| From foo@baz Sun Jun 17 12:07:34 CEST 2018 |
| From: Dave Hansen <dave.hansen@linux.intel.com> |
| Date: Wed, 9 May 2018 10:13:56 -0700 |
| Subject: x86/pkeys/selftests: Add a test for pkey 0 |
| |
| From: Dave Hansen <dave.hansen@linux.intel.com> |
| |
| [ Upstream commit 3488a600d90bcaf061b104dbcfbdc8d99b398312 ] |
| |
| Protection key 0 is the default key for all memory and will |
| not normally come back from pkey_alloc(). But, you might |
| still want pass it to mprotect_pkey(). |
| |
| This check ensures that you can use pkey 0. |
| |
| 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/20180509171356.9E40B254@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 | 30 ++++++++++++++++++++++++++ |
| 1 file changed, 30 insertions(+) |
| |
| --- a/tools/testing/selftests/x86/protection_keys.c |
| +++ b/tools/testing/selftests/x86/protection_keys.c |
| @@ -1184,6 +1184,35 @@ void test_pkey_alloc_exhaust(int *ptr, u |
| } |
| } |
| |
| +/* |
| + * pkey 0 is special. It is allocated by default, so you do not |
| + * have to call pkey_alloc() to use it first. Make sure that it |
| + * is usable. |
| + */ |
| +void test_mprotect_with_pkey_0(int *ptr, u16 pkey) |
| +{ |
| + long size; |
| + int prot; |
| + |
| + assert(pkey_last_malloc_record); |
| + size = pkey_last_malloc_record->size; |
| + /* |
| + * This is a bit of a hack. But mprotect() requires |
| + * huge-page-aligned sizes when operating on hugetlbfs. |
| + * So, make sure that we use something that's a multiple |
| + * of a huge page when we can. |
| + */ |
| + if (size >= HPAGE_SIZE) |
| + size = HPAGE_SIZE; |
| + prot = pkey_last_malloc_record->prot; |
| + |
| + /* Use pkey 0 */ |
| + mprotect_pkey(ptr, size, prot, 0); |
| + |
| + /* Make sure that we can set it back to the original pkey. */ |
| + mprotect_pkey(ptr, size, prot, pkey); |
| +} |
| + |
| void test_ptrace_of_child(int *ptr, u16 pkey) |
| { |
| __attribute__((__unused__)) int peek_result; |
| @@ -1378,6 +1407,7 @@ void (*pkey_tests[])(int *ptr, u16 pkey) |
| test_kernel_gup_write_to_write_disabled_region, |
| test_executing_on_unreadable_memory, |
| test_implicit_mprotect_exec_only_memory, |
| + test_mprotect_with_pkey_0, |
| test_ptrace_of_child, |
| test_pkey_syscalls_on_non_allocated_pkey, |
| test_pkey_syscalls_bad_args, |