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  • Márton Németh's avatar
    perf_event: Remove redundant zero fill · 96b02d78
    Márton Németh authored
    The buffer is first zeroed out by memset(). Then strncpy() is
    used to fill the content. The strncpy() function also pads the
    string till the end of the specified length, which is redundant.
    The strncpy() does not ensures that the string will be properly
    closed with 0. Use strlcpy() instead.
    
    The semantic match that finds this kind of pattern is as
    follows: (http://coccinelle.lip6.fr/)
    
    // <smpl>
    @@
    expression buffer;
    expression size;
    expression str;
    @@
    	memset(buffer, 0, size);
    	...
    -	strncpy(
    +	strlcpy(
    	buffer, str, sizeof(buffer)
    	);
    @@
    expression buffer;
    expression size;
    expression str;
    @@
    	memset(&buffer, 0, size);
    	...
    -	strncpy(
    +	strlcpy(
    	&buffer, str, sizeof(buffer));
    @@
    expression buffer;
    identifier field;
    expression size;
    expression str;
    @@
    	memset(buffer, 0, size);
    	...
    -	strncpy(
    +	strlcpy(
    	buffer->field, str, sizeof(buffer->field)
    	);
    @@
    expression buffer;
    identifier field;
    expression size;
    expression str;
    @@
    	memset(&buffer, 0, size);
    	...
    -	strncpy(
    +	strlcpy(
    	buffer.field, str, sizeof(buffer.field));
    // </smpl>
    
    On strncpy() vs strlcpy() see
    http://www.gratisoft.us/todd/papers/strlcpy.html
    
     .
    
    Signed-off-by: default avatarMárton Németh <nm127@freemail.hu>
    Cc: Julia Lawall <julia@diku.dk>
    Cc: cocci@diku.dk
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Paul Mackerras <paulus@samba.org>
    LKML-Reference: <4B086547.5040100@freemail.hu>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    96b02d78