[tip: x86/urgent] x86/pat: Pass valid address to sanitize_phys()

[tip-bot2 for Jeff Moyer]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     aeef8b5089b76852bd84889f2809e69a7cfb414e
Gitweb:        https://git.kernel.org/tip/aeef8b5089b76852bd84889f2809e69a7cfb414e
Author:        Jeff Moyer <jmoyer@xxxxxxxxxx>
AuthorDate:    Wed, 11 Aug 2021 17:07:37 -04:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Thu, 02 Sep 2021 21:53:18 +02:00

x86/pat: Pass valid address to sanitize_phys()

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:

 WARNING: CPU: 26 PID: 749 at arch/x86/mm/pat.c:354 reserve_memtype+0x262/0x450
 reserve_memtype failed: [mem 0x3ffffff00000-0xffffffffffffffff], req uncached-minus
 Call Trace:
  [<ffffffffa427b1f2>] reserve_memtype+0x262/0x450
  [<ffffffffa42764aa>] ioremap_nocache+0x1a/0x20
  [<ffffffffc04620a1>] mpt3sas_base_map_resources+0x151/0xa60 [mpt3sas]
  [<ffffffffc0465555>] mpt3sas_base_attach+0xf5/0xa50 [mpt3sas]
 ---[ end trace 6d6eea4438db89ef ]---
 ioremap reserve_memtype failed -22
 mpt3sas_cm0: unable to map adapter memory! or resource not found
 mpt3sas_cm0: failure at drivers/scsi/mpt3sas/mpt3sas_scsih.c:10597/_scsih_probe()!

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>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/x49o8a3pu5i.fsf@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
---
 arch/x86/mm/pat/memtype.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c
index 3112ca7..4ba2a3e 100644
--- a/arch/x86/mm/pat/memtype.c
+++ b/arch/x86/mm/pat/memtype.c
@@ -583,7 +583,12 @@ int memtype_reserve(u64 start, u64 end, enum page_cache_mode req_type,
 	int err = 0;
 
 	start = sanitize_phys(start);
-	end = sanitize_phys(end);
+
+	/*
+	 * The end address passed into this function is exclusive, but
+	 * sanitize_phys() expects an inclusive address.
+	 */
+	end = sanitize_phys(end - 1) + 1;
 	if (start >= end) {
 		WARN(1, "%s failed: [mem %#010Lx-%#010Lx], req %s\n", __func__,
 				start, end - 1, cattr_name(req_type));