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linux/lib/test-string_helpers.c
Jason A. Donenfeld 81895a65ec treewide: use prandom_u32_max() when possible, part 1 
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:

@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)

@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@

-       RAND = get_random_u32();
        ... when != RAND
-       RAND %= (E);
+       RAND = prandom_u32_max(E);

// 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))

// Add one to the literal.
@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 == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
        print("Skipping 0x%x for cleanup elsewhere" % (value))
        cocci.include_match(False)
elif value & (value + 1) != 0:
        print("Skipping 0x%x because it's not a power of two minus one" % (value))
        cocci.include_match(False)
elif literal.startswith('0x'):
        coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
        coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))

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

-       (FUNC()@p & (LITERAL))
+       prandom_u32_max(RESULT)

@collapse_ret@
type T;
identifier VAR;
expression E;
@@

 {
-       T VAR;
-       VAR = (E);
-       return VAR;
+       return E;
 }

@drop_var@
type T;
identifier VAR;
@@

 {
-       T VAR;
        ... when != VAR
 }

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11 17:42:55 -06:00

610 lines
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/*
* Test cases for lib/string_helpers.c module.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/string.h>
#include <linux/string_helpers.h>
static __init bool test_string_check_buf(const char *name, unsigned int flags,
char *in, size_t p,
char *out_real, size_t q_real,
char *out_test, size_t q_test)
{
if (q_real == q_test && !memcmp(out_test, out_real, q_test))
return true;
pr_warn("Test '%s' failed: flags = %#x\n", name, flags);
print_hex_dump(KERN_WARNING, "Input: ", DUMP_PREFIX_NONE, 16, 1,
in, p, true);
print_hex_dump(KERN_WARNING, "Expected: ", DUMP_PREFIX_NONE, 16, 1,
out_test, q_test, true);
print_hex_dump(KERN_WARNING, "Got: ", DUMP_PREFIX_NONE, 16, 1,
out_real, q_real, true);
return false;
}
struct test_string {
const char *in;
const char *out;
unsigned int flags;
};
static const struct test_string strings[] __initconst = {
{
.in = "\\f\\ \\n\\r\\t\\v",
.out = "\f\\ \n\r\t\v",
.flags = UNESCAPE_SPACE,
},
{
.in = "\\40\\1\\387\\0064\\05\\040\\8a\\110\\777",
.out = " \001\00387\0064\005 \\8aH?7",
.flags = UNESCAPE_OCTAL,
},
{
.in = "\\xv\\xa\\x2c\\xD\\x6f2",
.out = "\\xv\n,\ro2",
.flags = UNESCAPE_HEX,
},
{
.in = "\\h\\\\\\\"\\a\\e\\",
.out = "\\h\\\"\a\e\\",
.flags = UNESCAPE_SPECIAL,
},
};
static void __init test_string_unescape(const char *name, unsigned int flags,
bool inplace)
{
int q_real = 256;
char *in = kmalloc(q_real, GFP_KERNEL);
char *out_test = kmalloc(q_real, GFP_KERNEL);
char *out_real = kmalloc(q_real, GFP_KERNEL);
int i, p = 0, q_test = 0;
if (!in || !out_test || !out_real)
goto out;
for (i = 0; i < ARRAY_SIZE(strings); i++) {
const char *s = strings[i].in;
int len = strlen(strings[i].in);
/* Copy string to in buffer */
memcpy(&in[p], s, len);
p += len;
/* Copy expected result for given flags */
if (flags & strings[i].flags) {
s = strings[i].out;
len = strlen(strings[i].out);
}
memcpy(&out_test[q_test], s, len);
q_test += len;
}
in[p++] = '\0';
/* Call string_unescape and compare result */
if (inplace) {
memcpy(out_real, in, p);
if (flags == UNESCAPE_ANY)
q_real = string_unescape_any_inplace(out_real);
else
q_real = string_unescape_inplace(out_real, flags);
} else if (flags == UNESCAPE_ANY) {
q_real = string_unescape_any(in, out_real, q_real);
} else {
q_real = string_unescape(in, out_real, q_real, flags);
}
test_string_check_buf(name, flags, in, p - 1, out_real, q_real,
out_test, q_test);
out:
kfree(out_real);
kfree(out_test);
kfree(in);
}
struct test_string_1 {
const char *out;
unsigned int flags;
};
#define TEST_STRING_2_MAX_S1 32
struct test_string_2 {
const char *in;
struct test_string_1 s1[TEST_STRING_2_MAX_S1];
};
#define TEST_STRING_2_DICT_0 NULL
static const struct test_string_2 escape0[] __initconst = {{
.in = "\f\\ \n\r\t\v",
.s1 = {{
.out = "\\f\\ \\n\\r\\t\\v",
.flags = ESCAPE_SPACE,
},{
.out = "\\f\\134\\040\\n\\r\\t\\v",
.flags = ESCAPE_SPACE | ESCAPE_OCTAL,
},{
.out = "\\f\\x5c\\x20\\n\\r\\t\\v",
.flags = ESCAPE_SPACE | ESCAPE_HEX,
},{
/* terminator */
}}
},{
.in = "\\h\\\"\a\e\\",
.s1 = {{
.out = "\\\\h\\\\\\\"\\a\\e\\\\",
.flags = ESCAPE_SPECIAL,
},{
.out = "\\\\\\150\\\\\\\"\\a\\e\\\\",
.flags = ESCAPE_SPECIAL | ESCAPE_OCTAL,
},{
.out = "\\\\\\x68\\\\\\\"\\a\\e\\\\",
.flags = ESCAPE_SPECIAL | ESCAPE_HEX,
},{
/* terminator */
}}
},{
.in = "\eb \\C\007\"\x90\r]",
.s1 = {{
.out = "\eb \\C\007\"\x90\\r]",
.flags = ESCAPE_SPACE,
},{
.out = "\\eb \\\\C\\a\\\"\x90\r]",
.flags = ESCAPE_SPECIAL,
},{
.out = "\\eb \\\\C\\a\\\"\x90\\r]",
.flags = ESCAPE_SPACE | ESCAPE_SPECIAL,
},{
.out = "\\033\\142\\040\\134\\103\\007\\042\\220\\015\\135",
.flags = ESCAPE_OCTAL,
},{
.out = "\\033\\142\\040\\134\\103\\007\\042\\220\\r\\135",
.flags = ESCAPE_SPACE | ESCAPE_OCTAL,
},{
.out = "\\e\\142\\040\\\\\\103\\a\\\"\\220\\015\\135",
.flags = ESCAPE_SPECIAL | ESCAPE_OCTAL,
},{
.out = "\\e\\142\\040\\\\\\103\\a\\\"\\220\\r\\135",
.flags = ESCAPE_SPACE | ESCAPE_SPECIAL | ESCAPE_OCTAL,
},{
.out = "\eb \\C\007\"\x90\r]",
.flags = ESCAPE_NP,
},{
.out = "\eb \\C\007\"\x90\\r]",
.flags = ESCAPE_SPACE | ESCAPE_NP,
},{
.out = "\\eb \\C\\a\"\x90\r]",
.flags = ESCAPE_SPECIAL | ESCAPE_NP,
},{
.out = "\\eb \\C\\a\"\x90\\r]",
.flags = ESCAPE_SPACE | ESCAPE_SPECIAL | ESCAPE_NP,
},{
.out = "\\033b \\C\\007\"\\220\\015]",
.flags = ESCAPE_OCTAL | ESCAPE_NP,
},{
.out = "\\033b \\C\\007\"\\220\\r]",
.flags = ESCAPE_SPACE | ESCAPE_OCTAL | ESCAPE_NP,
},{
.out = "\\eb \\C\\a\"\\220\\r]",
.flags = ESCAPE_SPECIAL | ESCAPE_SPACE | ESCAPE_OCTAL |
ESCAPE_NP,
},{
.out = "\\x1bb \\C\\x07\"\\x90\\x0d]",
.flags = ESCAPE_NP | ESCAPE_HEX,
},{
/* terminator */
}}
},{
.in = "\007 \eb\"\x90\xCF\r",
.s1 = {{
.out = "\007 \eb\"\\220\\317\r",
.flags = ESCAPE_OCTAL | ESCAPE_NA,
},{
.out = "\007 \eb\"\\x90\\xcf\r",
.flags = ESCAPE_HEX | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\xCF\r",
.flags = ESCAPE_NA,
},{
/* terminator */
}}
},{
/* terminator */
}};
#define TEST_STRING_2_DICT_1 "b\\ \t\r\xCF"
static const struct test_string_2 escape1[] __initconst = {{
.in = "\f\\ \n\r\t\v",
.s1 = {{
.out = "\f\\134\\040\n\\015\\011\v",
.flags = ESCAPE_OCTAL,
},{
.out = "\f\\x5c\\x20\n\\x0d\\x09\v",
.flags = ESCAPE_HEX,
},{
.out = "\f\\134\\040\n\\015\\011\v",
.flags = ESCAPE_ANY | ESCAPE_APPEND,
},{
.out = "\\014\\134\\040\\012\\015\\011\\013",
.flags = ESCAPE_OCTAL | ESCAPE_APPEND | ESCAPE_NAP,
},{
.out = "\\x0c\\x5c\\x20\\x0a\\x0d\\x09\\x0b",
.flags = ESCAPE_HEX | ESCAPE_APPEND | ESCAPE_NAP,
},{
.out = "\f\\134\\040\n\\015\\011\v",
.flags = ESCAPE_OCTAL | ESCAPE_APPEND | ESCAPE_NA,
},{
.out = "\f\\x5c\\x20\n\\x0d\\x09\v",
.flags = ESCAPE_HEX | ESCAPE_APPEND | ESCAPE_NA,
},{
/* terminator */
}}
},{
.in = "\\h\\\"\a\xCF\e\\",
.s1 = {{
.out = "\\134h\\134\"\a\\317\e\\134",
.flags = ESCAPE_OCTAL,
},{
.out = "\\134h\\134\"\a\\317\e\\134",
.flags = ESCAPE_ANY | ESCAPE_APPEND,
},{
.out = "\\134h\\134\"\\007\\317\\033\\134",
.flags = ESCAPE_OCTAL | ESCAPE_APPEND | ESCAPE_NAP,
},{
.out = "\\134h\\134\"\a\\317\e\\134",
.flags = ESCAPE_OCTAL | ESCAPE_APPEND | ESCAPE_NA,
},{
/* terminator */
}}
},{
.in = "\eb \\C\007\"\x90\r]",
.s1 = {{
.out = "\e\\142\\040\\134C\007\"\x90\\015]",
.flags = ESCAPE_OCTAL,
},{
/* terminator */
}}
},{
.in = "\007 \eb\"\x90\xCF\r",
.s1 = {{
.out = "\007 \eb\"\x90\xCF\r",
.flags = ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\xCF\r",
.flags = ESCAPE_SPACE | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\xCF\r",
.flags = ESCAPE_SPECIAL | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\xCF\r",
.flags = ESCAPE_SPACE | ESCAPE_SPECIAL | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\\317\r",
.flags = ESCAPE_OCTAL | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\\317\r",
.flags = ESCAPE_SPACE | ESCAPE_OCTAL | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\\317\r",
.flags = ESCAPE_SPECIAL | ESCAPE_OCTAL | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\\317\r",
.flags = ESCAPE_ANY | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\\xcf\r",
.flags = ESCAPE_HEX | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\\xcf\r",
.flags = ESCAPE_SPACE | ESCAPE_HEX | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\\xcf\r",
.flags = ESCAPE_SPECIAL | ESCAPE_HEX | ESCAPE_NA,
},{
.out = "\007 \eb\"\x90\\xcf\r",
.flags = ESCAPE_SPACE | ESCAPE_SPECIAL | ESCAPE_HEX | ESCAPE_NA,
},{
/* terminator */
}}
},{
.in = "\007 \eb\"\x90\xCF\r",
.s1 = {{
.out = "\007 \eb\"\x90\xCF\r",
.flags = ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\xCF\\r",
.flags = ESCAPE_SPACE | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\xCF\r",
.flags = ESCAPE_SPECIAL | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\xCF\\r",
.flags = ESCAPE_SPACE | ESCAPE_SPECIAL | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\\317\\015",
.flags = ESCAPE_OCTAL | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\\317\\r",
.flags = ESCAPE_SPACE | ESCAPE_OCTAL | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\\317\\015",
.flags = ESCAPE_SPECIAL | ESCAPE_OCTAL | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\\317\r",
.flags = ESCAPE_ANY | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\\xcf\\x0d",
.flags = ESCAPE_HEX | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\\xcf\\r",
.flags = ESCAPE_SPACE | ESCAPE_HEX | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\\xcf\\x0d",
.flags = ESCAPE_SPECIAL | ESCAPE_HEX | ESCAPE_NAP,
},{
.out = "\007 \eb\"\x90\\xcf\\r",
.flags = ESCAPE_SPACE | ESCAPE_SPECIAL | ESCAPE_HEX | ESCAPE_NAP,
},{
/* terminator */
}}
},{
/* terminator */
}};
static const struct test_string strings_upper[] __initconst = {
{
.in = "abcdefgh1234567890test",
.out = "ABCDEFGH1234567890TEST",
},
{
.in = "abCdeFgH1234567890TesT",
.out = "ABCDEFGH1234567890TEST",
},
};
static const struct test_string strings_lower[] __initconst = {
{
.in = "ABCDEFGH1234567890TEST",
.out = "abcdefgh1234567890test",
},
{
.in = "abCdeFgH1234567890TesT",
.out = "abcdefgh1234567890test",
},
};
static __init const char *test_string_find_match(const struct test_string_2 *s2,
unsigned int flags)
{
const struct test_string_1 *s1 = s2->s1;
unsigned int i;
if (!flags)
return s2->in;
/* Test cases are NULL-aware */
flags &= ~ESCAPE_NULL;
/* ESCAPE_OCTAL has a higher priority */
if (flags & ESCAPE_OCTAL)
flags &= ~ESCAPE_HEX;
for (i = 0; i < TEST_STRING_2_MAX_S1 && s1->out; i++, s1++)
if (s1->flags == flags)
return s1->out;
return NULL;
}
static __init void
test_string_escape_overflow(const char *in, int p, unsigned int flags, const char *esc,
int q_test, const char *name)
{
int q_real;
q_real = string_escape_mem(in, p, NULL, 0, flags, esc);
if (q_real != q_test)
pr_warn("Test '%s' failed: flags = %#x, osz = 0, expected %d, got %d\n",
name, flags, q_test, q_real);
}
static __init void test_string_escape(const char *name,
const struct test_string_2 *s2,
unsigned int flags, const char *esc)
{
size_t out_size = 512;
char *out_test = kmalloc(out_size, GFP_KERNEL);
char *out_real = kmalloc(out_size, GFP_KERNEL);
char *in = kmalloc(256, GFP_KERNEL);
int p = 0, q_test = 0;
int q_real;
if (!out_test || !out_real || !in)
goto out;
for (; s2->in; s2++) {
const char *out;
int len;
/* NULL injection */
if (flags & ESCAPE_NULL) {
in[p++] = '\0';
/* '\0' passes isascii() test */
if (flags & ESCAPE_NA && !(flags & ESCAPE_APPEND && esc)) {
out_test[q_test++] = '\0';
} else {
out_test[q_test++] = '\\';
out_test[q_test++] = '0';
}
}
/* Don't try strings that have no output */
out = test_string_find_match(s2, flags);
if (!out)
continue;
/* Copy string to in buffer */
len = strlen(s2->in);
memcpy(&in[p], s2->in, len);
p += len;
/* Copy expected result for given flags */
len = strlen(out);
memcpy(&out_test[q_test], out, len);
q_test += len;
}
q_real = string_escape_mem(in, p, out_real, out_size, flags, esc);
test_string_check_buf(name, flags, in, p, out_real, q_real, out_test,
q_test);
test_string_escape_overflow(in, p, flags, esc, q_test, name);
out:
kfree(in);
kfree(out_real);
kfree(out_test);
}
#define string_get_size_maxbuf 16
#define test_string_get_size_one(size, blk_size, exp_result10, exp_result2) \
do { \
BUILD_BUG_ON(sizeof(exp_result10) >= string_get_size_maxbuf); \
BUILD_BUG_ON(sizeof(exp_result2) >= string_get_size_maxbuf); \
__test_string_get_size((size), (blk_size), (exp_result10), \
(exp_result2)); \
} while (0)
static __init void test_string_get_size_check(const char *units,
const char *exp,
char *res,
const u64 size,
const u64 blk_size)
{
if (!memcmp(res, exp, strlen(exp) + 1))
return;
res[string_get_size_maxbuf - 1] = '\0';
pr_warn("Test 'test_string_get_size' failed!\n");
pr_warn("string_get_size(size = %llu, blk_size = %llu, units = %s)\n",
size, blk_size, units);
pr_warn("expected: '%s', got '%s'\n", exp, res);
}
static __init void __test_string_get_size(const u64 size, const u64 blk_size,
const char *exp_result10,
const char *exp_result2)
{
char buf10[string_get_size_maxbuf];
char buf2[string_get_size_maxbuf];
string_get_size(size, blk_size, STRING_UNITS_10, buf10, sizeof(buf10));
string_get_size(size, blk_size, STRING_UNITS_2, buf2, sizeof(buf2));
test_string_get_size_check("STRING_UNITS_10", exp_result10, buf10,
size, blk_size);
test_string_get_size_check("STRING_UNITS_2", exp_result2, buf2,
size, blk_size);
}
static __init void test_string_get_size(void)
{
/* small values */
test_string_get_size_one(0, 512, "0 B", "0 B");
test_string_get_size_one(1, 512, "512 B", "512 B");
test_string_get_size_one(1100, 1, "1.10 kB", "1.07 KiB");
/* normal values */
test_string_get_size_one(16384, 512, "8.39 MB", "8.00 MiB");
test_string_get_size_one(500118192, 512, "256 GB", "238 GiB");
test_string_get_size_one(8192, 4096, "33.6 MB", "32.0 MiB");
/* weird block sizes */
test_string_get_size_one(3000, 1900, "5.70 MB", "5.44 MiB");
/* huge values */
test_string_get_size_one(U64_MAX, 4096, "75.6 ZB", "64.0 ZiB");
test_string_get_size_one(4096, U64_MAX, "75.6 ZB", "64.0 ZiB");
}
static void __init test_string_upper_lower(void)
{
char *dst;
int i;
for (i = 0; i < ARRAY_SIZE(strings_upper); i++) {
const char *s = strings_upper[i].in;
int len = strlen(strings_upper[i].in) + 1;
dst = kmalloc(len, GFP_KERNEL);
if (!dst)
return;
string_upper(dst, s);
if (memcmp(dst, strings_upper[i].out, len)) {
pr_warn("Test 'string_upper' failed : expected %s, got %s!\n",
strings_upper[i].out, dst);
kfree(dst);
return;
}
kfree(dst);
}
for (i = 0; i < ARRAY_SIZE(strings_lower); i++) {
const char *s = strings_lower[i].in;
int len = strlen(strings_lower[i].in) + 1;
dst = kmalloc(len, GFP_KERNEL);
if (!dst)
return;
string_lower(dst, s);
if (memcmp(dst, strings_lower[i].out, len)) {
pr_warn("Test 'string_lower failed : : expected %s, got %s!\n",
strings_lower[i].out, dst);
kfree(dst);
return;
}
kfree(dst);
}
}
static int __init test_string_helpers_init(void)
{
unsigned int i;
pr_info("Running tests...\n");
for (i = 0; i < UNESCAPE_ALL_MASK + 1; i++)
test_string_unescape("unescape", i, false);
test_string_unescape("unescape inplace",
prandom_u32_max(UNESCAPE_ANY + 1), true);
/* Without dictionary */
for (i = 0; i < ESCAPE_ALL_MASK + 1; i++)
test_string_escape("escape 0", escape0, i, TEST_STRING_2_DICT_0);
/* With dictionary */
for (i = 0; i < ESCAPE_ALL_MASK + 1; i++)
test_string_escape("escape 1", escape1, i, TEST_STRING_2_DICT_1);
/* Test string_get_size() */
test_string_get_size();
/* Test string upper(), string_lower() */
test_string_upper_lower();
return -EINVAL;
}
module_init(test_string_helpers_init);
MODULE_LICENSE("Dual BSD/GPL");
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