Re: [PATCH v2 1/2] Fix wrong EOF compare

[Michal Nazarewicz]

On Fri, Jan 11 2013, Minchan Kim <minchan@xxxxxxxxxx> wrote:
> The C standards allows the character type char to be singed or unsinged,
> depending on the platform and compiler. Most of systems uses signed char,
> but those based on PowerPC and ARM processors typically use unsigned char.
> This can lead to unexpected results when the variable is used to compare
> with EOF(-1). It happens my ARM system and this patch fixes it.
>
> Cc: Mel Gorman <mgorman@xxxxxxx>
> Cc: Andy Whitcroft <apw@xxxxxxxxxxxx>
> Cc: Alexander Nyberg <alexn@xxxxxxxxx>
> Cc: Michal Nazarewicz <mina86@xxxxxxxxxx>

Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>

> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
> ---
>  Documentation/page_owner.c |    7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/page_owner.c b/Documentation/page_owner.c
> index f0156e1..43dde96 100644
> --- a/Documentation/page_owner.c
> +++ b/Documentation/page_owner.c
> @@ -32,12 +32,13 @@ int read_block(char *buf, FILE *fin)
>  {
>  	int ret = 0;
>  	int hit = 0;
> +	int val;
>  	char *curr = buf;
>  
>  	for (;;) {
> -		*curr = getc(fin);
> -		if (*curr == EOF) return -1;
> -
> +		val = getc(fin);
> +		if (val == EOF) return -1;
> +		*curr = val;
>  		ret++;
>  		if (*curr == '\n' && hit == 1)
>  			return ret - 1;

-- 
Best regards,                                         _     _
.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  MichaÅ âmina86â Nazarewicz    (o o)
ooo +----<email/xmpp: mpn@xxxxxxxxxx>--------------ooO--(_)--Ooo--

Attachment: pgp00000.pgp
Description: PGP signature