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Subject: Re: [PATCH 3/8] powerpc: convert strcpy to strlcpy in prom_init
To:     Daniel Walker <danielwa@cisco.com>, Will Deacon <will@kernel.org>,
        ob Herring <robh@kernel.org>,
        Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>,
        Andrew Morton <akpm@linux-foundation.org>, x86@kernel.org,
        linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Cc:     xe-linux-external@cisco.com, Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>, linux-kernel@vger.kernel.org
References: <41021d66db2ab427c14255d2a24bb4517c8b58fd.1617126961.git.danielwa@cisco.com>
 <0c80a08ad4cf788c75043c1615c05bad893f4fde.1617126961.git.danielwa@cisco.com>
From:   Christophe Leroy <christophe.leroy@csgroup.eu>
Message-ID: <d7b0b382-056f-d800-d96a-adc0338378a2@csgroup.eu>
Date:   Fri, 2 Apr 2021 19:32:33 +0200
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Le 30/03/2021 à 19:56, Daniel Walker a écrit :
> There's only two users of strcpy and one is the command
> line handling. The generic command line handling uses strlcpy
> and it makes sense to convert this one other user to strlcpy to
> keep prom_init size consistent.
> 
> Cc: xe-linux-external@cisco.com
> Signed-off-by: Daniel Walker <danielwa@cisco.com>

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>

> ---
>   arch/powerpc/kernel/prom_init.c | 25 +++++++++++++++----------
>   1 file changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
> index ccf77b985c8f..2c2f33155317 100644
> --- a/arch/powerpc/kernel/prom_init.c
> +++ b/arch/powerpc/kernel/prom_init.c
> @@ -242,15 +242,6 @@ static int __init prom_strcmp(const char *cs, const char *ct)
>   	return 0;
>   }
>   
> -static char __init *prom_strcpy(char *dest, const char *src)
> -{
> -	char *tmp = dest;
> -
> -	while ((*dest++ = *src++) != '\0')
> -		/* nothing */;
> -	return tmp;
> -}
> -
>   static int __init prom_strncmp(const char *cs, const char *ct, size_t count)
>   {
>   	unsigned char c1, c2;
> @@ -276,6 +267,20 @@ static size_t __init prom_strlen(const char *s)
>   	return sc - s;
>   }
>   
> +static size_t __init prom_strlcpy(char *dest, const char *src, size_t size)
> +{
> +	size_t ret = prom_strlen(src);
> +
> +	if (size) {
> +		size_t len = (ret >= size) ? size - 1 : ret;
> +
> +		memcpy(dest, src, len);
> +		dest[len] = '\0';
> +	}
> +	return ret;
> +}
> +
> +
>   static int __init prom_memcmp(const void *cs, const void *ct, size_t count)
>   {
>   	const unsigned char *su1, *su2;
> @@ -2702,7 +2707,7 @@ static void __init flatten_device_tree(void)
>   
>   	/* Add "phandle" in there, we'll need it */
>   	namep = make_room(&mem_start, &mem_end, 16, 1);
> -	prom_strcpy(namep, "phandle");
> +	prom_strlcpy(namep, "phandle", 8);
>   	mem_start = (unsigned long)namep + prom_strlen(namep) + 1;
>   
>   	/* Build string array */
>