From: GNU Libc Maintainers <debian-glibc@lists.debian.org>
Date: Wed, 31 Jan 2024 20:45:37 +0000 (+0100)
Subject: git-main_stack
X-Git-Tag: archive/raspbian/2.37-15_deb13u1+rpi1^2~59
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=e6128ab4ca94462f4b79f91fe5ce19505add1b98;p=glibc.git

git-main_stack

commit 807690610916df8aef17cd14bfadd5d4b6e699a9
Author: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date:   Sun Sep 3 21:11:09 2023 +0200

    htl: Fix stack information for main thread

    We can easily directly ask the kernel with vm_region rather than
    assuming a one-page stack.


Gbp-Pq: Topic hurd-i386
Gbp-Pq: Name git-main_stack.diff
---

diff --git a/sysdeps/mach/hurd/htl/pt-sysdep.c b/sysdeps/mach/hurd/htl/pt-sysdep.c
index 3960ffd6d..aa946110c 100644
--- a/sysdeps/mach/hurd/htl/pt-sysdep.c
+++ b/sysdeps/mach/hurd/htl/pt-sysdep.c
@@ -62,12 +62,36 @@ _init_routine (void *stack)
 
   if (stack != NULL)
     {
-      /* We are getting initialized due to dlopening a library using libpthread
-         while the main program was not linked against libpthread.  */
+      /* We are given a stack, use it.  */
+
+      /* Get the stack area information */
+      vm_address_t addr = (vm_address_t) stack;
+      vm_size_t vm_size;
+      vm_prot_t prot, max_prot;
+      vm_inherit_t inherit;
+      boolean_t is_shared;
+      memory_object_name_t obj;
+      vm_offset_t offset;
+
+      if (__vm_region (__mach_task_self (), &addr,
+		     &vm_size, &prot, &max_prot, &inherit, &is_shared,
+		     &obj, &offset) == KERN_SUCCESS)
+	__mach_port_deallocate (__mach_task_self (), obj);
+      else
+	{
+	  /* Uh.  Assume at least a page.  */
+	  vm_size = __vm_page_size;
+#if _STACK_GROWS_DOWN
+	  addr = (vm_address_t) stack - vm_size;
+#else
+	  addr = (vm_address_t) stack + vm_size;
+#endif
+	}
+
       /* Avoid allocating another stack */
       attrp = &attr;
       __pthread_attr_init (attrp);
-      __pthread_attr_setstack (attrp, stack, __vm_page_size);
+      __pthread_attr_setstack (attrp, (void *) addr, vm_size);
     }
 
   /* Create the pthread structure for the main thread (i.e. us).  */