clone testcases in LTP

clone testcases in LTP

[Nathan Straz]

Could someone in the Linux ia64 community look at the clone system call
tests that the LTP has under ltp/testcases/kernel/syscalls/clone?  I
know that ia64 uses clone2() instead of clone() but I don't know where
the differences are documented.  I would like to get these test cases,
or some variation or them, compiling and running on ia64.

Thanks,
-- 
Nate Straz                                              nstraz@sgi.com
sgi, inc                                           http://www.sgi.com/
Linux Test Project                                  http://ltp.sf.net/

Re: clone testcases in LTP

[David Mosberger]

>>>>> On Wed, 9 Jul 2003 16:32:59 -0500, Nathan Straz <nstraz@sgi.com> said:

  Nathan> Could someone in the Linux ia64 community look at the clone
  Nathan> system call tests that the LTP has under
  Nathan> ltp/testcases/kernel/syscalls/clone?  I know that ia64 uses
  Nathan> clone2() instead of clone() but I don't know where the
  Nathan> differences are documented.  I would like to get these test
  Nathan> cases, or some variation or them, compiling and running on
  Nathan> ia64.

The only difference between clone() and clone2() is the explicit
stack-size argument.  clone2() is discussed in detail in my book, but
if you're already familiar with clone(), it's easy to understand
what's going on.  Here is the pseudo prototype (from glibc):

/* int  __clone2(int (*fn) (void *arg), void *child_stack_base,		*/
/*	         size_t child_stack_size, int flags, void *arg,		*/
/*	         pid_t *parent_tid, void *tls, pid_t *child_tid)	*/

	--david

Re: clone testcases in LTP

[Nathan Straz]

On Wed, Jul 09, 2003 at 03:17:42PM -0700, David Mosberger wrote:
> The only difference between clone() and clone2() is the explicit
> stack-size argument.  clone2() is discussed in detail in my book, but
> if you're already familiar with clone(), it's easy to understand
> what's going on.  Here is the pseudo prototype (from glibc):
> 
> /* int  __clone2(int (*fn) (void *arg), void *child_stack_base,	*/
> /*	         size_t child_stack_size, int flags, void *arg,		*/
> /*	         pid_t *parent_tid, void *tls, pid_t *child_tid)	*/

Hmm, that prototype seems to have a lot more args than the clone man
page states:

   #include <sched.h>
   int clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
   _syscall2(int, clone, int, flags, void *, child_stack);

What are the parameters parent_tid, tls, and child_tid supposed to be?
-- 
Nate Straz                                              nstraz@sgi.com
sgi, inc                                           http://www.sgi.com/
Linux Test Project                                  http://ltp.sf.net/

Re: clone testcases in LTP

[David Mosberger]

>>>>> On Thu, 10 Jul 2003 11:18:38 -0500, Nathan Straz <nstraz@sgi.com> said:

  >> /* int __clone2(int (*fn) (void *arg), void *child_stack_base, */
  >> /* size_t child_stack_size, int flags, void *arg, */ /* pid_t
  >> *parent_tid, void *tls, pid_t *child_tid) */

  Nathan> Hmm, that prototype seems to have a lot more args than the
  Nathan> clone man page states:

  Nathan>    #include <sched.h> int clone(int (*fn)(void *), void
  Nathan> *child_stack, int flags, void *arg); _syscall2(int, clone,
  Nathan> int, flags, void *, child_stack);

  Nathan> What are the parameters parent_tid, tls, and child_tid
  Nathan> supposed to be?

Hint 1: search google for "NPTL".
Hint 2: it's nothing ia64-specific.
Hint 3: the arguments are ignored unless you specify certain CLONE* flags,
        so the interface remains backwards-compatible.

Hope this helps.

	--david

Re: clone testcases in LTP

[Peter Chubb]

>>>>> "David" = David Mosberger <davidm@napali.hpl.hp.com> writes:

>>>>> On Thu, 10 Jul 2003 11:18:38 -0500, Nathan Straz <nstraz@sgi.com> said:
>>> /* int __clone2(int (*fn) (void *arg), void *child_stack_base, */
>>> /* size_t child_stack_size, int flags, void *arg, */ /* pid_t
>>> *parent_tid, void *tls, pid_t *child_tid) */

I'm not finding that clone2() works -- We get a segfault in the cloned
process when it returns.

This is the program:

#include <stdio.h>
#include <sys/wait.h>
#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>

int func(void *arg) { 
    fprintf(stderr, "In child\n"); 
    return 0;
} 
 
int main(void) 
{ 
        int pagesize = sysconf(_SC_PAGESIZE); 
        char *stack;
	int status;
        pid_t kidpid; 
 
#define STACKSIZE (pagesize*8) 
        stack = valloc(STACKSIZE); 
        if ((kidpid = __clone2(func, stack, STACKSIZE, SIGCHLD, NULL,
		    NULL,  NULL, NULL)) = -1) 
                perror("clone"); 
        else { 
                waitpid(kidpid, &status, __WALL);
                if (status) 
                   fprintf(stderr, "child failed: status %x\n", 
				   status); 
	} 
        return 0; 
}

I see:

In child
child failed: status b

where b translates to segfault.

Peter c

Re: clone testcases in LTP

[David Mosberger]

>>>>> On Fri, 11 Jul 2003 09:22:42 +1000, Peter Chubb <peter@chubb.wattle.id.au> said:

  Peter> I'm not finding that clone2() works -- We get a segfault in the cloned
  Peter> process when it returns.

  Peter> __clone2(func, stack, STACKSIZE, SIGCHLD, NULL, NULL,  NULL, NULL))

Umh, you're creating a new process with a different initial function.
I doubt this has ever been tested.  It probably should work, but I
don't know of any app doing this for real (either you fork, or you
create a thread).

	--david

Re: clone testcases in LTP

[Peter Chubb]

>>>>> "David" = David Mosberger <davidm@napali.hpl.hp.com> writes:

>>>>> On Fri, 11 Jul 2003 09:22:42 +1000, Peter Chubb <peter@chubb.wattle.id.au> said:
Peter> I'm not finding that clone2() works -- We get a segfault in the
Peter> cloned process when it returns.

Peter> __clone2(func, stack, STACKSIZE, SIGCHLD, NULL, NULL, NULL,
Peter> NULL))

David> Umh, you're creating a new process with a different initial
David> function.  I doubt this has ever been tested.  It probably
David> should work, but I don't know of any app doing this for real
David> (either you fork, or you create a thread).

The library __clone2() call should cope with this.
It does, essentially,

   switch(kidpid = sys_clone2(flags, stackbase, stacksize, ptidp, tlsp, tidp)) {
   case -1:
	goto __syscall_error;
   case 0:
	exit(fn(arg));
   default:
	return kidpid;
   }

Peter C

Re: clone testcases in LTP

[Ian Wienand]

[-- Attachment #1: Type: text/plain, Size: 2023 bytes --]

On Wed, Jul 09, 2003 at 03:17:42PM -0700, David Mosberger wrote:
>   Nathan> Could someone in the Linux ia64 community look at the clone
>   Nathan> system call tests that the LTP has under
> The only difference between clone() and clone2() is the explicit
> stack-size argument.

And that you pass the bottom of the stack, not the top?  Also, are
there explicit alignment requirements?  I thought it needed to be
aligned to page size (or maybe it was 16 bytes).  And should the stack
size be at a minimum ~8K, to allow enough room for register stack?

I have noticed a problem from the LTP tests.  Either I'm doing
something wrong (likely related to my assumptions above) or there is
something wrong.  See clone2.c below.  gdb doesn't catch the new
thread, but if you watch with strace you see the new thread gets a
SEGV somewhere in the dynamic loader on exit, and doesn't set the
return value properly.  The LTP tests pick this up.

This doesn't happen if thread() explicitly calls _exit(), rather than
just return (which should just call _exit).  This makes me think it's
something to do with __clone2 in in glibc.  It looks OK to me by
inspection, but unfortunately I am going away for some weeks today so
can't look into this much further.

Am I misunderstanding something?  Should my example work?

(I attached what I did anyway.  BTW the files have DOS line feeds,
which seems wrong)

-i
ianw@gelato.unsw.edu.au
http://www.gelato.unsw.edu.au

--- clone2.c ---
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sched.h>
#include <sys/wait.h>
#include <sys/types.h>
 
#define MB (1024*1024)
 
int thread(void *nothing)
{
        printf("HELLO\n");
        return 100;
}
 
int main(void)
{
 
    int ret, status;
 
    char *child_stack_base;
    child_stack_base = valloc( MB );
    printf("I see the stack @ %lx\n", child_stack_base);
 
    ret = __clone2(&thread, child_stack_base , MB, SIGCHLD);
 
    wait(&status);
    printf("Child exited (%d)\n", WEXITSTATUS(status));
     
    exit(0);
 
}

[-- Attachment #2: ltp-clone.patch --]
[-- Type: text/plain, Size: 9695 bytes --]

Only in ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/: .nfs0000000000c943670000009d
diff -u ltp-full-20030606/testcases/kernel/syscalls/clone/clone01.c ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone01.c
--- ltp-full-20030606/testcases/kernel/syscalls/clone/clone01.c	2003-05-15 05:59:50.000000000 +1000
+++ ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone01.c	2003-07-11 10:24:11.000000000 +1000
@@ -75,13 +75,23 @@
 #include "test.h"
 #include "usctest.h"
 
+#if defined (__ia64__)
+#define CHILD_STACK_SIZE 65536
+#else
 #define CHILD_STACK_SIZE 1024
+#endif
 
 #if defined (__s390__) || (__s390x__)
 #define clone __clone
 extern int __clone(int(void*),void*,int,void*);
 #endif
 
+#if defined (__ia64__)
+#define clone2 __clone2
+extern int  __clone2(int(void*),void*,size_t,int,void*);
+#endif
+
+
 static void setup();
 static void cleanup();
 static int do_child();
@@ -109,7 +119,7 @@
 	setup();
 
 	/* Allocate stack for child */
-	if((child_stack = (void *) malloc(CHILD_STACK_SIZE)) == NULL) {
+	if((child_stack = (void *) valloc(CHILD_STACK_SIZE)) == NULL) {
 		tst_brkm(TBROK, cleanup, "Cannot allocate stack for child");
 	}
 
@@ -124,6 +134,8 @@
 		 */
 #ifdef __hppa__
 		TEST(clone(do_child, child_stack, SIGCHLD, NULL));
+#elif defined (__ia64__)
+		TEST(clone2(do_child, child_stack, CHILD_STACK_SIZE, SIGCHLD, NULL));
 #else
 		TEST(clone(do_child, child_stack + CHILD_STACK_SIZE, SIGCHLD, NULL));
 #endif	
diff -u ltp-full-20030606/testcases/kernel/syscalls/clone/clone02.c ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone02.c
--- ltp-full-20030606/testcases/kernel/syscalls/clone/clone02.c	2003-05-15 05:59:50.000000000 +1000
+++ ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone02.c	2003-07-11 10:24:04.000000000 +1000
@@ -94,7 +94,12 @@
 #include "test.h"
 #include "usctest.h"
 
+#if defined (__ia64__)
+#define CHILD_STACK_SIZE 65536
+#else
 #define CHILD_STACK_SIZE 1024
+#endif
+
 #define FLAG_ALL CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | SIGCHLD
 #define FLAG_NONE SIGCHLD
 #define PARENT_VALUE 1
@@ -107,6 +112,10 @@
 extern int __clone(int(void*),void*,int,void*);
 #endif
 
+#if defined (__ia64__)
+#define clone2 __clone2
+extern int  __clone2(int(void*),void*,size_t,int,void*);
+#endif
 
 static void setup();
 static int test_setup();
@@ -165,7 +174,7 @@
 	setup();
 
 	/* Allocate stack for child */
-	if((child_stack = (void *) malloc(CHILD_STACK_SIZE)) == NULL) {
+	if((child_stack = (void *) valloc(CHILD_STACK_SIZE)) == NULL) {
 		tst_brkm(TBROK, cleanup, "Cannot allocate stack for child");
 	}
 
@@ -188,6 +197,9 @@
 #ifdef __hppa__
 			TEST(clone(child_fn, child_stack,
 				   test_cases[i].flags, NULL));
+#elif (defined __ia64__)
+			TEST(clone2(child_fn, child_stack, 
+				    CHILD_STACK_SIZE, test_cases[i].flags, NULL));
 #else
 			TEST(clone(child_fn, child_stack + CHILD_STACK_SIZE,
 				   test_cases[i].flags, NULL));
@@ -217,6 +229,7 @@
 			 * parent function. If both functions returned
 			 * successfully, test passed, else failed
 			 */	
+			
 			if ((WIFEXITED(status)) && (WEXITSTATUS(status)) &&
 			    (test_cases[i].parent_fn())) {
 				tst_resm(TPASS, "Test Passed");
@@ -358,7 +371,6 @@
 
 	/* save child pid */
 	child_pid = getpid();
-
 	if (test_VM() && test_FILES() && test_FS() && test_SIG()) {
 		return 1;
 	}
diff -u ltp-full-20030606/testcases/kernel/syscalls/clone/clone03.c ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone03.c
--- ltp-full-20030606/testcases/kernel/syscalls/clone/clone03.c	2003-05-15 05:59:50.000000000 +1000
+++ ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone03.c	2003-07-11 10:23:52.000000000 +1000
@@ -72,13 +72,21 @@
 #include "test.h"
 #include "usctest.h"
 
+#if defined (__ia64__)
+#define CHILD_STACK_SIZE 65536
+#else
 #define CHILD_STACK_SIZE 1024
+#endif
 
 #if defined (__s390__) || (__s390x__)
 #define clone __clone
 extern int __clone(int(void*),void*,int,void*);
 #endif
 
+#if defined (__ia64__)
+#define clone2 __clone2
+extern int  __clone2(int(void*),void*,size_t,int,void*);
+#endif
 
 static void setup();
 static void cleanup();
@@ -109,7 +117,7 @@
 	setup();
 
 	/* Allocate stack for child */
-	if((child_stack = (void *) malloc(CHILD_STACK_SIZE)) == NULL) {
+	if((child_stack = (void *) valloc(CHILD_STACK_SIZE)) == NULL) {
 		tst_brkm(TBROK, cleanup, "Cannot allocate stack for child");
 	}
 
@@ -129,6 +137,8 @@
 		 */
 #ifdef __hppa__
 		TEST(clone(child_fn, child_stack, (int)NULL, NULL));
+#elif (defined __ia64__)
+		TEST(clone2(child_fn, child_stack, CHILD_STACK_SIZE, (int)NULL, NULL));
 #else
 		TEST(clone(child_fn, child_stack + CHILD_STACK_SIZE, (int)NULL, NULL));
 #endif
@@ -234,6 +244,7 @@
 	if ((close(pfd[1])) == -1) {
 		tst_resm(TWARN, "close(pfd[1]) failed");
 	}
+
 	return 1;
 }
 
diff -u ltp-full-20030606/testcases/kernel/syscalls/clone/clone04.c ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone04.c
--- ltp-full-20030606/testcases/kernel/syscalls/clone/clone04.c	2003-05-15 05:59:50.000000000 +1000
+++ ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone04.c	2003-07-11 10:23:38.000000000 +1000
@@ -73,13 +73,24 @@
 #include "test.h"
 #include "usctest.h"
 
+
+#if defined (__ia64__)
+#define CHILD_STACK_SIZE 65536
+#else
 #define CHILD_STACK_SIZE 1024
+#endif
 
 #if defined (__s390__) || (__s390x__)
 #define clone __clone
 extern int __clone(int(void*),void*,int,void*);
 #endif
 
+
+#if defined (__ia64__)
+#define clone2 __clone2
+extern int  __clone2(int(void*),void*,size_t,int,void*);
+#endif
+
 static void cleanup(void);
 static void setup(void);
 static int child_fn();
@@ -117,7 +128,7 @@
 	setup();			/* global setup */
 
 	/* Allocate stack for child */
-	child_stack = (void *) malloc(CHILD_STACK_SIZE);
+	child_stack = (void *) valloc(CHILD_STACK_SIZE);
 
 	/* The following loop checks looping state if -i option given */
 
@@ -132,7 +143,7 @@
 						 "child, skipping test case");
 					continue;
 				}
-#ifdef __hppa__				
+#if (defined  __hppa__) || (defined __ia64)
 				test_stack = child_stack;
 #else
 				test_stack = child_stack + CHILD_STACK_SIZE;
@@ -144,8 +155,13 @@
 			/*
 			 * call the system call with the TEST() macro
 		 	 */
+#ifdef __ia64__
+			TEST(clone2(test_cases[ind].child_fn, test_stack,
+				    CHILD_STACK_SIZE, (int)NULL, NULL));
+#else
 			TEST(clone(test_cases[ind].child_fn, test_stack,
-				   (int)NULL, NULL));
+				    CHILD_STACK_SIZE, (int)NULL, NULL));
+#endif
 	
 			if ((TEST_RETURN == -1) &&
 			    (TEST_ERRNO == test_cases[ind].exp_errno)) {
diff -u ltp-full-20030606/testcases/kernel/syscalls/clone/clone05.c ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone05.c
--- ltp-full-20030606/testcases/kernel/syscalls/clone/clone05.c	2003-05-15 05:59:50.000000000 +1000
+++ ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone05.c	2003-07-11 10:23:31.000000000 +1000
@@ -76,8 +76,18 @@
 extern int __clone(int(void*),void*,int,void*);
 #endif
 
+#if defined (__ia64__)
+#define clone2 __clone2
+extern int  __clone2(int(void*),void*,size_t,int,void*);
+#endif
 
+#if defined (__ia64__)
+#define CHILD_STACK_SIZE 65536
+#else
 #define CHILD_STACK_SIZE 1024
+#endif
+
+#define MAX_LINE_LENGTH 256
 #define FLAG CLONE_VM | CLONE_VFORK
 
 static void setup();
@@ -108,7 +118,7 @@
 	setup();
 
 	/* Allocate stack for child */
-	if((child_stack = (void *) malloc(CHILD_STACK_SIZE)) == NULL) {
+	if((child_stack = (void *) valloc(CHILD_STACK_SIZE)) == NULL) {
 		tst_brkm(TBROK, cleanup, "Cannot allocate stack for child");
 	}
 
@@ -123,6 +133,8 @@
 		 */
 #ifdef __hppa__
 		TEST(clone(child_fn, child_stack, FLAG, NULL));
+#elif (defined __ia64__)
+		TEST(clone2(child_fn, child_stack, CHILD_STACK_SIZE, FLAG, NULL));
 #else
 		TEST(clone(child_fn, child_stack + CHILD_STACK_SIZE, FLAG, NULL));
 #endif
diff -u ltp-full-20030606/testcases/kernel/syscalls/clone/clone06.c ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone06.c
--- ltp-full-20030606/testcases/kernel/syscalls/clone/clone06.c	2003-05-15 05:59:50.000000000 +1000
+++ ltp-full-20030606-newgen/testcases/kernel/syscalls/clone/clone06.c	2003-07-11 10:23:19.000000000 +1000
@@ -82,8 +82,17 @@
 extern int __clone(int(void*),void*,int,void*);
 #endif
 
+#if defined (__ia64__)
+#define clone2 __clone2
+extern int  __clone2(int(void*),void*,size_t,int,void*);
+#endif
 
+#if defined (__ia64__)
+#define CHILD_STACK_SIZE 65536
+#else
 #define CHILD_STACK_SIZE 1024
+#endif
+
 #define MAX_LINE_LENGTH 256
 
 static void setup();
@@ -116,7 +125,7 @@
 	setup();
 
 	/* Allocate stack for child */
-	if((child_stack = (void *) malloc(CHILD_STACK_SIZE)) == NULL) {
+	if((child_stack = (void *) valloc(CHILD_STACK_SIZE)) == NULL) {
 		tst_brkm(TBROK, cleanup, "Cannot allocate stack for child");
 	}
 
@@ -136,6 +145,8 @@
 		 */
 #ifdef __hppa__
 		TEST(clone(child_environ, child_stack, (int)NULL, NULL));
+#elif (defined __ia64__)
+  		TEST(clone2(child_environ, child_stack, CHILD_STACK_SIZE, (int)NULL, NULL));
 #else
 		TEST(clone(child_environ, child_stack + CHILD_STACK_SIZE, (int)NULL, NULL));
 #endif
@@ -225,10 +236,11 @@
 	if ((close(pfd[0])) == -1) {
 		tst_brkm(TBROK, cleanup, "close(pfd[0]) failed");
 	}
-	
-	if ((sprintf(var, getenv("TERM"))) <= 0){
-		tst_resm(TWARN, "sprintf() failed");
+
+	if ( getenv("TERM") == NULL ) {
+		tst_resm(TWARN, "can't get TERM value");
 	}
+	strncpy(var, getenv("TERM"), sizeof(getenv("TERM")));
 
 	if ((write(pfd[1], var, MAX_LINE_LENGTH)) == -1) {
 		tst_resm(TWARN, "write to pipe failed");
@@ -238,7 +250,7 @@
 	if ((close(pfd[1])) == -1) {
 		tst_resm(TWARN, "close(pfd[1]) failed");
 	}
-	
+
 	return 0;
 }
 

Re: clone testcases in LTP

[David Mosberger]

>>>>> On Fri, 11 Jul 2003 10:35:12 +1000, Ian Wienand <ianw@gelato.unsw.edu.au> said:

  Ian> And that you pass the bottom of the stack, not the top?

Yes.

  Ian> Also, are there explicit alignment requirements?

Not from the kernel per se.

  Ian> I thought it needed to be aligned to page size (or maybe it was
  Ian> 16 bytes).

It the memory stack pointer has to be 16-byte aligned and the
register-backing store pointer has to be 8-byte aligned, as per
architecture/software conventions.

  Ian> And should the stack size be at a minimum ~8K, to allow enough
  Ian> room for register stack?

The kernel doesn't care about the stack size.  If you can live with 4KB,
fine.

  Ian> I have noticed a problem from the LTP tests.  Either I'm doing
  Ian> something wrong (likely related to my assumptions above) or there is
  Ian> something wrong.

It's entirely possible something is wrong (that's almost always
true).

  Ian> See clone2.c below.

Time to clarify my role (once again): I'm currently playing maintainer
of the ia64 linux tree.  That doesn't mean I fix or investigate all
bugs that come along.  If something is broken or not working as
expected then someone who cares should investigate.

It should be trivial for anyone who cares to reproduce this with the
Ski simulator.  This is exactly the type of questions that can be
solved very easily with a simulator.

	--david

Re: clone testcases in LTP

[Andreas Schwab]

Peter Chubb <peter@chubb.wattle.id.au> writes:

|> >>>>> "David" = David Mosberger <davidm@napali.hpl.hp.com> writes:
|> 
|> >>>>> On Thu, 10 Jul 2003 11:18:38 -0500, Nathan Straz <nstraz@sgi.com> said:
|> >>> /* int __clone2(int (*fn) (void *arg), void *child_stack_base, */
|> >>> /* size_t child_stack_size, int flags, void *arg, */ /* pid_t
|> >>> *parent_tid, void *tls, pid_t *child_tid) */
|> 
|> I'm not finding that clone2() works -- We get a segfault in the cloned
|> process when it returns.
|> 
|> This is the program:
|> 
|> #include <stdio.h>
|> #include <sys/wait.h>
|> #include <unistd.h>
|> #include <sys/types.h>
|> #include <stdlib.h>
|> 
|> int func(void *arg) { 
|>     fprintf(stderr, "In child\n"); 
|>     return 0;
|> } 

You can't return from the function, only exit() or _exit() works.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 Nürnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: clone testcases in LTP

[Nathan Straz]

On Fri, Jul 11, 2003 at 11:57:30AM +0200, Andreas Schwab wrote:
> Peter Chubb <peter@chubb.wattle.id.au> writes:
> |> I'm not finding that clone2() works -- We get a segfault in the cloned
> |> process when it returns.
> 
> You can't return from the function, only exit() or _exit() works.

That seems really odd that you can't return from the function.  The
clone man page (dated 2001-06-26) says either way is an option.  I did
test it with the explicit exit() call and that does clean up the
SIGSEGV.
-- 
Nate Straz                                              nstraz@sgi.com
sgi, inc                                           http://www.sgi.com/
Linux Test Project                                  http://ltp.sf.net/

Re: clone testcases in LTP

[Andreas Schwab]

Nathan Straz <nstraz@sgi.com> writes:

|> On Fri, Jul 11, 2003 at 11:57:30AM +0200, Andreas Schwab wrote:
|> > Peter Chubb <peter@chubb.wattle.id.au> writes:
|> > |> I'm not finding that clone2() works -- We get a segfault in the cloned
|> > |> process when it returns.
|> > 
|> > You can't return from the function, only exit() or _exit() works.
|> 
|> That seems really odd that you can't return from the function.

Please forget what I wrote, I've now realized that this is supposed to
work.

Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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