1 files changed, 30 insertions, 30 deletions

diff --git a/kernel/lib/mpi/mpicoder.c b/kernel/lib/mpi/mpicoder.c
index 3db76b8c1..e37dbf53e 100644
--- a/kernel/lib/mpi/mpicoder.c
+++ b/kernel/lib/mpi/mpicoder.c
@@ -128,6 +128,23 @@ leave:
 }
 EXPORT_SYMBOL_GPL(mpi_read_from_buffer);
 
+static int count_lzeros(MPI a)
+{
+	mpi_limb_t alimb;
+	int i, lzeros = 0;
+
+	for (i = a->nlimbs - 1; i >= 0; i--) {
+		alimb = a->d[i];
+		if (alimb == 0) {
+			lzeros += sizeof(mpi_limb_t);
+		} else {
+			lzeros += count_leading_zeros(alimb) / 8;
+			break;
+		}
+	}
+	return lzeros;
+}
+
 /**
  * mpi_read_buffer() - read MPI to a bufer provided by user (msb first)
  *
@@ -146,7 +163,7 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
 	uint8_t *p;
 	mpi_limb_t alimb;
 	unsigned int n = mpi_get_size(a);
-	int i, lzeros = 0;
+	int i, lzeros;
 
 	if (buf_len < n || !buf || !nbytes)
 		return -EINVAL;
@@ -154,14 +171,7 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
 	if (sign)
 		*sign = a->sign;
 
-	p = (void *)&a->d[a->nlimbs] - 1;
-
-	for (i = a->nlimbs * sizeof(alimb) - 1; i >= 0; i--, p--) {
-		if (!*p)
-			lzeros++;
-		else
-			break;
-	}
+	lzeros = count_lzeros(a);
 
 	p = buf;
 	*nbytes = n - lzeros;
@@ -343,7 +353,7 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes,
 	u8 *p, *p2;
 	mpi_limb_t alimb, alimb2;
 	unsigned int n = mpi_get_size(a);
-	int i, x, y = 0, lzeros = 0, buf_len;
+	int i, x, y = 0, lzeros, buf_len;
 
 	if (!nbytes || *nbytes < n)
 		return -EINVAL;
@@ -351,20 +361,15 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes,
 	if (sign)
 		*sign = a->sign;
 
-	p = (void *)&a->d[a->nlimbs] - 1;
-
-	for (i = a->nlimbs * sizeof(alimb) - 1; i >= 0; i--, p--) {
-		if (!*p)
-			lzeros++;
-		else
-			break;
-	}
+	lzeros = count_lzeros(a);
 
 	*nbytes = n - lzeros;
 	buf_len = sgl->length;
 	p2 = sg_virt(sgl);
 
-	for (i = a->nlimbs - 1; i >= 0; i--) {
+	for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB,
+			lzeros %= BYTES_PER_MPI_LIMB;
+		i >= 0; i--) {
 		alimb = a->d[i];
 		p = (u8 *)&alimb2;
 #if BYTES_PER_MPI_LIMB == 4
@@ -385,17 +390,12 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes,
 #error please implement for this limb size.
 #endif
 		if (lzeros > 0) {
-			if (lzeros >= sizeof(alimb)) {
-				p -= sizeof(alimb);
-				continue;
-			} else {
-				mpi_limb_t *limb1 = (void *)p - sizeof(alimb);
-				mpi_limb_t *limb2 = (void *)p - sizeof(alimb)
-							+ lzeros;
-				*limb1 = *limb2;
-				p -= lzeros;
-				y = lzeros;
-			}
+			mpi_limb_t *limb1 = (void *)p - sizeof(alimb);
+			mpi_limb_t *limb2 = (void *)p - sizeof(alimb)
+				+ lzeros;
+			*limb1 = *limb2;
+			p -= lzeros;
+			y = lzeros;
 			lzeros -= sizeof(alimb);
 		}