x75/0xc0
> [    9.999916]  [<ffffffffa46b6b9e>] driver_attach+0x1e/0x20
> [    9.999918]  [<ffffffffa46b6640>] bus_add_driver+0x200/0x2d0
> [    9.999920]  [<ffffffffa46b7cb4>] driver_register+0x64/0xf0
> [    9.999922]  [<ffffffffa45d3905>] __pci_register_driver+0xa5/0xc0
> [    9.999924]  [<ffffffffc049b000>] ? 0xffffffffc049afff
> [    9.999928]  [<ffffffffc049b16e>] _mpt3sas_init+0x16e/0x1000 [mpt3sas]
> [    9.999933]  [<ffffffffa420210a>] do_one_initcall+0xba/0x240
> [    9.999940]  [<ffffffffa431e95a>] load_module+0x271a/0x2bb0
> [    9.999946]  [<ffffffffa45b0600>] ? ddebug_proc_write+0x100/0x100
> [    9.999948]  [<ffffffffa431eedf>] SyS_init_module+0xef/0x140
> [    9.999954]  [<ffffffffa498fed2>] system_call_fastpath+0x25/0x2a
> [    9.999955] ---[ end trace 6d6eea4438db89ef ]---
> [    9.999957] ioremap reserve_memtype failed -22
> [   10.000087] mpt3sas_cm0: unable to map adapter memory! or resource not found
> [   10.000334] mpt3sas_cm0: failure at drivers/scsi/mpt3sas/mpt3sas_scsih.c:10597/_scsih_probe()!
>
> (Note that this warning was from an older distribution kernel, so line
> numbers and file names may not line up with the current tree.)
>
> Fix this by passing the inclusive end address to sanitize_phys().
>
> Fixes: 510ee090abc3 ("x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses")
> Signed-off-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>

Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>