From: Ram Pai <linuxram@xxxxxxxxxx> Subject: selftests/vm/pkeys: associate key on a mapped page and detect access violation Detect access-violation on a page to which access-disabled key is associated much after the page is mapped. Link: http://lkml.kernel.org/r/4a19cf9252c03dd883887e9002881599e6900d06.1585646528.git.sandipan@xxxxxxxxxxxxx Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxx> Signed-off: Sandipan Das <sandipan@xxxxxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Florian Weimer <fweimer@xxxxxxxxxx> Cc: "Desnes A. Nunes do Rosario" <desnesn@xxxxxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Michal Suchanek <msuchanek@xxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/vm/protection_keys.c | 19 +++++++++++++++++ 1 file changed, 19 insertions(+) --- a/tools/testing/selftests/vm/protection_keys.c~selftests-vm-pkeys-associate-key-on-a-mapped-page-and-detect-access-violation +++ a/tools/testing/selftests/vm/protection_keys.c @@ -984,6 +984,24 @@ void test_read_of_access_disabled_region dprintf1("*ptr: %d\n", ptr_contents); expected_pkey_fault(pkey); } + +void test_read_of_access_disabled_region_with_page_already_mapped(int *ptr, + u16 pkey) +{ + int ptr_contents; + + dprintf1("disabling access to PKEY[%02d], doing read @ %p\n", + pkey, ptr); + ptr_contents = read_ptr(ptr); + dprintf1("reading ptr before disabling the read : %d\n", + ptr_contents); + read_pkey_reg(); + pkey_access_deny(pkey); + ptr_contents = read_ptr(ptr); + dprintf1("*ptr: %d\n", ptr_contents); + expected_pkey_fault(pkey); +} + void test_write_of_write_disabled_region(int *ptr, u16 pkey) { dprintf1("disabling write access to PKEY[%02d], doing write\n", pkey); @@ -1390,6 +1408,7 @@ void test_mprotect_pkey_on_unsupported_c void (*pkey_tests[])(int *ptr, u16 pkey) = { test_read_of_write_disabled_region, test_read_of_access_disabled_region, + test_read_of_access_disabled_region_with_page_already_mapped, test_write_of_write_disabled_region, test_write_of_access_disabled_region, test_kernel_write_of_access_disabled_region, _
