On Thu, 30 Jan 2014 13:45:45 -0800 Sebastian Capella [off-list ref] wrote:

Quoting Andrew Morton (2014-01-30 13:22:51)

quoted

On Thu, 30 Jan 2014 13:11:57 -0800 Sebastian Capella [off-list ref] wrote:

quoted

+char *kstrimdup(const char *s, gfp_t gfp)
+{
+     char *buf;
+     char *begin = skip_spaces(s);
+     size_t len = strlen(begin);
+
+     while (len > 1 && isspace(begin[len - 1]))
+             len--;

That's off-by-one isn't it?  kstrimdup("   ") should return "", not " ".

quoted

+     buf = kmalloc_track_caller(len + 1, gfp);
+     if (!buf)
+             return NULL;
+
+     memcpy(buf, begin, len);
+     buf[len] = '\0';
+
+     return buf;
+}

Hi Andrew,

I think this is a little tricky.

For an empty string, the function relies on skip_spaces to point begin
at the \0'.

Alternately, if we don't have an empty string, we know we have at least 1
non-space, non-null character at begin[0], and there's no need to check it,
so the loop stops at [1].  If there's a space at 1, we just put the '\0'
there.

We could check at [0], but I think its already been checked by skip_spaces.

heh, OK, tricky.