MAP_ANON and MAP_ANONYMOUS

[kinichiro]

I think MAP_ANON should be replaced with MAP_ANONYMOUS.

Seeing this
http://austingroupbugs.net/view.php?id=850
I noticed these descriptions.

• MAP_ANON is synonym for MAP_ANONYMOUS
• MAP_ANON shall have the same value as MAP_ANONYMOUS

It seems that MAP_ANONYMOUS will be more common than MAP_ANON.

constant MAP_ANON is used in these files.
./crypto/compat/getentropy_linux.c
./crypto/compat/arc4random_linux.h
./crypto/compat/getentropy_solaris.c
./crypto/compat/arc4random_solaris.h
./crypto/compat/getentropy_osx.c
./crypto/compat/arc4random_osx.h
./tests/arc4randomforktest.c

Thanks.

[bob-beck]

What platform is this an issue on?

[kinichiro]

Hi,
HP-UX 11.31 itanium without gcc.
I checked header files, too.

[kinichiro]

I checked mmap man page of several platforms on the WWW.
And I listed that MAP_ANON and MAP_ANONYMOUS are supported or not.

                 MAP_ANON  MAP_ANONYMOUS
    OpenBSD         Y         Y(*)
    Linux           Y(*)      Y
    FreeBSD         Y         Y
    NetBSD          Y         N
    OSX             Y         N
    Solaris         Y         N
    HP-UX           N         Y
    AIX             N         Y
    IRIX            N         N
    (*) synonym to other

Simply replacing MAP_ANON with MAP_ANONYMOUS will cause another issue, sorry.

Instead of replacing, how about adding define, like this.

    #ifndef MAP_ANONYMOUS
    #define MAP_ANONYMOUS MAP_ANON
    #endif

Thanks.

[busterb]

We added a compat definition in af705b3

[kinichiro]

Sorry,
If LibreSSL keeps using MAP_ANON, this include/sys/mman.h fix should be like this.

#ifndef MAP_ANON
#ifdef MAP_ANONYMOUS
#define MAP_ANON MAP_ANONYMOUS
#else
#error "System does not support mapping anonymous pages?"
#endif
#endif

My recommendation was wrong.
This fix should be for the platform that does NOT define MAP_ANON but MAP_ANONYMOUS.
Sorry, again.

[busterb]

I see. Thanks for the note, this is now fixed.

[kinichiro]

Thanks for everything, busterb.
I confirmed this is fixed.