Commit 7adbf10e authored by Will Deacon's avatar Will Deacon Committed by Catalin Marinas
Browse files

arm64: compat: Allow signal page to be remapped 



For compatability with 32-bit Arm, allow the compat signal page to be
remapped via mremap().

Signed-off-by: default avatarWill Deacon <will@kernel.org>
Reviewed-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/20210318170738.7756-4-will@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent e9be47ea

arch/arm64/kernel/vdso.c

+9 −0
Original line number Diff line number Diff line
@@ -271,6 +271,14 @@ enum aarch32_map { 
static struct page *aarch32_vectors_page __ro_after_init;

static struct page *aarch32_sig_page __ro_after_init;



static int aarch32_sigpage_mremap(const struct vm_special_mapping *sm,

				  struct vm_area_struct *new_vma)

{

	current->mm->context.sigpage = (void *)new_vma->vm_start;



	return 0;

}



static struct vm_special_mapping aarch32_vdso_maps[] = {

	[AA32_MAP_VECTORS] = {

		.name	= "[vectors]", /* ABI */
@@ -279,6 +287,7 @@ static struct vm_special_mapping aarch32_vdso_maps[] = { 
	[AA32_MAP_SIGPAGE] = {

		.name	= "[sigpage]", /* ABI */

		.pages	= &aarch32_sig_page,

		.mremap	= aarch32_sigpage_mremap,

	},

	[AA32_MAP_VVAR] = {

		.name = "[vvar]",