[PATCH] sparc64: Fix page table walk for PUD hugepages

From: Nitin Gupta
Date: Fri Nov 03 2017 - 15:27:12 EST


For a PUD hugepage entry, we need to propagate bits [32:22]
from virtual address to resolve at 4M granularity. However,
the current code was incorrectly propagating bits [29:19].
This bug can cause incorrect data to be returned for pages
backed with 16G hugepages.

Signed-off-by: Nitin Gupta <nitin.m.gupta@xxxxxxxxxx>
Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

diff --git a/arch/sparc/include/asm/tsb.h b/arch/sparc/include/asm/tsb.h
index acf55063aa3d..ca0de1646f1e 100644
--- a/arch/sparc/include/asm/tsb.h
+++ b/arch/sparc/include/asm/tsb.h
@@ -216,7 +216,7 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
sllx REG2, 32, REG2; \
andcc REG1, REG2, %g0; \
be,pt %xcc, 700f; \
- sethi %hi(0x1ffc0000), REG2; \
+ sethi %hi(0xffe00000), REG2; \
sllx REG2, 1, REG2; \
brgez,pn REG1, FAIL_LABEL; \
andn REG1, REG2, REG1; \
--
2.13.1