[SLOF] [PATCH slof v2] sloffs: Fix -Wunused-result gcc warnings in read/write

[Alexey Kardashevskiy]

On 13/11/2019 17:30, Alexey Kardashevskiy wrote:
> This fixes these:
> 
> sloffs.c:466:2: warning: ignoring return value of ‘read’, declared with attribute warn_unused_result [-Wunused-result]
>   read(fd, data, header_len);
>   ^~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>

Pushed out.


> ---
> Changes:
> v2:
> * size_t -> ssize_t
> * %ld for size_t -> %zd
> * changed error handling in sloffs_header() - now it frees sloffs->name
> ---
>  tools/sloffs.c | 36 +++++++++++++++++++++++++++++++-----
>  1 file changed, 31 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/sloffs.c b/tools/sloffs.c
> index 9a1eace8d619..264b0eabcb0f 100644
> --- a/tools/sloffs.c
> +++ b/tools/sloffs.c
> @@ -22,6 +22,7 @@
>  #include <byteswap.h>
>  #include <getopt.h>
>  #include <time.h>
> +#include <errno.h>
>  
>  #include <calculatecrc.h>
>  #include <crclib.h>
> @@ -176,6 +177,7 @@ sloffs_header(const int fd)
>  	struct sloffs file;
>  	struct sloffs *sloffs;
>  	struct stH *header;
> +	ssize_t rc;
>  
>  	header = (struct stH *)malloc(sizeof(struct stH));
>  
> @@ -187,7 +189,12 @@ sloffs_header(const int fd)
>  		return NULL;
>  	}
>  
> -	read(fd, header, sizeof(struct stH));
> +	rc = read(fd, header, sizeof(struct stH));
> +	if (rc != sizeof(struct stH)) {
> +		printf("Reading header, rc %ld, errno %d\n", rc, errno);
> +		free(header);
> +		header = NULL;
> +	}
>  	free(sloffs->name);
>  	return header;
>  }
> @@ -298,6 +305,7 @@ sloffs_append(const int file, const char *name, const char *dest)
>  	struct sloffs new_file;
>  	uint64_t read_len;
>  	int i;
> +	ssize_t rc;
>  
>  	fd = open(name, O_RDONLY);
>  
> @@ -328,7 +336,11 @@ sloffs_append(const int file, const char *name, const char *dest)
>  
>  	/* write byte at the end to be able to mmap it */
>  	lseek(out, new_len - 1, SEEK_SET);
> -	write(out, "", 1);
> +	rc = write(out, "", 1);
> +	if (rc != 1) {
> +		printf("Extending file failed, rc %ld, errno %d\n", rc, errno);
> +		exit(1);
> +	}
>  	write_start = mmap(NULL, new_len, PROT_READ | PROT_WRITE,
>  			   MAP_SHARED, out, 0);
>  
> @@ -427,6 +439,7 @@ sloffs_dump(const int fd)
>  	int i;
>  	uint64_t crc;
>  	uint64_t header_len;
> +	ssize_t rc;
>  
>  	header = sloffs_header(fd);
>  
> @@ -463,7 +476,11 @@ sloffs_dump(const int fd)
>  	/* no copy the header to memory to crc test it */
>  	data = malloc(header_len);
>  	lseek(fd, 0, SEEK_SET);
> -	read(fd, data, header_len);
> +	rc = read(fd, data, header_len);
> +	if (rc != (ssize_t) header_len) {
> +		printf("Reading header failed, rc %zd, errno %d\n", rc, errno);
> +		return;
> +	}
>  	crc = calCRCword((unsigned char *)data, header_length(fd), 0);
>  	free(data);
>  	if (!crc)
> @@ -476,7 +493,11 @@ sloffs_dump(const int fd)
>  	/* move to the CRC */
>  	lseek(fd, crc - 8, SEEK_SET);
>  	/* read it */
> -	read(fd, &crc, 8);
> +	rc = read(fd, &crc, 8);
> +	if (rc != 8) {
> +		printf("Reading crc failed, rc %zd, errno %d\n", rc, errno);
> +		return;
> +	}
>  	crc = be64_to_cpu(crc);
>  	printf("  Image CRC   : 0x%016lx CRC check: ", crc);
>  	crc = check_image_crc(fd, be64_to_cpu(header->flashlen));
> @@ -581,6 +602,7 @@ sloffs_copy(const int file, const char *name)
>  	unsigned char *write_buf;
>  	int i;
>  	struct stH *header;
> +	ssize_t rc;
>  
>  	header = sloffs_header(file);
>  
> @@ -598,7 +620,11 @@ sloffs_copy(const int file, const char *name)
>  	}
>  	/* write byte at the end to be able to mmap it */
>  	lseek(out, len - 1, SEEK_SET);
> -	write(out, "", 1);
> +	rc = write(out, "", 1);
> +	if (rc != 1) {
> +		printf("Extending file failed, rc %zd, errno %d\n", rc, errno);
> +		exit(1);
> +	}
>  	write_buf = mmap(NULL, len, PROT_WRITE, MAP_SHARED, out, 0);
>  
>  	if (write_buf == MAP_FAILED) {
> 

-- 
Alexey