[LTP] [PATCH v2 6/6] syscalls/set_thread_area01: Refactor into new API
Ricardo B. Marlière
rbm@suse.com
Fri Mar 28 11:12:51 CET 2025
Hello Andrea,
On Fri Mar 28, 2025 at 6:50 AM -03, Andrea Cervesato wrote:
> Hi!
>
> This test is weird. It stays inside set_thread_area folder, but it's
> testing get_thread_area(2) as well. We should probably create a new
> testing folder for get_thread_area(2), splitting test in two, doing the
> exact same thing: verifying that syscalls can be executed correctly and
> raises the correct errors.
That is not the original intent of the test, which depends on what
happens when calling set_thread_area with the correct value, which then
changed what happens with the get_thread_area call.
>
> More comments below.
>
> On 3/27/25 15:28, Ricardo B. Marliere via ltp wrote:
>> From: Ricardo B. Marlière <rbm@suse.com>
>>
>> Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
>> ---
>> .../syscalls/set_thread_area/set_thread_area.h | 31 ------
>> .../syscalls/set_thread_area/set_thread_area01.c | 120 ++++++---------------
>> 2 files changed, 35 insertions(+), 116 deletions(-)
>>
>> 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..bbc219756b414617222435416c6ecd63a06c5b41 100644
>> --- a/testcases/kernel/syscalls/set_thread_area/set_thread_area01.c
>> +++ b/testcases/kernel/syscalls/set_thread_area/set_thread_area01.c
>> @@ -1,60 +1,37 @@
>> -/*************************************************************************
>> +// 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
>> - *
>> - * 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
>> - *
>> - ************************************************************************/
>> + * Copyright (c) 2025 SUSE LLC Ricardo B. Marlière <rbm@suse.com>
>> + */
>>
>> -#include "set_thread_area.h"
>> +/*\
>> + * The test will first 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.
>> + * Therefore, a subsequent call to get_thread_area using the same pointer will
>> + * be valid. The same process is done but using -2 instead, which returns EINVAL
>> + * to both calls. Finally, it's done one more time but to an invalid pointer and
>> + * therefore an EFAULT is returned.
> This is a really specific technical explanation which could be easily
> generated by AI or a person who's reading the test code :-)
> What we need in the tests description is something that describe the
> logic behind the test, abstracting from the technical implementations,
> which could stay in [Algorithm] part.
> In short, we should be able to read the description at first glance and
> to understand the reason why a test has been made for.
See the comment below,
>> + */
>>
>> -char *TCID = "set_thread_area_01";
>> -int TST_TOTAL = 6;
>> +#include "tst_test.h"
>>
>> -#if defined(HAVE_ASM_LDT_H) && defined(HAVE_STRUCT_USER_DESC)
>> +#ifdef __i386__
>> +#include "lapi/ldt.h"
>>
>> -static void cleanup(void)
>> -{
>> -}
>> +#define VALUE_AND_STRING(val) val, #val
> We never use syscall_name in the whole test, so we can remove this macro
> which is complicating the code.
>>
>> -static void setup(void)
>> -{
>> - TEST_PAUSE;
>> -}
>> +static struct user_desc u_info1 = {.entry_number = -1 };
>> +static struct user_desc u_info2 = {.entry_number = -2 };
>>
>> -struct test {
>> +static struct tst_case {
>> int syscall;
> This is not needed if we split the test.
>> const char *const syscall_name;
> This is never used.
>> - thread_area_s *u_info;
>> + struct user_desc *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.
The test description was an elaboration of this comment. This is the
reason why it calls set_ then get_. But if its too detailed I'll try
simplifying it.
>> - */
>> -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[] = {
>> +} tst_cases[] = {
>> {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},
>> @@ -63,49 +40,22 @@ static struct test tests[] = {
>> {VALUE_AND_STRING(__NR_get_thread_area), (void *)-9, -1, EFAULT},
> We have 2 more errno to test according to man pages. We should probably
> add them.
>> };
>>
>> -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;
>> - }
>> +void run(unsigned int i)
>> +{
>> + struct tst_case *tc = &tst_cases[i];
>>
>> - 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;
>> - }
>> + if (tc->exp_errno)
>> + TST_EXP_FAIL(tst_syscall(tc->syscall, tc->u_info), tc->exp_errno);
>> + else
>> + TST_EXP_PASS(tst_syscall(tc->syscall, tc->u_info));
>> +}
>>
>> - tst_resm(TPASS, "%s returned %li errno %i (%s)",
>> - tests[i].syscall_name, TEST_RETURN,
>> - TEST_ERRNO, strerror(TEST_ERRNO));
>> - }
>> - }
>> +static struct tst_test test = {
>> + .test = run,
>> + .tcnt = ARRAY_SIZE(tst_cases),
>> +};
>>
>> - cleanup();
>> - tst_exit();
>> -}
>> #else
>> -int main(void)
>> -{
>> - tst_brkm(TCONF, NULL,
>> - "set_thread_area isn't available for this architecture");
>> -}
>> -#endif
>> +TST_TEST_TCONF("Test supported only on i386");
>> +#endif /* __i386__ */
>>
> I guess we can skip this test from the modify_ldt testing suite and
> create a new patch-set only for these 2 syscalls: get_thread_area(2) and
> set_thread_area(2).
Sure.
Thanks for reviewing,
- Ricardo.
>
> Kind Regards,
> Andrea Cervesato
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