On 3/9/2020 9:35 PM, Peter Maydell wrote:
On Mon, 9 Mar 2020 at 13:23, Liu, Jingqi <jingqi....@intel.com> wrote:
On 3/6/2020 12:40 AM, Peter Maydell wrote:
On Thu, 5 Mar 2020 at 16:11, Ján Tomko <jto...@redhat.com> wrote:
On a Thursday in 2020, Jingqi Liu wrote:
The CONFIG_LINUX symbol is always not defined in this file.
This fixes that "config-host.h" header file is not included
for getting macros.
Signed-off-by: Jingqi Liu <jingqi....@intel.com>
---
util/mmap-alloc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index 27dcccd8ec..24c0e380f3 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -10,6 +10,8 @@
* later. See the COPYING file in the top-level directory.
*/
+#include "config-host.h"
+
According to CODING_STYLE.rst, qemu/osdep.h is the header file
that should be included first, before all the other includes.
So the minimal fix would be moving qemu/osdep.h up here.
Yes, osdep must always be first.
#ifdef CONFIG_LINUX
#include <linux/mman.h>
#else /* !CONFIG_LINUX */
Do we really need this? osdep.h will pull in sys/mman.h
for you, which should define the MAP_* constants.
Also, you have no fallbmack for "I'm on Linux but the
system headers don't define MAP_SHARED_VALIDATE or
MAP_SYNC". Wouldn't it be better to just have
#ifndef MAP_SYNC
#define MAP_SYNC 0
#endif
etc ?
osdep.h pulls in sys/mman.h, which defines the MAP_* constants
except for MAP_SYNC and MAP_SHARED_VALIDATE on Linux.
Why not? Is this just "not yet in the version of glibc
we're using", or is it a bug/missed feature in glibc
that needs to be addressed there ?
I'm using the version 2.27 of glibc.
I downloaded the version 2.28 of glibc source for compilation and
installation.
I found MAP_SYNC and MAP_SHARED_VALIDATE are defined in this version.
Seems it's older glibc version issue.
How about just adding the following code in util/mmap-alloc.c ?
#ifndef MAP_SYNC
#define MAP_SYNC 0x80000
#endif
#ifndef MAP_SHARED_VALIDATE
#define MAP_SHARED_VALIDATE 0x03
#endif
You don't want to do that for non-Linux systems, so there
you need to fall back to defining them to be 0.
Are there any systems (distros) where the standard system
sys/mman.h does not define these new MAP_* constants but we
still really really need to use them? If not, then we
could just have the fallback-to-0 fallback everywhere.
Good point.
So as you mentioned, it would be better to just have the following code:
#ifndef MAP_SYNC
#define MAP_SYNC 0
#endif
#ifndef MAP_SHARED_VALIDATE
#define MAP_SHARED_VALIDATE 0
#endif
Thanks,
Jingqi
thanks
-- PMM
