[PATCH 08/12] rodata_test: refactor tests

2018-12-21 Thread Igor Stoppa
Refactor the test cases, in preparation for using them also for testing
__wr_after_init memory, when available.

Signed-off-by: Igor Stoppa 

CC: Andy Lutomirski 
CC: Nadav Amit 
CC: Matthew Wilcox 
CC: Peter Zijlstra 
CC: Kees Cook 
CC: Dave Hansen 
CC: Mimi Zohar 
CC: Thiago Jung Bauermann 
CC: Ahmed Soliman 
CC: linux-integr...@vger.kernel.org
CC: kernel-harden...@lists.openwall.com
CC: linux...@kvack.org
CC: linux-kernel@vger.kernel.org
---
 mm/rodata_test.c | 48 
 1 file changed, 28 insertions(+), 20 deletions(-)

diff --git a/mm/rodata_test.c b/mm/rodata_test.c
index d908c8769b48..e1349520b436 100644
--- a/mm/rodata_test.c
+++ b/mm/rodata_test.c
@@ -14,44 +14,52 @@
 #include 
 #include 
 
-static const int rodata_test_data = 0xC3;
+#define INIT_TEST_VAL 0xC3
 
-void rodata_test(void)
+static const int rodata_test_data = INIT_TEST_VAL;
+
+static bool test_data(char *data_type, const int *data,
+ unsigned long start, unsigned long end)
 {
-   unsigned long start, end;
int zero = 0;
 
/* test 1: read the value */
/* If this test fails, some previous testrun has clobbered the state */
-   if (!rodata_test_data) {
-   pr_err("test 1 fails (start data)\n");
-   return;
+   if (*data != INIT_TEST_VAL) {
+   pr_err("%s: test 1 fails (init data value)\n", data_type);
+   return false;
}
 
/* test 2: write to the variable; this should fault */
-   if (!probe_kernel_write((void *)_test_data,
-   (void *), sizeof(zero))) {
-   pr_err("test data was not read only\n");
-   return;
+   if (!probe_kernel_write((void *)data, (void *), sizeof(zero))) {
+   pr_err("%s: test data was not read only\n", data_type);
+   return false;
}
 
/* test 3: check the value hasn't changed */
-   if (rodata_test_data == zero) {
-   pr_err("test data was changed\n");
-   return;
+   if (*data != INIT_TEST_VAL) {
+   pr_err("%s: test data was changed\n", data_type);
+   return false;
}
 
/* test 4: check if the rodata section is PAGE_SIZE aligned */
-   start = (unsigned long)__start_rodata;
-   end = (unsigned long)__end_rodata;
if (start & (PAGE_SIZE - 1)) {
-   pr_err("start of .rodata is not page size aligned\n");
-   return;
+   pr_err("%s: start of data is not page size aligned\n",
+  data_type);
+   return false;
}
if (end & (PAGE_SIZE - 1)) {
-   pr_err("end of .rodata is not page size aligned\n");
-   return;
+   pr_err("%s: end of data is not page size aligned\n",
+  data_type);
+   return false;
}
+   pr_info("%s tests were successful", data_type);
+   return true;
+}
 
-   pr_info("all tests were successful\n");
+void rodata_test(void)
+{
+   test_data("rodata", _test_data,
+ (unsigned long)&__start_rodata,
+ (unsigned long)&__end_rodata);
 }
-- 
2.19.1



[PATCH 08/12] rodata_test: refactor tests

2018-12-19 Thread Igor Stoppa
Refactor the test cases, in preparation for using them also for testing
__wr_after_init memory, when available.

Signed-off-by: Igor Stoppa 

CC: Andy Lutomirski 
CC: Nadav Amit 
CC: Matthew Wilcox 
CC: Peter Zijlstra 
CC: Kees Cook 
CC: Dave Hansen 
CC: Mimi Zohar 
CC: linux-integr...@vger.kernel.org
CC: kernel-harden...@lists.openwall.com
CC: linux...@kvack.org
CC: linux-kernel@vger.kernel.org
---
 mm/rodata_test.c | 48 
 1 file changed, 28 insertions(+), 20 deletions(-)

diff --git a/mm/rodata_test.c b/mm/rodata_test.c
index d908c8769b48..e1349520b436 100644
--- a/mm/rodata_test.c
+++ b/mm/rodata_test.c
@@ -14,44 +14,52 @@
 #include 
 #include 
 
-static const int rodata_test_data = 0xC3;
+#define INIT_TEST_VAL 0xC3
 
-void rodata_test(void)
+static const int rodata_test_data = INIT_TEST_VAL;
+
+static bool test_data(char *data_type, const int *data,
+ unsigned long start, unsigned long end)
 {
-   unsigned long start, end;
int zero = 0;
 
/* test 1: read the value */
/* If this test fails, some previous testrun has clobbered the state */
-   if (!rodata_test_data) {
-   pr_err("test 1 fails (start data)\n");
-   return;
+   if (*data != INIT_TEST_VAL) {
+   pr_err("%s: test 1 fails (init data value)\n", data_type);
+   return false;
}
 
/* test 2: write to the variable; this should fault */
-   if (!probe_kernel_write((void *)_test_data,
-   (void *), sizeof(zero))) {
-   pr_err("test data was not read only\n");
-   return;
+   if (!probe_kernel_write((void *)data, (void *), sizeof(zero))) {
+   pr_err("%s: test data was not read only\n", data_type);
+   return false;
}
 
/* test 3: check the value hasn't changed */
-   if (rodata_test_data == zero) {
-   pr_err("test data was changed\n");
-   return;
+   if (*data != INIT_TEST_VAL) {
+   pr_err("%s: test data was changed\n", data_type);
+   return false;
}
 
/* test 4: check if the rodata section is PAGE_SIZE aligned */
-   start = (unsigned long)__start_rodata;
-   end = (unsigned long)__end_rodata;
if (start & (PAGE_SIZE - 1)) {
-   pr_err("start of .rodata is not page size aligned\n");
-   return;
+   pr_err("%s: start of data is not page size aligned\n",
+  data_type);
+   return false;
}
if (end & (PAGE_SIZE - 1)) {
-   pr_err("end of .rodata is not page size aligned\n");
-   return;
+   pr_err("%s: end of data is not page size aligned\n",
+  data_type);
+   return false;
}
+   pr_info("%s tests were successful", data_type);
+   return true;
+}
 
-   pr_info("all tests were successful\n");
+void rodata_test(void)
+{
+   test_data("rodata", _test_data,
+ (unsigned long)&__start_rodata,
+ (unsigned long)&__end_rodata);
 }
-- 
2.19.1