[PATCH] qsort: Fix a typo causing unnecessary malloc/free

[Xi Ruoyao]

On Tue, 2024-01-23 at 03:54 +0800, Xi Ruoyao wrote:
> On Mon, 2024-01-22 at 11:46 -0800, H.J. Lu wrote:
> > On Mon, Jan 22, 2024 at 11:32 AM Xi Ruoyao <xry111@xry111.site> wrote:
> > > 
> > > In qsort_r we allocate a buffer sized QSORT_STACK_SIZE (1024) on stack
> > > and we intend to use it if all elements can fit into it.  But there is a
> > > typo:
> > > 
> > >      if (total_size < sizeof buf)

Hmm, and it seems this should be "<=" instead of "<".  I'm preparing a
V2 with the operator changed too, and the BZ number in commit message...

> > >        buf = tmp;
> > >      else
> > >        /* allocate a buffer on heap and use it ... */
> > > 
> > > Here "buf" is a pointer, thus sizeof buf is just 4 or 8, instead of
> > > 1024.
> > 
> > This sounds like a real bug.  A glibc bug report is needed to track it.
> 
> https://sourceware.org/bugzilla/show_bug.cgi?id=31276
> 

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University