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authorPetr Mladek <pmladek@suse.com>2021-06-29 09:51:58 +0200
committerPetr Mladek <pmladek@suse.com>2021-06-29 09:51:58 +0200
commitd8c032145fccfead0c3f733e7b6aaa4e81f9d326 (patch)
tree7b150b83d4341c8bc646f33a7b0cb928dab4ee8a /lib/vsprintf.c
parent80ae552917228b97ca9f7df83f74ac306d6fd68f (diff)
parentd327ea15a305024ef0085252fa3657bbb1ce25f5 (diff)
Merge branch 'for-5.14-vsprintf-scanf' into for-linus
Diffstat (limited to 'lib/vsprintf.c')
-rw-r--r--lib/vsprintf.c88
1 files changed, 53 insertions, 35 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 8d5142ae742e..18818d966928 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -53,6 +53,31 @@
#include <linux/string_helpers.h>
#include "kstrtox.h"
+static unsigned long long simple_strntoull(const char *startp, size_t max_chars,
+ char **endp, unsigned int base)
+{
+ const char *cp;
+ unsigned long long result = 0ULL;
+ size_t prefix_chars;
+ unsigned int rv;
+
+ cp = _parse_integer_fixup_radix(startp, &base);
+ prefix_chars = cp - startp;
+ if (prefix_chars < max_chars) {
+ rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
+ /* FIXME */
+ cp += (rv & ~KSTRTOX_OVERFLOW);
+ } else {
+ /* Field too short for prefix + digit, skip over without converting */
+ cp = startp + max_chars;
+ }
+
+ if (endp)
+ *endp = (char *)cp;
+
+ return result;
+}
+
/**
* simple_strtoull - convert a string to an unsigned long long
* @cp: The start of the string
@@ -63,18 +88,7 @@
*/
unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
{
- unsigned long long result;
- unsigned int rv;
-
- cp = _parse_integer_fixup_radix(cp, &base);
- rv = _parse_integer(cp, base, &result);
- /* FIXME */
- cp += (rv & ~KSTRTOX_OVERFLOW);
-
- if (endp)
- *endp = (char *)cp;
-
- return result;
+ return simple_strntoull(cp, INT_MAX, endp, base);
}
EXPORT_SYMBOL(simple_strtoull);
@@ -109,6 +123,21 @@ 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 cp[0] == '-' && max_chars == 1.
+ * If max_chars == 0 we can drop through and pass it to simple_strntoull()
+ * and the content of *cp is irrelevant.
+ */
+ 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 +148,7 @@ 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, INT_MAX, endp, base);
}
EXPORT_SYMBOL(simple_strtoll);
@@ -3538,8 +3564,12 @@ 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))
@@ -3549,25 +3579,13 @@ 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 : INT_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 : INT_MAX,
+ &next, base);
switch (qualifier) {
case 'H': /* that's 'hh' in format */