| From foo@baz Sun Jun 17 12:07:34 CEST 2018 |
| From: Dave Hansen <dave.hansen@linux.intel.com> |
| Date: Wed, 9 May 2018 10:13:48 -0700 |
| Subject: x86/pkeys/selftests: Add PROT_EXEC test |
| |
| From: Dave Hansen <dave.hansen@linux.intel.com> |
| |
| [ Upstream commit 6af17cf89e99b64cf1f660bf848755442ab2f047 ] |
| |
| Under the covers, implement executable-only memory with |
| protection keys when userspace calls mprotect(PROT_EXEC). |
| |
| But, we did not have a selftest for that. Now we do. |
| |
| 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/20180509171348.9EEE4BEF@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 | 44 ++++++++++++++++++++++++++ |
| 1 file changed, 44 insertions(+) |
| |
| --- a/tools/testing/selftests/x86/protection_keys.c |
| +++ b/tools/testing/selftests/x86/protection_keys.c |
| @@ -1303,6 +1303,49 @@ void test_executing_on_unreadable_memory |
| expected_pk_fault(pkey); |
| } |
| |
| +void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey) |
| +{ |
| + void *p1; |
| + int scratch; |
| + int ptr_contents; |
| + int ret; |
| + |
| + dprintf1("%s() start\n", __func__); |
| + |
| + p1 = get_pointer_to_instructions(); |
| + lots_o_noops_around_write(&scratch); |
| + ptr_contents = read_ptr(p1); |
| + dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents); |
| + |
| + /* Use a *normal* mprotect(), not mprotect_pkey(): */ |
| + ret = mprotect(p1, PAGE_SIZE, PROT_EXEC); |
| + pkey_assert(!ret); |
| + |
| + dprintf2("pkru: %x\n", rdpkru()); |
| + |
| + /* Make sure this is an *instruction* fault */ |
| + madvise(p1, PAGE_SIZE, MADV_DONTNEED); |
| + lots_o_noops_around_write(&scratch); |
| + do_not_expect_pk_fault("executing on PROT_EXEC memory"); |
| + ptr_contents = read_ptr(p1); |
| + dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents); |
| + expected_pk_fault(UNKNOWN_PKEY); |
| + |
| + /* |
| + * Put the memory back to non-PROT_EXEC. Should clear the |
| + * exec-only pkey off the VMA and allow it to be readable |
| + * again. Go to PROT_NONE first to check for a kernel bug |
| + * that did not clear the pkey when doing PROT_NONE. |
| + */ |
| + ret = mprotect(p1, PAGE_SIZE, PROT_NONE); |
| + pkey_assert(!ret); |
| + |
| + ret = mprotect(p1, PAGE_SIZE, PROT_READ|PROT_EXEC); |
| + pkey_assert(!ret); |
| + ptr_contents = read_ptr(p1); |
| + do_not_expect_pk_fault("plain read on recently PROT_EXEC area"); |
| +} |
| + |
| void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey) |
| { |
| int size = PAGE_SIZE; |
| @@ -1327,6 +1370,7 @@ void (*pkey_tests[])(int *ptr, u16 pkey) |
| test_kernel_gup_of_access_disabled_region, |
| test_kernel_gup_write_to_write_disabled_region, |
| test_executing_on_unreadable_memory, |
| + test_implicit_mprotect_exec_only_memory, |
| test_ptrace_of_child, |
| test_pkey_syscalls_on_non_allocated_pkey, |
| test_pkey_syscalls_bad_args, |