cr50: merge always_memset() and memset()stabilize-rust-14220.B-cr50_stab

There is no point in having separate implementation of always_memset()
which is slow and takes few extra bytes. Make memset's body available
as memset_core() with volatile dest *, thus making it always called
same as with always_memset(). Both memset() and always_memset() becomes
just wrappers on top.

BUG=none
TEST=make BOARD=cr50 CRYPTO_TEST=1; board boots, FIPS tests passes,
tpm_test.py works.

Signed-off-by: Vadim Sukhomlinov <sukhomlinov@google.com>
Change-Id: I68b3f89e757521e94df646f7d643411c53a10da7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3155725
Reviewed-by: Vadim Sukhomlinov <sukhomlinov@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Tested-by: Vadim Sukhomlinov <sukhomlinov@chromium.org>
Commit-Queue: Vadim Sukhomlinov <sukhomlinov@chromium.org>

1 files changed, 11 insertions, 15 deletions

diff --git a/board/cr50/dcrypto/util.c b/board/cr50/dcrypto/util.c
index 117fec60b4..2529036d4f 100644
--- a/board/cr50/dcrypto/util.c
+++ b/board/cr50/dcrypto/util.c
@@ -80,12 +80,11 @@ __stdlib_compat void *memcpy(void *dest, const void *src, size_t len)
 	return dest;
 }
 
-
-__stdlib_compat __visible void *memset(void *dest, int c, size_t len)
+static void *memset_core(volatile void *dest, int c, size_t len)
 {
-	char *d = (char *)dest;
+	volatile char *d = (volatile char *)dest;
 	uint32_t cccc;
-	uint32_t *dw;
+	volatile uint32_t *dw;
 	char *head;
 	char * const tail = (char *)dest + len;
 	/* Set 'body' to the last word boundary */
@@ -106,18 +105,22 @@ __stdlib_compat __visible void *memset(void *dest, int c, size_t len)
 		*(d++) = c;
 
 	/* Copy body */
-	dw = (uint32_t *)d;
+	dw = (volatile uint32_t *)d;
 	while (dw < body)
 		*(dw++) = cccc;
 
 	/* Copy tail */
-	d = (char *)dw;
+	d = (volatile char *)dw;
 	while (d < tail)
 		*(d++) = c;
 
-	return dest;
+	return (void *)dest;
 }
 
+__stdlib_compat __visible void *memset(void *dest, int c, size_t len)
+{
+	return memset_core(dest, c, len);
+}
 
 __stdlib_compat void *memmove(void *dest, const void *src, size_t len)
 {
@@ -204,14 +207,7 @@ __stdlib_compat int strncmp(const char *s1, const char *s2, size_t n)
 	return 0;
 }
 
-static void always_memset_impl(volatile char *s, int c, size_t n)
-{
-	while (n--)
-		*s++ = c;
-}
-
 void *always_memset(void *s, int c, size_t n)
 {
-	always_memset_impl(s, c, n);
-	return s;
+	return memset_core(s, c, n);
 }