PR/56338 CVS commit: src/sys/uvm

["Juergen Hannken-Illjes" <hannken%netbsd.org@localhost>]

The following reply was made to PR pkg/56338; it has been noted by GNATS.

From: "Juergen Hannken-Illjes" <hannken%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/56338 CVS commit: src/sys/uvm
Date: Sun, 27 Mar 2022 20:18:05 +0000

 Module Name:	src
 Committed By:	hannken
 Date:		Sun Mar 27 20:18:05 UTC 2022
 
 Modified Files:
 	src/sys/uvm: uvm_mmap.c
 
 Log Message:
 Make mmap() with "len == 0" an error if not MAP_ANON.  We should return
 an error for MAP_ANON too but unfortunately our /libexec/ld.elf_so
 sometimes creates an empty anon mapping for the bss of a shared library.
 
 At least FreeBSD and Solaris return this error too and according to POSIX
 "If len is zero, mmap() shall fail and no mapping shall be established".
 
 Fixes PR pkg/56338 Installing qt5-qtdeclarative leaves a dangling reference
 
 The dangling reference here originates from vn_mmap() taking a vnode
 reference for this empty mapping that will never be released.
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.176 -r1.177 src/sys/uvm/uvm_mmap.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.