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Date: Wed, 28 Nov 2018 15:11:45 -0800
From: Andrew Morton <akpm@...ux-foundation.org>
To: Rick Edgecombe <rick.p.edgecombe@...el.com>
Cc: luto@...nel.org, will.deacon@....com, linux-mm@...ck.org,
 linux-kernel@...r.kernel.org, kernel-hardening@...ts.openwall.com,
 naveen.n.rao@...ux.vnet.ibm.com, anil.s.keshavamurthy@...el.com,
 davem@...emloft.net, mhiramat@...nel.org, rostedt@...dmis.org,
 mingo@...hat.com, ast@...nel.org, daniel@...earbox.net, jeyu@...nel.org,
 netdev@...r.kernel.org, ard.biesheuvel@...aro.org, jannh@...gle.com,
 kristen@...ux.intel.com, dave.hansen@...el.com, deneen.t.dock@...el.com
Subject: Re: [PATCH 2/2] x86/modules: Make x86 allocs to flush when free

On Tue, 27 Nov 2018 16:07:54 -0800 Rick Edgecombe <rick.p.edgecombe@...el.com> wrote:

> Change the module allocations to flush before freeing the pages.
> 
> ...
>
> --- a/arch/x86/kernel/module.c
> +++ b/arch/x86/kernel/module.c
> @@ -87,8 +87,8 @@ void *module_alloc(unsigned long size)
>  	p = __vmalloc_node_range(size, MODULE_ALIGN,
>  				    MODULES_VADDR + get_module_load_offset(),
>  				    MODULES_END, GFP_KERNEL,
> -				    PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
> -				    __builtin_return_address(0));
> +				    PAGE_KERNEL_EXEC, VM_IMMEDIATE_UNMAP,
> +				    NUMA_NO_NODE, __builtin_return_address(0));
>  	if (p && (kasan_module_alloc(p, size) < 0)) {
>  		vfree(p);
>  		return NULL;

Should any other architectures do this?

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