Subject: [PATCH 1/2] powerpc/mm/book3s54/pkeys: make pkey access check work on execute_only_key

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Sat, 27 Jun 2020 12:31:46 +0530

pkey_access_permitted() should not check for pkey is available in UAMOR or not.
The kernel needs to do that check only while allocating keys. This also makes
sure execute_only_key which is marked as non-manageable via UAMOR gives the
right access check return w.r.t pkey_access_permitted().

This fix the page fault loop when using PROT_EXEC as below

addr = mmap(0, page_sz, PROT_EXEC, MAP_FILE | MAP_PRIVATE, fildes, 0);
x =  *addr);

Fixes: c46241a370a6 ("powerpc/pkeys: Check vma before returning key fault error to the user")

Reported-by: Jan Stancek <[email-masked]>
Signed-off-by: Aneesh Kumar K.V <[email-masked]>
---
 arch/powerpc/mm/book3s64/pkeys.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 1199fc2bfaec..ca5fcb4bff32 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -353,9 +353,6 @@ static bool pkey_access_permitted(int pkey, bool write, bool execute)
 	int pkey_shift;
 	u64 amr;
 
-	if (!is_pkey_enabled(pkey))
-		return true;
-
 	pkey_shift = pkeyshift(pkey);
 	if (execute && !(read_iamr() & (IAMR_EX_BIT << pkey_shift)))
 		return true;
-- 
2.26.2