Generally the signal handler restores the state of the pkey register before returning. However there are times when the read/write operation can legitamely fail without invoking the signal handler. Eg: A sys_read() operaton to a write-protected page should be disallowed. In such a case the state of the pkey register is not restored to its original state. The test case is responsible for restoring the key register state to its original value.
cc: Dave Hansen dave.hansen@intel.com cc: Florian Weimer fweimer@redhat.com Signed-off-by: Ram Pai linuxram@us.ibm.com --- tools/testing/selftests/vm/protection_keys.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c index 437ee74..42c068a 100644 --- a/tools/testing/selftests/vm/protection_keys.c +++ b/tools/testing/selftests/vm/protection_keys.c @@ -1003,6 +1003,7 @@ void test_read_of_write_disabled_region(int *ptr, u16 pkey) ptr_contents = read_ptr(ptr); dprintf1("*ptr: %d\n", ptr_contents); dprintf1("\n"); + pkey_write_allow(pkey); } void test_read_of_access_disabled_region(int *ptr, u16 pkey) { @@ -1082,6 +1083,7 @@ void test_kernel_write_of_access_disabled_region(int *ptr, u16 pkey) ret = read(test_fd, ptr, 1); dprintf1("read ret: %d\n", ret); pkey_assert(ret); + pkey_access_allow(pkey); } void test_kernel_write_of_write_disabled_region(int *ptr, u16 pkey) { @@ -1094,6 +1096,7 @@ void test_kernel_write_of_write_disabled_region(int *ptr, u16 pkey) if (ret < 0 && (DEBUG_LEVEL > 0)) perror("verbose read result (OK for this to be bad)"); pkey_assert(ret); + pkey_write_allow(pkey); }
void test_kernel_gup_of_access_disabled_region(int *ptr, u16 pkey) @@ -1113,6 +1116,7 @@ void test_kernel_gup_of_access_disabled_region(int *ptr, u16 pkey) vmsplice_ret = vmsplice(pipe_fds[1], &iov, 1, SPLICE_F_GIFT); dprintf1("vmsplice() ret: %d\n", vmsplice_ret); pkey_assert(vmsplice_ret == -1); + pkey_access_allow(pkey);
close(pipe_fds[0]); close(pipe_fds[1]); @@ -1133,6 +1137,7 @@ void test_kernel_gup_write_to_write_disabled_region(int *ptr, u16 pkey) if (DEBUG_LEVEL > 0) perror("futex"); dprintf1("futex() ret: %d\n", futex_ret); + pkey_write_allow(pkey); }
/* Assumes that all pkeys other than 'pkey' are unallocated */