2020-10-01 19:54:29

by Petr Vorel

[permalink] [raw]
Subject: [PATCH 1/1] uapi: Don't include <linux/sysinfo.h> in <linux/kernel.h>

+ update code where needed (include <linux/sysinfo.h> in code which
included <linux/kernel.h> only to get struct sysinfo or SI_LOAD_SHIFT).

The reason is to avoid indirect <linux/sysinfo.h> include when using
some network headers: <linux/netlink.h> or others [1] ->
<linux/kernel.h> -> <linux/sysinfo.h>.

This indirect include causes redefinition of struct sysinfo when
included both <sys/sysinfo.h> and some of network headers:

In file included from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/kernel.h:5,
from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/netlink.h:5,
from ../include/tst_netlink.h:14,
from tst_crypto.c:13:
x86_64-buildroot-linux-musl/sysroot/usr/include/linux/sysinfo.h:8:8: error: redefinition of ‘struct sysinfo’
struct sysinfo {
^~~~~~~
In file included from ../include/tst_safe_macros.h:15,
from ../include/tst_test.h:93,
from tst_crypto.c:11:
x86_64-buildroot-linux-musl/sysroot/usr/include/sys/sysinfo.h:10:8: note: originally defined here

[1] or <linux/sysctl.h>, <linux/ethtool.h>, <linux/mroute6.h>, <linux/ethtool.h>

Suggested-by: Rich Felker <[email protected]>
Signed-off-by: Petr Vorel <[email protected]>
---
Hi,

this looks to be long standing problem: python-psutil [2], iproute2 [3],
even for glibc in the past [4] and it tried to be solved before [5].

This will require glibc fix after:

+++ sysdeps/unix/sysv/linux/sys/sysinfo.h
@@ -21,7 +21,7 @@
#include <features.h>

/* Get sysinfo structure from kernel header. */
-#include <linux/kernel.h>
+#include <linux/sysinfo.h>

__BEGIN_DECLS


Kind regards,
Petr

[2] https://git.buildroot.net/buildroot/commit/?id=ab930190d7754b7f5fdda115b2069d00f1320861
[3] http://patchwork.ozlabs.org/project/netdev/patch/602128d22db86bd67e11dec8fe40a73832c222c9.1559230347.git.baruch@tkos.co.il/
[4] https://www.mail-archive.com/[email protected]/msg15363.html
[5] https://lore.kernel.org/patchwork/patch/449607/

drivers/scsi/mpt3sas/mpt3sas_base.c | 2 +-
fs/eventpoll.c | 2 +-
fs/proc/meminfo.c | 2 +-
include/linux/mm.h | 1 +
include/uapi/linux/kernel.h | 2 --
kernel/debug/kdb/kdb_main.c | 2 +-
kernel/sys.c | 2 +-
mm/page_alloc.c | 2 +-
net/ipv4/inetpeer.c | 2 +-
net/rds/ib_recv.c | 2 +-
10 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 8062bd99add8..6c84c92e5112 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -43,7 +43,7 @@
* USA.
*/

-#include <linux/kernel.h>
+#include <linux/sysinfo.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/init.h>
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 8107e06d7f6f..a4c2e199f9ea 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -7,7 +7,7 @@
*/

#include <linux/init.h>
-#include <linux/kernel.h>
+#include <linux/sysinfo.h>
#include <linux/sched/signal.h>
#include <linux/fs.h>
#include <linux/file.h>
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 887a5532e449..c80e42e1eaf9 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -1,7 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/fs.h>
#include <linux/init.h>
-#include <linux/kernel.h>
+#include <linux/sysinfo.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/mman.h>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index b2f370f0b420..4ac1af86db59 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -7,6 +7,7 @@
#ifdef __KERNEL__

#include <linux/mmdebug.h>
+#include <linux/sysinfo.h>
#include <linux/gfp.h>
#include <linux/bug.h>
#include <linux/list.h>
diff --git a/include/uapi/linux/kernel.h b/include/uapi/linux/kernel.h
index 0ff8f7477847..e95f8cd801cd 100644
--- a/include/uapi/linux/kernel.h
+++ b/include/uapi/linux/kernel.h
@@ -2,8 +2,6 @@
#ifndef _UAPI_LINUX_KERNEL_H
#define _UAPI_LINUX_KERNEL_H

-#include <linux/sysinfo.h>
-
/*
* 'kernel.h' contains some often-used function prototypes etc
*/
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 5c7949061671..3193b9dd90e8 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -14,7 +14,7 @@
#include <linux/ctype.h>
#include <linux/types.h>
#include <linux/string.h>
-#include <linux/kernel.h>
+#include <linux/sysinfo.h>
#include <linux/kmsg_dump.h>
#include <linux/reboot.h>
#include <linux/sched.h>
diff --git a/kernel/sys.c b/kernel/sys.c
index ab6c409b1159..9a3ee7ba84a7 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -16,7 +16,7 @@
#include <linux/kmod.h>
#include <linux/perf_event.h>
#include <linux/resource.h>
-#include <linux/kernel.h>
+#include <linux/sysinfo.h>
#include <linux/workqueue.h>
#include <linux/capability.h>
#include <linux/device.h>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fab5e97dc9ca..42e14c5392a6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -24,7 +24,7 @@
#include <linux/jiffies.h>
#include <linux/memblock.h>
#include <linux/compiler.h>
-#include <linux/kernel.h>
+#include <linux/sysinfo.h>
#include <linux/kasan.h>
#include <linux/module.h>
#include <linux/suspend.h>
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index ff327a62c9ce..1c7385dab1c4 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -15,7 +15,7 @@
#include <linux/random.h>
#include <linux/timer.h>
#include <linux/time.h>
-#include <linux/kernel.h>
+#include <linux/sysinfo.h>
#include <linux/mm.h>
#include <linux/net.h>
#include <linux/workqueue.h>
diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c
index 694d411dc72f..81425a2863e0 100644
--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -30,7 +30,7 @@
* SOFTWARE.
*
*/
-#include <linux/kernel.h>
+#include <linux/sysinfo.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
--
2.28.0


2020-10-01 20:30:25

by Rich Felker

[permalink] [raw]
Subject: Re: [musl] [PATCH 1/1] uapi: Don't include <linux/sysinfo.h> in <linux/kernel.h>

On Thu, Oct 01, 2020 at 09:52:31PM +0200, Petr Vorel wrote:
> + update code where needed (include <linux/sysinfo.h> in code which
> included <linux/kernel.h> only to get struct sysinfo or SI_LOAD_SHIFT).
>
> The reason is to avoid indirect <linux/sysinfo.h> include when using
> some network headers: <linux/netlink.h> or others [1] ->
> <linux/kernel.h> -> <linux/sysinfo.h>.
>
> This indirect include causes redefinition of struct sysinfo when
> included both <sys/sysinfo.h> and some of network headers:
>
> In file included from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/kernel.h:5,
> from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/netlink.h:5,
> from ../include/tst_netlink.h:14,
> from tst_crypto.c:13:
> x86_64-buildroot-linux-musl/sysroot/usr/include/linux/sysinfo.h:8:8: error: redefinition of ‘struct sysinfo’
> struct sysinfo {
> ^~~~~~~
> In file included from ../include/tst_safe_macros.h:15,
> from ../include/tst_test.h:93,
> from tst_crypto.c:11:
> x86_64-buildroot-linux-musl/sysroot/usr/include/sys/sysinfo.h:10:8: note: originally defined here
>
> [1] or <linux/sysctl.h>, <linux/ethtool.h>, <linux/mroute6.h>, <linux/ethtool.h>
>
> Suggested-by: Rich Felker <[email protected]>
> Signed-off-by: Petr Vorel <[email protected]>
> ---
> Hi,
>
> this looks to be long standing problem: python-psutil [2], iproute2 [3],
> even for glibc in the past [4] and it tried to be solved before [5].
>
> This will require glibc fix after:

You can't do this; it breaks the existing contract with glibc. New
kernel headers can't force a glibc upgrade. You just have to get rid
of use of <linux/kernel.h> elsewhere in the uapi headers. It was a
mistake that <linux/sysinfo.h> was ever separated out of
<linux/kernel.h> since it didn't (and couldn't) fix the contract that
<linux/kernel.h> exposes struct sysinfo (and that it's misnamed). But
it's no big deal. This can all be fixed without any breakage anywhere
just by not using it.

Rich