[RFC v6 56/62] selftest/vm: detect no key violation on a freed key
From: Ram Pai <hidden>
Date: 2017-07-16 04:00:29
Also in:
linux-mm, linuxppc-dev, lkml
Subsystem:
kernel selftest framework, the rest · Maintainers:
Shuah Khan, Linus Torvalds
a access-denied key should not trigger any key violation after the key has been freed. Signed-off-by: Ram Pai <redacted> --- tools/testing/selftests/vm/protection_keys.c | 25 +++++++++++++++++++++++++ 1 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index bf27bcd..47c23cc 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c@@ -1026,6 +1026,30 @@ void test_read_of_access_disabled_region_with_page_already_mapped(int *ptr, expected_pkey_fault(pkey); } +void test_read_of_access_disabled_but_freed_key_region(int *ptr, u16 pkey) +{ + int ptr_contents; + + dprintf1("disabling access to PKEY[%02d], doing read @ %p\n", + pkey, ptr); + + /* read the content */ + ptr_contents = read_ptr(ptr); + do_not_expect_pkey_fault(); + + /* deny key access */ + pkey_access_deny(pkey); + ptr_contents = read_ptr(ptr); + dprintf1("*ptr: %d\n", ptr_contents); + expected_pkey_fault(pkey); + + /* free the key without restoring access */ + pkey_access_deny(pkey); + sys_pkey_free(pkey); + ptr_contents = read_ptr(ptr); + do_not_expect_pkey_fault(); +} + void test_write_of_write_disabled_region(int *ptr, u16 pkey) { dprintf1("disabling write access to PKEY[%02d], doing write\n", pkey);
@@ -1333,6 +1357,7 @@ void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey) test_pkey_syscalls_on_non_allocated_pkey, test_pkey_syscalls_bad_args, test_pkey_alloc_exhaust, + test_read_of_access_disabled_but_freed_key_region, }; void run_tests_once(void)
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1.7.1