linux/lib/cmdline_kunit.c
Jason A. Donenfeld 7e3cf0843f treewide: use get_random_{u8,u16}() when possible, part 1
Rather than truncate a 32-bit value to a 16-bit value or an 8-bit value,
simply use the get_random_{u8,u16}() functions, which are faster than
wasting the additional bytes from a 32-bit value. This was done
mechanically with this coccinelle script:

@@
expression E;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u16;
typedef __be16;
typedef __le16;
typedef u8;
@@
(
- (get_random_u32() & 0xffff)
+ get_random_u16()
|
- (get_random_u32() & 0xff)
+ get_random_u8()
|
- (get_random_u32() % 65536)
+ get_random_u16()
|
- (get_random_u32() % 256)
+ get_random_u8()
|
- (get_random_u32() >> 16)
+ get_random_u16()
|
- (get_random_u32() >> 24)
+ get_random_u8()
|
- (u16)get_random_u32()
+ get_random_u16()
|
- (u8)get_random_u32()
+ get_random_u8()
|
- (__be16)get_random_u32()
+ (__be16)get_random_u16()
|
- (__le16)get_random_u32()
+ (__le16)get_random_u16()
|
- prandom_u32_max(65536)
+ get_random_u16()
|
- prandom_u32_max(256)
+ get_random_u8()
|
- E->inet_id = get_random_u32()
+ E->inet_id = get_random_u16()
)

@@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u16;
identifier v;
@@
- u16 v = get_random_u32();
+ u16 v = get_random_u16();

@@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u8;
identifier v;
@@
- u8 v = get_random_u32();
+ u8 v = get_random_u8();

@@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u16;
u16 v;
@@
-  v = get_random_u32();
+  v = get_random_u16();

@@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u8;
u8 v;
@@
-  v = get_random_u32();
+  v = get_random_u8();

// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@

        ((T)get_random_u32()@p & (LITERAL))

// Examine limits
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@

value = None
if literal.startswith('0x'):
        value = int(literal, 16)
elif literal[0] in '123456789':
        value = int(literal, 10)
if value is None:
        print("I don't know how to handle %s" % (literal))
        cocci.include_match(False)
elif value < 256:
        coccinelle.RESULT = cocci.make_ident("get_random_u8")
elif value < 65536:
        coccinelle.RESULT = cocci.make_ident("get_random_u16")
else:
        print("Skipping large mask of %s" % (literal))
        cocci.include_match(False)

// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
identifier add_one.RESULT;
identifier FUNC;
@@

-       (FUNC()@p & (LITERAL))
+       (RESULT() & LITERAL)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11 17:42:58 -06:00

157 lines
4.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Test cases for API provided by cmdline.c
*/
#include <kunit/test.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include <linux/string.h>
static const char *cmdline_test_strings[] = {
"\"\"", "" , "=" , "\"-", "," , "-," , ",-" , "-" ,
"+," , "--", ",,", "''" , "\"\",", "\",\"", "-\"\"", "\"",
};
static const int cmdline_test_values[] = {
1, 1, 1, 1, 2, 3, 2, 3,
1, 3, 2, 1, 1, 1, 3, 1,
};
static_assert(ARRAY_SIZE(cmdline_test_strings) == ARRAY_SIZE(cmdline_test_values));
static const char *cmdline_test_range_strings[] = {
"-7" , "--7" , "-1-2" , "7--9",
"7-" , "-7--9", "7-9," , "9-7" ,
"5-a", "a-5" , "5-8" , ",8-5",
"+,1", "-,4" , "-3,0-1,6", "4,-" ,
" +2", " -9" , "0-1,-3,6", "- 9" ,
};
static const int cmdline_test_range_values[][16] = {
{ 1, -7, }, { 0, -0, }, { 4, -1, 0, +1, 2, }, { 0, 7, },
{ 0, +7, }, { 0, -7, }, { 3, +7, 8, +9, 0, }, { 0, 9, },
{ 0, +5, }, { 0, -0, }, { 4, +5, 6, +7, 8, }, { 0, 0, },
{ 0, +0, }, { 0, -0, }, { 4, -3, 0, +1, 6, }, { 1, 4, },
{ 0, +0, }, { 0, -0, }, { 4, +0, 1, -3, 6, }, { 0, 0, },
};
static_assert(ARRAY_SIZE(cmdline_test_range_strings) == ARRAY_SIZE(cmdline_test_range_values));
static void cmdline_do_one_test(struct kunit *test, const char *in, int rc, int offset)
{
const char *fmt = "Pattern: %s";
const char *out = in;
int dummy;
int ret;
ret = get_option((char **)&out, &dummy);
KUNIT_EXPECT_EQ_MSG(test, ret, rc, fmt, in);
KUNIT_EXPECT_PTR_EQ_MSG(test, out, in + offset, fmt, in);
}
static void cmdline_test_noint(struct kunit *test)
{
unsigned int i = 0;
do {
const char *str = cmdline_test_strings[i];
int rc = 0;
int offset;
/* Only first and leading '-' will advance the pointer */
offset = !!(*str == '-');
cmdline_do_one_test(test, str, rc, offset);
} while (++i < ARRAY_SIZE(cmdline_test_strings));
}
static void cmdline_test_lead_int(struct kunit *test)
{
unsigned int i = 0;
char in[32];
do {
const char *str = cmdline_test_strings[i];
int rc = cmdline_test_values[i];
int offset;
sprintf(in, "%u%s", get_random_u8(), str);
/* Only first '-' after the number will advance the pointer */
offset = strlen(in) - strlen(str) + !!(rc == 2);
cmdline_do_one_test(test, in, rc, offset);
} while (++i < ARRAY_SIZE(cmdline_test_strings));
}
static void cmdline_test_tail_int(struct kunit *test)
{
unsigned int i = 0;
char in[32];
do {
const char *str = cmdline_test_strings[i];
/* When "" or "-" the result will be valid integer */
int rc = strcmp(str, "") ? (strcmp(str, "-") ? 0 : 1) : 1;
int offset;
sprintf(in, "%s%u", str, get_random_u8());
/*
* Only first and leading '-' not followed by integer
* will advance the pointer.
*/
offset = rc ? strlen(in) : !!(*str == '-');
cmdline_do_one_test(test, in, rc, offset);
} while (++i < ARRAY_SIZE(cmdline_test_strings));
}
static void cmdline_do_one_range_test(struct kunit *test, const char *in,
unsigned int n, const int *e)
{
unsigned int i;
int r[16];
int *p;
memset(r, 0, sizeof(r));
get_options(in, ARRAY_SIZE(r), r);
KUNIT_EXPECT_EQ_MSG(test, r[0], e[0], "in test %u (parsed) expected %d numbers, got %d",
n, e[0], r[0]);
for (i = 1; i < ARRAY_SIZE(r); i++)
KUNIT_EXPECT_EQ_MSG(test, r[i], e[i], "in test %u at %u", n, i);
memset(r, 0, sizeof(r));
get_options(in, 0, r);
KUNIT_EXPECT_EQ_MSG(test, r[0], e[0], "in test %u (validated) expected %d numbers, got %d",
n, e[0], r[0]);
p = memchr_inv(&r[1], 0, sizeof(r) - sizeof(r[0]));
KUNIT_EXPECT_PTR_EQ_MSG(test, p, NULL, "in test %u at %u out of bound", n, p - r);
}
static void cmdline_test_range(struct kunit *test)
{
unsigned int i = 0;
do {
const char *str = cmdline_test_range_strings[i];
const int *e = cmdline_test_range_values[i];
cmdline_do_one_range_test(test, str, i, e);
} while (++i < ARRAY_SIZE(cmdline_test_range_strings));
}
static struct kunit_case cmdline_test_cases[] = {
KUNIT_CASE(cmdline_test_noint),
KUNIT_CASE(cmdline_test_lead_int),
KUNIT_CASE(cmdline_test_tail_int),
KUNIT_CASE(cmdline_test_range),
{}
};
static struct kunit_suite cmdline_test_suite = {
.name = "cmdline",
.test_cases = cmdline_test_cases,
};
kunit_test_suite(cmdline_test_suite);
MODULE_LICENSE("GPL");