[LTP] [PATCH v2] Migrating the libhugetlbfs/testcases/truncate.c test

[LTP] [PATCH v2] Migrating the libhugetlbfs/testcases/truncate.c test

[Shirisha G]

Test Description:
Test is used to verify the correct functionality and
compatibility of the library with the "truncate" system
call when operating on files residing in a mounted
huge page filesystem.

Signed-off-by: Shirisha G <shirisha@linux.ibm.com>
---
v2:
 -Corrected typo
---
 runtest/hugetlb                               |  1 +
 testcases/kernel/mem/.gitignore               |  1 +
 .../kernel/mem/hugetlb/hugemmap/hugemmap33.c  | 72 +++++++++++++++++++
 3 files changed, 74 insertions(+)
 create mode 100644 testcases/kernel/mem/hugetlb/hugemmap/hugemmap33.c

diff --git a/runtest/hugetlb b/runtest/hugetlb
index 299c07ac9..1300e80fb 100644
--- a/runtest/hugetlb
+++ b/runtest/hugetlb
@@ -35,6 +35,7 @@ hugemmap29 hugemmap29
 hugemmap30 hugemmap30
 hugemmap31 hugemmap31
 hugemmap32 hugemmap32
+hugemmap33 hugemmap33
 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 7258489ed..d130d4dcd 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -34,6 +34,7 @@
 /hugetlb/hugemmap/hugemmap30
 /hugetlb/hugemmap/hugemmap31
 /hugetlb/hugemmap/hugemmap32
+/hugetlb/hugemmap/hugemmap33
 /hugetlb/hugeshmat/hugeshmat01
 /hugetlb/hugeshmat/hugeshmat02
 /hugetlb/hugeshmat/hugeshmat03
diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap33.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap33.c
new file mode 100644
index 000000000..a4a071b53
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap33.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2005-2006 IBM Corporation.
+ * Author: David Gibson & Adam Litke
+ */
+
+/*\
+ * [Description]
+ *
+ * Test Name: truncate
+ *
+ * Test case is used to verify the correct functionality
+ * and compatibility of the library with the "truncate" system call when
+ * operating on files residing in a mounted huge page filesystem.
+ */
+
+#include "hugetlb.h"
+
+#define RANDOM_CONSTANT	0x1234ABCD
+#define MNTPOINT "hugetlbfs/"
+long hpage_size;
+int fd;
+
+
+
+static void sigbus_handler(int signum LTP_ATTRIBUTE_UNUSED)
+{
+	tst_res(TPASS, "Test Passed");
+	exit(0);
+}
+
+static void run_test(void)
+{
+	void *p;
+	volatile unsigned int *q;
+	struct sigaction my_sigaction;
+	my_sigaction.sa_handler = sigbus_handler;
+	p = SAFE_MMAP(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_SHARED,
+			fd, 0);
+	if (p == MAP_FAILED)
+		tst_res(TFAIL, "mmap failed..!!");
+	q = p;
+	*q = 0;
+	SAFE_SIGACTION(SIGBUS, &my_sigaction, NULL);
+	SAFE_FTRUNCATE(fd, 0);
+	*q;
+        tst_res(TFAIL, "Didn't SIGBUS");
+}
+
+
+void setup(void)
+{
+	hpage_size = tst_get_hugepage_size();
+    	fd = tst_creat_unlinked(MNTPOINT, 0);
+}
+
+void cleanup(void)
+{
+    	if (fd > 0)
+	    SAFE_CLOSE(fd);
+}
+
+static struct tst_test test = {
+	.needs_root = 1,
+	.mntpoint = MNTPOINT,
+	.needs_hugetlbfs = 1,
+	.needs_tmpdir = 1,
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run_test,
+	.hugepages = {1, TST_NEEDS},
+};
-- 
2.39.3


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Re: [LTP] [PATCH v2] Migrating the libhugetlbfs/testcases/truncate.c test

[Cyril Hrubis]

Hi!
> +/*\
> + * [Description]
> + *
> + * Test Name: truncate
> + * Test case is used to verify the correct functionality
> + * and compatibility of the library with the "truncate" system call when
> + * operating on files residing in a mounted huge page filesystem.
> + */
> +
> +#include "hugetlb.h"
> +
> +#define RANDOM_CONSTANT	0x1234ABCD
             ^
	     THis is not used at all.

> +#define MNTPOINT "hugetlbfs/"
> +long hpage_size;
> +int fd;

These two should be static.

> +
> +
> +static void sigbus_handler(int signum LTP_ATTRIBUTE_UNUSED)
> +{
> +	tst_res(TPASS, "Test Passed");
> +	exit(0);

It's not safe to call exit(0) from a signal handler.

What should be done instead is to:

- add global static volatile int variable
- reset it before we attempt to access the truncated memory
- set it in the signal handler
- print TPASS/TFAIL based on the value of the variable in the run_test()
  function

> +}
> +
> +static void run_test(void)
> +{
> +	void *p;
> +	volatile unsigned int *q;
         ^
	I do not think that this has to be volatile.

	All in all this can be just:

	unsigned int *p;

	...

	p = SAFE_MMAP();

	...

	*p = 0;

> +	struct sigaction my_sigaction;
> +	my_sigaction.sa_handler = sigbus_handler;
> +	p = SAFE_MMAP(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_SHARED,
> +			fd, 0);
> +	if (p == MAP_FAILED)
> +		tst_res(TFAIL, "mmap failed..!!");

SAFE_MMAP() cannot fail, it does exit the test with a failure if the it
fails to map the memory.

> +	q = p;
> +	*q = 0;
> +	SAFE_SIGACTION(SIGBUS, &my_sigaction, NULL);

I guess that we can set up the handler in the setup instead.

> +	SAFE_FTRUNCATE(fd, 0);
> +	*q;
> +        tst_res(TFAIL, "Didn't SIGBUS");

And we should SAFE_UNMAP() the memory here.

Also does the test work with -i 2 ?

> +}
> +
> +
> +void setup(void)
> +{
> +	hpage_size = tst_get_hugepage_size();
> +    	fd = tst_creat_unlinked(MNTPOINT, 0);
   ^
   Wrong indentation, please make sure to run 'make check' and fix all
   the reported problems.

> +}
> +
> +void cleanup(void)
> +{
> +    	if (fd > 0)
> +	    SAFE_CLOSE(fd);
> +}
> +
> +static struct tst_test test = {
> +	.needs_root = 1,
> +	.mntpoint = MNTPOINT,
> +	.needs_hugetlbfs = 1,
> +	.needs_tmpdir = 1,
> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.test_all = run_test,
> +	.hugepages = {1, TST_NEEDS},
> +};
> -- 
> 2.39.3
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

-- 
Cyril Hrubis
chrubis@suse.cz

-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

Re: [LTP] [PATCH v2] Migrating the libhugetlbfs/testcases/truncate.c test

[Shirisha ganta]

On Fri, 2023-09-08 at 14:15 +0200, Cyril Hrubis wrote:
> Hi!
> > +/*\
> > + * [Description]
> > + *
> > + * Test Name: truncate
> > + * Test case is used to verify the correct functionality
> > + * and compatibility of the library with the "truncate" system
> > call when
> > + * operating on files residing in a mounted huge page filesystem.
> > + */
> > +
> > +#include "hugetlb.h"
> > +
> > +#define RANDOM_CONSTANT	0x1234ABCD
>              ^
> 	     THis is not used at all.
Will take care of this in v3.
> 
> > +#define MNTPOINT "hugetlbfs/"
> > +long hpage_size;
> > +int fd;
> 
> These two should be static.
Will take care of this in v3.
> 
> > +
> > +
> > +static void sigbus_handler(int signum LTP_ATTRIBUTE_UNUSED)
> > +{
> > +	tst_res(TPASS, "Test Passed");
> > +	exit(0);
> 
> It's not safe to call exit(0) from a signal handler.
> 
> What should be done instead is to:
> 
> - add global static volatile int variable
> - reset it before we attempt to access the truncated memory
> - set it in the signal handler
> - print TPASS/TFAIL based on the value of the variable in the
> run_test()
>   function
> 
Will take care of this in v3.
> > +}
> > +
> > +static void run_test(void)
> > +{
> > +	void *p;
> > +	volatile unsigned int *q;
>          ^
> 	I do not think that this has to be volatile.
> 
> 	All in all this can be just:
> 
> 	unsigned int *p;
> 
> 	...
> 
> 	p = SAFE_MMAP();
> 
> 	...
> 
> 	*p = 0;

This has to be volatile. The test logic is hunting for a bug
that changes the value of q.
> 
> > +	struct sigaction my_sigaction;
> > +	my_sigaction.sa_handler = sigbus_handler;
> > +	p = SAFE_MMAP(NULL, hpage_size, PROT_READ|PROT_WRITE,
> > MAP_SHARED,
> > +			fd, 0);
> > +	if (p == MAP_FAILED)
> > +		tst_res(TFAIL, "mmap failed..!!");
> 
> SAFE_MMAP() cannot fail, it does exit the test with a failure if the
> it
> fails to map the memory.

Will take care of this in v3.
> 
> > +	q = p;
> > +	*q = 0;
> > +	SAFE_SIGACTION(SIGBUS, &my_sigaction, NULL);
> 
> I guess that we can set up the handler in the setup instead.

Will take care of this in v3.
> 
> > +	SAFE_FTRUNCATE(fd, 0);
> > +	*q;
> > +        tst_res(TFAIL, "Didn't SIGBUS");
> 
> And we should SAFE_UNMAP() the memory here.

Sure will take care of this in v3.
> 
> Also does the test work with -i 2 ?
The new Version ie., v3 works
> 
> > +}
> > +
> > +
> > +void setup(void)
> > +{
> > +	hpage_size = tst_get_hugepage_size();
> > +    	fd = tst_creat_unlinked(MNTPOINT, 0);
>    ^
>    Wrong indentation, please make sure to run 'make check' and fix
> all
>    the reported problems.

Done in v3.
> 
> > +}
> > +
> > +void cleanup(void)
> > +{
> > +    	if (fd > 0)
> > +	    SAFE_CLOSE(fd);
> > +}
> > +
> > +static struct tst_test test = {
> > +	.needs_root = 1,
> > +	.mntpoint = MNTPOINT,
> > +	.needs_hugetlbfs = 1,
> > +	.needs_tmpdir = 1,
> > +	.setup = setup,
> > +	.cleanup = cleanup,
> > +	.test_all = run_test,
> > +	.hugepages = {1, TST_NEEDS},
> > +};
> > -- 
> > 2.39.3
> > 
> > 
> > -- 
> > Mailing list info: https://lists.linux.it/listinfo/ltp


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