Commit fd193829 authored by Robert P. J. Day's avatar Robert P. J. Day Committed by Linus Torvalds

lib: allow memparse() to accept a NULL and ignorable second parm

Extend memparse() to allow the caller to use a NULL second parameter, which
would represent no interest in returning the address of the end of the parsed

In numerous cases, callers invoke memparse() to parse a possibly-suffixed
string (such as "64K" or "2G" or whatever) and define a character pointer to
accept the end pointer being returned by memparse() even though they have no
interest in it and promptly throw it away.

This (backward-compatible) enhancement allows callers to use NULL in the cases
where they just don't care about getting back that end pointer.

[ coding-style fixes]
Signed-off-by: Robert P. J. Day's avatarRobert P. J. Day <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent cb345d73
......@@ -116,7 +116,7 @@ char *get_options(const char *str, int nints, int *ints)
* memparse - parse a string with mem suffixes into a number
* @ptr: Where parse begins
* @retptr: (output) Pointer to next char after parse completes
* @retptr: (output) Optional pointer to next char after parse completes
* Parses a string into a number. The number stored at @ptr is
* potentially suffixed with %K (for kilobytes, or 1024 bytes),
......@@ -126,11 +126,13 @@ char *get_options(const char *str, int nints, int *ints)
* megabyte, or one gigabyte, respectively.
unsigned long long memparse (char *ptr, char **retptr)
unsigned long long memparse(char *ptr, char **retptr)
unsigned long long ret = simple_strtoull (ptr, retptr, 0);
char *endptr; /* local pointer to end of parsed string */
switch (**retptr) {
unsigned long long ret = simple_strtoull(ptr, &endptr, 0);
switch (*endptr) {
case 'G':
case 'g':
ret <<= 10;
......@@ -140,10 +142,14 @@ unsigned long long memparse (char *ptr, char **retptr)
case 'K':
case 'k':
ret <<= 10;
if (retptr)
*retptr = endptr;
return ret;
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment