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[PATCH RESEND v2 07/14] lib/mpi: mpi_read_buffer(): replace open coded endian conversion

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Currently, the endian conversion from CPU order to BE is open coded in
mpi_read_buffer().

Replace this by the centrally provided cpu_to_be*() macros.
Copy from the temporary storage on stack to the destination buffer
by means of memcpy().

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
---
 lib/mpi/mpicoder.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index 2fd8d41..a999ee1 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -21,6 +21,7 @@
 #include <linux/bitops.h>
 #include <linux/count_zeros.h>
 #include <linux/byteorder/generic.h>
+#include <linux/string.h>
 #include "mpi-internal.h"
 
 #define MAX_EXTERN_MPI_BITS 16384
@@ -164,7 +165,13 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
 		    int *sign)
 {
 	uint8_t *p;
-	mpi_limb_t alimb;
+#if BYTES_PER_MPI_LIMB == 4
+	__be32 alimb;
+#elif BYTES_PER_MPI_LIMB == 8
+	__be64 alimb;
+#else
+#error please implement for this limb size.
+#endif
 	unsigned int n = mpi_get_size(a);
 	int i, lzeros;
 
@@ -187,25 +194,15 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
 	for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB,
 			lzeros %= BYTES_PER_MPI_LIMB;
 		i >= 0; i--) {
-		alimb = a->d[i];
 #if BYTES_PER_MPI_LIMB == 4
-		*p++ = alimb >> 24;
-		*p++ = alimb >> 16;
-		*p++ = alimb >> 8;
-		*p++ = alimb;
+		alimb = cpu_to_be32(a->d[i]);
 #elif BYTES_PER_MPI_LIMB == 8
-		*p++ = alimb >> 56;
-		*p++ = alimb >> 48;
-		*p++ = alimb >> 40;
-		*p++ = alimb >> 32;
-		*p++ = alimb >> 24;
-		*p++ = alimb >> 16;
-		*p++ = alimb >> 8;
-		*p++ = alimb;
+		alimb = cpu_to_be64(a->d[i]);
 #else
 #error please implement for this limb size.
 #endif
-
+		memcpy(p, &alimb, BYTES_PER_MPI_LIMB);
+		p += BYTES_PER_MPI_LIMB;
 		if (lzeros > 0) {
 			mpi_limb_t *limb1 = (void *)p - sizeof(alimb);
 			mpi_limb_t *limb2 = (void *)p - sizeof(alimb)
-- 
2.7.3

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[PATCH RESEND v2 00/14] lib/mpi: bug fixes and cleanup Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 05/14] lib/mpi: mpi_write_sgl(): replace open coded endian conversion Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 06/14] lib/mpi: mpi_read_buffer(): optimize skipping of leading zero limbs Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 12/14] lib/mpi: mpi_read_raw_from_sgl(): fix nbits calculation Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 10/14] lib/mpi: mpi_read_raw_from_sgl(): don't include leading zero SGEs in nbytes Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 07/14] lib/mpi: mpi_read_buffer(): replace open coded endian conversion Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 08/14] lib/mpi: mpi_read_buffer(): fix buffer overflow Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 13/14] lib/mpi: mpi_read_raw_from_sgl(): sanitize meaning of indices Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 14/14] lib/mpi: mpi_read_raw_from_sgl(): fix out-of-bounds buffer access Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 11/14] lib/mpi: mpi_read_raw_from_sgl(): purge redundant clearing of nbits Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:30 +0100
  [PATCH RESEND v2 03/14] lib/mpi: mpi_write_sgl(): purge redundant pointer arithmetic Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:40 +0100
  [PATCH RESEND v2 02/14] lib/mpi: mpi_write_sgl(): fix style issue with lzero decrement Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:40 +0100
  [PATCH RESEND v2 04/14] lib/mpi: mpi_write_sgl(): fix out-of-bounds stack access Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:40 +0100
  [PATCH RESEND v2 01/14] lib/mpi: mpi_write_sgl(): fix skipping of leading zero limbs Nicolai Stange <nicstange@gmail.com> - 2016-03-21 14:40 +0100
  Re: [PATCH RESEND v2 00/14] lib/mpi: bug fixes and cleanup Tadeusz Struk <tadeusz.struk@intel.com> - 2016-03-22 06:00 +0100
    Re: [PATCH RESEND v2 00/14] lib/mpi: bug fixes and cleanup Nicolai Stange <nicstange@gmail.com> - 2016-03-22 08:10 +0100
      Re: [PATCH RESEND v2 00/14] lib/mpi: bug fixes and cleanup Tadeusz Struk <tadeusz.struk@intel.com> - 2016-03-22 15:20 +0100

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