2014-01-19 21:50:56

by Luis Henriques

Subject: [PATCH] gss_krb5: use lcm from kernel lib

Replace hardcoded lowest common multiple algorithm by the lcm()
function in kernel lib.

Signed-off-by: Luis Henriques <[email protected]>
---
net/sunrpc/auth_gss/gss_krb5_keys.c | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_krb5_keys.c b/net/sunrpc/auth_gss/gss_krb5_keys.c
index 76e42e6..a16c5b6 100644
--- a/net/sunrpc/auth_gss/gss_krb5_keys.c
+++ b/net/sunrpc/auth_gss/gss_krb5_keys.c
@@ -59,6 +59,7 @@
#include <linux/crypto.h>
#include <linux/sunrpc/gss_krb5.h>
#include <linux/sunrpc/xdr.h>
+#include <linux/lcm.h>

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
@@ -72,7 +73,7 @@
static void krb5_nfold(u32 inbits, const u8 *in,
u32 outbits, u8 *out)
{
- int a, b, c, lcm;
+ unsigned long ulcm;
int byte, i, msbit;

/* the code below is more readable if I make these bytes
@@ -82,17 +83,7 @@ static void krb5_nfold(u32 inbits, const u8 *in,
outbits >>= 3;

/* first compute lcm(n,k) */
-
- a = outbits;
- b = inbits;
-
- while (b != 0) {
- c = b;
- b = a%b;
- a = c;
- }
-
- lcm = outbits*inbits/a;
+ ulcm = lcm(inbits, outbits);

/* now do the real work */

@@ -101,7 +92,7 @@ static void krb5_nfold(u32 inbits, const u8 *in,

/* this will end up cycling through k lcm(k,n)/k times, which
is correct */
- for (i = lcm-1; i >= 0; i--) {
+ for (i = ulcm-1; i >= 0; i--) {
/* compute the msbit in k which gets added into this byte */
msbit = (
/* first, start with the msbit in the first,
--
1.8.3.2

Cheers,
--
Luis

2014-01-22 18:12:45

by J. Bruce Fields

Subject: Re: [PATCH] gss_krb5: use lcm from kernel lib

On Sun, Jan 19, 2014 at 09:50:51PM +0000, Luis Henriques wrote:
> Replace hardcoded lowest common multiple algorithm by the lcm()
> function in kernel lib.

Looks OK to me. Applying for 3.14 if Trond hasn't already picked it up.

--b.

>
> Signed-off-by: Luis Henriques <[email protected]>
> ---
> net/sunrpc/auth_gss/gss_krb5_keys.c | 17 ++++-------------
> 1 file changed, 4 insertions(+), 13 deletions(-)
>
> diff --git a/net/sunrpc/auth_gss/gss_krb5_keys.c b/net/sunrpc/auth_gss/gss_krb5_keys.c
> index 76e42e6..a16c5b6 100644
> --- a/net/sunrpc/auth_gss/gss_krb5_keys.c
> +++ b/net/sunrpc/auth_gss/gss_krb5_keys.c
> @@ -59,6 +59,7 @@
> #include <linux/crypto.h>
> #include <linux/sunrpc/gss_krb5.h>
> #include <linux/sunrpc/xdr.h>
> +#include <linux/lcm.h>
>
> #ifdef RPC_DEBUG
> # define RPCDBG_FACILITY RPCDBG_AUTH
> @@ -72,7 +73,7 @@
> static void krb5_nfold(u32 inbits, const u8 *in,
> u32 outbits, u8 *out)
> {
> - int a, b, c, lcm;
> + unsigned long ulcm;
> int byte, i, msbit;
>
> /* the code below is more readable if I make these bytes
> @@ -82,17 +83,7 @@ static void krb5_nfold(u32 inbits, const u8 *in,
> outbits >>= 3;
>
> /* first compute lcm(n,k) */
> -
> - a = outbits;
> - b = inbits;
> -
> - while (b != 0) {
> - c = b;
> - b = a%b;
> - a = c;
> - }
> -
> - lcm = outbits*inbits/a;
> + ulcm = lcm(inbits, outbits);
>
> /* now do the real work */
>
> @@ -101,7 +92,7 @@ static void krb5_nfold(u32 inbits, const u8 *in,
>
> /* this will end up cycling through k lcm(k,n)/k times, which
> is correct */
> - for (i = lcm-1; i >= 0; i--) {
> + for (i = ulcm-1; i >= 0; i--) {
> /* compute the msbit in k which gets added into this byte */
> msbit = (
> /* first, start with the msbit in the first,
> --
> 1.8.3.2
>
> Cheers,
> --
> Luis