Re: [LTP] [PATCH 10/29] Hugetlb: Migrating libhugetlbfs huge_at_4GB_normal_below

[Cyril Hrubis <chrubis@suse.cz>]

> Migrating the libhugetlbfs/testcases/huge_at_4GB_normal_below.c test
> 
> Test Description: Designed to pick up a bug on ppc64 where
> touches_hugepage_high_range() falsely reported true for ranges reaching
> below 4GB
> 
> Signed-off-by: Tarun Sahu <tsahu@linux.ibm.com>
> ---
>  runtest/hugetlb                               |   1 +
>  testcases/kernel/mem/.gitignore               |   1 +
>  .../kernel/mem/hugetlb/hugemmap/hugemmap13.c  | 160 ++++++++++++++++++
>  3 files changed, 162 insertions(+)
>  create mode 100644 testcases/kernel/mem/hugetlb/hugemmap/hugemmap13.c
> 
> diff --git a/runtest/hugetlb b/runtest/hugetlb
> index 4c16e1e7c..2029ee4b3 100644
> --- a/runtest/hugetlb
> +++ b/runtest/hugetlb
> @@ -14,6 +14,7 @@ hugemmap09 hugemmap09
>  hugemmap10 hugemmap10
>  hugemmap11 hugemmap11
>  hugemmap12 hugemmap12
> +hugemmap13 hugemmap13
>  hugemmap05_1 hugemmap05 -m
>  hugemmap05_2 hugemmap05 -s
>  hugemmap05_3 hugemmap05 -s -m
> diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
> index adea760c7..5955ed613 100644
> --- a/testcases/kernel/mem/.gitignore
> +++ b/testcases/kernel/mem/.gitignore
> @@ -13,6 +13,7 @@
>  /hugetlb/hugemmap/hugemmap10
>  /hugetlb/hugemmap/hugemmap11
>  /hugetlb/hugemmap/hugemmap12
> +/hugetlb/hugemmap/hugemmap13
>  /hugetlb/hugeshmat/hugeshmat01
>  /hugetlb/hugeshmat/hugeshmat02
>  /hugetlb/hugeshmat/hugeshmat03
> diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap13.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap13.c
> new file mode 100644
> index 000000000..0eae937ab
> --- /dev/null
> +++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap13.c
> @@ -0,0 +1,160 @@
> +// SPDX-License-Identifier: LGPL-2.1-or-later
> +/*
> + * Copyright (C) 2005-2006 David Gibson & Adam Litke, IBM Corporation.
> + *
> + * Test Name: Huge at 4GB normal below
> + *
> + * Test Description: Designed to pick up a bug on ppc64 where
> + * touches_hugepage_high_range() falsely reported true for ranges reaching
> + * below 4GB
> + *
> + * WARNING: The offsets and addresses used within are specifically
> + * calculated to trigger the bug as it existed.  Don't mess with them
> + * unless you *really* know what you're doing.
> + *
> + * HISTORY
> + *  Written by David Gibson & Adam Litke
> + *
> + */
> +
> +#define _GNU_SOURCE
> +#include <stdio.h>
> +#include <sys/mount.h>
> +#include <limits.h>
> +#include <sys/param.h>
> +#include <sys/types.h>
> +
> +#include "hugetlb.h"
> +
> +#define FOURGB (1UL << 32)
> +
> +static int  fd = -1;
> +static char hfile[MAXPATHLEN];
> +static unsigned long hpage_size;
> +static char *verbose;
> +
> +static void run_test(void)
> +{
> +	int page_size;
> +	int fd;
> +	void *p, *q;
> +	unsigned long lowaddr;
> +	int err;
> +
> +	page_size = getpagesize();
> +
> +	fd = SAFE_OPEN(hfile, O_RDWR | O_CREAT, 0600);
> +	SAFE_UNLINK(hfile);
> +
> +	p = mmap((void *)FOURGB, hpage_size, PROT_READ|PROT_WRITE,
> +		 MAP_SHARED | MAP_FIXED, fd, 0);
> +	if (p == MAP_FAILED) {
> +		/* slice 0 (high) spans from 4G-1T */
> +		unsigned long below_start = FOURGB;
> +		unsigned long above_end = 1024L*1024*1024*1024;
> +
> +		if (range_is_mapped(below_start, above_end) == 1) {
> +			if (verbose) {
> +				tst_res(TINFO, "region 4G-IT is not free");
> +				tst_res(TINFO|TERRNO, "mmap() failed");

This should be single TINFO message.

> +			}
> +			tst_res(TPASS, "Successful but inconclusive");
> +			SAFE_CLOSE(fd);
> +			return;
> +		}
> +		tst_res(TFAIL|TERRNO, "mmap() huge");
> +		goto fail;
> +	}
> +	if (p != (void *)FOURGB) {
> +		tst_res(TFAIL, "Wrong address with MAP_FIXED huge");
> +		goto fail;
> +	}
> +
> +	if (verbose)
> +		tst_res(TINFO, "Mapped hugetlb at %p", p);
> +
> +	memset(p, 0, hpage_size);
> +
> +	err = test_addr_huge(p);
> +	if (err != 1) {
> +		tst_res(TFAIL, "Mapped address is not hugepage");
> +		goto fail;
> +	}

Again I fail to see how this is useful. This check looks to me like a
circular definition at best. We create file on hugetlbfs, stat() it and
check that the magic matches.

> +	/* Test just below 4GB to check for off-by-one errors */
> +	lowaddr = FOURGB - page_size;
> +	q = mmap((void *)lowaddr, page_size, PROT_READ|PROT_WRITE,
> +		 MAP_SHARED|MAP_FIXED|MAP_ANONYMOUS, 0, 0);
> +	if (p == MAP_FAILED) {
> +		unsigned long below_start = FOURGB - page_size;
> +		unsigned long above_end = FOURGB;
> +
> +		if (range_is_mapped(below_start, above_end) == 1) {
> +			if (verbose) {
> +				tst_res(TINFO, "region (4G-page)-4G is not free\n");
> +				tst_res(TINFO|TERRNO, "mmap() failed");

Here as well, single message.

> +			}
> +			tst_res(TPASS, "Successful but inconclusive");
> +			SAFE_MUNMAP(p, hpage_size);
> +			SAFE_CLOSE(fd);
> +			return;
> +		}
> +		tst_res(TFAIL|TERRNO, "mmap() normal");
> +		goto fail;
> +	}
> +	if (q != (void *)lowaddr) {
> +		tst_res(TFAIL, "Wrong address with MAP_FIXED normal");
> +		goto fail;
> +	}
> +
> +	memset(q, 0, page_size);
> +
> +	tst_res(TPASS, "Successful");
> +	SAFE_MUNMAP(p, hpage_size);
> +	SAFE_MUNMAP(q, page_size);
> +	SAFE_CLOSE(fd);
> +	return;
> +fail:
> +	tst_brk(TBROK, "Once failed, No point in continuing the test");
> +}

And the usuall comments apply as well.

-- 
Cyril Hrubis
chrubis@suse.cz

-- 
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