Re: [PATCH v4 05/12] elf: Allow arch to tweak initial mmap prot flags

[Catalin Marinas]

On Wed, Dec 11, 2019 at 03:41:59PM +0000, Mark Brown wrote:
> From: Dave Martin <Dave.Martin@xxxxxxx>
> 
> An arch may want to tweak the mmap prot flags for an
> ELFexecutable's initial mappings.  For example, arm64 is going to
> need to add PROT_BTI for executable pages in an ELF process whose
> executable is marked as using Branch Target Identification (an
> ARMv8.5-A control flow integrity feature).
> 
> So that this can be done in a generic way, add a hook
> arch_elf_adjust_prot() to modify the prot flags as desired: arches
> can select CONFIG_HAVE_ELF_PROT and implement their own backend
> where necessary.
> 
> By default, leave the prot flags unchanged.
> 
> Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>

Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>