Re: [AD] More "mprotect" troubles (4.2.1 showstopper?)

[Peter Wang <tjaden@xxxxxxxxxx>]

On 2006-03-18, Peter Wang <tjaden@xxxxxxxxxx> wrote:
> On 2006-03-13, Hans de Goede <j.w.r.degoede@xxxxxxxxxx> wrote:
> > That is what the current code did, but appereantly mprotect on malloces 
> > mem is a no no, mprotect is (officially, POSIX) only supported on mmap 
> > returned mem. So either we must create a mmap once the current 
> > scratchmem using code is done and then memcopy the code, or (as I have 
> > done) replace scratchmem by an mmap based scratchmem implementation 
> > (I've only replaced it for the use in code generation). This will 
> > actually be faster then the old way, since mremap should be much faster 
> > then realloc.
> 
> > @@ -439,7 +441,7 @@
> >   #ifdef ALLEGRO_WINDOWS
> >     /* Play nice with Windows executable memory protection */
> >     VirtualProtect(_scratch_mem, _scratch_mem_size, PAGE_EXECUTE_READWRITE, &old_protect);
> > - #elif defined(HAVE_MPROTECT)
> > + #elif defined(HAVE_MPROTECT) && !defined(USE_MMAP_GEN_CODE_BUF)
> >     {
> >        char *p = (char *)((unsigned long)_scratch_mem & ~(PAGE_SIZE-1ul));
> >        if (mprotect(p, _scratch_mem_size + ((char *)_scratch_mem - p),
> > @@ -448,22 +450,29 @@
> 
> Hi, this part of the code is missing from Allegro.  I recognised it from
> https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=185214 but are
> there any more changes required?  A patch would be appreciated if you
> have one ready.

Never mind, I found it :)  I have attached an updated patch but not
really tested it yet.

The following comment does not make much sense.  Could you rephrase it?

/* mremap is only available under Linux, so is selinux which is the reason for
 * USE_MMAP_GEN_CODE_BUF so that is no problem.
 */

Peter

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