From: GNU Libc Maintainers <debian-glibc@lists.debian.org>
Date: Sun, 8 Sep 2019 20:34:02 +0000 (+0100)
Subject: submitted-anon-mmap-shared
X-Git-Tag: archive/raspbian/2.29-1+rpi1^2~64
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=5899510b4269e98f3d72cdc8c4a02c623c441fe8;p=glibc.git

submitted-anon-mmap-shared

Optimizing anonymous maps brings bugs, and does not optimize much anyway.

https://sourceware.org/bugzilla/show_bug.cgi?id=19903


Gbp-Pq: Topic hurd-i386
Gbp-Pq: Name submitted-anon-mmap-shared.diff
---

diff --git a/sysdeps/mach/hurd/mmap.c b/sysdeps/mach/hurd/mmap.c
index 071e3c39b..f97d99019 100644
--- a/sysdeps/mach/hurd/mmap.c
+++ b/sysdeps/mach/hurd/mmap.c
@@ -44,29 +44,6 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset)
   if ((mapaddr & (__vm_page_size - 1)) || (offset & (__vm_page_size - 1)))
     return (void *) (long int) __hurd_fail (EINVAL);
 
-  if ((flags & (MAP_TYPE|MAP_INHERIT)) == MAP_ANON
-      && prot == (PROT_READ|PROT_WRITE)) /* cf VM_PROT_DEFAULT */
-    {
-      /* vm_allocate has (a little) less overhead in the kernel too.  */
-      err = __vm_allocate (__mach_task_self (), &mapaddr, len, mapaddr == 0);
-
-      if (err == KERN_NO_SPACE)
-	{
-	  if (flags & MAP_FIXED)
-	    {
-	      /* XXX this is not atomic as it is in unix! */
-	      /* The region is already allocated; deallocate it first.  */
-	      err = __vm_deallocate (__mach_task_self (), mapaddr, len);
-	      if (!err)
-		err = __vm_allocate (__mach_task_self (), &mapaddr, len, 0);
-	    }
-	  else if (mapaddr != 0)
-	    err = __vm_allocate (__mach_task_self (), &mapaddr, len, 1);
-	}
-
-      return err ? (void *) (long int) __hurd_fail (err) : (void *) mapaddr;
-    }
-
   vmprot = VM_PROT_NONE;
   if (prot & PROT_READ)
     vmprot |= VM_PROT_READ;