main/linux-lts: backport export mmu_feature_keys as non-GPL

This is needed for ZFS 2.1.5 on PowerPC, background:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1009242

main/linux-lts/APKBUILD

@@ -7,7 +7,7 @@ case $pkgver in
 	*.*.*)	_kernver=${pkgver%.*};;
 	*.*) _kernver=$pkgver;;
 esac
-pkgrel=0
+pkgrel=1
 pkgdesc="Linux lts kernel"
 url="https://www.kernel.org"
 depends="initramfs-generator"
@@ -20,6 +20,7 @@ install=
 source="https://cdn.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/linux-$_kernver.tar.xz
 	0001-powerpc-config-defang-gcc-check-for-stack-protector-.patch
 	vmlinux-zstd.patch
+	ppc-export_mmu_feature_keys_as_non-GPL.patch
 
 	lts.aarch64.config
 	lts.armv7.config
@@ -305,4 +306,5 @@ a6021519a9c71ae86199b87f458f3814d67c03cc005301d48d4a9f44280627fad4a70138ee4e0c42
 c0ddfee06f958192653d840ca14fd60d5d3d88311b1335d691fc4d4c5a7575c5771351a0ec5e3d34544c76c34e4ee8731cc45fa18da77909924f0b9b6ef75d87  virt.x86.config
 fd5dea1a2ada211e1cf673553a0e2df3af7ffc4ae35b316b0d009145bcddf984cfd98c2b1e91de08c10a3442e32ff470d1285ef5d291068fb319160bb9552cf1  virt.x86_64.config
 08ede2bc8363a24a6f843021fee93ebe46d2bc01d2bf732fa140bbd5aa99130f00ea021b2b86a49a021a48368fe4d2e848604c7d86a801d268df83c02a183cab  patch-5.15.49.xz
+bb374cecb32f32f2fe669ed00abbbe35a91ddcda469801a5cc4a4941605aa1768cd872a54906acf77d627ee7addd21b0565f73495a49e34c5bce3865deb4b45a  ppc-export_mmu_feature_keys_as_non-GPL.patch
 "

main/linux-lts/ppc-export_mmu_feature_keys_as_non-GPL.patch

+From d9e5c3e9e75162f845880535957b7fd0b4637d23 Mon Sep 17 00:00:00 2001
+From: Kevin Hao <haokexin@gmail.com>
+Date: Tue, 29 Mar 2022 16:57:09 +0800
+Subject: [PATCH] powerpc: Export mmu_feature_keys[] as non-GPL
+
+When the mmu_feature_keys[] was introduced in the commit c12e6f24d413
+("powerpc: Add option to use jump label for mmu_has_feature()"),
+it is unlikely that it would be used either directly or indirectly in
+the out of tree modules. So we exported it as GPL only.
+
+But with the evolution of the codes, especially the PPC_KUAP support, it
+may be indirectly referenced by some primitive macro or inline functions
+such as get_user() or __copy_from_user_inatomic(), this will make it
+impossible to build many non GPL modules (such as ZFS) on ppc
+architecture. Fix this by exposing the mmu_feature_keys[] to the non-GPL
+modules too.
+
+Fixes: 7613f5a66bec ("powerpc/64s/kuap: Use mmu_has_feature()")
+Reported-by: Nathaniel Filardo <nwfilardo@gmail.com>
+Signed-off-by: Kevin Hao <haokexin@gmail.com>
+Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
+Link: https://lore.kernel.org/r/20220329085709.4132729-1-haokexin@gmail.com
+---
+ arch/powerpc/kernel/cputable.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
+index 7bd6546b9fde..f9b3def5b254 100644
+--- a/arch/powerpc/kernel/cputable.c
++++ b/arch/powerpc/kernel/cputable.c
+@@ -2119,7 +2119,7 @@ void __init cpu_feature_keys_init(void)
+ struct static_key_true mmu_feature_keys[NUM_MMU_FTR_KEYS] = {
+ 			[0 ... NUM_MMU_FTR_KEYS - 1] = STATIC_KEY_TRUE_INIT
+ };
+-EXPORT_SYMBOL_GPL(mmu_feature_keys);
++EXPORT_SYMBOL(mmu_feature_keys);
+ 
+ void __init mmu_feature_keys_init(void)
+ {
+-- 
+2.36.1
+