ACK: [PATCH] lib: fwts_alloc: fix portability warnings from cppcheck on void * arithmetic

[ivanhu]

On 2016年08月17日 18:36, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> Minor fix, ensure we don't do void * pointer arithmetic as the behaviour
> is undefined (even though most compilers assume it is a char * sized).
>
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
>  src/lib/src/fwts_alloc.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/src/lib/src/fwts_alloc.c b/src/lib/src/fwts_alloc.c
> index 28a66f6..96e87c6 100644
> --- a/src/lib/src/fwts_alloc.c
> +++ b/src/lib/src/fwts_alloc.c
> @@ -69,28 +69,28 @@ typedef struct {
>   */
>  static void *fwts_low_mmap_walkdown(const size_t requested_size)
>  {
> -	void *addr;
> +	uint8_t *addr;
>  	size_t page_size = fwts_page_size();
>  	size_t sz = (requested_size + page_size) & ~(page_size - 1);
>  	size_t pages = sz / page_size;
>  	unsigned char vec[pages];
> -	static void *last_addr = (void *)LIMIT_2GB;
> +	static uint8_t *last_addr = (uint8_t *)LIMIT_2GB;
>
>  	if (requested_size == 0)	/* Illegal */
>  		return MAP_FAILED;
>
> -	for (addr = last_addr - sz; addr > (void *)LIMIT_START; addr -= CHUNK_SIZE) {
> +	for (addr = last_addr - sz; addr > (uint8_t *)LIMIT_START; addr -= CHUNK_SIZE) {
>  		void *mapping;
>
>  		/* Already mapped? */
> -		if (mincore(addr, pages, vec) == 0)
> +		if (mincore((void *)addr, pages, vec) == 0)
>  			continue;
>
>  		/* Not mapped but mincore returned something unexpected? */
>  		if (errno != ENOMEM)
>  			continue;
>
> -		mapping = mmap(addr, requested_size, PROT_READ | PROT_WRITE,
> +		mapping = mmap((void *)addr, requested_size, PROT_READ | PROT_WRITE,
>  			MAP_SHARED | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
>  		if (mapping != MAP_FAILED) {
>  			last_addr = mapping;
> @@ -98,7 +98,7 @@ static void *fwts_low_mmap_walkdown(const size_t requested_size)
>  		}
>  	}
>  	/* We've scanned all of memory, give up on subsequent calls */
> -	last_addr = (void *)LIMIT_START;
> +	last_addr = (uint8_t *)LIMIT_START;
>
>  	return MAP_FAILED;
>  }
> @@ -139,7 +139,7 @@ static void *fwts_low_mmap(const size_t requested_size)
>  		if ((first_addr_start == NULL) &&
>  		    (addr_start > (void*)LIMIT_START)) {
>  			size_t sz = (requested_size + CHUNK_SIZE) & ~(CHUNK_SIZE - 1);
> -			void *addr = (uint8_t*)addr_start - sz;
> +			uint8_t *addr = (uint8_t *)addr_start - sz;
>
>  			/*
>  			 * If addr is over the 2GB limit and we know
> @@ -147,8 +147,8 @@ static void *fwts_low_mmap(const size_t requested_size)
>  			 * be able to map a region below the 2GB limit as
>  			 * nothing is already mapped there
>  			 */
> -			if (addr > (void*)LIMIT_2GB)
> -				addr = (void*)LIMIT_2GB - sz;
> +			if (addr > (uint8_t *)LIMIT_2GB)
> +				addr = (uint8_t *)LIMIT_2GB - sz;
>
>  			ret = mmap(addr, requested_size, PROT_READ | PROT_WRITE,
>  				MAP_SHARED | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
>

Acked-by: Ivan Hu <ivan.hu at canonical.com>