Thread (19 messages) 19 messages, 3 authors, 2022-03-16

Re: [EXT] Re: [PATCH v5 4/5] crypto: caam - add in-kernel interface for blob generator

From: Ahmad Fatoum <a.fatoum@pengutronix.de>
Date: 2022-03-14 15:34:25
Also in: keyrings, linux-crypto, linux-integrity, lkml

Hello Pankaj,

On 25.02.22 13:20, Pankaj Gupta wrote:
quoted
quoted
quoted
+static u32 *caam_blob_alloc_desc(size_t keymod_len) {
+    size_t len;
+
+    /* header + (key mod immediate) + 2x pointers + op */
+    len = 4 + (4 + ALIGN(keymod_len, 4)) + 2*(4 + 4 +
+ CAAM_PTR_SZ_MAX) + 4;
Nit: the amount of magic numbers is overwhelming here. I neither
understand the statement nor how that comment should help me to
understand it.

header              =  4
(key mod immediate) = (4 + ALIGN(keymod_len, 4))
2x pointer          =  2 * (4 + 4 + CAAM_PTR_SZ_MAX)
op                  =  4
Instead of the function caam_blob_alloc_desc(), it will be great if the caller functions caam_encap_blob()/caam_encap_blob (), could add local array:
uint32_t desc[CAAM_DESC_BYTES_MAX];
I just looked into this and placing desc on stack is not possible
as it is used for DMA inside caam_jr_enqueue().

Cheers,
Ahmad


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