diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/vsprintf.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 61e6f0d2b3..3b924ec5e0 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -13,6 +13,7 @@ #include <linux/types.h> #include <linux/string.h> #include <linux/ctype.h> +#include <errno.h> #include <common.h> #if !defined (CONFIG_PANIC_HANG) @@ -61,6 +62,56 @@ unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base) return result; } +/** + * strict_strtoul - convert a string to an unsigned long strictly + * @cp: The string to be converted + * @base: The number base to use + * @res: The converted result value + * + * strict_strtoul converts a string to an unsigned long only if the + * string is really an unsigned long string, any string containing + * any invalid char at the tail will be rejected and -EINVAL is returned, + * only a newline char at the tail is acceptible because people generally + * change a module parameter in the following way: + * + * echo 1024 > /sys/module/e1000/parameters/copybreak + * + * echo will append a newline to the tail. + * + * It returns 0 if conversion is successful and *res is set to the converted + * value, otherwise it returns -EINVAL and *res is set to 0. + * + * simple_strtoul just ignores the successive invalid characters and + * return the converted value of prefix part of the string. + * + * Copied this function from Linux 2.6.38 commit ID: + * 521cb40b0c44418a4fd36dc633f575813d59a43d + * + */ +int strict_strtoul(const char *cp, unsigned int base, unsigned long *res) +{ + char *tail; + unsigned long val; + size_t len; + + *res = 0; + len = strlen(cp); + if (len == 0) + return -EINVAL; + + val = simple_strtoul(cp, &tail, base); + if (tail == cp) + return -EINVAL; + + if ((*tail == '\0') || + ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) { + *res = val; + return 0; + } + + return -EINVAL; +} + long simple_strtol(const char *cp,char **endp,unsigned int base) { if(*cp=='-') |
