lkml.org 
[lkml]   [2018]   [Feb]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v12 20/22] selftests/vm: testcases must restore pkey-permissions
Date
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 */
--
1.7.1
\
 
 \ /
  Last update: 2018-02-22 02:58    [W:0.170 / U:0.540 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site