Re: [PATCH v4 1/2] mm: add kstrimdup function

On Wed, 2014-01-29 at 19:41 -0800, Sebastian Capella wrote:

Quoting Joe Perches (2014-01-29 17:24:28)

...

Why not minimize the malloc length too?

I figured it would be mostly for small trimming, but it seems like it could be and advantage and used more generally this way.

I have a couple of small changes to return NULL in empty string/all ws cases and fix a buffer underrun.

How does this look?

[]

char *kstrimdup(const char *s, gfp_t gfp) { char *buf; const char *begin = skip_spaces(s); size_t len = strlen(begin);

removing begin and just using s would work

    if (len == 0)                                                            
            return NULL;                                                     
                                                                             
    while (len > 1 && isspace(begin[len - 1]))                               
            len--;                                                           
                                                                             
    buf = kmalloc_track_caller(len + 1, gfp);                                
    if (!buf)                                                                
            return NULL;                                                     
                                                                             
    memcpy(buf, begin, len);                                                 
    buf[len] = '\0';                                                            
                                                                             
    return buf;                                                              

}

What should the return be to this string?

" "

Should it be "" or " " or NULL?

I don't think it should be NULL. I don't think it should be " ".

cheers, Joe