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- // SPDX-License-Identifier: GPL-2.0
- /*
- * KUnit test of proc sysctl.
- */
- #include <kunit/test.h>
- #include <linux/sysctl.h>
- #define KUNIT_PROC_READ 0
- #define KUNIT_PROC_WRITE 1
- /*
- * Test that proc_dointvec will not try to use a NULL .data field even when the
- * length is non-zero.
- */
- static void sysctl_test_api_dointvec_null_tbl_data(struct kunit *test)
- {
- struct ctl_table null_data_table = {
- .procname = "foo",
- /*
- * Here we are testing that proc_dointvec behaves correctly when
- * we give it a NULL .data field. Normally this would point to a
- * piece of memory where the value would be stored.
- */
- .data = NULL,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- /*
- * proc_dointvec expects a buffer in user space, so we allocate one. We
- * also need to cast it to __user so sparse doesn't get mad.
- */
- void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int),
- GFP_USER);
- size_t len;
- loff_t pos;
- /*
- * We don't care what the starting length is since proc_dointvec should
- * not try to read because .data is NULL.
- */
- len = 1234;
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&null_data_table,
- KUNIT_PROC_READ, buffer, &len,
- &pos));
- KUNIT_EXPECT_EQ(test, 0, len);
- /*
- * See above.
- */
- len = 1234;
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&null_data_table,
- KUNIT_PROC_WRITE, buffer, &len,
- &pos));
- KUNIT_EXPECT_EQ(test, 0, len);
- }
- /*
- * Similar to the previous test, we create a struct ctrl_table that has a .data
- * field that proc_dointvec cannot do anything with; however, this time it is
- * because we tell proc_dointvec that the size is 0.
- */
- static void sysctl_test_api_dointvec_table_maxlen_unset(struct kunit *test)
- {
- int data = 0;
- struct ctl_table data_maxlen_unset_table = {
- .procname = "foo",
- .data = &data,
- /*
- * So .data is no longer NULL, but we tell proc_dointvec its
- * length is 0, so it still shouldn't try to use it.
- */
- .maxlen = 0,
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int),
- GFP_USER);
- size_t len;
- loff_t pos;
- /*
- * As before, we don't care what buffer length is because proc_dointvec
- * cannot do anything because its internal .data buffer has zero length.
- */
- len = 1234;
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&data_maxlen_unset_table,
- KUNIT_PROC_READ, buffer, &len,
- &pos));
- KUNIT_EXPECT_EQ(test, 0, len);
- /*
- * See previous comment.
- */
- len = 1234;
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&data_maxlen_unset_table,
- KUNIT_PROC_WRITE, buffer, &len,
- &pos));
- KUNIT_EXPECT_EQ(test, 0, len);
- }
- /*
- * Here we provide a valid struct ctl_table, but we try to read and write from
- * it using a buffer of zero length, so it should still fail in a similar way as
- * before.
- */
- static void sysctl_test_api_dointvec_table_len_is_zero(struct kunit *test)
- {
- int data = 0;
- /* Good table. */
- struct ctl_table table = {
- .procname = "foo",
- .data = &data,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int),
- GFP_USER);
- /*
- * However, now our read/write buffer has zero length.
- */
- size_t len = 0;
- loff_t pos;
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buffer,
- &len, &pos));
- KUNIT_EXPECT_EQ(test, 0, len);
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, buffer,
- &len, &pos));
- KUNIT_EXPECT_EQ(test, 0, len);
- }
- /*
- * Test that proc_dointvec refuses to read when the file position is non-zero.
- */
- static void sysctl_test_api_dointvec_table_read_but_position_set(
- struct kunit *test)
- {
- int data = 0;
- /* Good table. */
- struct ctl_table table = {
- .procname = "foo",
- .data = &data,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int),
- GFP_USER);
- /*
- * We don't care about our buffer length because we start off with a
- * non-zero file position.
- */
- size_t len = 1234;
- /*
- * proc_dointvec should refuse to read into the buffer since the file
- * pos is non-zero.
- */
- loff_t pos = 1;
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buffer,
- &len, &pos));
- KUNIT_EXPECT_EQ(test, 0, len);
- }
- /*
- * Test that we can read a two digit number in a sufficiently size buffer.
- * Nothing fancy.
- */
- static void sysctl_test_dointvec_read_happy_single_positive(struct kunit *test)
- {
- int data = 0;
- /* Good table. */
- struct ctl_table table = {
- .procname = "foo",
- .data = &data,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- size_t len = 4;
- loff_t pos = 0;
- char *buffer = kunit_kzalloc(test, len, GFP_USER);
- char __user *user_buffer = (char __user *)buffer;
- /* Store 13 in the data field. */
- *((int *)table.data) = 13;
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ,
- user_buffer, &len, &pos));
- KUNIT_ASSERT_EQ(test, 3, len);
- buffer[len] = '\0';
- /* And we read 13 back out. */
- KUNIT_EXPECT_STREQ(test, "13\n", buffer);
- }
- /*
- * Same as previous test, just now with negative numbers.
- */
- static void sysctl_test_dointvec_read_happy_single_negative(struct kunit *test)
- {
- int data = 0;
- /* Good table. */
- struct ctl_table table = {
- .procname = "foo",
- .data = &data,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- size_t len = 5;
- loff_t pos = 0;
- char *buffer = kunit_kzalloc(test, len, GFP_USER);
- char __user *user_buffer = (char __user *)buffer;
- *((int *)table.data) = -16;
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ,
- user_buffer, &len, &pos));
- KUNIT_ASSERT_EQ(test, 4, len);
- buffer[len] = '\0';
- KUNIT_EXPECT_STREQ(test, "-16\n", buffer);
- }
- /*
- * Test that a simple positive write works.
- */
- static void sysctl_test_dointvec_write_happy_single_positive(struct kunit *test)
- {
- int data = 0;
- /* Good table. */
- struct ctl_table table = {
- .procname = "foo",
- .data = &data,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- char input[] = "9";
- size_t len = sizeof(input) - 1;
- loff_t pos = 0;
- char *buffer = kunit_kzalloc(test, len, GFP_USER);
- char __user *user_buffer = (char __user *)buffer;
- memcpy(buffer, input, len);
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE,
- user_buffer, &len, &pos));
- KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
- KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
- KUNIT_EXPECT_EQ(test, 9, *((int *)table.data));
- }
- /*
- * Same as previous test, but now with negative numbers.
- */
- static void sysctl_test_dointvec_write_happy_single_negative(struct kunit *test)
- {
- int data = 0;
- struct ctl_table table = {
- .procname = "foo",
- .data = &data,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- char input[] = "-9";
- size_t len = sizeof(input) - 1;
- loff_t pos = 0;
- char *buffer = kunit_kzalloc(test, len, GFP_USER);
- char __user *user_buffer = (char __user *)buffer;
- memcpy(buffer, input, len);
- KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE,
- user_buffer, &len, &pos));
- KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
- KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
- KUNIT_EXPECT_EQ(test, -9, *((int *)table.data));
- }
- /*
- * Test that writing a value smaller than the minimum possible value is not
- * allowed.
- */
- static void sysctl_test_api_dointvec_write_single_less_int_min(
- struct kunit *test)
- {
- int data = 0;
- struct ctl_table table = {
- .procname = "foo",
- .data = &data,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- size_t max_len = 32, len = max_len;
- loff_t pos = 0;
- char *buffer = kunit_kzalloc(test, max_len, GFP_USER);
- char __user *user_buffer = (char __user *)buffer;
- unsigned long abs_of_less_than_min = (unsigned long)INT_MAX
- - (INT_MAX + INT_MIN) + 1;
- /*
- * We use this rigmarole to create a string that contains a value one
- * less than the minimum accepted value.
- */
- KUNIT_ASSERT_LT(test,
- (size_t)snprintf(buffer, max_len, "-%lu",
- abs_of_less_than_min),
- max_len);
- KUNIT_EXPECT_EQ(test, -EINVAL, proc_dointvec(&table, KUNIT_PROC_WRITE,
- user_buffer, &len, &pos));
- KUNIT_EXPECT_EQ(test, max_len, len);
- KUNIT_EXPECT_EQ(test, 0, *((int *)table.data));
- }
- /*
- * Test that writing the maximum possible value works.
- */
- static void sysctl_test_api_dointvec_write_single_greater_int_max(
- struct kunit *test)
- {
- int data = 0;
- struct ctl_table table = {
- .procname = "foo",
- .data = &data,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE_HUNDRED,
- };
- size_t max_len = 32, len = max_len;
- loff_t pos = 0;
- char *buffer = kunit_kzalloc(test, max_len, GFP_USER);
- char __user *user_buffer = (char __user *)buffer;
- unsigned long greater_than_max = (unsigned long)INT_MAX + 1;
- KUNIT_ASSERT_GT(test, greater_than_max, (unsigned long)INT_MAX);
- KUNIT_ASSERT_LT(test, (size_t)snprintf(buffer, max_len, "%lu",
- greater_than_max),
- max_len);
- KUNIT_EXPECT_EQ(test, -EINVAL, proc_dointvec(&table, KUNIT_PROC_WRITE,
- user_buffer, &len, &pos));
- KUNIT_ASSERT_EQ(test, max_len, len);
- KUNIT_EXPECT_EQ(test, 0, *((int *)table.data));
- }
- static struct kunit_case sysctl_test_cases[] = {
- KUNIT_CASE(sysctl_test_api_dointvec_null_tbl_data),
- KUNIT_CASE(sysctl_test_api_dointvec_table_maxlen_unset),
- KUNIT_CASE(sysctl_test_api_dointvec_table_len_is_zero),
- KUNIT_CASE(sysctl_test_api_dointvec_table_read_but_position_set),
- KUNIT_CASE(sysctl_test_dointvec_read_happy_single_positive),
- KUNIT_CASE(sysctl_test_dointvec_read_happy_single_negative),
- KUNIT_CASE(sysctl_test_dointvec_write_happy_single_positive),
- KUNIT_CASE(sysctl_test_dointvec_write_happy_single_negative),
- KUNIT_CASE(sysctl_test_api_dointvec_write_single_less_int_min),
- KUNIT_CASE(sysctl_test_api_dointvec_write_single_greater_int_max),
- {}
- };
- static struct kunit_suite sysctl_test_suite = {
- .name = "sysctl_test",
- .test_cases = sysctl_test_cases,
- };
- kunit_test_suites(&sysctl_test_suite);
- MODULE_LICENSE("GPL v2");
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