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authorJan Beulich <JBeulich@suse.com>2012-12-17 16:01:31 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-17 17:15:18 -0800
commit53809751ac230a3611b5cdd375f3389f3207d471 (patch)
tree8555da83945aaba9291f0d9ff09d271043e36263 /lib
parent375da3a76dc49f10c35e243ebef62df12e3adf4e (diff)
downloadvexpress-lsk-53809751ac230a3611b5cdd375f3389f3207d471.tar.gz
sscanf: don't ignore field widths for numeric conversions
This is another step towards better standard conformance. Rather than adding a local buffer to store the specified portion of the string (with the need to enforce an arbitrary maximum supported width to limit the buffer size), do a maximum width conversion and then drop as much of it as is necessary to meet the caller's request. Also fail on negative field widths. Uses the deprecated simple_strto*() functions because kstrtoXX() fail on non-zero terminated strings. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/vsprintf.c96
1 files changed, 53 insertions, 43 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 41da0741a66..292fcb174a3 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -23,12 +23,12 @@
#include <linux/ctype.h>
#include <linux/kernel.h>
#include <linux/kallsyms.h>
+#include <linux/math64.h>
#include <linux/uaccess.h>
#include <linux/ioport.h>
#include <net/addrconf.h>
#include <asm/page.h> /* for PAGE_SIZE */
-#include <asm/div64.h>
#include <asm/sections.h> /* for dereference_function_descriptor() */
#include "kstrtox.h"
@@ -2016,7 +2016,11 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
char digit;
int num = 0;
u8 qualifier;
- u8 base;
+ unsigned int base;
+ union {
+ long long s;
+ unsigned long long u;
+ } val;
s16 field_width;
bool is_sign;
@@ -2056,8 +2060,11 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
/* get field width */
field_width = -1;
- if (isdigit(*fmt))
+ if (isdigit(*fmt)) {
field_width = skip_atoi(&fmt);
+ if (field_width <= 0)
+ break;
+ }
/* get conversion qualifier */
qualifier = -1;
@@ -2157,58 +2164,61 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
|| (base == 0 && !isdigit(digit)))
break;
+ if (is_sign)
+ val.s = qualifier != 'L' ?
+ simple_strtol(str, &next, base) :
+ simple_strtoll(str, &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;
+ }
+ }
+
switch (qualifier) {
case 'H': /* that's 'hh' in format */
- if (is_sign) {
- signed char *s = (signed char *)va_arg(args, signed char *);
- *s = (signed char)simple_strtol(str, &next, base);
- } else {
- unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
- *s = (unsigned char)simple_strtoul(str, &next, base);
- }
+ if (is_sign)
+ *va_arg(args, signed char *) = val.s;
+ else
+ *va_arg(args, unsigned char *) = val.u;
break;
case 'h':
- if (is_sign) {
- short *s = (short *)va_arg(args, short *);
- *s = (short)simple_strtol(str, &next, base);
- } else {
- unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
- *s = (unsigned short)simple_strtoul(str, &next, base);
- }
+ if (is_sign)
+ *va_arg(args, short *) = val.s;
+ else
+ *va_arg(args, unsigned short *) = val.u;
break;
case 'l':
- if (is_sign) {
- long *l = (long *)va_arg(args, long *);
- *l = simple_strtol(str, &next, base);
- } else {
- unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
- *l = simple_strtoul(str, &next, base);
- }
+ if (is_sign)
+ *va_arg(args, long *) = val.s;
+ else
+ *va_arg(args, unsigned long *) = val.u;
break;
case 'L':
- if (is_sign) {
- long long *l = (long long *)va_arg(args, long long *);
- *l = simple_strtoll(str, &next, base);
- } else {
- unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
- *l = simple_strtoull(str, &next, base);
- }
+ if (is_sign)
+ *va_arg(args, long long *) = val.s;
+ else
+ *va_arg(args, unsigned long long *) = val.u;
break;
case 'Z':
case 'z':
- {
- size_t *s = (size_t *)va_arg(args, size_t *);
- *s = (size_t)simple_strtoul(str, &next, base);
- }
- break;
+ *va_arg(args, size_t *) = val.u;
+ break;
default:
- if (is_sign) {
- int *i = (int *)va_arg(args, int *);
- *i = (int)simple_strtol(str, &next, base);
- } else {
- unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
- *i = (unsigned int)simple_strtoul(str, &next, base);
- }
+ if (is_sign)
+ *va_arg(args, int *) = val.s;
+ else
+ *va_arg(args, unsigned int *) = val.u;
break;
}
num++;