Re: [PATCH] ndctl: move test/dax-errors buffer to global to avoid gcc optimization

[Vishal Verma <vishal.l.verma@intel.com>]

On 09/15, Dave Jiang wrote:
> Some gcc toolchain are optimizing out the memcpy and this causes dax-errors
> to not trigger the SIG_BUS when doing memcpy on an mmap'd buffer. By moving
> the buffer to a global variable this bypasses the optimization and allow
> the test to work as intended.
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  test/dax-errors.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 

Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>

> diff --git a/test/dax-errors.c b/test/dax-errors.c
> index 11d0031..9ea5c91 100644
> --- a/test/dax-errors.c
> +++ b/test/dax-errors.c
> @@ -17,6 +17,8 @@
>  
>  static sigjmp_buf sj_env;
>  static int sig_count;
> +/* buf is global in order to avoid gcc memcpy optimization */
> +static void *buf;
>  
>  static void sigbus_hdl(int sig, siginfo_t *siginfo, void *ptr)
>  {
> @@ -27,7 +29,7 @@ static void sigbus_hdl(int sig, siginfo_t *siginfo, void *ptr)
>  
>  static int test_dax_read_err(int fd)
>  {
> -	void *base, *buf;
> +	void *base;
>  	int rc = 0;
>  
>  	if (fd < 0) {
> 
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