kernel: 5.4: import wireguard backport

Rather than using the clunky, old, slower wireguard-linux-compat out of
tree module, this commit does a patch-by-patch backport of upstream's
wireguard to 5.4. This specific backport is in widespread use, being
part of SUSE's enterprise kernel, Oracle's enterprise kernel, Google's
Android kernel, Gentoo's distro kernel, and probably more I've forgotten
about. It's definately the "more proper" way of adding wireguard to a
kernel than the ugly compat.h hell of the wireguard-linux-compat repo.
And most importantly for OpenWRT, it allows using the same module
configuration code for 5.10 as for 5.4, with no need for bifurcation.

These patches are from the backport tree which is maintained in the
open here: https://git.zx2c4.com/wireguard-linux/log/?h=backport-5.4.y
I'll be sending PRs to update this as needed.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 171 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.4/080-wireguard-0044-crypto-arm-arm64-mips-poly1305-remove-redundant-non-.patch b/target/linux/generic/backport-5.4/080-wireguard-0044-crypto-arm-arm64-mips-poly1305-remove-redundant-non-.patch
new file mode 100644
index 0000000000..e1c719fc01
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0044-crypto-arm-arm64-mips-poly1305-remove-redundant-non-.patch
@@ -0,0 +1,171 @@
+From 3b1cffd5e47b394b8c0a92583e26acf599022364 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Sun, 5 Jan 2020 22:40:49 -0500
+Subject: [PATCH 044/124] crypto: {arm,arm64,mips}/poly1305 - remove redundant
+ non-reduction from emit
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+commit 31899908a0d248b030b4464425b86c717e0007d4 upstream.
+
+This appears to be some kind of copy and paste error, and is actually
+dead code.
+
+Pre: f = 0 ⇒ (f >> 32) = 0
+    f = (f >> 32) + le32_to_cpu(digest[0]);
+Post: 0 ≤ f < 2³²
+    put_unaligned_le32(f, dst);
+
+Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0
+    f = (f >> 32) + le32_to_cpu(digest[1]);
+Post: 0 ≤ f < 2³²
+    put_unaligned_le32(f, dst + 4);
+
+Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0
+    f = (f >> 32) + le32_to_cpu(digest[2]);
+Post: 0 ≤ f < 2³²
+    put_unaligned_le32(f, dst + 8);
+
+Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0
+    f = (f >> 32) + le32_to_cpu(digest[3]);
+Post: 0 ≤ f < 2³²
+    put_unaligned_le32(f, dst + 12);
+
+Therefore this sequence is redundant. And Andy's code appears to handle
+misalignment acceptably.
+
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Tested-by: Ard Biesheuvel <ardb@kernel.org>
+Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
+Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ arch/arm/crypto/poly1305-glue.c   | 18 ++----------------
+ arch/arm64/crypto/poly1305-glue.c | 18 ++----------------
+ arch/mips/crypto/poly1305-glue.c  | 18 ++----------------
+ 3 files changed, 6 insertions(+), 48 deletions(-)
+
+--- a/arch/arm/crypto/poly1305-glue.c
++++ b/arch/arm/crypto/poly1305-glue.c
+@@ -20,7 +20,7 @@
+ 
+ void poly1305_init_arm(void *state, const u8 *key);
+ void poly1305_blocks_arm(void *state, const u8 *src, u32 len, u32 hibit);
+-void poly1305_emit_arm(void *state, __le32 *digest, const u32 *nonce);
++void poly1305_emit_arm(void *state, u8 *digest, const u32 *nonce);
+ 
+ void __weak poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit)
+ {
+@@ -179,9 +179,6 @@ EXPORT_SYMBOL(poly1305_update_arch);
+ 
+ void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
+ {
+-	__le32 digest[4];
+-	u64 f = 0;
+-
+ 	if (unlikely(dctx->buflen)) {
+ 		dctx->buf[dctx->buflen++] = 1;
+ 		memset(dctx->buf + dctx->buflen, 0,
+@@ -189,18 +186,7 @@ void poly1305_final_arch(struct poly1305
+ 		poly1305_blocks_arm(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
+ 	}
+ 
+-	poly1305_emit_arm(&dctx->h, digest, dctx->s);
+-
+-	/* mac = (h + s) % (2^128) */
+-	f = (f >> 32) + le32_to_cpu(digest[0]);
+-	put_unaligned_le32(f, dst);
+-	f = (f >> 32) + le32_to_cpu(digest[1]);
+-	put_unaligned_le32(f, dst + 4);
+-	f = (f >> 32) + le32_to_cpu(digest[2]);
+-	put_unaligned_le32(f, dst + 8);
+-	f = (f >> 32) + le32_to_cpu(digest[3]);
+-	put_unaligned_le32(f, dst + 12);
+-
++	poly1305_emit_arm(&dctx->h, dst, dctx->s);
+ 	*dctx = (struct poly1305_desc_ctx){};
+ }
+ EXPORT_SYMBOL(poly1305_final_arch);
+--- a/arch/arm64/crypto/poly1305-glue.c
++++ b/arch/arm64/crypto/poly1305-glue.c
+@@ -21,7 +21,7 @@
+ asmlinkage void poly1305_init_arm64(void *state, const u8 *key);
+ asmlinkage void poly1305_blocks(void *state, const u8 *src, u32 len, u32 hibit);
+ asmlinkage void poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit);
+-asmlinkage void poly1305_emit(void *state, __le32 *digest, const u32 *nonce);
++asmlinkage void poly1305_emit(void *state, u8 *digest, const u32 *nonce);
+ 
+ static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
+ 
+@@ -162,9 +162,6 @@ EXPORT_SYMBOL(poly1305_update_arch);
+ 
+ void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
+ {
+-	__le32 digest[4];
+-	u64 f = 0;
+-
+ 	if (unlikely(dctx->buflen)) {
+ 		dctx->buf[dctx->buflen++] = 1;
+ 		memset(dctx->buf + dctx->buflen, 0,
+@@ -172,18 +169,7 @@ void poly1305_final_arch(struct poly1305
+ 		poly1305_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
+ 	}
+ 
+-	poly1305_emit(&dctx->h, digest, dctx->s);
+-
+-	/* mac = (h + s) % (2^128) */
+-	f = (f >> 32) + le32_to_cpu(digest[0]);
+-	put_unaligned_le32(f, dst);
+-	f = (f >> 32) + le32_to_cpu(digest[1]);
+-	put_unaligned_le32(f, dst + 4);
+-	f = (f >> 32) + le32_to_cpu(digest[2]);
+-	put_unaligned_le32(f, dst + 8);
+-	f = (f >> 32) + le32_to_cpu(digest[3]);
+-	put_unaligned_le32(f, dst + 12);
+-
++	poly1305_emit(&dctx->h, dst, dctx->s);
+ 	*dctx = (struct poly1305_desc_ctx){};
+ }
+ EXPORT_SYMBOL(poly1305_final_arch);
+--- a/arch/mips/crypto/poly1305-glue.c
++++ b/arch/mips/crypto/poly1305-glue.c
+@@ -15,7 +15,7 @@
+ 
+ asmlinkage void poly1305_init_mips(void *state, const u8 *key);
+ asmlinkage void poly1305_blocks_mips(void *state, const u8 *src, u32 len, u32 hibit);
+-asmlinkage void poly1305_emit_mips(void *state, __le32 *digest, const u32 *nonce);
++asmlinkage void poly1305_emit_mips(void *state, u8 *digest, const u32 *nonce);
+ 
+ void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
+ {
+@@ -134,9 +134,6 @@ EXPORT_SYMBOL(poly1305_update_arch);
+ 
+ void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
+ {
+-	__le32 digest[4];
+-	u64 f = 0;
+-
+ 	if (unlikely(dctx->buflen)) {
+ 		dctx->buf[dctx->buflen++] = 1;
+ 		memset(dctx->buf + dctx->buflen, 0,
+@@ -144,18 +141,7 @@ void poly1305_final_arch(struct poly1305
+ 		poly1305_blocks_mips(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
+ 	}
+ 
+-	poly1305_emit_mips(&dctx->h, digest, dctx->s);
+-
+-	/* mac = (h + s) % (2^128) */
+-	f = (f >> 32) + le32_to_cpu(digest[0]);
+-	put_unaligned_le32(f, dst);
+-	f = (f >> 32) + le32_to_cpu(digest[1]);
+-	put_unaligned_le32(f, dst + 4);
+-	f = (f >> 32) + le32_to_cpu(digest[2]);
+-	put_unaligned_le32(f, dst + 8);
+-	f = (f >> 32) + le32_to_cpu(digest[3]);
+-	put_unaligned_le32(f, dst + 12);
+-
++	poly1305_emit_mips(&dctx->h, dst, dctx->s);
+ 	*dctx = (struct poly1305_desc_ctx){};
+ }
+ EXPORT_SYMBOL(poly1305_final_arch);