From: Ram Pai <linuxram@us.ibm.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: shuahkh@osg.samsung.com, linux-kselftest@vger.kernel.org,
mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org,
linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org,
mingo@redhat.com, mhocko@kernel.org, bauerman@linux.vnet.ibm.com,
fweimer@redhat.com, msuchanek@suse.de,
aneesh.kumar@linux.vnet.ibm.com
Subject: Re: [PATCH v13 18/24] selftests/vm: fix an assertion in test_pkey_alloc_exhaust()
Date: Tue, 17 Jul 2018 09:08:28 -0700 [thread overview]
Message-ID: <20180717160828.GF5790@ram.oc3035372033.ibm.com> (raw)
In-Reply-To: <55227442-a573-62b1-3206-1f3065a4b55f@intel.com>
On Wed, Jun 20, 2018 at 08:11:07AM -0700, Dave Hansen wrote:
> On 06/13/2018 05:45 PM, Ram Pai wrote:
> > /*
> > - * There are 16 pkeys supported in hardware. Three are
> > - * allocated by the time we get here:
> > - * 1. The default key (0)
> > - * 2. One possibly consumed by an execute-only mapping.
> > - * 3. One allocated by the test code and passed in via
> > - * 'pkey' to this function.
> > - * Ensure that we can allocate at least another 13 (16-3).
> > + * There are NR_PKEYS pkeys supported in hardware. arch_reserved_keys()
> > + * are reserved. One of which is the default key(0). One can be taken
> > + * up by an execute-only mapping.
> > + * Ensure that we can allocate at least the remaining.
> > */
> > - pkey_assert(i >= NR_PKEYS-3);
> > + pkey_assert(i >= (NR_PKEYS-arch_reserved_keys()-1));
>
> We recently had a bug here. I fixed it and left myself a really nice
> comment so I and others wouldn't screw it up in the future.
>
> Does this kill my nice, new comment?
part of your nice comment has been moved into the header file. The arch
specific header file explains where and how the reserved keys are used.
--
Ram Pai
next prev parent reply other threads:[~2018-07-17 16:08 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-14 0:44 [PATCH v13 00/24] selftests, powerpc, x86 : Memory Protection Keys Ram Pai
2018-06-14 0:44 ` [PATCH v13 01/24] selftests/x86: Move protecton key selftest to arch neutral directory Ram Pai
2018-06-14 0:44 ` [PATCH v13 02/24] selftests/vm: rename all references to pkru to a generic name Ram Pai
2018-06-14 0:44 ` [PATCH v13 03/24] selftests/vm: move generic definitions to header file Ram Pai
2018-06-14 0:44 ` [PATCH v13 04/24] selftests/vm: move arch-specific definitions to arch-specific header Ram Pai
2018-06-14 0:44 ` [PATCH v13 05/24] selftests/vm: Make gcc check arguments of sigsafe_printf() Ram Pai
2018-06-14 0:44 ` [PATCH v13 06/24] selftests/vm: typecast the pkey register Ram Pai
2018-06-14 0:44 ` [PATCH v13 07/24] selftests/vm: generic function to handle shadow key register Ram Pai
2018-06-14 0:44 ` [PATCH v13 08/24] selftests/vm: fix the wrong assert in pkey_disable_set() Ram Pai
2018-06-20 14:47 ` Dave Hansen
2018-07-17 15:58 ` Ram Pai
2018-07-17 17:53 ` Dave Hansen
2018-06-14 0:45 ` [PATCH v13 09/24] selftests/vm: fixed bugs in pkey_disable_clear() Ram Pai
2018-06-14 0:45 ` [PATCH v13 10/24] selftests/vm: clear the bits in shadow reg when a pkey is freed Ram Pai
2018-06-20 14:49 ` Dave Hansen
2018-07-17 16:00 ` Ram Pai
2018-06-14 0:45 ` [PATCH v13 11/24] selftests/vm: fix alloc_random_pkey() to make it really random Ram Pai
2018-06-14 0:45 ` [PATCH v13 12/24] selftests/vm: introduce two arch independent abstraction Ram Pai
2018-06-14 0:45 ` [PATCH v13 13/24] selftests/vm: pkey register should match shadow pkey Ram Pai
2018-06-20 14:53 ` Dave Hansen
2018-07-17 16:02 ` Ram Pai
2018-06-14 0:45 ` [PATCH v13 14/24] selftests/vm: generic cleanup Ram Pai
2018-06-20 14:57 ` Dave Hansen
2018-06-14 0:45 ` [PATCH v13 15/24] selftests/vm: powerpc implementation for generic abstraction Ram Pai
2018-06-20 15:06 ` Dave Hansen
2018-06-14 0:45 ` [PATCH v13 16/24] selftests/vm: clear the bits in shadow reg when a pkey is freed Ram Pai
2018-06-20 15:07 ` Dave Hansen
2018-07-17 16:03 ` Ram Pai
2018-06-14 0:45 ` [PATCH v13 17/24] selftests/vm: powerpc implementation to check support for pkey Ram Pai
2018-06-20 15:09 ` Dave Hansen
2018-07-17 16:05 ` Ram Pai
2018-06-14 0:45 ` [PATCH v13 18/24] selftests/vm: fix an assertion in test_pkey_alloc_exhaust() Ram Pai
2018-06-20 15:11 ` Dave Hansen
2018-07-17 16:08 ` Ram Pai [this message]
2018-06-14 0:45 ` [PATCH v13 19/24] selftests/vm: associate key on a mapped page and detect access violation Ram Pai
2018-06-20 15:16 ` Dave Hansen
2018-07-17 16:13 ` Ram Pai
2018-07-17 17:56 ` Dave Hansen
2018-07-17 19:10 ` Ram Pai
2018-06-14 0:45 ` [PATCH v13 20/24] selftests/vm: associate key on a mapped page and detect write violation Ram Pai
2018-06-14 0:45 ` [PATCH v13 21/24] selftests/vm: detect write violation on a mapped access-denied-key page Ram Pai
2018-06-14 0:45 ` [PATCH v13 22/24] selftests/vm: testcases must restore pkey-permissions Ram Pai
2018-06-20 15:20 ` Dave Hansen
2018-07-17 16:09 ` Ram Pai
2018-06-14 0:45 ` [PATCH v13 23/24] selftests/vm: sub-page allocator Ram Pai
2018-06-14 0:45 ` [PATCH v13 24/24] selftests/vm: test correct behavior of pkey-0 Ram Pai
2018-06-20 15:22 ` Dave Hansen
2018-06-14 20:19 ` [PATCH v13 00/24] selftests, powerpc, x86 : Memory Protection Keys Florian Weimer
2018-06-15 0:58 ` Ram Pai
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