[LTP] [PATCH 4/4] mmapstress03: Fix 32bit test on 64bit kernel

[Jan Stancek]

----- Original Message -----
> From: "Cyril Hrubis" <chrubis@suse.cz>
> To: ltp@lists.linux.it
> Sent: Thursday, 12 January, 2017 2:23:39 PM
> Subject: [LTP] [PATCH 4/4] mmapstress03: Fix 32bit test on 64bit kernel
> 
> The ridiculously large mapping size has to be adjusted based on the
> kernel addressing size not on a pointer size otherwise the testcase
> segfaults when 32bit binary is executed on 64bit kernel.
> 
> Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
> ---
>  testcases/kernel/mem/mmapstress/mmapstress03.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/testcases/kernel/mem/mmapstress/mmapstress03.c
> b/testcases/kernel/mem/mmapstress/mmapstress03.c
> index 76a77a9..fe25b7a 100644
> --- a/testcases/kernel/mem/mmapstress/mmapstress03.c
> +++ b/testcases/kernel/mem/mmapstress/mmapstress03.c
> @@ -45,6 +45,7 @@
>  #include <stdlib.h>
>  
>  #include "test.h"
> +#include "tst_kernel.h"
>  
>  char *TCID = "mmapstress03";
>  FILE *temp;
> @@ -61,7 +62,6 @@ void ok_exit();
>  #define ERROR(M) (void)fprintf(stderr, "%s: errno = %d: " M "\n", TCID, \
>  			errno)
>  #define NEG1	(char *)-1
> -#define POINTER_SIZE	(sizeof(void *) << 3)
>  
>  static void do_test(void* brk_max, long pagesize);
>  
> @@ -69,6 +69,7 @@ int main(void)
>  {
>  	char *brk_max_addr, *hole_addr, *brk_start, *hole_start;
>  	size_t pagesize = (size_t) sysconf(_SC_PAGE_SIZE);
> +	int kernel_bits = tst_kernel_bits();
>  
>  	if ((brk_start = sbrk(0)) == NEG1) {
>  		ERROR("initial sbrk failed");
> @@ -137,9 +138,10 @@ int main(void)
>  		ERROR("failed to fiddle with brk at the end");
>  		anyfail();
>  	}
> +
>  	/* Ask for a ridiculously large mmap region at a high address */
> -	if (mmap((void*) (1UL << (POINTER_SIZE - 1)) - pagesize,
> -		 (size_t) ((1UL << (POINTER_SIZE - 1)) - pagesize),
> +	if (mmap((void*) (1UL << (kernel_bits - 1)) - pagesize,

Since this has same range as below, shouldn't it be also 1ULL?
Entire series looks OK to me.

Regards,
Jan

> +		 (size_t) ((1ULL << (kernel_bits - 1)) - pagesize),
>  		 PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_FIXED | MAP_SHARED,
>  		 0, 0)
>  	    != (void*) - 1) {
> --
> 2.7.3
> 
> 
> --
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>