Re: [LTP] [PATCH v4] syscalls/set_thread_area01: Refactor into new API

["Ricardo B. Marli��re via ltp" <ltp@lists.linux.it>]

On Mon Apr 7, 2025 at 9:16 AM -03, Andrea Cervesato wrote:
> Hi!
>
> The patches look good.weI still have the issue with lapi/ldt.h import, 
> probably due to missing CONFIG_MODIFY_LDT_SYSCALL in some distros: 
> https://github.com/acerv/ltp/actions/runs/14308513692/job/40097717910
> We will need the lapi/ldt.h fallback in 
> 898cc14ad412fb521867b43fed5c4e067b76f809.
>

Yes! Sent in v7: (I will check against the CI from now on)

https://lore.kernel.org/all/20250407-conversions-modify_ldt-v7-0-cbeb379360a5@suse.com

> Besides this issue that you already know:
>
> Reviewed-by: Andrea Cervesato <andrea.cervesato@suse.com>

Thanks for reviewing,
-	Ricardo.


>
> On 4/4/25 18:26, Ricardo B. Marlière via ltp wrote:
>> From: Ricardo B. Marlière <rbm@suse.com>
>>
>> Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
>> ---
>> Hello,
>>
>> This patch is available at:
>>
>> https://github.com/rbmarliere/ltp/tree/conversions/set_thread_area
>>
>> It's a single patch, on top of this prerequisite:
>>
>> https://lore.kernel.org/ltp/20250402-conversions-modify_ldt-v6-0-2e4b0e27870e@suse.com/T/#t
>>
>> Thanks,
>> -	Ricardo.
>> ---
>> Changes in v4:
>> - Added set_thread_area02 to runtest/syscalls
>> - Added missing static modifiers
>> - Fixed formatting issue in .bufs
>> - Removed struct tvariant in set_thread_area02
>> - Renamed entry -> u_info to follow manpage standard
>> - Added expected errnos to set_thread_area02 description
>> - Link to v3: https://lore.kernel.org/r/20250403-conversions-set_thread_area-v3-1-df977366be32@suse.com
>>
>> Changes in v3:
>> - Moved syscall wrappers to include/lapi/ldt.h
>> - Split the test into a new set_thread_area02.c file
>> - Used guarded buffers
>> - Used .supported_archs instead of #ifdef __i386__
>> - Used .test_variants and .tcnt+.test in set_thread_area02.c
>> - Tweaked test decriptions
>> - Link to v2: https://lore.kernel.org/r/20250403-conversions-set_thread_area-v2-1-a177e5c2b28d@suse.com
>>
>> Changes in v2:
>> - Used tst_test.test_all instead of .test
>> - Removed VALUE_AND_STRING macro
>> - Added local wrappers to the syscalls
>> - Fixed the test description
>> - Added a comment quote from the set_thread_area manual to add context
>> - Link to v1: https://lore.kernel.org/all/20250327-conversions-modify_ldt-v2-6-2907d4d3f6c0@suse.com
>> ---
>>   include/lapi/ldt.h                                 |  10 ++
>>   runtest/syscalls                                   |   1 +
>>   .../kernel/syscalls/set_thread_area/.gitignore     |   3 +-
>>   .../syscalls/set_thread_area/set_thread_area.h     |  31 -----
>>   .../syscalls/set_thread_area/set_thread_area01.c   | 137 +++++++--------------
>>   .../syscalls/set_thread_area/set_thread_area02.c   |  57 +++++++++
>>   6 files changed, 113 insertions(+), 126 deletions(-)
>>
>> diff --git a/include/lapi/ldt.h b/include/lapi/ldt.h
>> index 068a577cf113ba47a45d29920c6adb6851f4fc52..7c619c5c9ed8731e124499346c88333b0b1267b3 100644
>> --- a/include/lapi/ldt.h
>> +++ b/include/lapi/ldt.h
>> @@ -33,4 +33,14 @@ static inline int safe_modify_ldt(const char *file, const int lineno, int func,
>>   #define SAFE_MODIFY_LDT(func, ptr, bytecount) \
>>   	safe_modify_ldt(__FILE__, __LINE__, (func), (ptr), (bytecount))
>>   
>> +static inline int set_thread_area(const struct user_desc *u_info)
>> +{
>> +	return tst_syscall(__NR_set_thread_area, u_info);
>> +}
>> +
>> +static inline int get_thread_area(const struct user_desc *u_info)
>> +{
>> +	return tst_syscall(__NR_get_thread_area, u_info);
>> +}
>> +
>>   #endif /* LAPI_LDT_H__ */
>> diff --git a/runtest/syscalls b/runtest/syscalls
>> index 05b3e0d376fae3adf1eb29c22c0b83fa49eee56f..234b14f8bd66db1283b046c103682e937bff0052 100644
>> --- a/runtest/syscalls
>> +++ b/runtest/syscalls
>> @@ -1340,6 +1340,7 @@ set_mempolicy04 set_mempolicy04
>>   
>>   set_robust_list01 set_robust_list01
>>   set_thread_area01 set_thread_area01
>> +set_thread_area02 set_thread_area02
>>   set_tid_address01 set_tid_address01
>>   
>>   setdomainname01	setdomainname01
>> diff --git a/testcases/kernel/syscalls/set_thread_area/.gitignore b/testcases/kernel/syscalls/set_thread_area/.gitignore
>> index 547eb86e3c4ee86e2343067867c3bb027e0ee85a..b80ce741812c33fd9af47ecba8561ef385212e97 100644
>> --- a/testcases/kernel/syscalls/set_thread_area/.gitignore
>> +++ b/testcases/kernel/syscalls/set_thread_area/.gitignore
>> @@ -1 +1,2 @@
>> -/set_thread_area01
>> +set_thread_area01
>> +set_thread_area02
>> diff --git a/testcases/kernel/syscalls/set_thread_area/set_thread_area.h b/testcases/kernel/syscalls/set_thread_area/set_thread_area.h
>> deleted file mode 100644
>> index 2bd2469d549ecf8c5c589a0a9485f886d043f7ed..0000000000000000000000000000000000000000
>> --- a/testcases/kernel/syscalls/set_thread_area/set_thread_area.h
>> +++ /dev/null
>> @@ -1,31 +0,0 @@
>> -#include <stdio.h>
>> -#include <errno.h>
>> -
>> -/* Harness Specific Include Files. */
>> -#include "test.h"
>> -#include "lapi/syscalls.h"
>> -#include "config.h"
>> -
>> -#if defined HAVE_ASM_LDT_H
>> -#include <linux/unistd.h>
>> -#include <asm/ldt.h>
>> -
>> -#if defined HAVE_STRUCT_USER_DESC
>> -typedef struct user_desc thread_area_s;
>> -#elif defined HAVE_STRUCT_MODIFY_LDT_LDT_S
>> -typedef struct modify_ldt_ldt_s thread_area_s;
>> -#else
>> -typedef struct user_desc {
>> -	unsigned int entry_number;
>> -	unsigned long int base_addr;
>> -	unsigned int limit;
>> -	unsigned int seg_32bit:1;
>> -	unsigned int contents:2;
>> -	unsigned int read_exec_only:1;
>> -	unsigned int limit_in_pages:1;
>> -	unsigned int seg_not_present:1;
>> -	unsigned int useable:1;
>> -	unsigned int empty:25;
>> -} thread_area_s;
>> -#endif /* HAVE_STRUCT_USER_DESC */
>> -#endif /* HAVE_ASM_LDT_H */
>> diff --git a/testcases/kernel/syscalls/set_thread_area/set_thread_area01.c b/testcases/kernel/syscalls/set_thread_area/set_thread_area01.c
>> index 30626d5e90ebf8e20624c370cc4474cb51a6b102..3892d42a53a8ad2065c4da337e89d5265a529ee5 100644
>> --- a/testcases/kernel/syscalls/set_thread_area/set_thread_area01.c
>> +++ b/testcases/kernel/syscalls/set_thread_area/set_thread_area01.c
>> @@ -1,111 +1,60 @@
>> -/*************************************************************************
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>>    * Copyright (c) Crackerjack Project., 2007
>>    * Copyright (c) Manas Kumar Nayak <maknayak@in.ibm.com>
>>    * Copyright (c) Cyril Hrubis <chrubis@suse.cz> 2011
>> + * Copyright (c) 2025 SUSE LLC Ricardo B. Marlière <rbm@suse.com>
>> + */
>> +
>> +/*\
>> + * Basic test of i386 thread-local storage for set_thread_area and
>> + * get_thread_area syscalls. It verifies a simple write and read of an entry
>> + * works.
>>    *
>> - * This program is free software;  you can redistribute it and/or modify
>> - * it under the terms of the GNU General Public License as published by
>> - * the Free Software Foundation; either version 2 of the License, or
>> - * (at your option) any later version.
>> - *
>> - * This program is distributed in the hope that it will be useful,
>> - * but WITHOUT ANY WARRANTY;  without even the implied warranty of
>> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
>> - * the GNU General Public License for more details.
>> - *
>> - * You should have received a copy of the GNU General Public License
>> - * along with this program;  if not, write to the Free Software
>> - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
>> + * [Algorithm]
>>    *
>> - ************************************************************************/
>> + * - Call set_thread_area to a struct user_desc pointer with entry_number = -1,
>> + *   which will be set to a free entry_number upon exiting.
>> + * - Call get_thread_area to read the new entry.
>> + * - Use the new entry_number in another pointer and call get_thread_area.
>> + * - Make sure they have the same data.
>> + */
>>   
>> -#include "set_thread_area.h"
>> +#include "tst_test.h"
>>   
>> -char *TCID = "set_thread_area_01";
>> -int TST_TOTAL = 6;
>> +#include "lapi/ldt.h"
>>   
>> -#if defined(HAVE_ASM_LDT_H) && defined(HAVE_STRUCT_USER_DESC)
>> +static struct user_desc *u_info1;
>> +static struct user_desc *u_info2;
>>   
>> -static void cleanup(void)
>> +static void run(void)
>>   {
>> +	TST_EXP_PASS_SILENT(set_thread_area(u_info1));
>> +	TST_EXP_PASS_SILENT(get_thread_area(u_info1));
>> +
>> +	u_info2->entry_number = u_info1->entry_number;
>> +	TST_EXP_PASS_SILENT(get_thread_area(u_info2));
>> +
>> +	TST_EXP_PASS(memcmp(u_info1, u_info2, sizeof(struct user_desc)));
>>   }
>>   
>>   static void setup(void)
>>   {
>> -	TEST_PAUSE;
>> +	/* When set_thread_area() is passed an entry_number of -1, it  searches
>> +	 * for a free TLS entry. If set_thread_area() finds a free TLS entry,
>> +	 * the value of u_info->entry_number is set upon return to show which
>> +	 * entry was changed.
>> +	 */
>> +	u_info1->entry_number = -1;
>>   }
>>   
>> -struct test {
>> -	int syscall;
>> -	const char *const syscall_name;
>> -	thread_area_s *u_info;
>> -	int exp_ret;
>> -	int exp_errno;
>> -};
>> -
>> -/*
>> - * The set_thread_area uses a free entry_number if entry number is set to -1
>> - * and upon the syscall exit the entry number is set to entry which was used.
>> - * So when we call get_thread_area on u_info1, the entry number is initalized
>> - * corectly by the previous set_thread_area.
>> - */
>> -static struct user_desc u_info1 = {.entry_number = -1 };
>> -static struct user_desc u_info2 = {.entry_number = -2 };
>> -
>> -#define VALUE_AND_STRING(val) val, #val
>> -
>> -static struct test tests[] = {
>> -	{VALUE_AND_STRING(__NR_set_thread_area), &u_info1, 0, 0},
>> -	{VALUE_AND_STRING(__NR_get_thread_area), &u_info1, 0, 0},
>> -	{VALUE_AND_STRING(__NR_set_thread_area), &u_info2, -1, EINVAL},
>> -	{VALUE_AND_STRING(__NR_get_thread_area), &u_info2, -1, EINVAL},
>> -	{VALUE_AND_STRING(__NR_set_thread_area), (void *)-9, -1, EFAULT},
>> -	{VALUE_AND_STRING(__NR_get_thread_area), (void *)-9, -1, EFAULT},
>> +static struct tst_test test = {
>> +	.setup = setup,
>> +	.test_all = run,
>> +	.supported_archs = (const char *const[]){ "x86", NULL },
>> +	.bufs = (struct tst_buffers[]) {
>> +			{ &u_info1, .size = sizeof(struct user_desc) },
>> +			{ &u_info2, .size = sizeof(struct user_desc) },
>> +			{},
>> +		},
>>   };
>> -
>> -int main(int argc, char *argv[])
>> -{
>> -	int lc;
>> -	unsigned i;
>> -
>> -	tst_parse_opts(argc, argv, NULL, NULL);
>> -
>> -	setup();
>> -
>> -	for (lc = 0; TEST_LOOPING(lc); lc++) {
>> -		for (i = 0; i < sizeof(tests) / sizeof(struct test); i++) {
>> -			TEST(tst_syscall(tests[i].syscall, tests[i].u_info));
>> -
>> -			if (TEST_RETURN != tests[i].exp_ret) {
>> -				tst_resm(TFAIL, "%s returned %li expected %i",
>> -					 tests[i].syscall_name,
>> -					 TEST_RETURN, tests[i].exp_ret);
>> -				continue;
>> -			}
>> -
>> -			if (TEST_ERRNO != tests[i].exp_errno) {
>> -				tst_resm(TFAIL,
>> -					 "%s failed with %i (%s) expected %i (%s)",
>> -					 tests[i].syscall_name, TEST_ERRNO,
>> -					 strerror(TEST_ERRNO),
>> -					 tests[i].exp_errno,
>> -					 strerror(tests[i].exp_errno));
>> -				continue;
>> -			}
>> -
>> -			tst_resm(TPASS, "%s returned %li errno %i (%s)",
>> -				 tests[i].syscall_name, TEST_RETURN,
>> -				 TEST_ERRNO, strerror(TEST_ERRNO));
>> -		}
>> -	}
>> -
>> -	cleanup();
>> -	tst_exit();
>> -}
>> -#else
>> -int main(void)
>> -{
>> -	tst_brkm(TCONF, NULL,
>> -		 "set_thread_area isn't available for this architecture");
>> -}
>> -#endif
>> diff --git a/testcases/kernel/syscalls/set_thread_area/set_thread_area02.c b/testcases/kernel/syscalls/set_thread_area/set_thread_area02.c
>> new file mode 100644
>> index 0000000000000000000000000000000000000000..f1997974e62a9db6c4a984f2dbe2725dc1bf17df
>> --- /dev/null
>> +++ b/testcases/kernel/syscalls/set_thread_area/set_thread_area02.c
>> @@ -0,0 +1,57 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Copyright (c) Crackerjack Project., 2007
>> + * Copyright (c) Manas Kumar Nayak <maknayak@in.ibm.com>
>> + * Copyright (c) Cyril Hrubis <chrubis@suse.cz> 2011
>> + * Copyright (c) 2025 SUSE LLC Ricardo B. Marlière <rbm@suse.com>
>> + */
>> +
>> +/*\
>> + * Tests set_thread_area and get_thread_area syscalls for their expected errors:
>> + *
>> + * - EINVAL u_info->entry_number is out of bounds.
>> + * - EFAULT u_info is an invalid pointer.
>> + */
>> +
>> +#include "tst_test.h"
>> +
>> +#include "lapi/ldt.h"
>> +
>> +static struct user_desc *u_info;
>> +
>> +static struct tcase {
>> +	struct user_desc *u_info;
>> +	int exp_errno;
>> +} tcases[] = {
>> +	{ NULL, EINVAL },
>> +	{ (void *)-9, EFAULT },
>> +};
>> +
>> +static void run(unsigned int i)
>> +{
>> +	struct tcase tc = tcases[i];
>> +
>> +	if (tst_variant)
>> +		TST_EXP_FAIL(get_thread_area(tc.u_info), tc.exp_errno);
>> +	else
>> +		TST_EXP_FAIL(set_thread_area(tc.u_info), tc.exp_errno);
>> +}
>> +
>> +static void setup(void)
>> +{
>> +	/* This makes *entry invalid */
>> +	u_info->entry_number = -2;
>> +	tcases[0].u_info = u_info;
>> +}
>> +
>> +static struct tst_test test = {
>> +	.setup = setup,
>> +	.tcnt = ARRAY_SIZE(tcases),
>> +	.test = run,
>> +	.test_variants = 2,
>> +	.supported_archs = (const char *const[]){ "x86", NULL },
>> +	.bufs = (struct tst_buffers[]) {
>> +			{ &u_info, .size = sizeof(struct user_desc) },
>> +			{},
>> +		},
>> +};
>>
>> ---
>> base-commit: 898cc14ad412fb521867b43fed5c4e067b76f809
>> change-id: 20250403-conversions-set_thread_area-07a90e0cd449
>> prerequisite-message-id: <20250402-conversions-modify_ldt-v6-0-2e4b0e27870e@suse.com>
>> prerequisite-patch-id: 490a3e6bc4004db5234224b6fd6d4bf5030b219d
>> prerequisite-patch-id: 962bb815444eb2de9756dd2659e097567b6d6fe8
>> prerequisite-patch-id: a8357fb870a8d7278e206b4fc65f1d9450fee802
>>
>> Best regards,


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