[igt-dev] [PATCH i-g-t 07/12] i915/gem_mmap_offset: Verify all regions with ptrace

[Zbigniew Kempczyński]

On Thu, Sep 01, 2022 at 01:44:37PM +0200, Zbigniew Kempczyński wrote:
> From: Chris Wilson <chris.p.wilson at intel.com>
> 
> Check we can use ptrace to query *ptr of each mmap for each region.

Looks we haven't checked local memory before, so:

Reviewed-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>

--
Zbigniew

> 
> Signed-off-by: Chris Wilson <chris.p.wilson at intel.com>
> ---
>  tests/i915/gem_mmap_offset.c | 84 ++++++++++++++++++++----------------
>  1 file changed, 46 insertions(+), 38 deletions(-)
> 
> diff --git a/tests/i915/gem_mmap_offset.c b/tests/i915/gem_mmap_offset.c
> index faadbd4ee6..806a9d68f4 100644
> --- a/tests/i915/gem_mmap_offset.c
> +++ b/tests/i915/gem_mmap_offset.c
> @@ -370,64 +370,72 @@ static void test_ptrace(int i915)
>  	const unsigned int SZ = 3 * 4096;
>  	unsigned long *ptr, *cpy;
>  	unsigned long AA, CC;
> -	uint32_t bo;
>  
>  	memset(&AA, 0xaa, sizeof(AA));
>  	memset(&CC, 0x55, sizeof(CC));
>  
>  	cpy = malloc(SZ);
> -	bo = gem_create(i915, SZ);
> +	igt_assert(cpy);
>  
> -	for_each_mmap_offset_type(i915, t) {
> -		ptr = __mmap_offset(i915, bo, 0, SZ,
> -				    PROT_READ | PROT_WRITE,
> -				    t->type);
> -		if (!ptr)
> -			continue;
> +	for_each_memory_region(r, i915) {
> +		uint64_t size = SZ;
> +		uint32_t bo;
>  
> -		igt_dynamic_f("%s", t->name) {
> -			pid_t pid;
> +		igt_assert_eq(__gem_create_in_memory_region_list(i915, &bo, &size, 0, &r->ci, 1), 0);
> +		make_resident(i915, 0, bo);
>  
> -			memset(cpy, AA, SZ);
> -			memset(ptr, CC, SZ);
> +		for_each_mmap_offset_type(i915, t) {
> +			ptr = __mmap_offset(i915, bo, 0, size,
> +					    PROT_READ | PROT_WRITE,
> +					    t->type);
> +			if (!ptr)
> +				continue;
>  
> -			igt_assert(!memchr_inv(ptr, CC, SZ));
> -			igt_assert(!memchr_inv(cpy, AA, SZ));
> +			igt_dynamic_f("%s-%s", r->name, t->name) {
> +				pid_t pid;
>  
> -			igt_fork(child, 1) {
> -				ptrace(PTRACE_TRACEME, 0, NULL, NULL);
> -				raise(SIGSTOP);
> -			}
> +				memset(cpy, AA, SZ);
> +				memset(ptr, CC, SZ);
>  
> -			/* Wait for the child to ready themselves [SIGSTOP] */
> -			pid = wait(NULL);
> +				igt_assert(!memchr_inv(ptr, CC, SZ));
> +				igt_assert(!memchr_inv(cpy, AA, SZ));
>  
> -			ptrace(PTRACE_ATTACH, pid, NULL, NULL);
> -			for (int i = 0; i < SZ / sizeof(long); i++) {
> -				long ret;
> +				igt_fork(child, 1) {
> +					ptrace(PTRACE_TRACEME, 0, NULL, NULL);
> +					raise(SIGSTOP);
> +				}
>  
> -				ret = ptrace(PTRACE_PEEKDATA, pid, ptr + i);
> -				igt_assert_eq_u64(ret, CC);
> -				cpy[i] = ret;
> +				/* Wait for the child to ready themselves [SIGSTOP] */
> +				pid = wait(NULL);
>  
> -				ret = ptrace(PTRACE_POKEDATA, pid, ptr + i, AA);
> -				igt_assert_eq(ret, 0l);
> -			}
> -			ptrace(PTRACE_DETACH, pid, NULL, NULL);
> +				ptrace(PTRACE_ATTACH, pid, NULL, NULL);
> +				for (int i = 0; i < SZ / sizeof(long); i++) {
> +					long ret;
> +
> +					ret = ptrace(PTRACE_PEEKDATA, pid, ptr + i);
> +					igt_assert_eq_u64(ret, CC);
> +					cpy[i] = ret;
> +
> +					ret = ptrace(PTRACE_POKEDATA, pid, ptr + i, AA);
> +					igt_assert_eq(ret, 0l);
> +				}
> +				ptrace(PTRACE_DETACH, pid, NULL, NULL);
>  
> -			/* Wakeup the child for it to exit */
> -			kill(SIGCONT, pid);
> -			igt_waitchildren();
> +				/* Wakeup the child for it to exit */
> +				kill(SIGCONT, pid);
> +				igt_waitchildren();
>  
> -			/* The two buffers should now be swapped */
> -			igt_assert(!memchr_inv(ptr, AA, SZ));
> -			igt_assert(!memchr_inv(cpy, CC, SZ));
> +				/* The two buffers should now be swapped */
> +				igt_assert(!memchr_inv(ptr, AA, SZ));
> +				igt_assert(!memchr_inv(cpy, CC, SZ));
> +			}
> +
> +			munmap(ptr, size);
>  		}
>  
> -		munmap(ptr, SZ);
> +		gem_close(i915, bo);
>  	}
>  
> -	gem_close(i915, bo);
>  	free(cpy);
>  }
>  
> -- 
> 2.34.1
>