Re: gdb 6.7.50.20071219-cvs doesn't build on Linux/ia64

[Andreas Schwab <schwab@suse.de>]

Daniel Jacobowitz <drow@false.org> writes:

> On Wed, Dec 19, 2007 at 09:50:49AM -0800, H.J. Lu wrote:
>> This regression was introduced by
>> 
>> 2007-11-01  Daniel Jacobowitz  <dan@codesourcery.com>
>> 
>>         * linux-low.c (linux_tracefork_grandchild): New. 
>>         (linux_tracefork_child): Use clone.
>>         (linux_test_for_tracefork): Use clone; allocate and free a
>> stack.
>> 
>> Daniel, can you look into it?
>
> It is an otherwise trivial use of clone.  Could someone with access
> to an ia64-linux system try adding a clone2 case?

This seems to work:

2007-12-19  Andreas Schwab  <schwab@suse.de>

	* linux-low.c (STACK_SIZE): Define.
	(linux_tracefork_child): Use it.  Use __clone2 on ia64.
	(linux_test_for_tracefork): Likewise.

--- linux-low.c	19 Dez 2007 21:34:04 +0100	1.68
+++ linux-low.c	19 Dez 2007 22:05:14 +0100	
@@ -1743,12 +1743,20 @@ linux_tracefork_grandchild (void *arg)
   _exit (0);
 }
 
+#define STACK_SIZE 4096
+
 static int
 linux_tracefork_child (void *arg)
 {
   ptrace (PTRACE_TRACEME, 0, 0, 0);
   kill (getpid (), SIGSTOP);
-  clone (linux_tracefork_grandchild, arg, CLONE_VM | SIGCHLD, NULL);
+#ifdef __ia64__
+  __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
+	    CLONE_VM | SIGCHLD, NULL);
+#else
+  clone (linux_tracefork_grandchild, (char *) arg + STACK_SIZE,
+	 CLONE_VM | SIGCHLD, NULL);
+#endif
   _exit (0);
 }
 
@@ -1776,13 +1784,18 @@ linux_test_for_tracefork (void)
 {
   int child_pid, ret, status;
   long second_pid;
-  char *stack = malloc (8192);
+  char *stack = malloc (STACK_SIZE * 4);
 
   linux_supports_tracefork_flag = 0;
 
   /* Use CLONE_VM instead of fork, to support uClinux (no MMU).  */
-  child_pid = clone (linux_tracefork_child, stack + 2048,
-		     CLONE_VM | SIGCHLD, stack + 6144);
+#ifdef __ia64__
+  child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
+			CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
+#else
+  child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
+		     CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
+#endif
   if (child_pid == -1)
     perror_with_name ("clone");
 

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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