[LTP] [PATCH v8] Refactor fork05 using new LTP API

Andrea Cervesato andrea.cervesato@suse.de
Thu Sep 12 15:53:02 CEST 2024


From: Andrea Cervesato <andrea.cervesato@suse.com>

General code cleanup and a new ascii doc description. user_desc struct
is now imported from the kernel headers.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
commit description
fixed TPASS condition
.forks_child = 1

 testcases/kernel/syscalls/fork/fork05.c | 226 ++++++++----------------
 1 file changed, 72 insertions(+), 154 deletions(-)

diff --git a/testcases/kernel/syscalls/fork/fork05.c b/testcases/kernel/syscalls/fork/fork05.c
index 9a99cff1d..b5146d27b 100644
--- a/testcases/kernel/syscalls/fork/fork05.c
+++ b/testcases/kernel/syscalls/fork/fork05.c
@@ -1,150 +1,75 @@
+// 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.
+ *     Author: Ulrich Drepper / Nate Straz , Red Hat
+ * Copyright (C) 2023 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * [Description]
  *
- * 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.
+ * This test verifies that LDT is propagated correctly from parent process to
+ * the child process.
  *
- * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
- * Mountain View, CA  94043, or:
+ * On Friday, May 2, 2003 at 09:47:00AM MST, Ulrich Drepper wrote:
  *
- * http://www.sgi.com$
+ *  Robert Williamson wrote:
  *
- * For further information regarding this notice, see:$
+ *  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?
  *
- * http://oss.sgi.com/projects/GenInfo/NoticeExplan/
+ *  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.
  *
+ * On Sat, Aug 12, 2000 at 12:47:31PM -0700, Ulrich Drepper wrote:
  *
- *    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
+ *  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.
  *
- *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 `---------------------------
+ *  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:
  *
- *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   `------------------------
- *>
- *> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *  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.
  */
 
-#include <stdio.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <sys/wait.h>
-#include "lapi/syscalls.h"
-#include "test.h"
-
-char *TCID = "fork05";
+#include "tst_test.h"
 
-static char *environ_list[] = { "TERM", "NoTSetzWq", "TESTPROG" };
+#if defined(__i386__)
 
-#define NUMBER_OF_ENVIRON (sizeof(environ_list)/sizeof(char *))
-int TST_TOTAL = NUMBER_OF_ENVIRON;
-
-#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)
-{
-	tst_syscall(__NR_modify_ldt, func, ptr, bytecount);
-}
+#include "lapi/syscalls.h"
+#include <asm/ldt.h>
 
-int main(void)
+static void run(void)
 {
-	struct modify_ldt_ldt_s ldt0;
-	int lo;
+	struct user_desc ldt0;
+	int base_addr = 42;
+	int status;
 	pid_t pid;
-	int res;
+	int lo;
 
 	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;
@@ -152,51 +77,44 @@ int main(void)
 	ldt0.limit_in_pages = 0;
 	ldt0.seg_not_present = 0;
 	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) {
+	pid = SAFE_FORK();
+	if (!pid) {
 		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);
-
-		if (lo != 99)
-			tst_resm(TFAIL, "Test failed");
-		else
-			tst_resm(TPASS, "Test passed");
-		exit(lo != 99);
-	} else {
-		waitpid(pid, &res, 0);
-	}
+		tst_res(TINFO, "a = %d", lo);
 
-	return WIFSIGNALED(res);
-}
+		TST_EXP_EQ_LI(lo, 99);
 
-#else /* if defined(linux) && defined(__i386__) */
+		exit(0);
+	}
 
-int main(void)
-{
-	tst_resm(TINFO, "%%fs test only for ix86");
+	SAFE_WAITPID(pid, &status, 0);
 
-	/*
-	 * should be successful on all non-ix86 platforms.
-	 */
-	tst_exit();
+	if (WIFEXITED(status) && !WEXITSTATUS(status))
+		tst_res(TPASS, "Child did exit with 0");
+	else
+		tst_res(TFAIL, "Child %s", tst_strstatus(status));
 }
 
-#endif /* if defined(linux) && defined(__i386__) */
+static struct tst_test test = {
+	.test_all = run,
+	.forks_child = 1,
+};
+
+#else
+	TST_TEST_TCONF("Test only supports Intel 32 bits");
+#endif
-- 
2.43.0



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