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From: Nicolai Stange <nicstange@gmail.com>
To: Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>
Cc: Tadeusz Struk <tadeusz.struk@intel.com>,
	Michal Marek <mmarek@suse.com>,
	Andrzej Zaborowski <andrew.zaborowski@intel.com>,
	Stephan Mueller <smueller@chronox.de>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	Nicolai Stange <nicstange@gmail.com>
Subject: [PATCH RESEND v2 09/14] lib/mpi: mpi_read_raw_from_sgl(): replace len argument by nbytes
Date: Mon, 21 Mar 2016 14:26:10 +0100	[thread overview]
Message-ID: <1458566775-5239-10-git-send-email-nicstange@gmail.com> (raw)
In-Reply-To: <1458566775-5239-1-git-send-email-nicstange@gmail.com>

Currently, the nbytes local variable is calculated from the len argument
as follows:

  ... mpi_read_raw_from_sgl(..., unsigned int len)
  {
    unsigned nbytes;
    ...
    if (!ents)
      nbytes = 0;
    else
      nbytes = len - lzeros;
    ...
  }

Given that nbytes is derived from len in a trivial way and that the len
argument is shadowed by a local len variable in several loops, this is just
confusing.

Rename the len argument to nbytes and get rid of the nbytes local variable.
Do the nbytes calculation in place.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
---
 lib/mpi/mpicoder.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index 27582e2..2de2c7d 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -418,15 +418,15 @@ EXPORT_SYMBOL_GPL(mpi_write_to_sgl);
  * a new MPI and reads the content of the sgl to the MPI.
  *
  * @sgl:	scatterlist to read from
- * @len:	number of bytes to read
+ * @nbytes:	number of bytes to read
  *
  * Return:	Pointer to a new MPI or NULL on error
  */
-MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len)
+MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
 {
 	struct scatterlist *sg;
 	int x, i, j, z, lzeros, ents;
-	unsigned int nbits, nlimbs, nbytes;
+	unsigned int nbits, nlimbs;
 	mpi_limb_t a;
 	MPI val = NULL;
 
@@ -455,7 +455,7 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len)
 	if (!ents)
 		nbytes = 0;
 	else
-		nbytes = len - lzeros;
+		nbytes -= lzeros;
 
 	nbits = nbytes * 8;
 	if (nbits > MAX_EXTERN_MPI_BITS) {
-- 
2.7.3

  parent reply	other threads:[~2016-03-21 13:26 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-21 13:26 [PATCH RESEND v2 00/14] lib/mpi: bug fixes and cleanup Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 01/14] lib/mpi: mpi_write_sgl(): fix skipping of leading zero limbs Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 02/14] lib/mpi: mpi_write_sgl(): fix style issue with lzero decrement Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 03/14] lib/mpi: mpi_write_sgl(): purge redundant pointer arithmetic Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 04/14] lib/mpi: mpi_write_sgl(): fix out-of-bounds stack access Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 05/14] lib/mpi: mpi_write_sgl(): replace open coded endian conversion Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 06/14] lib/mpi: mpi_read_buffer(): optimize skipping of leading zero limbs Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 07/14] lib/mpi: mpi_read_buffer(): replace open coded endian conversion Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 08/14] lib/mpi: mpi_read_buffer(): fix buffer overflow Nicolai Stange
2016-03-21 13:26 ` Nicolai Stange [this message]
2016-03-21 13:26 ` [PATCH RESEND v2 10/14] lib/mpi: mpi_read_raw_from_sgl(): don't include leading zero SGEs in nbytes Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 11/14] lib/mpi: mpi_read_raw_from_sgl(): purge redundant clearing of nbits Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 12/14] lib/mpi: mpi_read_raw_from_sgl(): fix nbits calculation Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 13/14] lib/mpi: mpi_read_raw_from_sgl(): sanitize meaning of indices Nicolai Stange
2016-03-21 13:26 ` [PATCH RESEND v2 14/14] lib/mpi: mpi_read_raw_from_sgl(): fix out-of-bounds buffer access Nicolai Stange
2016-03-22  4:54 ` [PATCH RESEND v2 00/14] lib/mpi: bug fixes and cleanup Tadeusz Struk
2016-03-22  7:06   ` Nicolai Stange
2016-03-22 14:10     ` Tadeusz Struk

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