From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f200.google.com (mail-qt0-f200.google.com [209.85.216.200]) by kanga.kvack.org (Postfix) with ESMTP id A120A6B026A for ; Thu, 18 Jan 2018 20:52:03 -0500 (EST) Received: by mail-qt0-f200.google.com with SMTP id e2so368380qti.3 for ; Thu, 18 Jan 2018 17:52:03 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id s76sor6102575qkl.21.2018.01.18.17.52.02 for (Google Transport Security); Thu, 18 Jan 2018 17:52:02 -0800 (PST) From: Ram Pai Subject: [PATCH v10 08/27] powerpc: implementation for arch_set_user_pkey_access() Date: Thu, 18 Jan 2018 17:50:29 -0800 Message-Id: <1516326648-22775-9-git-send-email-linuxram@us.ibm.com> In-Reply-To: <1516326648-22775-1-git-send-email-linuxram@us.ibm.com> References: <1516326648-22775-1-git-send-email-linuxram@us.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: mpe@ellerman.id.au, mingo@redhat.com, akpm@linux-foundation.org, corbet@lwn.net, arnd@arndb.de Cc: linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, dave.hansen@intel.com, benh@kernel.crashing.org, paulus@samba.org, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, hbabu@us.ibm.com, mhocko@kernel.org, bauerman@linux.vnet.ibm.com, ebiederm@xmission.com, linuxram@us.ibm.com This patch provides the detailed implementation for a user to allocate a key and enable it in the hardware. It provides the plumbing, but it cannot be used till the system call is implemented. The next patch will do so. Reviewed-by: Thiago Jung Bauermann Signed-off-by: Ram Pai --- arch/powerpc/include/asm/pkeys.h | 6 ++++- arch/powerpc/mm/pkeys.c | 40 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+), 1 deletions(-) diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h index 9964b46..2500a90 100644 --- a/arch/powerpc/include/asm/pkeys.h +++ b/arch/powerpc/include/asm/pkeys.h @@ -139,10 +139,14 @@ static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, return 0; } +extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, + unsigned long init_val); static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val) { - return 0; + if (static_branch_likely(&pkey_disabled)) + return -EINVAL; + return __arch_set_user_pkey_access(tsk, pkey, init_val); } extern void pkey_mm_init(struct mm_struct *mm); diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c index e1dc45b..eca04cd 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -9,6 +9,7 @@ * (at your option) any later version. */ +#include #include DEFINE_STATIC_KEY_TRUE(pkey_disabled); @@ -17,6 +18,9 @@ u32 initial_allocation_mask; /* Bits set for reserved keys */ #define AMR_BITS_PER_PKEY 2 +#define AMR_RD_BIT 0x1UL +#define AMR_WR_BIT 0x2UL +#define IAMR_EX_BIT 0x1UL #define PKEY_REG_BITS (sizeof(u64)*8) #define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey+1) * AMR_BITS_PER_PKEY)) @@ -112,6 +116,20 @@ static inline void write_uamor(u64 value) mtspr(SPRN_UAMOR, value); } +static bool is_pkey_enabled(int pkey) +{ + u64 uamor = read_uamor(); + u64 pkey_bits = 0x3ul << pkeyshift(pkey); + u64 uamor_pkey_bits = (uamor & pkey_bits); + + /* + * Both the bits in UAMOR corresponding to the key should be set or + * reset. + */ + WARN_ON(uamor_pkey_bits && (uamor_pkey_bits != pkey_bits)); + return !!(uamor_pkey_bits); +} + static inline void init_amr(int pkey, u8 init_bits) { u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey)); @@ -154,3 +172,25 @@ void __arch_deactivate_pkey(int pkey) { pkey_status_change(pkey, false); } + +/* + * Set the access rights in AMR IAMR and UAMOR registers for @pkey to that + * specified in @init_val. + */ +int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, + unsigned long init_val) +{ + u64 new_amr_bits = 0x0ul; + + if (!is_pkey_enabled(pkey)) + return -EINVAL; + + /* Set the bits we need in AMR: */ + if (init_val & PKEY_DISABLE_ACCESS) + new_amr_bits |= AMR_RD_BIT | AMR_WR_BIT; + else if (init_val & PKEY_DISABLE_WRITE) + new_amr_bits |= AMR_WR_BIT; + + init_amr(pkey, new_amr_bits); + return 0; +} -- 1.7.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org