From aef759db63fd4cfad5b585db96cf05f34d04cbd9 Mon Sep 17 00:00:00 2001 From: Ram Pai Date: Thu, 4 Jun 2020 16:52:29 -0700 Subject: [PATCH] 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. Signed-off-by: Ram Pai Signed-off: Sandipan Das Signed-off-by: Andrew Morton Acked-by: Dave Hansen Cc: Dave Hansen Cc: Florian Weimer Cc: "Desnes A. Nunes do Rosario" Cc: Ingo Molnar Cc: Thiago Jung Bauermann Cc: "Aneesh Kumar K.V" Cc: Michael Ellerman Cc: Michal Hocko Cc: Michal Suchanek Cc: Shuah Khan Link: http://lkml.kernel.org/r/4a19cf9252c03dd883887e9002881599e6900d06.1585646528.git.sandipan@linux.ibm.com Signed-off-by: Linus Torvalds --- tools/testing/selftests/vm/protection_keys.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c index 95f1730..f65d384 100644 --- a/tools/testing/selftests/vm/protection_keys.c +++ b/tools/testing/selftests/vm/protection_keys.c @@ -984,6 +984,24 @@ void test_read_of_access_disabled_region(int *ptr, u16 pkey) 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_cpu(int *ptr, u16 pkey) 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, -- 2.7.4