| From foo@baz Sun Jun 17 12:07:34 CEST 2018 |
| From: Dave Hansen <dave.hansen@linux.intel.com> |
| Date: Wed, 9 May 2018 10:13:50 -0700 |
| Subject: x86/pkeys/selftests: Fix pkey exhaustion test off-by-one |
| |
| From: Dave Hansen <dave.hansen@linux.intel.com> |
| |
| [ Upstream commit f50b4878329ab61d8e05796f655adeb6f5fb57c6 ] |
| |
| In our "exhaust all pkeys" test, we make sure that there |
| is the expected number available. Turns out that the |
| test did not cover the execute-only key, but discussed |
| it anyway. It did *not* discuss the test-allocated |
| key. |
| |
| Now that we have a test for the mprotect(PROT_EXEC) case, |
| this off-by-one issue showed itself. Correct the off-by- |
| one and add the explanation for the case we missed. |
| |
| Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> |
| Cc: Andrew Morton <akpm@linux-foundation.org> |
| Cc: Dave Hansen <dave.hansen@intel.com> |
| Cc: Linus Torvalds <torvalds@linux-foundation.org> |
| Cc: Michael Ellermen <mpe@ellerman.id.au> |
| Cc: Peter Zijlstra <peterz@infradead.org> |
| Cc: Ram Pai <linuxram@us.ibm.com> |
| Cc: Shuah Khan <shuah@kernel.org> |
| Cc: Thomas Gleixner <tglx@linutronix.de> |
| Cc: linux-mm@kvack.org |
| Link: http://lkml.kernel.org/r/20180509171350.E1656B95@viggo.jf.intel.com |
| Signed-off-by: Ingo Molnar <mingo@kernel.org> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| tools/testing/selftests/x86/protection_keys.c | 13 ++++++++----- |
| 1 file changed, 8 insertions(+), 5 deletions(-) |
| |
| --- a/tools/testing/selftests/x86/protection_keys.c |
| +++ b/tools/testing/selftests/x86/protection_keys.c |
| @@ -1163,12 +1163,15 @@ void test_pkey_alloc_exhaust(int *ptr, u |
| pkey_assert(i < NR_PKEYS*2); |
| |
| /* |
| - * There are 16 pkeys supported in hardware. One is taken |
| - * up for the default (0) and another can be taken up by |
| - * an execute-only mapping. Ensure that we can allocate |
| - * at least 14 (16-2). |
| + * 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). |
| */ |
| - pkey_assert(i >= NR_PKEYS-2); |
| + pkey_assert(i >= NR_PKEYS-3); |
| |
| for (i = 0; i < nr_allocated_pkeys; i++) { |
| err = sys_pkey_free(allocated_pkeys[i]); |