From: Ram Pai <linuxram@us.ibm.com>
To: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
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
Subject: Re: [RFC v6 19/62] powerpc: ability to create execute-disabled pkeys
Date: Sat, 29 Jul 2017 16:24:46 -0700 [thread overview]
Message-ID: <20170729232446.GG5664@ram.oc3035372033.ibm.com> (raw)
In-Reply-To: <87bmo63p7c.fsf@linux.vnet.ibm.com>
On Thu, Jul 27, 2017 at 11:54:31AM -0300, Thiago Jung Bauermann wrote:
>
> Ram Pai <linuxram@us.ibm.com> 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.
The architectural neutral code allows the implementation to define the
macros to its taste. powerpc headers due to legacy reason includes the
include/uapi/asm-generic/mman-common.h header. That header includes the
generic definitions of only PKEY_DISABLE_ACCESS and PKEY_DISABLE_WRITE.
Unfortunately we end up importing them. I dont want to depend on them.
Any changes there could effect us. Example if the generic uapi header
changed PKEY_DISABLE_ACCESS to 0x4, we will have a conflict with
PKEY_DISABLE_EXECUTE. Hence I undef them and define the it my way.
>
> 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 <asm/firmware.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)
>
> #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 <uapi/asm-generic/mman-common.h>
> +#include <asm/mman.h>
> #include <linux/pkeys.h> /* 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 */
I suppose we can do it this way aswell. but dont like the way it is
spreading the defines accross multiple files.
>
>
> > 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.
yes. the comment is misleading. I just took it out.
RP
>
> --
> Thiago Jung Bauermann
> IBM Linux Technology Center
--
Ram Pai
--
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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-07-29 23:25 UTC|newest]
Thread overview: 103+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-16 3:56 [RFC v6 00/62] powerpc: Memory Protection Keys Ram Pai
2017-07-16 3:56 ` [RFC v6 01/62] powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Ram Pai
2017-07-20 5:51 ` Aneesh Kumar K.V
2017-07-20 22:03 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 02/62] powerpc: Free up four 64K PTE bits in 64K " Ram Pai
2017-07-20 5:53 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 03/62] powerpc: introduce pte_set_hash_slot() helper Ram Pai
2017-07-20 5:56 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 04/62] powerpc: introduce pte_get_hash_gslot() helper Ram Pai
2017-07-20 5:57 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 05/62] powerpc: capture the PTE format changes in the dump pte report Ram Pai
2017-07-20 5:56 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 06/62] powerpc: use helper functions in __hash_page_64K() for 64K PTE Ram Pai
2017-07-20 5:58 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 07/62] powerpc: use helper functions in __hash_page_huge() " Ram Pai
2017-07-20 5:58 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 08/62] powerpc: use helper functions in __hash_page_4K() " Ram Pai
2017-07-16 3:56 ` [RFC v6 09/62] powerpc: use helper functions in __hash_page_4K() for 4K PTE Ram Pai
2017-07-16 3:56 ` [RFC v6 10/62] powerpc: use helper functions in flush_hash_page() Ram Pai
2017-07-16 3:56 ` [RFC v6 11/62] powerpc: initial pkey plumbing Ram Pai
2017-07-20 6:04 ` Aneesh Kumar K.V
2017-07-20 22:11 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 12/62] mm: introduce an additional vma bit for powerpc pkey Ram Pai
2017-07-16 3:56 ` [RFC v6 13/62] powerpc: track allocation status of all pkeys Ram Pai
2017-07-27 14:01 ` Thiago Jung Bauermann
2017-07-29 22:43 ` Ram Pai
2017-07-31 18:15 ` Thiago Jung Bauermann
2017-07-16 3:56 ` [RFC v6 14/62] powerpc: helper function to read,write AMR,IAMR,UAMOR registers Ram Pai
2017-07-16 3:56 ` [RFC v6 15/62] powerpc: helper functions to initialize AMR, IAMR and UMOR registers Ram Pai
2017-07-27 20:40 ` Thiago Jung Bauermann
2017-07-30 0:38 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 16/62] powerpc: cleaup AMR,iAMR when a key is allocated or freed Ram Pai
2017-07-16 3:56 ` [RFC v6 17/62] powerpc: implementation for arch_set_user_pkey_access() Ram Pai
2017-07-27 14:15 ` Thiago Jung Bauermann
2017-07-29 22:59 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 18/62] powerpc: sys_pkey_alloc() and sys_pkey_free() system calls Ram Pai
2017-07-16 3:56 ` [RFC v6 19/62] powerpc: ability to create execute-disabled pkeys Ram Pai
2017-07-27 14:54 ` Thiago Jung Bauermann
2017-07-27 15:34 ` Thiago Jung Bauermann
2017-07-29 23:24 ` Ram Pai [this message]
2017-07-31 12:59 ` Michael Ellerman
2017-07-16 3:56 ` [RFC v6 20/62] powerpc: store and restore the pkey state across context switches Ram Pai
2017-07-27 17:32 ` Thiago Jung Bauermann
2017-07-29 23:31 ` Ram Pai
2017-07-31 13:00 ` Michael Ellerman
2017-07-16 3:56 ` [RFC v6 21/62] powerpc: introduce execute-only pkey Ram Pai
2017-07-28 22:17 ` Thiago Jung Bauermann
2017-07-30 0:51 ` Ram Pai
2017-07-31 16:19 ` Thiago Jung Bauermann
2017-08-01 6:46 ` Michael Ellerman
2017-08-01 16:14 ` Thiago Jung Bauermann
2017-08-02 9:40 ` Michael Ellerman
[not found] ` <20170817233555.GC5427@ram.oc3035372033.ibm.com>
2017-08-17 23:42 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 22/62] powerpc: ability to associate pkey to a vma Ram Pai
2017-07-16 3:56 ` [RFC v6 23/62] powerpc: implementation for arch_override_mprotect_pkey() Ram Pai
2017-07-16 3:56 ` [RFC v6 24/62] powerpc: map vma key-protection bits to pte key bits Ram Pai
2017-07-16 3:56 ` [RFC v6 25/62] powerpc: sys_pkey_mprotect() system call Ram Pai
2017-07-16 3:56 ` [RFC v6 26/62] powerpc: Program HPTE key protection bits Ram Pai
2017-07-20 6:28 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 27/62] powerpc: helper to validate key-access permissions of a pte Ram Pai
2017-07-20 6:42 ` Aneesh Kumar K.V
2017-07-20 22:15 ` Ram Pai
2017-07-21 6:51 ` Aneesh Kumar K.V
2017-07-21 16:42 ` Ram Pai
2017-07-28 21:00 ` Thiago Jung Bauermann
2017-07-30 0:39 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 28/62] powerpc: check key protection for user page access Ram Pai
2017-07-16 3:56 ` [RFC v6 29/62] powerpc: Macro the mask used for checking DSI exception Ram Pai
2017-07-16 3:56 ` [RFC v6 30/62] powerpc: implementation for arch_vma_access_permitted() Ram Pai
2017-07-16 3:56 ` [RFC v6 31/62] powerpc: Handle exceptions caused by pkey violation Ram Pai
2017-07-16 3:56 ` [RFC v6 32/62] powerpc: capture AMR register content on " Ram Pai
2017-07-16 3:56 ` [RFC v6 33/62] powerpc: introduce get_pte_pkey() helper Ram Pai
2017-07-16 3:56 ` [RFC v6 34/62] powerpc: capture the violated protection key on fault Ram Pai
2017-07-16 3:56 ` [RFC v6 35/62] powerpc: Deliver SEGV signal on pkey violation Ram Pai
2017-08-19 19:09 ` Eric W. Biederman
2017-08-22 18:06 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 36/62] mm: introduce arch_pkeys_enabled() Ram Pai
2017-07-16 3:56 ` [RFC v6 37/62] x86: implementation for arch_pkeys_enabled() Ram Pai
2017-07-16 3:56 ` [RFC v6 38/62] powerpc: " Ram Pai
2017-07-16 3:56 ` [RFC v6 39/62] mm: display pkey in smaps if arch_pkeys_enabled() is true Ram Pai
2017-07-16 3:56 ` [RFC v6 40/62] x86: delete arch_show_smap() Ram Pai
2017-07-16 3:56 ` [RFC v6 41/62] selftest/x86: Move protecton key selftest to arch neutral directory Ram Pai
2017-07-16 3:56 ` [RFC v6 42/62] selftest/vm: rename all references to pkru to a generic name Ram Pai
2017-07-16 3:56 ` [RFC v6 43/62] selftest/vm: move generic definitions to header file Ram Pai
2017-07-16 3:56 ` [RFC v6 44/62] selftest/vm: typecast the pkey register Ram Pai
2017-07-16 3:56 ` [RFC v6 45/62] selftest/vm: generics function to handle shadow key register Ram Pai
2017-07-16 3:56 ` [RFC v6 46/62] selftest/vm: fix the wrong assert in pkey_disable_set() Ram Pai
2017-07-16 3:56 ` [RFC v6 47/62] selftest/vm: fixed bugs in pkey_disable_clear() Ram Pai
2017-07-16 3:56 ` [RFC v6 48/62] selftest/vm: clear the bits in shadow reg when a pkey is freed Ram Pai
2017-07-16 3:56 ` [RFC v6 49/62] selftest/vm: fix alloc_random_pkey() to make it really random Ram Pai
2017-07-16 3:56 ` [RFC v6 50/62] selftest/vm: introduce two arch independent abstraction Ram Pai
2017-07-16 3:56 ` [RFC v6 51/62] selftest/vm: pkey register should match shadow pkey Ram Pai
2017-07-16 3:56 ` [RFC v6 52/62] selftest/vm: generic cleanup Ram Pai
2017-07-16 3:56 ` [RFC v6 53/62] selftest/vm: powerpc implementation for generic abstraction Ram Pai
2017-07-16 3:56 ` [RFC v6 54/62] selftest/vm: fix an assertion in test_pkey_alloc_exhaust() Ram Pai
2017-07-16 3:56 ` [RFC v6 55/62] selftest/vm: associate key on a mapped page and detect access violation Ram Pai
2017-07-16 3:56 ` [RFC v6 56/62] selftest/vm: detect no key violation on a freed key Ram Pai
2017-07-16 3:56 ` [RFC v6 57/62] selftest/vm: associate key on a mapped page and detect write violation Ram Pai
2017-07-16 3:57 ` [RFC v6 58/62] selftest/vm: detect no write key-violation on a freed key Ram Pai
2017-07-16 3:57 ` [RFC v6 59/62] selftest/vm: detect write violation on a mapped access-denied-key page Ram Pai
2017-07-16 3:57 ` [RFC v6 60/62] selftest/vm: sub-page allocator Ram Pai
2017-07-16 3:57 ` [RFC v6 61/62] Documentation/x86: Move protecton key documentation to arch neutral directory Ram Pai
2017-07-16 3:57 ` [RFC v6 62/62] Documentation/vm: PowerPC specific updates to memory protection keys Ram Pai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170729232446.GG5664@ram.oc3035372033.ibm.com \
--to=linuxram@us.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=arnd@arndb.de \
--cc=bauerman@linux.vnet.ibm.com \
--cc=corbet@lwn.net \
--cc=dave.hansen@intel.com \
--cc=khandual@linux.vnet.ibm.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mhocko@kernel.org \
--cc=mingo@redhat.com \
--cc=paulus@samba.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).