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From:   ira.weiny@intel.com
To:     Dave Hansen <dave.hansen@linux.intel.com>,
        "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc:     Ira Weiny <ira.weiny@intel.com>,
        "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/5] powerpc/pkeys: Properly type pkey in init_{i}amr()
Date:   Thu, 10 Mar 2022 16:57:40 -0800
Message-Id: <20220311005742.1060992-4-ira.weiny@intel.com>
In-Reply-To: <20220311005742.1060992-1-ira.weiny@intel.com>
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From: Ira Weiny <ira.weiny@intel.com>

Negative values passed to pkeyshift() will cause an overflow of the amr
and imar values.  Pkey should not be negative in this call path and u8
is large enough for the 32 pkeys available on powerpc.

Change pkey to u8 in init_amr() and init_iamr().

To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/powerpc/mm/book3s64/pkeys.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 753e62ba67af..d6456f8846de 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -310,7 +310,7 @@ void pkey_mm_init(struct mm_struct *mm)
 	mm->context.execute_only_pkey = execute_only_key;
 }
 
-static inline void init_amr(int pkey, u8 init_bits)
+static inline void init_amr(u8 pkey, u8 init_bits)
 {
 	u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
 	u64 old_amr = current_thread_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
@@ -318,7 +318,7 @@ static inline void init_amr(int pkey, u8 init_bits)
 	current->thread.regs->amr = old_amr | new_amr_bits;
 }
 
-static inline void init_iamr(int pkey, u8 init_bits)
+static inline void init_iamr(u8 pkey, u8 init_bits)
 {
 	u64 new_iamr_bits = (((u64)init_bits & 0x1UL) << pkeyshift(pkey));
 	u64 old_iamr = current_thread_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
-- 
2.35.1