From: "Robert P. J. Day" 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 string. 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. Signed-off-by: Robert P. J. Day Signed-off-by: Andrew Morton --- lib/cmdline.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff -puN lib/cmdline.c~lib-allow-memparse-to-accept-a-null-and-ignorable-second-parm lib/cmdline.c --- a/lib/cmdline.c~lib-allow-memparse-to-accept-a-null-and-ignorable-second-parm +++ a/lib/cmdline.c @@ -116,7 +116,7 @@ char *get_options(const char *str, int n /** * 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), @@ -128,9 +128,11 @@ char *get_options(const char *str, int n 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 +142,15 @@ unsigned long long memparse (char *ptr, case 'K': case 'k': ret <<= 10; - (*retptr)++; + endptr++; default: break; } + + if (retptr) { + *retptr = endptr; + } + return ret; } _