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, 244 insertions, 0 deletions

diff --git a/crypto/cmac.c b/crypto/cmac.c
new file mode 100644
index 000000000..83e58937f
--- /dev/null
+++ b/crypto/cmac.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * CMAC: Cipher Block Mode for Authentication
+ *
+ * Copyright © 2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+ *
+ * Based on work by:
+ *  Copyright © 2013 Tom St Denis <tstdenis@elliptictech.com>
+ * Based on crypto/xcbc.c:
+ *  Copyright © 2006 USAGI/WIDE Project,
+ *   Author: Kazunori Miyazawa <miyazawa@linux-ipv6.org>
+ */
+
+#include <crypto/internal/cipher.h>
+#include <crypto/internal/hash.h>
+#include <crypto/utils.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+/*
+ * +------------------------
+ * | <parent tfm>
+ * +------------------------
+ * | cmac_tfm_ctx
+ * +------------------------
+ * | consts (block size * 2)
+ * +------------------------
+ */
+struct cmac_tfm_ctx {
+	struct crypto_cipher *child;
+	__be64 consts[];
+};
+
+static int crypto_cmac_digest_setkey(struct crypto_shash *parent,
+				     const u8 *inkey, unsigned int keylen)
+{
+	struct cmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
+	unsigned int bs = crypto_shash_blocksize(parent);
+	__be64 *consts = ctx->consts;
+	u64 _const[2];
+	int i, err = 0;
+	u8 msb_mask, gfmask;
+
+	err = crypto_cipher_setkey(ctx->child, inkey, keylen);
+	if (err)
+		return err;
+
+	/* encrypt the zero block */
+	memset(consts, 0, bs);
+	crypto_cipher_encrypt_one(ctx->child, (u8 *)consts, (u8 *)consts);
+
+	switch (bs) {
+	case 16:
+		gfmask = 0x87;
+		_const[0] = be64_to_cpu(consts[1]);
+		_const[1] = be64_to_cpu(consts[0]);
+
+		/* gf(2^128) multiply zero-ciphertext with u and u^2 */
+		for (i = 0; i < 4; i += 2) {
+			msb_mask = ((s64)_const[1] >> 63) & gfmask;
+			_const[1] = (_const[1] << 1) | (_const[0] >> 63);
+			_const[0] = (_const[0] << 1) ^ msb_mask;
+
+			consts[i + 0] = cpu_to_be64(_const[1]);
+			consts[i + 1] = cpu_to_be64(_const[0]);
+		}
+
+		break;
+	case 8:
+		gfmask = 0x1B;
+		_const[0] = be64_to_cpu(consts[0]);
+
+		/* gf(2^64) multiply zero-ciphertext with u and u^2 */
+		for (i = 0; i < 2; i++) {
+			msb_mask = ((s64)_const[0] >> 63) & gfmask;
+			_const[0] = (_const[0] << 1) ^ msb_mask;
+
+			consts[i] = cpu_to_be64(_const[0]);
+		}
+
+		break;
+	}
+
+	return 0;
+}
+
+static int crypto_cmac_digest_init(struct shash_desc *pdesc)
+{
+	int bs = crypto_shash_blocksize(pdesc->tfm);
+	u8 *prev = shash_desc_ctx(pdesc);
+
+	memset(prev, 0, bs);
+	return 0;
+}
+
+static int crypto_cmac_digest_update(struct shash_desc *pdesc, const u8 *p,
+				     unsigned int len)
+{
+	struct crypto_shash *parent = pdesc->tfm;
+	struct cmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
+	struct crypto_cipher *tfm = tctx->child;
+	int bs = crypto_shash_blocksize(parent);
+	u8 *prev = shash_desc_ctx(pdesc);
+
+	do {
+		crypto_xor(prev, p, bs);
+		crypto_cipher_encrypt_one(tfm, prev, prev);
+		p += bs;
+		len -= bs;
+	} while (len >= bs);
+	return len;
+}
+
+static int crypto_cmac_digest_finup(struct shash_desc *pdesc, const u8 *src,
+				    unsigned int len, u8 *out)
+{
+	struct crypto_shash *parent = pdesc->tfm;
+	struct cmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
+	struct crypto_cipher *tfm = tctx->child;
+	int bs = crypto_shash_blocksize(parent);
+	u8 *prev = shash_desc_ctx(pdesc);
+	unsigned int offset = 0;
+
+	crypto_xor(prev, src, len);
+	if (len != bs) {
+		prev[len] ^= 0x80;
+		offset += bs;
+	}
+	crypto_xor(prev, (const u8 *)tctx->consts + offset, bs);
+	crypto_cipher_encrypt_one(tfm, out, prev);
+	return 0;
+}
+
+static int cmac_init_tfm(struct crypto_shash *tfm)
+{
+	struct shash_instance *inst = shash_alg_instance(tfm);
+	struct cmac_tfm_ctx *ctx = crypto_shash_ctx(tfm);
+	struct crypto_cipher_spawn *spawn;
+	struct crypto_cipher *cipher;
+
+	spawn = shash_instance_ctx(inst);
+	cipher = crypto_spawn_cipher(spawn);
+	if (IS_ERR(cipher))
+		return PTR_ERR(cipher);
+
+	ctx->child = cipher;
+
+	return 0;
+}
+
+static void cmac_exit_tfm(struct crypto_shash *tfm)
+{
+	struct cmac_tfm_ctx *ctx = crypto_shash_ctx(tfm);
+	crypto_free_cipher(ctx->child);
+}
+
+static int cmac_create(struct crypto_template *tmpl, struct rtattr **tb)
+{
+	struct shash_instance *inst;
+	struct crypto_cipher_spawn *spawn;
+	struct crypto_alg *alg;
+	u32 mask;
+	int err;
+
+	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
+	if (err)
+		return err;
+
+	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+	if (!inst)
+		return -ENOMEM;
+	spawn = shash_instance_ctx(inst);
+
+	err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
+				 crypto_attr_alg_name(tb[1]), 0, mask);
+	if (err)
+		goto err_free_inst;
+	alg = crypto_spawn_cipher_alg(spawn);
+
+	switch (alg->cra_blocksize) {
+	case 16:
+	case 8:
+		break;
+	default:
+		err = -EINVAL;
+		goto err_free_inst;
+	}
+
+	err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
+	if (err)
+		goto err_free_inst;
+
+	inst->alg.base.cra_priority = alg->cra_priority;
+	inst->alg.base.cra_blocksize = alg->cra_blocksize;
+	inst->alg.base.cra_ctxsize = sizeof(struct cmac_tfm_ctx) +
+				     alg->cra_blocksize * 2;
+	inst->alg.base.cra_flags = CRYPTO_AHASH_ALG_BLOCK_ONLY |
+				   CRYPTO_AHASH_ALG_FINAL_NONZERO;
+
+	inst->alg.digestsize = alg->cra_blocksize;
+	inst->alg.descsize = alg->cra_blocksize;
+	inst->alg.init = crypto_cmac_digest_init;
+	inst->alg.update = crypto_cmac_digest_update;
+	inst->alg.finup = crypto_cmac_digest_finup;
+	inst->alg.setkey = crypto_cmac_digest_setkey;
+	inst->alg.init_tfm = cmac_init_tfm;
+	inst->alg.exit_tfm = cmac_exit_tfm;
+
+	inst->free = shash_free_singlespawn_instance;
+
+	err = shash_register_instance(tmpl, inst);
+	if (err) {
+err_free_inst:
+		shash_free_singlespawn_instance(inst);
+	}
+	return err;
+}
+
+static struct crypto_template crypto_cmac_tmpl = {
+	.name = "cmac",
+	.create = cmac_create,
+	.module = THIS_MODULE,
+};
+
+static int __init crypto_cmac_module_init(void)
+{
+	return crypto_register_template(&crypto_cmac_tmpl);
+}
+
+static void __exit crypto_cmac_module_exit(void)
+{
+	crypto_unregister_template(&crypto_cmac_tmpl);
+}
+
+module_init(crypto_cmac_module_init);
+module_exit(crypto_cmac_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CMAC keyed hash algorithm");
+MODULE_ALIAS_CRYPTO("cmac");
+MODULE_IMPORT_NS("CRYPTO_INTERNAL");