// 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 static int i_zero; static int i_one_hundred = 100; /* * 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 = &i_zero, .extra2 = &i_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 = &i_zero, .extra2 = &i_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 = &i_zero, .extra2 = &i_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 = &i_zero, .extra2 = &i_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 = &i_zero, .extra2 = &i_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 = &i_zero, .extra2 = &i_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 = &i_zero, .extra2 = &i_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 = &i_zero, .extra2 = &i_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 = &i_zero, .extra2 = &i_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 = &i_zero, .extra2 = &i_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");