diff mbox series

[v2] Refactor fork05 using new LTP API

Message ID 20240312151324.13236-1-andrea.cervesato@suse.de
State Superseded
Headers show
Series [v2] Refactor fork05 using new LTP API | expand

Commit Message

Andrea Cervesato March 12, 2024, 3:13 p.m. UTC 
From: Andrea Cervesato <andrea.cervesato@suse.com>

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
modify_ldt_ldt_s struct has been replaced by user_desc after kernel 2.4 that
is not supported by LTP

 testcases/kernel/syscalls/fork/fork05.c | 243 ++++++++----------------
 1 file changed, 82 insertions(+), 161 deletions(-)

Comments

Cyril Hrubis March 13, 2024, 11:49 a.m. UTC | #1 
Hi!
> + * On Friday, May 2, 2003 at 09:47:00AM MST, Ulrich Drepper wrote:
> + * >Robert Williamson wrote:
> + * >
> + * >>   I'm getting a SIGSEGV with one of our tests, fork05.c, that apparently
> + * >> you wrote (attached below).  The test passes on my 2.5.68 machine running
> + * >> SuSE 8.0 (glibc 2.2.5 and Linuxthreads), however it segmentation faults on
> + * >> RedHat 9 running 2.5.68.  The test seems to "break" when it attempts to run
> + * >> the assembly code....could you take a look at it?
> + * >
> + * >There is no need to look at it, I know it cannot work anymore on recent
> + * >systems.  Either change all uses of %gs to %fs or skip the entire patch
> + * >if %gs has a nonzero value.
> + * >
> + * >- --
> + * >- --------------.                        ,-.            444 Castro Street
> + * >Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
> + * >Red Hat         `--' drepper at redhat.com `---------------------------
>   *
> + * On Sat, Aug 12, 2000 at 12:47:31PM -0700, Ulrich Drepper wrote:
> + * > Ever since the %gs handling was fixed in the 2.3.99 series the
> + * > appended test program worked.  Now with 2.4.0-test6 it's not working
> + * > again.  Looking briefly over the patch from test5 to test6 I haven't
> + * > seen an immediate candidate for the breakage.  It could be missing
> + * > propagation of the LDT to the new process (and therefore an invalid
> + * > segment descriptor) or simply clearing %gs.
> + * >
> + * > Anyway, this is what you should see and what you get with test5:
> + * >
> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + * > a = 42
> + * > %gs = 0x0007
> + * > %gs = 0x0007
> + * > a = 99
> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + * >
> + * > This is what you get with test6:
> + * >
> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + * > a = 42
> + * > %gs = 0x0007
> + * > %gs = 0x0000
> + * > <SEGFAULT>
> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + * >
> + * > If somebody is actually creating a test suite for the kernel, please
> + * > add this program.  It's mostly self-contained.  The correct handling
> + * > of %gs is really important since glibc 2.2 will make heavy use of it.
> + * >
> + * > - --
> + * > - ---------------.                          ,-.   1325 Chesapeake Terrace
> + * > Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
> + * > Red Hat          `--' drepper at redhat.com   `------------------------
> + * >
> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   */

Uff, this renders very ugly in the documentation. Can we at least drop
the email signatures and rewrite the text a bit?

> -#include <stdio.h>
> -#include <fcntl.h>
> -#include <unistd.h>
> -#include <stdlib.h>
> -#include <sys/wait.h>
> +#include <asm/ldt.h>
>  #include "lapi/syscalls.h"
> -#include "test.h"
> -
> -char *TCID = "fork05";
> -
> -static char *environ_list[] = { "TERM", "NoTSetzWq", "TESTPROG" };
> -
> -#define NUMBER_OF_ENVIRON (sizeof(environ_list)/sizeof(char *))
> -int TST_TOTAL = NUMBER_OF_ENVIRON;
> +#include "tst_test.h"
>  
>  #if defined(linux) && defined(__i386__)
>  
> -struct modify_ldt_ldt_s {
> -	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;
> -};
> -
> -static int a = 42;
> -
> -static void modify_ldt(int func, struct modify_ldt_ldt_s *ptr, int bytecount)
> +static void run(void)
>  {
> -	tst_syscall(__NR_modify_ldt, func, ptr, bytecount);
> -}
> -
> -int main(void)
> -{
> -	struct modify_ldt_ldt_s ldt0;
> +	struct user_desc ldt0;
> +	int base_addr = 42;
>  	int lo;
> -	pid_t pid;
> -	int res;
>  
>  	ldt0.entry_number = 0;
> -	ldt0.base_addr = (long)&a;
> +	ldt0.base_addr = (long)&base_addr;
>  	ldt0.limit = 4;
>  	ldt0.seg_32bit = 1;
>  	ldt0.contents = 0;
> @@ -154,49 +90,34 @@ int main(void)
>  	ldt0.useable = 1;
>  	ldt0.empty = 0;
>  
> -	modify_ldt(1, &ldt0, sizeof(ldt0));
> +	tst_syscall(__NR_modify_ldt, 1, &ldt0, sizeof(ldt0));
>  
>  	asm volatile ("movw %w0, %%fs"::"q" (7));
> -
>  	asm volatile ("movl %%fs:0, %0":"=r" (lo));
> -	tst_resm(TINFO, "a = %d", lo);
> +	tst_res(TINFO, "a = %d", lo);
>  
>  	asm volatile ("pushl %%fs; popl %0":"=q" (lo));
> -	tst_resm(TINFO, "%%fs = %#06hx", lo);
> +	tst_res(TINFO, "%%fs = %#06hx", lo);
>  
>  	asm volatile ("movl %0, %%fs:0"::"r" (99));
>  
> -	pid = fork();
> -
> -	if (pid == 0) {
> +	if (!SAFE_FORK()) {
>  		asm volatile ("pushl %%fs; popl %0":"=q" (lo));
> -		tst_resm(TINFO, "%%fs = %#06hx", lo);
> +		tst_res(TINFO, "%%fs = %#06hx", lo);
>  
>  		asm volatile ("movl %%fs:0, %0":"=r" (lo));
> -		tst_resm(TINFO, "a = %d", lo);
> +		tst_res(TINFO, "a = %d", lo);
> +
> +		TST_EXP_EQ_LI(lo, 99);
>  
> -		if (lo != 99)
> -			tst_resm(TFAIL, "Test failed");
> -		else
> -			tst_resm(TPASS, "Test passed");

Huh, why have you dropped the only TPASS/TFAIL in the test?

>  		exit(lo != 99);

	This should be just exit(0).

> -	} else {
> -		waitpid(pid, &res, 0);
>  	}
> -
> -	return WIFSIGNALED(res);


I guess that we can do waitpid() for the process and fail the test if we
get SIGSEGV here as well.


>  }
>  
> -#else /* if defined(linux) && defined(__i386__) */
> -
> -int main(void)
> -{
> -	tst_resm(TINFO, "%%fs test only for ix86");
> -
> -	/*
> -	 * should be successful on all non-ix86 platforms.
> -	 */
> -	tst_exit();
> -}
> +static struct tst_test test = {
> +	.run_all = run
> +};
>  
> -#endif /* if defined(linux) && defined(__i386__) */
> +#else /* defined(linux) && defined(__i386__) */
> +	TST_TEST_TCONF("Test only supports linux 32 bits");
> +#endif
> -- 
> 2.35.3
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp
Andrea Cervesato March 13, 2024, 12:28 p.m. UTC | #2 
Hi!

On 3/13/24 12:49, Cyril Hrubis wrote:
> Hi!
>> + * On Friday, May 2, 2003 at 09:47:00AM MST, Ulrich Drepper wrote:
>> + * >Robert Williamson wrote:
>> + * >
>> + * >>   I'm getting a SIGSEGV with one of our tests, fork05.c, that apparently
>> + * >> you wrote (attached below).  The test passes on my 2.5.68 machine running
>> + * >> SuSE 8.0 (glibc 2.2.5 and Linuxthreads), however it segmentation faults on
>> + * >> RedHat 9 running 2.5.68.  The test seems to "break" when it attempts to run
>> + * >> the assembly code....could you take a look at it?
>> + * >
>> + * >There is no need to look at it, I know it cannot work anymore on recent
>> + * >systems.  Either change all uses of %gs to %fs or skip the entire patch
>> + * >if %gs has a nonzero value.
>> + * >
>> + * >- --
>> + * >- --------------.                        ,-.            444 Castro Street
>> + * >Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
>> + * >Red Hat         `--' drepper at redhat.com `---------------------------
>>    *
>> + * On Sat, Aug 12, 2000 at 12:47:31PM -0700, Ulrich Drepper wrote:
>> + * > Ever since the %gs handling was fixed in the 2.3.99 series the
>> + * > appended test program worked.  Now with 2.4.0-test6 it's not working
>> + * > again.  Looking briefly over the patch from test5 to test6 I haven't
>> + * > seen an immediate candidate for the breakage.  It could be missing
>> + * > propagation of the LDT to the new process (and therefore an invalid
>> + * > segment descriptor) or simply clearing %gs.
>> + * >
>> + * > Anyway, this is what you should see and what you get with test5:
>> + * >
>> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> + * > a = 42
>> + * > %gs = 0x0007
>> + * > %gs = 0x0007
>> + * > a = 99
>> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> + * >
>> + * > This is what you get with test6:
>> + * >
>> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> + * > a = 42
>> + * > %gs = 0x0007
>> + * > %gs = 0x0000
>> + * > <SEGFAULT>
>> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> + * >
>> + * > If somebody is actually creating a test suite for the kernel, please
>> + * > add this program.  It's mostly self-contained.  The correct handling
>> + * > of %gs is really important since glibc 2.2 will make heavy use of it.
>> + * >
>> + * > - --
>> + * > - ---------------.                          ,-.   1325 Chesapeake Terrace
>> + * > Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
>> + * > Red Hat          `--' drepper at redhat.com   `------------------------
>> + * >
>> + * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>    */
> Uff, this renders very ugly in the documentation. Can we at least drop
> the email signatures and rewrite the text a bit?
Yes it's horrible, but I didn't know what to do with this. I will try to 
do my best..
>> -#include <stdio.h>
>> -#include <fcntl.h>
>> -#include <unistd.h>
>> -#include <stdlib.h>
>> -#include <sys/wait.h>
>> +#include <asm/ldt.h>
>>   #include "lapi/syscalls.h"
>> -#include "test.h"
>> -
>> -char *TCID = "fork05";
>> -
>> -static char *environ_list[] = { "TERM", "NoTSetzWq", "TESTPROG" };
>> -
>> -#define NUMBER_OF_ENVIRON (sizeof(environ_list)/sizeof(char *))
>> -int TST_TOTAL = NUMBER_OF_ENVIRON;
>> +#include "tst_test.h"
>>   
>>   #if defined(linux) && defined(__i386__)
>>   
>> -struct modify_ldt_ldt_s {
>> -	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;
>> -};
>> -
>> -static int a = 42;
>> -
>> -static void modify_ldt(int func, struct modify_ldt_ldt_s *ptr, int bytecount)
>> +static void run(void)
>>   {
>> -	tst_syscall(__NR_modify_ldt, func, ptr, bytecount);
>> -}
>> -
>> -int main(void)
>> -{
>> -	struct modify_ldt_ldt_s ldt0;
>> +	struct user_desc ldt0;
>> +	int base_addr = 42;
>>   	int lo;
>> -	pid_t pid;
>> -	int res;
>>   
>>   	ldt0.entry_number = 0;
>> -	ldt0.base_addr = (long)&a;
>> +	ldt0.base_addr = (long)&base_addr;
>>   	ldt0.limit = 4;
>>   	ldt0.seg_32bit = 1;
>>   	ldt0.contents = 0;
>> @@ -154,49 +90,34 @@ int main(void)
>>   	ldt0.useable = 1;
>>   	ldt0.empty = 0;
>>   
>> -	modify_ldt(1, &ldt0, sizeof(ldt0));
>> +	tst_syscall(__NR_modify_ldt, 1, &ldt0, sizeof(ldt0));
>>   
>>   	asm volatile ("movw %w0, %%fs"::"q" (7));
>> -
>>   	asm volatile ("movl %%fs:0, %0":"=r" (lo));
>> -	tst_resm(TINFO, "a = %d", lo);
>> +	tst_res(TINFO, "a = %d", lo);
>>   
>>   	asm volatile ("pushl %%fs; popl %0":"=q" (lo));
>> -	tst_resm(TINFO, "%%fs = %#06hx", lo);
>> +	tst_res(TINFO, "%%fs = %#06hx", lo);
>>   
>>   	asm volatile ("movl %0, %%fs:0"::"r" (99));
>>   
>> -	pid = fork();
>> -
>> -	if (pid == 0) {
>> +	if (!SAFE_FORK()) {
>>   		asm volatile ("pushl %%fs; popl %0":"=q" (lo));
>> -		tst_resm(TINFO, "%%fs = %#06hx", lo);
>> +		tst_res(TINFO, "%%fs = %#06hx", lo);
>>   
>>   		asm volatile ("movl %%fs:0, %0":"=r" (lo));
>> -		tst_resm(TINFO, "a = %d", lo);
>> +		tst_res(TINFO, "a = %d", lo);
>> +
>> +		TST_EXP_EQ_LI(lo, 99);
>>   
>> -		if (lo != 99)
>> -			tst_resm(TFAIL, "Test failed");
>> -		else
>> -			tst_resm(TPASS, "Test passed");
> Huh, why have you dropped the only TPASS/TFAIL in the test?
>
We have TST_EXP_EQ_LI()
>>   		exit(lo != 99);
> 	This should be just exit(0).
>
>> -	} else {
>> -		waitpid(pid, &res, 0);
>>   	}
>> -
>> -	return WIFSIGNALED(res);
>
> I guess that we can do waitpid() for the process and fail the test if we
> get SIGSEGV here as well.
>
>
>>   }
>>   
>> -#else /* if defined(linux) && defined(__i386__) */
>> -
>> -int main(void)
>> -{
>> -	tst_resm(TINFO, "%%fs test only for ix86");
>> -
>> -	/*
>> -	 * should be successful on all non-ix86 platforms.
>> -	 */
>> -	tst_exit();
>> -}
>> +static struct tst_test test = {
>> +	.run_all = run
>> +};
>>   
>> -#endif /* if defined(linux) && defined(__i386__) */
>> +#else /* defined(linux) && defined(__i386__) */
>> +	TST_TEST_TCONF("Test only supports linux 32 bits");
>> +#endif
>> -- 
>> 2.35.3
>>
>>
>> -- 
>> Mailing list info: https://lists.linux.it/listinfo/ltp

Andrea
Cyril Hrubis March 13, 2024, 12:31 p.m. UTC | #3 
Hi!
> > Huh, why have you dropped the only TPASS/TFAIL in the test?
> >
> We have TST_EXP_EQ_LI()

I'm blind today...
diff mbox series

Patch

diff --git a/testcases/kernel/syscalls/fork/fork05.c b/testcases/kernel/syscalls/fork/fork05.c
index 9a99cff1d..a52bb481c 100644
--- a/testcases/kernel/syscalls/fork/fork05.c
+++ b/testcases/kernel/syscalls/fork/fork05.c
@@ -1,150 +1,86 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
- * Portions Copyright (c) 2000 Ulrich Drepper
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2 of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
- * Further, this software is distributed without any warranty that it is
- * free of the rightful claim of any third person regarding infringement
- * or the like.  Any license provided herein, whether implied or
- * otherwise, applies only to this software file.  Patent licenses, if
- * any, provided herein do not apply to combinations of this program with
- * other software, or any other product whatsoever.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
- * Mountain View, CA  94043, or:
- *
- * http://www.sgi.com$
- *
- * For further information regarding this notice, see:$
- *
- * http://oss.sgi.com/projects/GenInfo/NoticeExplan/
- *
- *
- *    Linux Test Project - Silicon Graphics, Inc.
- *    TEST IDENTIFIER	: fork05
- *    EXECUTED BY	: anyone
- *    TEST TITLE	: Make sure LDT is propagated correctly
- *    TEST CASE TOTAL	: 1
- *    CPU TYPES		: i386
- *    AUTHORS		: Ulrich Drepper
- *			  Nate Straz
- *
- *On Friday, May 2, 2003 at 09:47:00AM MST, Ulrich Drepper wrote:
- *>Robert Williamson wrote:
- *>
- *>>   I'm getting a SIGSEGV with one of our tests, fork05.c, that apparently
- *>> you wrote (attached below).  The test passes on my 2.5.68 machine running
- *>> SuSE 8.0 (glibc 2.2.5 and Linuxthreads), however it segmentation faults on
- *>> RedHat 9 running 2.5.68.  The test seems to "break" when it attempts to run
- *>> the assembly code....could you take a look at it?
- *>
- *>There is no need to look at it, I know it cannot work anymore on recent
- *>systems.  Either change all uses of %gs to %fs or skip the entire patch
- *>if %gs has a nonzero value.
- *>
- *>- --
- *>- --------------.                        ,-.            444 Castro Street
- *>Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
- *>Red Hat         `--' drepper at redhat.com `---------------------------
- *
+ *     Author: Ulrich Drepper / Nate Straz , Red Hat
+ * Copyright (C) 2023 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * [Description]
  *
+ * This test verifies that LDT is propagated correctly from parent process to
+ * the child process.
  *
- *On Sat, Aug 12, 2000 at 12:47:31PM -0700, Ulrich Drepper wrote:
- *> Ever since the %gs handling was fixed in the 2.3.99 series the
- *> appended test program worked.  Now with 2.4.0-test6 it's not working
- *> again.  Looking briefly over the patch from test5 to test6 I haven't
- *> seen an immediate candidate for the breakage.  It could be missing
- *> propagation of the LDT to the new process (and therefore an invalid
- *> segment descriptor) or simply clearing %gs.
- *>
- *> Anyway, this is what you should see and what you get with test5:
- *>
- *> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *> a = 42
- *> %gs = 0x0007
- *> %gs = 0x0007
- *> a = 99
- *> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *>
- *> This is what you get with test6:
- *>
- *> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *> a = 42
- *> %gs = 0x0007
- *> %gs = 0x0000
- *> <SEGFAULT>
- *> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *>
- *> If somebody is actually creating a test suite for the kernel, please
- *> add this program.  It's mostly self-contained.  The correct handling
- *> of %gs is really important since glibc 2.2 will make heavy use of it.
- *>
- *> - --
- *> - ---------------.                          ,-.   1325 Chesapeake Terrace
- *> Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
- *> Red Hat          `--' drepper at redhat.com   `------------------------
- *>
- *> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * On Friday, May 2, 2003 at 09:47:00AM MST, Ulrich Drepper wrote:
+ * >Robert Williamson wrote:
+ * >
+ * >>   I'm getting a SIGSEGV with one of our tests, fork05.c, that apparently
+ * >> you wrote (attached below).  The test passes on my 2.5.68 machine running
+ * >> SuSE 8.0 (glibc 2.2.5 and Linuxthreads), however it segmentation faults on
+ * >> RedHat 9 running 2.5.68.  The test seems to "break" when it attempts to run
+ * >> the assembly code....could you take a look at it?
+ * >
+ * >There is no need to look at it, I know it cannot work anymore on recent
+ * >systems.  Either change all uses of %gs to %fs or skip the entire patch
+ * >if %gs has a nonzero value.
+ * >
+ * >- --
+ * >- --------------.                        ,-.            444 Castro Street
+ * >Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
+ * >Red Hat         `--' drepper at redhat.com `---------------------------
  *
+ * On Sat, Aug 12, 2000 at 12:47:31PM -0700, Ulrich Drepper wrote:
+ * > Ever since the %gs handling was fixed in the 2.3.99 series the
+ * > appended test program worked.  Now with 2.4.0-test6 it's not working
+ * > again.  Looking briefly over the patch from test5 to test6 I haven't
+ * > seen an immediate candidate for the breakage.  It could be missing
+ * > propagation of the LDT to the new process (and therefore an invalid
+ * > segment descriptor) or simply clearing %gs.
+ * >
+ * > Anyway, this is what you should see and what you get with test5:
+ * >
+ * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * > a = 42
+ * > %gs = 0x0007
+ * > %gs = 0x0007
+ * > a = 99
+ * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * >
+ * > This is what you get with test6:
+ * >
+ * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * > a = 42
+ * > %gs = 0x0007
+ * > %gs = 0x0000
+ * > <SEGFAULT>
+ * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * >
+ * > If somebody is actually creating a test suite for the kernel, please
+ * > add this program.  It's mostly self-contained.  The correct handling
+ * > of %gs is really important since glibc 2.2 will make heavy use of it.
+ * >
+ * > - --
+ * > - ---------------.                          ,-.   1325 Chesapeake Terrace
+ * > Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
+ * > Red Hat          `--' drepper at redhat.com   `------------------------
+ * >
+ * > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 
-#include <stdio.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <sys/wait.h>
+#include <asm/ldt.h>
 #include "lapi/syscalls.h"
-#include "test.h"
-
-char *TCID = "fork05";
-
-static char *environ_list[] = { "TERM", "NoTSetzWq", "TESTPROG" };
-
-#define NUMBER_OF_ENVIRON (sizeof(environ_list)/sizeof(char *))
-int TST_TOTAL = NUMBER_OF_ENVIRON;
+#include "tst_test.h"
 
 #if defined(linux) && defined(__i386__)
 
-struct modify_ldt_ldt_s {
-	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;
-};
-
-static int a = 42;
-
-static void modify_ldt(int func, struct modify_ldt_ldt_s *ptr, int bytecount)
+static void run(void)
 {
-	tst_syscall(__NR_modify_ldt, func, ptr, bytecount);
-}
-
-int main(void)
-{
-	struct modify_ldt_ldt_s ldt0;
+	struct user_desc ldt0;
+	int base_addr = 42;
 	int lo;
-	pid_t pid;
-	int res;
 
 	ldt0.entry_number = 0;
-	ldt0.base_addr = (long)&a;
+	ldt0.base_addr = (long)&base_addr;
 	ldt0.limit = 4;
 	ldt0.seg_32bit = 1;
 	ldt0.contents = 0;
@@ -154,49 +90,34 @@  int main(void)
 	ldt0.useable = 1;
 	ldt0.empty = 0;
 
-	modify_ldt(1, &ldt0, sizeof(ldt0));
+	tst_syscall(__NR_modify_ldt, 1, &ldt0, sizeof(ldt0));
 
 	asm volatile ("movw %w0, %%fs"::"q" (7));
-
 	asm volatile ("movl %%fs:0, %0":"=r" (lo));
-	tst_resm(TINFO, "a = %d", lo);
+	tst_res(TINFO, "a = %d", lo);
 
 	asm volatile ("pushl %%fs; popl %0":"=q" (lo));
-	tst_resm(TINFO, "%%fs = %#06hx", lo);
+	tst_res(TINFO, "%%fs = %#06hx", lo);
 
 	asm volatile ("movl %0, %%fs:0"::"r" (99));
 
-	pid = fork();
-
-	if (pid == 0) {
+	if (!SAFE_FORK()) {
 		asm volatile ("pushl %%fs; popl %0":"=q" (lo));
-		tst_resm(TINFO, "%%fs = %#06hx", lo);
+		tst_res(TINFO, "%%fs = %#06hx", lo);
 
 		asm volatile ("movl %%fs:0, %0":"=r" (lo));
-		tst_resm(TINFO, "a = %d", lo);
+		tst_res(TINFO, "a = %d", lo);
+
+		TST_EXP_EQ_LI(lo, 99);
 
-		if (lo != 99)
-			tst_resm(TFAIL, "Test failed");
-		else
-			tst_resm(TPASS, "Test passed");
 		exit(lo != 99);
-	} else {
-		waitpid(pid, &res, 0);
 	}
-
-	return WIFSIGNALED(res);
 }
 
-#else /* if defined(linux) && defined(__i386__) */
-
-int main(void)
-{
-	tst_resm(TINFO, "%%fs test only for ix86");
-
-	/*
-	 * should be successful on all non-ix86 platforms.
-	 */
-	tst_exit();
-}
+static struct tst_test test = {
+	.run_all = run
+};
 
-#endif /* if defined(linux) && defined(__i386__) */
+#else /* defined(linux) && defined(__i386__) */
+	TST_TEST_TCONF("Test only supports linux 32 bits");
+#endif