iio: proximity: isl29501: Fix return type of isl29501_register_writegrafted

isl29501_register_write() was returning a u32 instead of an int.
Since the function returns negative error codes (such as -ERANGE or
return values from i2c_smbus_write_byte_data()), returning an unsigned
integer type prevents callers from correctly checking for negative error
conditions.

Fix this by changing the function return type from u32 to int.

This was found through manual code review.

Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.")
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 153 insertions, 0 deletions

diff --git a/crypto/echainiv.c b/crypto/echainiv.c
new file mode 100644
index 000000000..e0a2d3209
--- /dev/null
+++ b/crypto/echainiv.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * echainiv: Encrypted Chain IV Generator
+ *
+ * This generator generates an IV based on a sequence number by multiplying
+ * it with a salt and then encrypting it with the same key as used to encrypt
+ * the plain text.  This algorithm requires that the block size be equal
+ * to the IV size.  It is mainly useful for CBC.
+ *
+ * This generator can only be used by algorithms where authentication
+ * is performed after encryption (i.e., authenc).
+ *
+ * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <crypto/internal/geniv.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/skcipher.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+static int echainiv_encrypt(struct aead_request *req)
+{
+	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
+	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
+	struct aead_request *subreq = aead_request_ctx(req);
+	__be64 nseqno;
+	u64 seqno;
+	u8 *info;
+	unsigned int ivsize = crypto_aead_ivsize(geniv);
+
+	if (req->cryptlen < ivsize)
+		return -EINVAL;
+
+	aead_request_set_tfm(subreq, ctx->child);
+
+	info = req->iv;
+
+	if (req->src != req->dst)
+		memcpy_sglist(req->dst, req->src,
+			      req->assoclen + req->cryptlen);
+
+	aead_request_set_callback(subreq, req->base.flags,
+				  req->base.complete, req->base.data);
+	aead_request_set_crypt(subreq, req->dst, req->dst,
+			       req->cryptlen, info);
+	aead_request_set_ad(subreq, req->assoclen);
+
+	memcpy(&nseqno, info + ivsize - 8, 8);
+	seqno = be64_to_cpu(nseqno);
+	memset(info, 0, ivsize);
+
+	scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
+
+	do {
+		u64 a;
+
+		memcpy(&a, ctx->salt + ivsize - 8, 8);
+
+		a |= 1;
+		a *= seqno;
+
+		memcpy(info + ivsize - 8, &a, 8);
+	} while ((ivsize -= 8));
+
+	return crypto_aead_encrypt(subreq);
+}
+
+static int echainiv_decrypt(struct aead_request *req)
+{
+	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
+	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
+	struct aead_request *subreq = aead_request_ctx(req);
+	crypto_completion_t compl;
+	void *data;
+	unsigned int ivsize = crypto_aead_ivsize(geniv);
+
+	if (req->cryptlen < ivsize)
+		return -EINVAL;
+
+	aead_request_set_tfm(subreq, ctx->child);
+
+	compl = req->base.complete;
+	data = req->base.data;
+
+	aead_request_set_callback(subreq, req->base.flags, compl, data);
+	aead_request_set_crypt(subreq, req->src, req->dst,
+			       req->cryptlen - ivsize, req->iv);
+	aead_request_set_ad(subreq, req->assoclen + ivsize);
+
+	scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
+
+	return crypto_aead_decrypt(subreq);
+}
+
+static int echainiv_aead_create(struct crypto_template *tmpl,
+				struct rtattr **tb)
+{
+	struct aead_instance *inst;
+	int err;
+
+	inst = aead_geniv_alloc(tmpl, tb);
+
+	if (IS_ERR(inst))
+		return PTR_ERR(inst);
+
+	err = -EINVAL;
+	if (inst->alg.ivsize & (sizeof(u64) - 1) || !inst->alg.ivsize)
+		goto free_inst;
+
+	inst->alg.encrypt = echainiv_encrypt;
+	inst->alg.decrypt = echainiv_decrypt;
+
+	inst->alg.init = aead_init_geniv;
+	inst->alg.exit = aead_exit_geniv;
+
+	inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
+	inst->alg.base.cra_ctxsize += inst->alg.ivsize;
+
+	err = aead_register_instance(tmpl, inst);
+	if (err) {
+free_inst:
+		inst->free(inst);
+	}
+	return err;
+}
+
+static struct crypto_template echainiv_tmpl = {
+	.name = "echainiv",
+	.create = echainiv_aead_create,
+	.module = THIS_MODULE,
+};
+
+static int __init echainiv_module_init(void)
+{
+	return crypto_register_template(&echainiv_tmpl);
+}
+
+static void __exit echainiv_module_exit(void)
+{
+	crypto_unregister_template(&echainiv_tmpl);
+}
+
+module_init(echainiv_module_init);
+module_exit(echainiv_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Encrypted Chain IV Generator");
+MODULE_ALIAS_CRYPTO("echainiv");