The existing code attempted to handle numbers by doing a strto[u]l(), ignoring the field width, and then repeatedly dividing to extract the field out of the full converted value. If the string contains a run of valid digits longer than will fit in a long or long long, this would overflow and no amount of dividing can recover the correct value.

This patch fixes vsscanf to obey number field widths when parsing the number.

A new _parse_integer_limit() is added that takes a limit for the number of characters to parse. The number field conversion in vsscanf is changed to use this new function.

If a number starts with a radix prefix, the field width must be long enough for at last one digit after the prefix. If not, it will be handled like this:

sscanf("0x4", "%1i", &i): i=0, scanning continues with the 'x' sscanf("0x4", "%2i", &i): i=0, scanning continues with the '4'

This is consistent with the observed behaviour of userland sscanf.

Note that this patch does NOT fix the problem of a single field value overflowing the target type. So for example:

sscanf("123456789abcdef", "%x", &i);

Will not produce the correct result because the value obviously overflows INT_MAX. But sscanf will report a successful conversion.

Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com --- lib/kstrtox.c | 13 ++++++-- lib/kstrtox.h | 2 ++ lib/vsprintf.c | 88 +++++++++++++++++++++++++++++--------------------- 3 files changed, 64 insertions(+), 39 deletions(-)

diff --git a/lib/kstrtox.c b/lib/kstrtox.c index a14ccf905055..0ac2ee8bd9d0 100644 --- a/lib/kstrtox.c +++ b/lib/kstrtox.c @@ -39,20 +39,22 @@ const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)

/* * Convert non-negative integer string representation in explicitly given radix - * to an integer. + * to an integer. A maximum of max_chars characters will be converted. + * * Return number of characters consumed maybe or-ed with overflow bit. * If overflow occurs, result integer (incorrect) is still returned. * * Don't you dare use this function. */ -unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p) +unsigned int _parse_integer_limit(const char *s, unsigned int base, + unsigned long long *p, size_t max_chars) { unsigned long long res; unsigned int rv;

res = 0; rv = 0; - while (1) { + for (; max_chars > 0; max_chars--) { unsigned int c = *s; unsigned int lc = c | 0x20; /* don't tolower() this line */ unsigned int val; @@ -82,6 +84,11 @@ unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long return rv; }

+unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p) +{ + return _parse_integer_limit(s, base, p, INT_MAX); +} + static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) { unsigned long long _res; diff --git a/lib/kstrtox.h b/lib/kstrtox.h index 3b4637bcd254..4c6536f85cac 100644 --- a/lib/kstrtox.h +++ b/lib/kstrtox.h @@ -4,6 +4,8 @@

#define KSTRTOX_OVERFLOW (1U << 31) const char *_parse_integer_fixup_radix(const char *s, unsigned int *base); +unsigned int _parse_integer_limit(const char *s, unsigned int base, + unsigned long long *res, size_t max_chars); unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *res);

#endif diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 8954ff94a53c..77a0b4d58174 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -53,29 +53,47 @@ #include <linux/string_helpers.h> #include "kstrtox.h"

-/** - * simple_strtoull - convert a string to an unsigned long long - * @cp: The start of the string - * @endp: A pointer to the end of the parsed string will be placed here - * @base: The number base to use - * - * This function has caveats. Please use kstrtoull instead. - */ -unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) +static unsigned long long simple_strntoull(const char *startp, size_t max_chars, + char **endp, unsigned int base) { - unsigned long long result; + const char *cp; + unsigned long long result = 0ULL; unsigned int rv;

- cp = _parse_integer_fixup_radix(cp, &base); - rv = _parse_integer(cp, base, &result); + if (max_chars == 0) { + cp = startp; + goto out; + } + + cp = _parse_integer_fixup_radix(startp, &base); + if ((cp - startp) >= max_chars) { + cp = startp + max_chars; + goto out; + } + + max_chars -= (cp - startp); + rv = _parse_integer_limit(cp, base, &result, max_chars); /* FIXME */ cp += (rv & ~KSTRTOX_OVERFLOW); - +out: if (endp) *endp = (char *)cp;

return result; } + +/** + * simple_strtoull - convert a string to an unsigned long long + * @cp: The start of the string + * @endp: A pointer to the end of the parsed string will be placed here + * @base: The number base to use + * + * This function has caveats. Please use kstrtoull instead. + */ +unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) +{ + return simple_strntoull(cp, UINT_MAX, endp, base); +} EXPORT_SYMBOL(simple_strtoull);

/** @@ -88,7 +106,7 @@ EXPORT_SYMBOL(simple_strtoull); */ unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) { - return simple_strtoull(cp, endp, base); + return simple_strntoull(cp, UINT_MAX, endp, base); } EXPORT_SYMBOL(simple_strtoul);

@@ -109,6 +127,19 @@ long simple_strtol(const char *cp, char **endp, unsigned int base) } EXPORT_SYMBOL(simple_strtol);

+static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, + unsigned int base) +{ + /* + * simple_strntoull safely handles receiving max_chars==0 in the + * case we start with max_chars==1 and find a '-' prefix. + */ + if (*cp == '-' && max_chars > 0) + return -simple_strntoull(cp + 1, max_chars - 1, endp, base); + + return simple_strntoull(cp, max_chars, endp, base); +} + /** * simple_strtoll - convert a string to a signed long long * @cp: The start of the string @@ -119,10 +150,7 @@ EXPORT_SYMBOL(simple_strtol); */ long long simple_strtoll(const char *cp, char **endp, unsigned int base) { - if (*cp == '-') - return -simple_strtoull(cp + 1, endp, base); - - return simple_strtoull(cp, endp, base); + return simple_strntoll(cp, UINT_MAX, endp, base); } EXPORT_SYMBOL(simple_strtoll);

@@ -3448,25 +3476,13 @@ int vsscanf(const char *buf, const char *fmt, va_list args) break;

if (is_sign) - val.s = qualifier != 'L' ? - simple_strtol(str, &next, base) : - simple_strtoll(str, &next, base); + val.s = simple_strntoll(str, + field_width > 0 ? field_width : UINT_MAX, + &next, base); else - val.u = qualifier != 'L' ? - simple_strtoul(str, &next, base) : - simple_strtoull(str, &next, base); - - if (field_width > 0 && next - str > field_width) { - if (base == 0) - _parse_integer_fixup_radix(str, &base); - while (next - str > field_width) { - if (is_sign) - val.s = div_s64(val.s, base); - else - val.u = div_u64(val.u, base); - --next; - } - } + val.u = simple_strntoull(str, + field_width > 0 ? field_width : UINT_MAX, + &next, base);

switch (qualifier) { case 'H': /* that's 'hh' in format */

Adds test_sscanf to test various number conversion cases, as number conversion was previously broken.

This also tests the simple_strtoxxx() functions exported from vsprintf.c.

Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com --- MAINTAINERS | 1 + lib/Kconfig.debug | 3 + lib/Makefile | 1 + lib/test_scanf.c | 747 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 752 insertions(+) create mode 100644 lib/test_scanf.c

diff --git a/MAINTAINERS b/MAINTAINERS index 7887d2161be4..d2bf38bd3d0c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18782,6 +18782,7 @@ S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk.git F: Documentation/core-api/printk-formats.rst F: lib/test_printf.c +F: lib/test_scanf.c F: lib/vsprintf.c

VT1211 HARDWARE MONITOR DRIVER diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c789b39ed527..b934dca35a0c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2054,6 +2054,9 @@ config TEST_KSTRTOX config TEST_PRINTF tristate "Test printf() family of functions at runtime"

+config TEST_SCANF + tristate "Test scanf() family of functions at runtime" + config TEST_BITMAP tristate "Test bitmap_*() family of functions at runtime" help diff --git a/lib/Makefile b/lib/Makefile index ce45af50983a..091463b8986a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -85,6 +85,7 @@ obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o obj-$(CONFIG_TEST_PRINTF) += test_printf.o +obj-$(CONFIG_TEST_SCANF) += test_scanf.o obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o obj-$(CONFIG_TEST_STRSCPY) += test_strscpy.o obj-$(CONFIG_TEST_UUID) += test_uuid.o diff --git a/lib/test_scanf.c b/lib/test_scanf.c new file mode 100644 index 000000000000..96d22d83a7dd --- /dev/null +++ b/lib/test_scanf.c @@ -0,0 +1,747 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Test cases for sscanf facility. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/bitops.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/overflow.h> +#include <linux/printk.h> +#include <linux/random.h> +#include <linux/slab.h> +#include <linux/string.h> + +#include "../tools/testing/selftests/kselftest_module.h" + +#define BUF_SIZE 1024 + +static unsigned total_tests __initdata; +static unsigned failed_tests __initdata; +static char *test_buffer __initdata; +static char *fmt_buffer __initdata; +static struct rnd_state rnd_state __initdata; + +typedef int (*check_fn)(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap); + +static void __scanf(4, 6) __init +_test(check_fn fn, const void *check_data, const char *string, const char *fmt, + int n_args, ...) +{ + va_list ap, ap_copy; + int ret; + + total_tests++; + + va_start(ap, n_args); + va_copy(ap_copy, ap); + ret = vsscanf(string, fmt, ap_copy); + va_end(ap_copy); + + if (ret != n_args) { + pr_warn("vsscanf("%s", "%s", ...) returned %d expected %d\n", + string, fmt, ret, n_args); + goto fail; + } + + ret = (*fn)(check_data, string, fmt, n_args, ap); + if (ret) + goto fail; + + va_end(ap); + + return; + +fail: + failed_tests++; + va_end(ap); +} + +#define _check_numbers_template(arg_fmt, expect, str, fmt, n_args, ap) \ +do { \ + pr_debug(""%s", "%s" ->\n", str, fmt); \ + for (; n_args > 0; --n_args, ++expect) { \ + typeof(*expect) got = *va_arg(ap, typeof(expect)); \ + pr_debug("\t" arg_fmt "\n", got); \ + if (got != *expect) { \ + pr_warn("vsscanf("%s", "%s", ...) expected " arg_fmt " got " arg_fmt "\n", \ + str, fmt, *expect, got); \ + return 1; \ + } \ + } \ + return 0; \ +} while (0) + +static int __init check_ull(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const unsigned long long *pval = check_data; + + _check_numbers_template("%llu", pval, string, fmt, n_args, ap); +} + +static int __init check_ll(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const long long *pval = check_data; + + _check_numbers_template("%lld", pval, string, fmt, n_args, ap); +} + +static int __init check_ulong(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const unsigned long *pval = check_data; + + _check_numbers_template("%lu", pval, string, fmt, n_args, ap); +} + +static int __init check_long(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const long *pval = check_data; + + _check_numbers_template("%ld", pval, string, fmt, n_args, ap); +} + +static int __init check_uint(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const unsigned int *pval = check_data; + + _check_numbers_template("%u", pval, string, fmt, n_args, ap); +} + +static int __init check_int(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const int *pval = check_data; + + _check_numbers_template("%d", pval, string, fmt, n_args, ap); +} + +static int __init check_ushort(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const unsigned short *pval = check_data; + + _check_numbers_template("%hu", pval, string, fmt, n_args, ap); +} + +static int __init check_short(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const short *pval = check_data; + + _check_numbers_template("%hd", pval, string, fmt, n_args, ap); +} + +static int __init check_uchar(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const unsigned char *pval = check_data; + + _check_numbers_template("%hhu", pval, string, fmt, n_args, ap); +} + +static int __init check_char(const void *check_data, const char *string, + const char *fmt, int n_args, va_list ap) +{ + const signed char *pval = check_data; + + _check_numbers_template("%hhd", pval, string, fmt, n_args, ap); +} + +/* Selection of interesting numbers to test, copied from test-kstrtox.c */ +static const unsigned long long numbers[] __initconst = { + 0x0ULL, + 0x1ULL, + 0x7fULL, + 0x80ULL, + 0x81ULL, + 0xffULL, + 0x100ULL, + 0x101ULL, + 0x7fffULL, + 0x8000ULL, + 0x8001ULL, + 0xffffULL, + 0x10000ULL, + 0x10001ULL, + 0x7fffffffULL, + 0x80000000ULL, + 0x80000001ULL, + 0xffffffffULL, + 0x100000000ULL, + 0x100000001ULL, + 0x7fffffffffffffffULL, + 0x8000000000000000ULL, + 0x8000000000000001ULL, + 0xfffffffffffffffeULL, + 0xffffffffffffffffULL, +}; + +#define value_representable_in_type(T, val) \ +(is_signed_type(T) \ + ? ((long long)(val) >= type_min(T)) && ((long long)(val) <= type_max(T)) \ + : ((unsigned long long)(val) >= type_min(T)) && \ + ((unsigned long long)(val) <= type_max(T))) + +#define test_one_number(T, gen_fmt, scan_fmt, val, fn) \ +do { \ + const T expect_val = (T)(val); \ + T result = ~expect_val; /* should be overwritten */ \ + \ + snprintf(test_buffer, BUF_SIZE, gen_fmt, expect_val); \ + _test(fn, &expect_val, test_buffer, "%" scan_fmt, 1, &result); \ +} while (0) + +#define simple_numbers_loop(T, gen_fmt, scan_fmt, fn) \ +do { \ + int i; \ + \ + for (i = 0; i < ARRAY_SIZE(numbers); ++i) { \ + if (!value_representable_in_type(T, numbers[i])) \ + continue; \ + \ + test_one_number(T, gen_fmt, scan_fmt, numbers[i], fn); \ + \ + if (is_signed_type(T)) \ + test_one_number(T, gen_fmt, scan_fmt, \ + -numbers[i], fn); \ + } \ +} while (0) + +static void __init numbers_simple(void) +{ + simple_numbers_loop(unsigned long long, "%llu", "llu", check_ull); + simple_numbers_loop(long long, "%lld", "lld", check_ll); + simple_numbers_loop(long long, "%lld", "lli", check_ll); + simple_numbers_loop(unsigned long long, "%llx", "llx", check_ull); + simple_numbers_loop(long long, "%llx", "llx", check_ll); + simple_numbers_loop(long long, "0x%llx", "lli", check_ll); + simple_numbers_loop(unsigned long long, "0x%llx", "llx", check_ull); + simple_numbers_loop(long long, "0x%llx", "llx", check_ll); + + simple_numbers_loop(unsigned long, "%lu", "lu", check_ulong); + simple_numbers_loop(long, "%ld", "ld", check_long); + simple_numbers_loop(long, "%ld", "li", check_long); + simple_numbers_loop(unsigned long, "%lx", "lx", check_ulong); + simple_numbers_loop(long, "%lx", "lx", check_long); + simple_numbers_loop(long, "0x%lx", "li", check_long); + simple_numbers_loop(unsigned long, "0x%lx", "lx", check_ulong); + simple_numbers_loop(long, "0x%lx", "lx", check_long); + + simple_numbers_loop(unsigned int, "%u", "u", check_uint); + simple_numbers_loop(int, "%d", "d", check_int); + simple_numbers_loop(int, "%d", "i", check_int); + simple_numbers_loop(unsigned int, "%x", "x", check_uint); + simple_numbers_loop(int, "%x", "x", check_int); + simple_numbers_loop(int, "0x%x", "i", check_int); + simple_numbers_loop(unsigned int, "0x%x", "x", check_uint); + simple_numbers_loop(int, "0x%x", "x", check_int); + + simple_numbers_loop(unsigned short, "%hu", "hu", check_ushort); + simple_numbers_loop(short, "%hd", "hd", check_short); + simple_numbers_loop(short, "%hd", "hi", check_short); + simple_numbers_loop(unsigned short, "%hx", "hx", check_ushort); + simple_numbers_loop(short, "%hx", "hx", check_short); + simple_numbers_loop(short, "0x%hx", "hi", check_short); + simple_numbers_loop(unsigned short, "0x%hx", "hx", check_ushort); + simple_numbers_loop(short, "0x%hx", "hx", check_short); + + simple_numbers_loop(unsigned char, "%hhu", "hhu", check_uchar); + simple_numbers_loop(signed char, "%hhd", "hhd", check_char); + simple_numbers_loop(signed char, "%hhd", "hhi", check_char); + simple_numbers_loop(unsigned char, "%hhx", "hhx", check_uchar); + simple_numbers_loop(signed char, "%hhx", "hhx", check_char); + simple_numbers_loop(signed char, "0x%hhx", "hhi", check_char); + simple_numbers_loop(unsigned char, "0x%hhx", "hhx", check_uchar); + simple_numbers_loop(signed char, "0x%hhx", "hhx", check_char); +} + +/* + * This gives a better variety of number "lengths" in a small sample than + * the raw prandom*() functions (Not mathematically rigorous!!). + * Variabilty of length and value is more important than perfect randomness. + */ +static u32 __init next_test_random(u32 max_bits) +{ + u32 n_bits = hweight32(prandom_u32_state(&rnd_state)) % (max_bits + 1); + + return prandom_u32_state(&rnd_state) & (UINT_MAX >> (32 - n_bits)); +} + +static unsigned long long __init next_test_random_ull(void) +{ + u32 rand1 = prandom_u32_state(&rnd_state); + u32 n_bits = (hweight32(rand1) * 3) % 64; + u64 val = (u64)prandom_u32_state(&rnd_state) * rand1; + + return val & (ULLONG_MAX >> (64 - n_bits)); +} + +#define random_for_type(T) \ + ((T)(sizeof(T) <= sizeof(u32) \ + ? next_test_random(BITS_PER_TYPE(T)) \ + : next_test_random_ull())) + +/* + * Define a pattern of negative and positive numbers to ensure we get + * some of both within the small number of samples in a test string. + */ +#define NEGATIVES_PATTERN 0x3246 /* 00110010 01000110 */ + +#define fill_random_array(arr) \ +do { \ + unsigned int neg_pattern = NEGATIVES_PATTERN; \ + int i; \ + \ + for (i = 0; i < ARRAY_SIZE(arr); ++i, neg_pattern >>= 1) { \ + (arr)[i] = random_for_type(typeof((arr)[0])); \ + if (is_signed_type(typeof((arr)[0])) && (neg_pattern & 1)) \ + (arr)[i] = -(arr)[i]; \ + } \ +} while (0) + +/* + * Convenience wrapper around snprintf() to append at buf_pos in buf, + * updating buf_pos and returning the number of characters appended. + * On error buf_pos is not changed and return value is 0. + */ +static int __init __printf(4, 5) +append_fmt(char *buf, int *buf_pos, int buf_len, const char *val_fmt, ...) +{ + va_list ap; + int field_len; + + va_start(ap, val_fmt); + field_len = vsnprintf(buf + *buf_pos, buf_len - *buf_pos, val_fmt, ap); + va_end(ap); + + if (field_len < 0) + field_len = 0; + + *buf_pos += field_len; + + return field_len; +} + +/* + * Convenience function to append the field delimiter string + * to both the value string and format string buffers. + */ +static void __init append_delim(char *str_buf, int *str_buf_pos, int str_buf_len, + char *fmt_buf, int *fmt_buf_pos, int fmt_buf_len, + const char *delim_str) +{ + append_fmt(str_buf, str_buf_pos, str_buf_len, delim_str); + append_fmt(fmt_buf, fmt_buf_pos, fmt_buf_len, delim_str); +} + +#define test_array_8(fn, check_data, string, fmt, arr) \ +do { \ + BUILD_BUG_ON(ARRAY_SIZE(arr) != 8); \ + _test(fn, check_data, string, fmt, 8, \ + &(arr)[0], &(arr)[1], &(arr)[2], &(arr)[3], \ + &(arr)[4], &(arr)[5], &(arr)[6], &(arr)[7]); \ +} while (0) + +#define numbers_list_8(T, gen_fmt, field_sep, scan_fmt, fn) \ +do { \ + int i, pos = 0, fmt_pos = 0; \ + T expect[8], result[8]; \ + \ + fill_random_array(expect); \ + \ + for (i = 0; i < ARRAY_SIZE(expect); ++i) { \ + if (i != 0) \ + append_delim(test_buffer, &pos, BUF_SIZE, \ + fmt_buffer, &fmt_pos, BUF_SIZE, \ + field_sep); \ + \ + append_fmt(test_buffer, &pos, BUF_SIZE, gen_fmt, expect[i]); \ + append_fmt(fmt_buffer, &fmt_pos, BUF_SIZE, "%%%s", scan_fmt); \ + } \ + \ + test_array_8(fn, expect, test_buffer, fmt_buffer, result); \ +} while (0) + +#define numbers_list_fix_width(T, gen_fmt, field_sep, width, scan_fmt, fn) \ +do { \ + char full_fmt[16]; \ + \ + snprintf(full_fmt, sizeof(full_fmt), "%u%s", width, scan_fmt); \ + numbers_list_8(T, gen_fmt, field_sep, full_fmt, fn); \ +} while (0) + +#define numbers_list_val_width(T, gen_fmt, field_sep, scan_fmt, fn) \ +do { \ + int i, val_len, pos = 0, fmt_pos = 0; \ + T expect[8], result[8]; \ + \ + fill_random_array(expect); \ + \ + for (i = 0; i < ARRAY_SIZE(expect); ++i) { \ + if (i != 0) \ + append_delim(test_buffer, &pos, BUF_SIZE, \ + fmt_buffer, &fmt_pos, BUF_SIZE, field_sep);\ + \ + val_len = append_fmt(test_buffer, &pos, BUF_SIZE, gen_fmt, \ + expect[i]); \ + append_fmt(fmt_buffer, &fmt_pos, BUF_SIZE, \ + "%%%u%s", val_len, scan_fmt); \ + } \ + \ + test_array_8(fn, expect, test_buffer, fmt_buffer, result); \ +} while (0) + +static void __init numbers_list(const char *delim) +{ + numbers_list_8(unsigned long long, "%llu", delim, "llu", check_ull); + numbers_list_8(long long, "%lld", delim, "lld", check_ll); + numbers_list_8(long long, "%lld", delim, "lli", check_ll); + numbers_list_8(unsigned long long, "%llx", delim, "llx", check_ull); + numbers_list_8(unsigned long long, "0x%llx", delim, "llx", check_ull); + numbers_list_8(long long, "0x%llx", delim, "lli", check_ll); + + numbers_list_8(unsigned long, "%lu", delim, "lu", check_ulong); + numbers_list_8(long, "%ld", delim, "ld", check_long); + numbers_list_8(long, "%ld", delim, "li", check_long); + numbers_list_8(unsigned long, "%lx", delim, "lx", check_ulong); + numbers_list_8(unsigned long, "0x%lx", delim, "lx", check_ulong); + numbers_list_8(long, "0x%lx", delim, "li", check_long); + + numbers_list_8(unsigned int, "%u", delim, "u", check_uint); + numbers_list_8(int, "%d", delim, "d", check_int); + numbers_list_8(int, "%d", delim, "i", check_int); + numbers_list_8(unsigned int, "%x", delim, "x", check_uint); + numbers_list_8(unsigned int, "0x%x", delim, "x", check_uint); + numbers_list_8(int, "0x%x", delim, "i", check_int); + + numbers_list_8(unsigned short, "%hu", delim, "hu", check_ushort); + numbers_list_8(short, "%hd", delim, "hd", check_short); + numbers_list_8(short, "%hd", delim, "hi", check_short); + numbers_list_8(unsigned short, "%hx", delim, "hx", check_ushort); + numbers_list_8(unsigned short, "0x%hx", delim, "hx", check_ushort); + numbers_list_8(short, "0x%hx", delim, "hi", check_short); + + numbers_list_8(unsigned char, "%hhu", delim, "hhu", check_uchar); + numbers_list_8(signed char, "%hhd", delim, "hhd", check_char); + numbers_list_8(signed char, "%hhd", delim, "hhi", check_char); + numbers_list_8(unsigned char, "%hhx", delim, "hhx", check_uchar); + numbers_list_8(unsigned char, "0x%hhx", delim, "hhx", check_uchar); + numbers_list_8(signed char, "0x%hhx", delim, "hhi", check_char); +} + +/* + * List of numbers separated by delim. Each field width specifier is the + * maximum possible digits for the given type and base. + */ +static void __init numbers_list_field_width_typemax(const char *delim) +{ + numbers_list_fix_width(unsigned long long, "%llu", delim, 20, "llu", check_ull); + numbers_list_fix_width(long long, "%lld", delim, 20, "lld", check_ll); + numbers_list_fix_width(long long, "%lld", delim, 20, "lli", check_ll); + numbers_list_fix_width(unsigned long long, "%llx", delim, 16, "llx", check_ull); + numbers_list_fix_width(unsigned long long, "0x%llx", delim, 18, "llx", check_ull); + numbers_list_fix_width(long long, "0x%llx", delim, 18, "lli", check_ll); + +#if BITS_PER_LONG == 64 + numbers_list_fix_width(unsigned long, "%lu", delim, 20, "lu", check_ulong); + numbers_list_fix_width(long, "%ld", delim, 20, "ld", check_long); + numbers_list_fix_width(long, "%ld", delim, 20, "li", check_long); + numbers_list_fix_width(unsigned long, "%lx", delim, 16, "lx", check_ulong); + numbers_list_fix_width(unsigned long, "0x%lx", delim, 18, "lx", check_ulong); + numbers_list_fix_width(long, "0x%lx", delim, 18, "li", check_long); +#else + numbers_list_fix_width(unsigned long, "%lu", delim, 10, "lu", check_ulong); + numbers_list_fix_width(long, "%ld", delim, 11, "ld", check_long); + numbers_list_fix_width(long, "%ld", delim, 11, "li", check_long); + numbers_list_fix_width(unsigned long, "%lx", delim, 8, "lx", check_ulong); + numbers_list_fix_width(unsigned long, "0x%lx", delim, 10, "lx", check_ulong); + numbers_list_fix_width(long, "0x%lx", delim, 10, "li", check_long); +#endif + + numbers_list_fix_width(unsigned int, "%u", delim, 10, "u", check_uint); + numbers_list_fix_width(int, "%d", delim, 11, "d", check_int); + numbers_list_fix_width(int, "%d", delim, 11, "i", check_int); + numbers_list_fix_width(unsigned int, "%x", delim, 8, "x", check_uint); + numbers_list_fix_width(unsigned int, "0x%x", delim, 10, "x", check_uint); + numbers_list_fix_width(int, "0x%x", delim, 10, "i", check_int); + + numbers_list_fix_width(unsigned short, "%hu", delim, 5, "hu", check_ushort); + numbers_list_fix_width(short, "%hd", delim, 6, "hd", check_short); + numbers_list_fix_width(short, "%hd", delim, 6, "hi", check_short); + numbers_list_fix_width(unsigned short, "%hx", delim, 4, "hx", check_ushort); + numbers_list_fix_width(unsigned short, "0x%hx", delim, 6, "hx", check_ushort); + numbers_list_fix_width(short, "0x%hx", delim, 6, "hi", check_short); + + numbers_list_fix_width(unsigned char, "%hhu", delim, 3, "hhu", check_uchar); + numbers_list_fix_width(signed char, "%hhd", delim, 4, "hhd", check_char); + numbers_list_fix_width(signed char, "%hhd", delim, 4, "hhi", check_char); + numbers_list_fix_width(unsigned char, "%hhx", delim, 2, "hhx", check_uchar); + numbers_list_fix_width(unsigned char, "0x%hhx", delim, 4, "hhx", check_uchar); + numbers_list_fix_width(signed char, "0x%hhx", delim, 4, "hhi", check_char); +} + +/* + * List of numbers separated by delim. Each field width specifier is the + * exact length of the corresponding value digits in the string being scanned. + */ +static void __init numbers_list_field_width_val_width(const char *delim) +{ + numbers_list_val_width(unsigned long long, "%llu", delim, "llu", check_ull); + numbers_list_val_width(long long, "%lld", delim, "lld", check_ll); + numbers_list_val_width(long long, "%lld", delim, "lli", check_ll); + numbers_list_val_width(unsigned long long, "%llx", delim, "llx", check_ull); + numbers_list_val_width(unsigned long long, "0x%llx", delim, "llx", check_ull); + numbers_list_val_width(long long, "0x%llx", delim, "lli", check_ll); + + numbers_list_val_width(unsigned long, "%lu", delim, "lu", check_ulong); + numbers_list_val_width(long, "%ld", delim, "ld", check_long); + numbers_list_val_width(long, "%ld", delim, "li", check_long); + numbers_list_val_width(unsigned long, "%lx", delim, "lx", check_ulong); + numbers_list_val_width(unsigned long, "0x%lx", delim, "lx", check_ulong); + numbers_list_val_width(long, "0x%lx", delim, "li", check_long); + + numbers_list_val_width(unsigned int, "%u", delim, "u", check_uint); + numbers_list_val_width(int, "%d", delim, "d", check_int); + numbers_list_val_width(int, "%d", delim, "i", check_int); + numbers_list_val_width(unsigned int, "%x", delim, "x", check_uint); + numbers_list_val_width(unsigned int, "0x%x", delim, "x", check_uint); + numbers_list_val_width(int, "0x%x", delim, "i", check_int); + + numbers_list_val_width(unsigned short, "%hu", delim, "hu", check_ushort); + numbers_list_val_width(short, "%hd", delim, "hd", check_short); + numbers_list_val_width(short, "%hd", delim, "hi", check_short); + numbers_list_val_width(unsigned short, "%hx", delim, "hx", check_ushort); + numbers_list_val_width(unsigned short, "0x%hx", delim, "hx", check_ushort); + numbers_list_val_width(short, "0x%hx", delim, "hi", check_short); + + numbers_list_val_width(unsigned char, "%hhu", delim, "hhu", check_uchar); + numbers_list_val_width(signed char, "%hhd", delim, "hhd", check_char); + numbers_list_val_width(signed char, "%hhd", delim, "hhi", check_char); + numbers_list_val_width(unsigned char, "%hhx", delim, "hhx", check_uchar); + numbers_list_val_width(unsigned char, "0x%hhx", delim, "hhx", check_uchar); + numbers_list_val_width(signed char, "0x%hhx", delim, "hhi", check_char); +} + +/* + * Slice a continuous string of digits without field delimiters, containing + * numbers of varying length, using the field width to extract each group + * of digits. For example the hex values c0,3,bf01,303 would have a + * string representation of "c03bf01303" and extracted with "%2x%1x%4x%3x". + */ +static void __init numbers_slice(void) +{ + numbers_list_field_width_val_width(""); +} + +#define test_number_prefix(T, str, scan_fmt, expect0, expect1, n_args, fn) \ +do { \ + const T expect[2] = { expect0, expect1 }; \ + T result[2] = {~expect[0], ~expect[1]}; \ + \ + _test(fn, &expect, str, scan_fmt, n_args, &result[0], &result[1]); \ +} while (0) + +/* + * Number prefix is >= field width. + * Expected behaviour is derived from testing userland sscanf. + */ +static void __init numbers_prefix_overflow(void) +{ + /* + * Negative decimal with a field of width 1, should quit scanning + * and return 0. + */ + test_number_prefix(long long, "-1 1", "%1lld %lld", 0, 0, 0, check_ll); + test_number_prefix(long, "-1 1", "%1ld %ld", 0, 0, 0, check_long); + test_number_prefix(int, "-1 1", "%1d %d", 0, 0, 0, check_int); + test_number_prefix(short, "-1 1", "%1hd %hd", 0, 0, 0, check_short); + test_number_prefix(signed char, "-1 1", "%1hhd %hhd", 0, 0, 0, check_char); + + test_number_prefix(long long, "-1 1", "%1lli %lli", 0, 0, 0, check_ll); + test_number_prefix(long, "-1 1", "%1li %li", 0, 0, 0, check_long); + test_number_prefix(int, "-1 1", "%1i %i", 0, 0, 0, check_int); + test_number_prefix(short, "-1 1", "%1hi %hi", 0, 0, 0, check_short); + test_number_prefix(signed char, "-1 1", "%1hhi %hhi", 0, 0, 0, check_char); + + /* + * 0x prefix in a field of width 1: 0 is a valid digit so should + * convert. Next field scan starts at the 'x' which isn't a digit so + * scan quits with one field converted. + */ + test_number_prefix(unsigned long long, "0xA7", "%1llx%llx", 0, 0, 1, check_ull); + test_number_prefix(unsigned long, "0xA7", "%1lx%lx", 0, 0, 1, check_ulong); + test_number_prefix(unsigned int, "0xA7", "%1x%x", 0, 0, 1, check_uint); + test_number_prefix(unsigned short, "0xA7", "%1hx%hx", 0, 0, 1, check_ushort); + test_number_prefix(unsigned char, "0xA7", "%1hhx%hhx", 0, 0, 1, check_uchar); + test_number_prefix(long long, "0xA7", "%1lli%llx", 0, 0, 1, check_ll); + test_number_prefix(long, "0xA7", "%1li%lx", 0, 0, 1, check_long); + test_number_prefix(int, "0xA7", "%1i%x", 0, 0, 1, check_int); + test_number_prefix(short, "0xA7", "%1hi%hx", 0, 0, 1, check_short); + test_number_prefix(char, "0xA7", "%1hhi%hhx", 0, 0, 1, check_char); + + /* + * 0x prefix in a field of width 2 using %x conversion: first field + * converts to 0. Next field scan starts at the character after "0x". + * Both fields will convert. + */ + test_number_prefix(unsigned long long, "0xA7", "%2llx%llx", 0, 0xa7, 2, check_ull); + test_number_prefix(unsigned long, "0xA7", "%2lx%lx", 0, 0xa7, 2, check_ulong); + test_number_prefix(unsigned int, "0xA7", "%2x%x", 0, 0xa7, 2, check_uint); + test_number_prefix(unsigned short, "0xA7", "%2hx%hx", 0, 0xa7, 2, check_ushort); + test_number_prefix(unsigned char, "0xA7", "%2hhx%hhx", 0, 0xa7, 2, check_uchar); + + /* + * 0x prefix in a field of width 2 using %i conversion: first field + * converts to 0. Next field scan starts at the character after "0x", + * which will convert if can be intepreted as decimal but will fail + * if it contains any hex digits (since no 0x prefix). + */ + test_number_prefix(long long, "0x67", "%2lli%lli", 0, 67, 2, check_ll); + test_number_prefix(long, "0x67", "%2li%li", 0, 67, 2, check_long); + test_number_prefix(int, "0x67", "%2i%i", 0, 67, 2, check_int); + test_number_prefix(short, "0x67", "%2hi%hi", 0, 67, 2, check_short); + test_number_prefix(char, "0x67", "%2hhi%hhi", 0, 67, 2, check_char); + + test_number_prefix(long long, "0xA7", "%2lli%lli", 0, 0, 1, check_ll); + test_number_prefix(long, "0xA7", "%2li%li", 0, 0, 1, check_long); + test_number_prefix(int, "0xA7", "%2i%i", 0, 0, 1, check_int); + test_number_prefix(short, "0xA7", "%2hi%hi", 0, 0, 1, check_short); + test_number_prefix(char, "0xA7", "%2hhi%hhi", 0, 0, 1, check_char); +} + +#define _test_simple_strtoxx(T, fn, gen_fmt, expect, base) \ +do { \ + T got; \ + char *endp; \ + int len; \ + bool fail = false; \ + \ + ++total_tests; \ + len = snprintf(test_buffer, BUF_SIZE, gen_fmt, expect); \ + got = (fn)(test_buffer, &endp, base); \ + pr_debug(#fn "("%s", %d) -> " gen_fmt "\n", test_buffer, base, got); \ + if (got != (expect)) { \ + fail = true; \ + pr_warn(#fn "("%s", %d): got " gen_fmt " expected " gen_fmt "\n", \ + test_buffer, base, got, expect); \ + } else if (endp != test_buffer + len) { \ + fail = true; \ + pr_warn(#fn "("%s", %d) startp=0x%px got endp=0x%px expected 0x%px\n", \ + test_buffer, base, test_buffer, \ + test_buffer + len, endp); \ + } \ + \ + if (fail) \ + ++failed_tests; \ +} while (0) + +#define test_simple_strtoxx(T, fn, gen_fmt, base) \ +do { \ + int i; \ + \ + for (i = 0; i < ARRAY_SIZE(numbers); ++i) { \ + _test_simple_strtoxx(T, fn, gen_fmt, (T)numbers[i], base); \ + \ + if (is_signed_type(T)) \ + _test_simple_strtoxx(T, fn, gen_fmt, \ + -(T)numbers[i], base); \ + } \ +} while (0) + +static void __init test_simple_strtoull(void) +{ + test_simple_strtoxx(unsigned long long, simple_strtoull, "%llu", 10); + test_simple_strtoxx(unsigned long long, simple_strtoull, "%llu", 0); + test_simple_strtoxx(unsigned long long, simple_strtoull, "%llx", 16); + test_simple_strtoxx(unsigned long long, simple_strtoull, "0x%llx", 16); + test_simple_strtoxx(unsigned long long, simple_strtoull, "0x%llx", 0); +} + +static void __init test_simple_strtoll(void) +{ + test_simple_strtoxx(long long, simple_strtoll, "%lld", 10); + test_simple_strtoxx(long long, simple_strtoll, "%lld", 0); + test_simple_strtoxx(long long, simple_strtoll, "%llx", 16); + test_simple_strtoxx(long long, simple_strtoll, "0x%llx", 16); + test_simple_strtoxx(long long, simple_strtoll, "0x%llx", 0); +} + +static void __init test_simple_strtoul(void) +{ + test_simple_strtoxx(unsigned long, simple_strtoul, "%lu", 10); + test_simple_strtoxx(unsigned long, simple_strtoul, "%lu", 0); + test_simple_strtoxx(unsigned long, simple_strtoul, "%lx", 16); + test_simple_strtoxx(unsigned long, simple_strtoul, "0x%lx", 16); + test_simple_strtoxx(unsigned long, simple_strtoul, "0x%lx", 0); +} + +static void __init test_simple_strtol(void) +{ + test_simple_strtoxx(long, simple_strtol, "%ld", 10); + test_simple_strtoxx(long, simple_strtol, "%ld", 0); + test_simple_strtoxx(long, simple_strtol, "%lx", 16); + test_simple_strtoxx(long, simple_strtol, "0x%lx", 16); + test_simple_strtoxx(long, simple_strtol, "0x%lx", 0); +} + +/* Selection of common delimiters/separators between numbers in a string. */ +static const char * const number_delimiters[] __initconst = { + " ", ":", ",", "-", "/", +}; + +static void __init test_numbers(void) +{ + int i; + + /* String containing only one number. */ + numbers_simple(); + + /* String with multiple numbers separated by delimiter. */ + for (i = 0; i < ARRAY_SIZE(number_delimiters); ++i) { + numbers_list(number_delimiters[i]); + + /* Field width may be longer than actual field digits. */ + numbers_list_field_width_typemax(number_delimiters[i]); + + /* Each field width exactly length of actual field digits. */ + numbers_list_field_width_val_width(number_delimiters[i]); + } + + /* Slice continuous sequence of digits using field widths. */ + numbers_slice(); + + numbers_prefix_overflow(); +} + +static void __init selftest(void) +{ + test_buffer = kmalloc(BUF_SIZE, GFP_KERNEL); + if (!test_buffer) + return; + + fmt_buffer = kmalloc(BUF_SIZE, GFP_KERNEL); + if (!fmt_buffer) + return; + + prandom_seed_state(&rnd_state, 3141592653589793238ULL); + + test_numbers(); + + test_simple_strtoull(); + test_simple_strtoll(); + test_simple_strtoul(); + test_simple_strtol(); +} + +KSTM_MODULE_LOADERS(test_scanf); +MODULE_AUTHOR("Richard Fitzgerald rf@opensource.cirrus.com"); +MODULE_LICENSE("GPL v2");

Adds a wrapper shell script for the test_scanf module.

Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com Reviewed-by: Petr Mladek pmladek@suse.com --- tools/testing/selftests/lib/Makefile | 2 +- tools/testing/selftests/lib/config | 1 + tools/testing/selftests/lib/scanf.sh | 4 ++++ 3 files changed, 6 insertions(+), 1 deletion(-) create mode 100755 tools/testing/selftests/lib/scanf.sh

diff --git a/tools/testing/selftests/lib/Makefile b/tools/testing/selftests/lib/Makefile index a105f094676e..ee71fc99d5b5 100644 --- a/tools/testing/selftests/lib/Makefile +++ b/tools/testing/selftests/lib/Makefile @@ -4,6 +4,6 @@ # No binaries, but make sure arg-less "make" doesn't trigger "run_tests" all:

-TEST_PROGS := printf.sh bitmap.sh prime_numbers.sh strscpy.sh +TEST_PROGS := printf.sh bitmap.sh prime_numbers.sh scanf.sh strscpy.sh

include ../lib.mk diff --git a/tools/testing/selftests/lib/config b/tools/testing/selftests/lib/config index b80ee3f6e265..776c8c42e78d 100644 --- a/tools/testing/selftests/lib/config +++ b/tools/testing/selftests/lib/config @@ -1,4 +1,5 @@ CONFIG_TEST_PRINTF=m +CONFIG_TEST_SCANTF=m CONFIG_TEST_BITMAP=m CONFIG_PRIME_NUMBERS=m CONFIG_TEST_STRSCPY=m diff --git a/tools/testing/selftests/lib/scanf.sh b/tools/testing/selftests/lib/scanf.sh new file mode 100755 index 000000000000..b59b8ba561c3 --- /dev/null +++ b/tools/testing/selftests/lib/scanf.sh @@ -0,0 +1,4 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# Tests the scanf infrastructure using test_scanf kernel module. +$(dirname $0)/../kselftest/module.sh "scanf" test_scanf

Sigh, I have just realized that Andy and Rasmus, the other vsprintf maintainers and reviewers, were not in CC. I am sorry for not noticing this earlier.

The patchset is ready for 5.12 from my POV.

Best Regards, Petr

On Thu 2020-12-17 18:00:54, Richard Fitzgerald wrote:

If a signed number field starts with a '-' the field width must be > 1, or unlimited, to allow at least one digit after the '-'.

This patch adds a check for this. If a signed field starts with '-' and field_width == 1 the scanf will quit.

It is ok for a signed number field to have a field width of 1 if it starts with a digit. In that case the single digit can be converted.

Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com

lib/vsprintf.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 14c9a6af1b23..8954ff94a53c 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -3433,8 +3433,12 @@ int vsscanf(const char *buf, const char *fmt, va_list args) str = skip_spaces(str); digit = *str;

• if (is_sign && digit == '-')
  

• if (is_sign && digit == '-') {
  

• 	if (field_width == 1)
  

• 		break;
  

• digit = *(str + 1);
  

• }
  

if (!digit || (base == 16 && !isxdigit(digit)) -- 2.20.1