From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Sun, 7 Jan 2018 12:31:36 +0000 (+0100)
Subject: hurd: Fix pwritev*
X-Git-Tag: glibc-2.27~166
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=200fc24b9dd2360bc850fe71ed22410051426d96;p=thirdparty%2Fglibc.git

hurd: Fix pwritev*

This follows c45d78aac ('posix: Fix generic p{read,write}v buffer allocation
(BZ#22457)'), which made pwritev to use __mmap instead of __posix_memalign,
but didn't pass PROT_READ to it, while the pwrite() call does need to
read the data we have just copied over.

	* sysdeps/posix/pwritev_common.c: Add PROT_READ to __mmap prot.
---

diff --git a/ChangeLog b/ChangeLog
index 8ddf37ebb88..f0eb187b384 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -36,6 +36,7 @@
 	(__glob64): Define GLIBC_2_27 versioned symbol instead of glob64.
 	* sysdeps/gnu/glob-lstat-compat.c: New file.
 	* sysdeps/gnu/glob64-lstat-compat.c: New file.
+	* sysdeps/posix/pwritev_common.c: Add PROT_READ to __mmap prot.
 
 2018-01-05  Tulio Magno Quites Machado Filho  <tuliom@linux.vnet.ibm.com>
 
diff --git a/sysdeps/posix/pwritev_common.c b/sysdeps/posix/pwritev_common.c
index bd0f5c52570..344ab4d61b5 100644
--- a/sysdeps/posix/pwritev_common.c
+++ b/sysdeps/posix/pwritev_common.c
@@ -55,7 +55,7 @@ PWRITEV (int fd, const struct iovec *vector, int count, OFF_T offset)
      but 1. it is system specific (not meant in generic implementation), and
      2. it would make the implementation more complex, and 3. it will require
      another syscall (fcntl).  */
-  void *buffer = __mmap (NULL, bytes, PROT_WRITE,
+  void *buffer = __mmap (NULL, bytes, PROT_READ | PROT_WRITE,
 		         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
   if (__glibc_unlikely (buffer == MAP_FAILED))
     return -1;