[PATCH 01/16] mm: use untagged_addr() for get_user_pages_fast addresses

From: Christoph Hellwig
Date: Tue Jun 25 2019 - 10:37:48 EST


This will allow sparc64, or any future architecture with memory tagging
to override its tags for get_user_pages and get_user_pages_fast.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Khalid Aziz <khalid.aziz@xxxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
---
mm/gup.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index ddde097cf9e4..6bb521db67ec 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2146,7 +2146,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
unsigned long flags;
int nr = 0;

- start &= PAGE_MASK;
+ start = untagged_addr(start) & PAGE_MASK;
len = (unsigned long) nr_pages << PAGE_SHIFT;
end = start + len;

@@ -2219,7 +2219,7 @@ int get_user_pages_fast(unsigned long start, int nr_pages,
unsigned long addr, len, end;
int nr = 0, ret = 0;

- start &= PAGE_MASK;
+ start = untagged_addr(start) & PAGE_MASK;
addr = start;
len = (unsigned long) nr_pages << PAGE_SHIFT;
end = start + len;
--
2.20.1