Patchwork lsprop: Fixes to work correctly when built little endian

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Submitter Michael Ellerman
Date Jan. 7, 2013, 4:23 a.m.
Message ID <1357532610-19416-1-git-send-email-michael@ellerman.id.au>
Download mbox | patch
Permalink /patch/209855/
State Not Applicable
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Comments

Michael Ellerman - Jan. 7, 2013, 4:23 a.m.
Add and use dt_swap_int() to byte swap on little endian.

Also declare buf as unsigned char, so that we don't sign extend when
printing values from it.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---

Ben, based on your patch, can you add your s-o-b? :
  https://lists.ozlabs.org/pipermail/linuxppc-dev/2008-May/056088.html
---
 src/lsprop.c |   17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)
Benjamin Herrenschmidt - Jan. 8, 2013, 2:12 a.m.
On Mon, 2013-01-07 at 15:23 +1100, Michael Ellerman wrote:
> Add and use dt_swap_int() to byte swap on little endian.
> 
> Also declare buf as unsigned char, so that we don't sign extend when
> printing values from it.
> 
> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
> ---
> 
> Ben, based on your patch, can you add your s-o-b? :
>   https://lists.ozlabs.org/pipermail/linuxppc-dev/2008-May/056088.html

I didn't know powerpc-utils required sob's :-)

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

> ---
>  src/lsprop.c |   17 ++++++++++++++---
>  1 file changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/src/lsprop.c b/src/lsprop.c
> index 5969a97..38a8fa5 100644
> --- a/src/lsprop.c
> +++ b/src/lsprop.c
> @@ -13,11 +13,22 @@
>  #include <sys/stat.h>
>  #include <sys/types.h>
>  #include <dirent.h>
> +#include <endian.h>
> +#include <byteswap.h>
> +
> +static inline unsigned int dt_swap_int(unsigned int data)
> +{
> +#if __BYTE_ORDER == __LITTLE_ENDIAN
> +	return bswap_32(data);
> +#else
> +	return data;
> +#endif
> +}
>  
>  int recurse;
>  int maxbytes = 128;
>  int words_per_line = 0;
> -char *buf;
> +unsigned char *buf;
>  
>  void lsprop(FILE *f, char *name);
>  void lsdir(char *name);
> @@ -183,7 +194,7 @@ void lsprop(FILE *f, char *name)
>      } else if ((n & 3) == 0) {
>  	nw = n >> 2;
>  	if (nw == 1) {
> -	    i = *(int *)buf;
> +	    i = dt_swap_int(*(int *)buf);
>  	    printf(" %.8x", i);
>  	    if (i > -0x10000 && !(i >= 0 && i <= 9))
>  		printf(" (%d)", i);
> @@ -201,7 +212,7 @@ void lsprop(FILE *f, char *name)
>  		if (i != 0)
>  		    printf("\n\t\t");
>  		for (j = 0; j < npl && i + j < nw; ++j)
> -		    printf(" %.8x", ((unsigned int *)buf)[i+j]);
> +		    printf(" %.8x", dt_swap_int(((unsigned int *)buf)[i+j]));
>  	    }
>  	}
>      } else {
Nathan Fontenot - Jan. 8, 2013, 3:55 a.m.
On 01/07/2013 08:12 PM, Benjamin Herrenschmidt wrote:
> On Mon, 2013-01-07 at 15:23 +1100, Michael Ellerman wrote:
>> Add and use dt_swap_int() to byte swap on little endian.
>>
>> Also declare buf as unsigned char, so that we don't sign extend when
>> printing values from it.
>>
>> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
>> ---
>>
>> Ben, based on your patch, can you add your s-o-b? :
>>   https://lists.ozlabs.org/pipermail/linuxppc-dev/2008-May/056088.html
> 
> I didn't know powerpc-utils required sob's :-)

Not technically, it's more a CYA thing. It (hopefully) keeps big blue legal
happy, which keeps me happy.

-Nathan

> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 
>> ---
>>  src/lsprop.c |   17 ++++++++++++++---
>>  1 file changed, 14 insertions(+), 3 deletions(-)
>>
>> diff --git a/src/lsprop.c b/src/lsprop.c
>> index 5969a97..38a8fa5 100644
>> --- a/src/lsprop.c
>> +++ b/src/lsprop.c
>> @@ -13,11 +13,22 @@
>>  #include <sys/stat.h>
>>  #include <sys/types.h>
>>  #include <dirent.h>
>> +#include <endian.h>
>> +#include <byteswap.h>
>> +
>> +static inline unsigned int dt_swap_int(unsigned int data)
>> +{
>> +#if __BYTE_ORDER == __LITTLE_ENDIAN
>> +	return bswap_32(data);
>> +#else
>> +	return data;
>> +#endif
>> +}
>>  
>>  int recurse;
>>  int maxbytes = 128;
>>  int words_per_line = 0;
>> -char *buf;
>> +unsigned char *buf;
>>  
>>  void lsprop(FILE *f, char *name);
>>  void lsdir(char *name);
>> @@ -183,7 +194,7 @@ void lsprop(FILE *f, char *name)
>>      } else if ((n & 3) == 0) {
>>  	nw = n >> 2;
>>  	if (nw == 1) {
>> -	    i = *(int *)buf;
>> +	    i = dt_swap_int(*(int *)buf);
>>  	    printf(" %.8x", i);
>>  	    if (i > -0x10000 && !(i >= 0 && i <= 9))
>>  		printf(" (%d)", i);
>> @@ -201,7 +212,7 @@ void lsprop(FILE *f, char *name)
>>  		if (i != 0)
>>  		    printf("\n\t\t");
>>  		for (j = 0; j < npl && i + j < nw; ++j)
>> -		    printf(" %.8x", ((unsigned int *)buf)[i+j]);
>> +		    printf(" %.8x", dt_swap_int(((unsigned int *)buf)[i+j]));
>>  	    }
>>  	}
>>      } else {
> 
>

Patch

diff --git a/src/lsprop.c b/src/lsprop.c
index 5969a97..38a8fa5 100644
--- a/src/lsprop.c
+++ b/src/lsprop.c
@@ -13,11 +13,22 @@ 
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <dirent.h>
+#include <endian.h>
+#include <byteswap.h>
+
+static inline unsigned int dt_swap_int(unsigned int data)
+{
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+	return bswap_32(data);
+#else
+	return data;
+#endif
+}
 
 int recurse;
 int maxbytes = 128;
 int words_per_line = 0;
-char *buf;
+unsigned char *buf;
 
 void lsprop(FILE *f, char *name);
 void lsdir(char *name);
@@ -183,7 +194,7 @@  void lsprop(FILE *f, char *name)
     } else if ((n & 3) == 0) {
 	nw = n >> 2;
 	if (nw == 1) {
-	    i = *(int *)buf;
+	    i = dt_swap_int(*(int *)buf);
 	    printf(" %.8x", i);
 	    if (i > -0x10000 && !(i >= 0 && i <= 9))
 		printf(" (%d)", i);
@@ -201,7 +212,7 @@  void lsprop(FILE *f, char *name)
 		if (i != 0)
 		    printf("\n\t\t");
 		for (j = 0; j < npl && i + j < nw; ++j)
-		    printf(" %.8x", ((unsigned int *)buf)[i+j]);
+		    printf(" %.8x", dt_swap_int(((unsigned int *)buf)[i+j]));
 	    }
 	}
     } else {