svn commit: r352585 - head/sys/kern

[Ryan Stone]

Thanks!

On Sat, Sep 21, 2019 at 4:03 PM Konstantin Belousov <kib at freebsd.org> wrote:
>
> Author: kib
> Date: Sat Sep 21 20:03:17 2019
> New Revision: 352585
> URL: https://svnweb.freebsd.org/changeset/base/352585
>
> Log:
>   kern.elf{32,64}.pie_base sysctl: enforce page alignment.
>
>   Requested by: rstone
>   Sponsored by: The FreeBSD Foundation
>   MFC after:    1 week
>
> Modified:
>   head/sys/kern/imgact_elf.c
>
> Modified: head/sys/kern/imgact_elf.c
> ==============================================================================
> --- head/sys/kern/imgact_elf.c  Sat Sep 21 19:51:57 2019        (r352584)
> +++ head/sys/kern/imgact_elf.c  Sat Sep 21 20:03:17 2019        (r352585)
> @@ -136,8 +136,24 @@ SYSCTL_INT(_kern_elf32, OID_AUTO, read_exec, CTLFLAG_R
>  #endif
>
>  static u_long __elfN(pie_base) = ET_DYN_LOAD_ADDR;
> -SYSCTL_ULONG(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, pie_base,
> -    CTLFLAG_RWTUN, &__elfN(pie_base), 0,
> +static int
> +sysctl_pie_base(SYSCTL_HANDLER_ARGS)
> +{
> +       u_long val;
> +       int error;
> +
> +       val = __elfN(pie_base);
> +       error = sysctl_handle_long(oidp, &val, 0, req);
> +       if (error != 0 || req->newptr == NULL)
> +               return (error);
> +       if ((val & PAGE_MASK) != 0)
> +               return (EINVAL);
> +       __elfN(pie_base) = val;
> +       return (0);
> +}
> +SYSCTL_PROC(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, pie_base,
> +    CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0,
> +    sysctl_pie_base, "LU",
>      "PIE load base without randomization");
>
>  SYSCTL_NODE(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, aslr, CTLFLAG_RW, 0,