Re: [PATCH(s)][RFC] variable size and signedness issues in ldt.c - potential problem?

["Randy.Dunlap" <rddunlap@osdl.org>]

On Mon, 12 Jan 2004 23:20:23 +0100 (CET) Jesper Juhl <juhl-lkml@dif.dk> wrote:

| 
| On Mon, 12 Jan 2004, Andrew Morton wrote:
| 
| > Jesper Juhl <juhl-lkml@dif.dk> wrote:
| > >
| > >
| > > >
| > > > -static int read_ldt(void __user * ptr, unsigned long bytecount)
| > > > +static int read_ldt(void __user *ptr, unsigned long bytecount)
| > > >  {
| > > >  	int err, i;
| > > >  	unsigned long size;
| > > > +	unsigned long bytes;
| > > >  	struct mm_struct * mm = current->mm;
| > > >
| > > >  	if (!mm->context.size)
| > > > @@ -144,7 +145,7 @@ static int read_ldt(void __user * ptr, u
| > > >  	__flush_tlb_global();
| > > >
| > > >  	for (i = 0; i < size; i += PAGE_SIZE) {
| > > > -		int nr = i / PAGE_SIZE, bytes;
| > > > +		int nr = i / PAGE_SIZE;
| > > >  		char *kaddr = kmap(mm->context.ldt_pages[nr]);
| > > >
| > > >  		bytes = size - i;
| > > >
| >
| > There is no additional overhead with the original code and it has the
| > advantage that the scope of `bytes' covers the minimum amount of code.  I
| > see no need to change this.
| >
| > Well.  There is a little bit of overhead of the code does:
| >
| > foo()
| > {
| > 	...
| > 	{
| > 		int i;
| > 		...
| > 	}
| > 	...
| > 	{
| > 		int i;
| > 		...
| > 	}
| > 	...
| > }
| >
| > because the compiler (some versions, at least) will use eight bytes of
| > stack rather than four.  But this is rarely a problem.
| >
| 
| Ok, I'll let it go :-)
| 
| 
| > > After creating the initial cleanup patch I've noticed several more
| > > instances of this 'bad style'. If there's any interrest in cleaning them
| > > up I'll be happy to create a patch.  Is this wanted?
| >
| > I'd say that this and the whitespace adjustments are far too trivial to be
| > raising patches at this time.
| >
| You are right, it /is/ trivial - I'll leave it alone for now.  Maybe later
| create a patch that does a more thorough cleanup and send it to the
| trivial patch monkey.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Or I can put it into the KJ patchset and just never send it onward.
That will at least get it some usage time.

BTW, if you want to stick with trivial_Rusty, that's OK with me too.
Rusty does a fine job and I'm not trying to compete with him.

--
~Randy
http://janitor.kernelnewbies.org/