Re: [PATCH v2] crypto/caam: Avoid GCC constprop bug warning

[Herbert Xu]

On Thu, Dec 01, 2022 at 07:30:22PM -0800, Kees Cook wrote:
>
> Getting rid of the if doesn't solve the warning. I can switch it to just
> "if (data)", though. That keeps GCC happy.

OK I misread the thread.

Anyhow, it appears that this warning only occurs due to a debug
printk in caam.  So how about something like this?

diff --git a/drivers/crypto/caam/desc_constr.h b/drivers/crypto/caam/desc_constr.h
index 62ce6421bb3f..b49c995e1cc6 100644
--- a/drivers/crypto/caam/desc_constr.h
+++ b/drivers/crypto/caam/desc_constr.h
@@ -163,7 +163,7 @@ static inline void append_data(u32 * const desc, const void *data, int len)
 {
 	u32 *offset = desc_end(desc);
 
-	if (len) /* avoid sparse warning: memcpy with byte count of 0 */
+	if (!IS_ENABLED(CONFIG_CRYPTO_DEV_FSL_CAAM_DEBUG) || data)
 		memcpy(offset, data, len);
 
 	(*desc) = cpu_to_caam32(caam32_to_cpu(*desc) +

Thanks,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt