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@xxxxxxxxx>
cc: Florian Weimer <fweimer@xxxxxxxxxx>
Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
---
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 caf634e..b5a9e6c 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -1011,6 +1011,7 @@ 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)
{
@@ -1090,6 +1091,7 @@ 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)
{
@@ -1102,6 +1104,7 @@ 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)
@@ -1121,6 +1124,7 @@ 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]);
@@ -1141,6 +1145,7 @@ 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 */
--
1.7.1
