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Violators will be prosecuted for from ; Thu, 27 Jul 2017 11:54:43 -0300 Received: from d24av04.br.ibm.com (d24av04.br.ibm.com [9.8.31.97]) by d24relay04.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6REsggB26148966 for ; Thu, 27 Jul 2017 11:54:42 -0300 Received: from d24av04.br.ibm.com (localhost [127.0.0.1]) by d24av04.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v6REsgA4006448 for ; Thu, 27 Jul 2017 11:54:42 -0300 References: <1500177424-13695-1-git-send-email-linuxram@us.ibm.com> <1500177424-13695-20-git-send-email-linuxram@us.ibm.com> From: Thiago Jung Bauermann Subject: Re: [RFC v6 19/62] powerpc: ability to create execute-disabled pkeys In-reply-to: <1500177424-13695-20-git-send-email-linuxram@us.ibm.com> Date: Thu, 27 Jul 2017 11:54:31 -0300 MIME-Version: 1.0 Content-Type: text/plain Message-Id: <87bmo63p7c.fsf@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ram Pai Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, arnd@arndb.de, corbet@lwn.net, mhocko@kernel.org, dave.hansen@intel.com, mingo@redhat.com, paulus@samba.org, aneesh.kumar@linux.vnet.ibm.com, akpm@linux-foundation.org, khandual@linux.vnet.ibm.com Ram Pai writes: > --- a/arch/powerpc/include/asm/pkeys.h > +++ b/arch/powerpc/include/asm/pkeys.h > @@ -2,6 +2,18 @@ > #define _ASM_PPC64_PKEYS_H > > extern bool pkey_inited; > +/* override any generic PKEY Permission defines */ > +#undef PKEY_DISABLE_ACCESS > +#define PKEY_DISABLE_ACCESS 0x1 > +#undef PKEY_DISABLE_WRITE > +#define PKEY_DISABLE_WRITE 0x2 > +#undef PKEY_DISABLE_EXECUTE > +#define PKEY_DISABLE_EXECUTE 0x4 > +#undef PKEY_ACCESS_MASK > +#define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS |\ > + PKEY_DISABLE_WRITE |\ > + PKEY_DISABLE_EXECUTE) > + Is it ok to #undef macros from another header? Especially since said header is in uapi (include/uapi/asm-generic/mman-common.h). Also, it's unnecessary to undef the _ACCESS and _WRITE macros since they are identical to the original definition. And since these macros are originally defined in an uapi header, the powerpc-specific ones should be in an uapi header as well, if I understand it correctly. An alternative solution is to define only PKEY_DISABLE_EXECUTE in arch/powerpc/include/uapi/asm/mman.h and then test for its existence to properly define PKEY_ACCESS_MASK in include/uapi/asm-generic/mman-common.h. What do you think of the code below? diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h index e31f5ee8e81f..67e6a3a343ae 100644 --- a/arch/powerpc/include/asm/pkeys.h +++ b/arch/powerpc/include/asm/pkeys.h @@ -4,17 +4,6 @@ #include extern bool pkey_inited; -/* override any generic PKEY Permission defines */ -#undef PKEY_DISABLE_ACCESS -#define PKEY_DISABLE_ACCESS 0x1 -#undef PKEY_DISABLE_WRITE -#define PKEY_DISABLE_WRITE 0x2 -#undef PKEY_DISABLE_EXECUTE -#define PKEY_DISABLE_EXECUTE 0x4 -#undef PKEY_ACCESS_MASK -#define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS |\ - PKEY_DISABLE_WRITE |\ - PKEY_DISABLE_EXECUTE) #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \ VM_PKEY_BIT3 | VM_PKEY_BIT4) diff --git a/arch/powerpc/include/uapi/asm/mman.h b/arch/powerpc/include/uapi/asm/mman.h index ab45cc2f3101..dee43feb7c53 100644 --- a/arch/powerpc/include/uapi/asm/mman.h +++ b/arch/powerpc/include/uapi/asm/mman.h @@ -45,4 +45,6 @@ #define MAP_HUGE_1GB (30 << MAP_HUGE_SHIFT) /* 1GB HugeTLB Page */ #define MAP_HUGE_16GB (34 << MAP_HUGE_SHIFT) /* 16GB HugeTLB Page */ +#define PKEY_DISABLE_EXECUTE 0x4 + #endif /* _UAPI_ASM_POWERPC_MMAN_H */ diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c index 72eb9a1bde79..777f8f8dff47 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -12,7 +12,7 @@ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ -#include +#include #include /* PKEY_* */ bool pkey_inited; diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h index 8c27db0c5c08..93e3841d9ada 100644 --- a/include/uapi/asm-generic/mman-common.h +++ b/include/uapi/asm-generic/mman-common.h @@ -74,7 +74,15 @@ #define PKEY_DISABLE_ACCESS 0x1 #define PKEY_DISABLE_WRITE 0x2 + +/* The arch-specific code may define PKEY_DISABLE_EXECUTE */ +#ifdef PKEY_DISABLE_EXECUTE +#define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS | \ + PKEY_DISABLE_WRITE | \ + PKEY_DISABLE_EXECUTE) +#else #define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS |\ PKEY_DISABLE_WRITE) +#endif #endif /* __ASM_GENERIC_MMAN_COMMON_H */ > diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c > index 98d0391..b9ad98d 100644 > --- a/arch/powerpc/mm/pkeys.c > +++ b/arch/powerpc/mm/pkeys.c > @@ -73,6 +73,7 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, > unsigned long init_val) > { > u64 new_amr_bits = 0x0ul; > + u64 new_iamr_bits = 0x0ul; > > if (!is_pkey_enabled(pkey)) > return -1; > @@ -85,5 +86,14 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, > > init_amr(pkey, new_amr_bits); > > + /* > + * By default execute is disabled. > + * To enable execute, PKEY_ENABLE_EXECUTE > + * needs to be specified. > + */ > + if ((init_val & PKEY_DISABLE_EXECUTE)) > + new_iamr_bits |= IAMR_EX_BIT; > + > + init_iamr(pkey, new_iamr_bits); > return 0; > } The comment seems to be from an earlier version which has the logic inverted, and there is no PKEY_ENABLE_EXECUTE. Should the comment be updated to the following? By default execute is enabled. To disable execute, PKEY_DISABLE_EXECUTE needs to be specified. -- Thiago Jung Bauermann IBM Linux Technology Center -- 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