* [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0
@ 2018-11-11 20:01 Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 1/8] rcutorture: Automatically create initrd directory Paul E. McKenney
` (7 more replies)
0 siblings, 8 replies; 9+ messages in thread
From: Paul E. McKenney @ 2018-11-11 20:01 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg, joel
Hello!
This series causes rcutorture to automatically generate the required
initrd when needed, instead of giving very obtuse error messages.
1. Automatically create initrd directory, courtesy of Connor Shu.
2. Add initrd support for systems lacking dracut.
3. Make initrd/init execute in userspace.
4. Add cross-compile capability to initrd.sh.
5. Always strip using the cross-compiler, courtesy of Willy Tarreau.
6. Check initrd/init instead of initrd only, courtesy of Willy Tarreau.
7. Import a copy of nolibc, courtesy of Willy Tarreau.
8. Make use of nolibc when available, courtesy of Willy Tarreau.
Thanx, Paul
------------------------------------------------------------------------
bin/kvm.sh | 8
bin/mkinitrd.sh | 174 +++-
bin/nolibc.h | 2197 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
doc/initrd.txt | 99 --
4 files changed, 2372 insertions(+), 106 deletions(-)
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH tip/core/rcu 1/8] rcutorture: Automatically create initrd directory
2018-11-11 20:01 [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0 Paul E. McKenney
@ 2018-11-11 20:01 ` Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 2/8] rcutorture: Add initrd support for systems lacking dracut Paul E. McKenney
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Paul E. McKenney @ 2018-11-11 20:01 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg, joel,
Connor Shu, Paul E . McKenney
From: Connor Shu <Connor.Shu@ibm.com>
The rcutorture scripts currently expect the user to create the
tools/testing/selftests/rcutorture/initrd directory. Should the user
fail to do this, the kernel build will fail with obscure and confusing
error messages. This commit therefore adds explicit checks for the
tools/testing/selftests/rcutorture/initrd directory, and if not present,
creates one on systems on which dracut is installed. If this directory
could not be created, a less obscure error message is emitted and the
test is aborted.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Connor Shu <Connor.Shu@ibm.com>
[ paulmck: Adapt the script to fit into the rcutorture framework and
severely abbreviate the initrd/init script. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
tools/testing/selftests/rcutorture/bin/kvm.sh | 8 +++
.../selftests/rcutorture/bin/mkinitrd.sh | 60 +++++++++++++++++++
2 files changed, 68 insertions(+)
create mode 100755 tools/testing/selftests/rcutorture/bin/mkinitrd.sh
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 5a7a62d76a50..19864f1cb27a 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -194,6 +194,14 @@ do
shift
done
+if test -z "$TORTURE_INITRD" || tools/testing/selftests/rcutorture/bin/mkinitrd.sh
+then
+ :
+else
+ echo No initrd and unable to create one, aborting test >&2
+ exit 1
+fi
+
CONFIGFRAG=${KVM}/configs/${TORTURE_SUITE}; export CONFIGFRAG
if test -z "$configs"
diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
new file mode 100755
index 000000000000..ae773760f396
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
@@ -0,0 +1,60 @@
+#!/bin/bash
+#
+# Create an initrd directory if one does not already exist.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, you can access it online at
+# http://www.gnu.org/licenses/gpl-2.0.html.
+#
+# Copyright (C) IBM Corporation, 2013
+#
+# Author: Connor Shu <Connor.Shu@ibm.com>
+
+D=tools/testing/selftests/rcutorture
+
+# Prerequisite checks
+[ -z "$D" ] && echo >&2 "No argument supplied" && exit 1
+if [ ! -d "$D" ]; then
+ echo >&2 "$D does not exist: Malformed kernel source tree?"
+ exit 1
+fi
+if [ -d "$D/initrd" ]; then
+ echo "$D/initrd already exists, no need to create it"
+ exit 0
+fi
+
+T=${TMPDIR-/tmp}/mkinitrd.sh.$$
+trap 'rm -rf $T' 0 2
+mkdir $T
+
+cat > $T/init << '__EOF___'
+#!/bin/sh
+while :
+do
+ sleep 1000000
+done
+__EOF___
+
+# Try using dracut to create initrd
+command -v dracut >/dev/null 2>&1 || { echo >&2 "Dracut not installed"; exit 1; }
+echo Creating $D/initrd using dracut.
+
+# Filesystem creation
+dracut --force --no-hostonly --no-hostonly-cmdline --module "base" $T/initramfs.img
+cd $D
+mkdir initrd
+cd initrd
+zcat $T/initramfs.img | cpio -id
+cp $T/init init
+echo Done creating $D/initrd using dracut
+exit 0
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH tip/core/rcu 2/8] rcutorture: Add initrd support for systems lacking dracut
2018-11-11 20:01 [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0 Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 1/8] rcutorture: Automatically create initrd directory Paul E. McKenney
@ 2018-11-11 20:01 ` Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 3/8] rcutorture: Make initrd/init execute in userspace Paul E. McKenney
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Paul E. McKenney @ 2018-11-11 20:01 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg, joel,
Paul E. McKenney
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
The support for creating initrd directories using dracut is a great
improvement over having to always hand-create them, it is a bit annoying
to have to install some otherwise irrelevant package just to be able to
run rcutorture. This commit therefore adds support for creating initrd
directories on systems innocent of dracut. You do need gcc, but then
again you need that to build the kernel (or to build llvm) in any case.
The idea is to create an initrd directory containing nothing but a
statically linked binary having a for-loop over a long-term sleep().
The result is a Linux kernel with almost no userspace: even the
time-honored /dev, /lib, /tmp, and /usr directories are gone. In fact,
the only directory present is "/", but only because I don't know how to
get rid of it, at least short of not having an initrd in the first place.
Although statically linked binaries are much maligned, and rightly so,
their disadvantages seem to be irrelevant for this particular use case.
From https://www.akkadia.org/drepper/no_static_linking.html:
1. Fixes are difficult to apply to hordes of widely scattered
statically linked binaries. But in this case, there is only one
binary, but there would otherwise be no fewer than four libraries.
2. Security measures like local address randomization cannot be used.
Prudence prevents me from asserting that it is impossible to
base a remote attack on a networking-free rcutorture instance.
Nevertheless, bonus points to the first person who comes up with
such an attack!
3. More efficient use of physical memory. Not in this case, given
that libc is 1.8MB and the statically linked binary "only" 800K.
4. Features such as locales, name service switch (NSS),
internationalized domain names (IDN) tool, and so on require
dynamic linking. Bonus points to the first person coming up
with a valid rcutorture use case requiring these features in
its initrd.
5. Accidental violations of (L)GPL. Actually, this change actually
helps -avoid- such violations by reducing the temptation to
pass around tarballs of rcutorture-ready initrd directories.
After all, the rcutorture scripts automatically create an initrd
directory for you, so why bother with the tarballs?
6. Tools and hacks like ltrace, LD_PRELOAD, LD_PROFILE, and LD_AUDIT
don't work. Again, bonus points to the first person coming up
with a valid rcutorture use case requiring these features in
its initrd.
Nevertheless, the script will use dracut if available, and will create the
statically linked binary only when dracut are missing. Those preferring
the smaller initrd directory resulting from the statically linked binary
(like me) are free to hand-edit mkinitrd.sh to remove the code using
dracut. ;-)
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
.../selftests/rcutorture/bin/mkinitrd.sh | 40 ++++++--
.../selftests/rcutorture/doc/initrd.txt | 99 +++----------------
2 files changed, 45 insertions(+), 94 deletions(-)
diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
index ae773760f396..87a87ffeaa85 100755
--- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
+++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
@@ -46,15 +46,41 @@ done
__EOF___
# Try using dracut to create initrd
-command -v dracut >/dev/null 2>&1 || { echo >&2 "Dracut not installed"; exit 1; }
-echo Creating $D/initrd using dracut.
+if command -v dracut >/dev/null 2>&1
+then
+ echo Creating $D/initrd using dracut.
+ # Filesystem creation
+ dracut --force --no-hostonly --no-hostonly-cmdline --module "base" $T/initramfs.img
+ cd $D
+ mkdir initrd
+ cd initrd
+ zcat $T/initramfs.img | cpio -id
+ cp $T/init init
+ chmod +x init
+ echo Done creating $D/initrd using dracut
+ exit 0
+fi
-# Filesystem creation
-dracut --force --no-hostonly --no-hostonly-cmdline --module "base" $T/initramfs.img
+# No dracut, so create a C-language initrd/init program and statically
+# link it. This results in a very small initrd, but might be a bit less
+# future-proof than dracut.
+echo "Could not find dracut, attempting C initrd"
cd $D
mkdir initrd
cd initrd
-zcat $T/initramfs.img | cpio -id
-cp $T/init init
-echo Done creating $D/initrd using dracut
+cat > init.c << '___EOF___'
+#include <unistd.h>
+
+int main(int argc, int argv[])
+{
+ for (;;)
+ sleep(1000*1000*1000); /* One gigasecond is ~30 years. */
+ return 0;
+}
+___EOF___
+gcc -static -Os -o init init.c
+strip init
+rm init.c
+echo "Done creating a statically linked C-language initrd"
+
exit 0
diff --git a/tools/testing/selftests/rcutorture/doc/initrd.txt b/tools/testing/selftests/rcutorture/doc/initrd.txt
index 833f826d6ec2..933b4fd12327 100644
--- a/tools/testing/selftests/rcutorture/doc/initrd.txt
+++ b/tools/testing/selftests/rcutorture/doc/initrd.txt
@@ -1,9 +1,12 @@
-This document describes one way to create the initrd directory hierarchy
-in order to allow an initrd to be built into your kernel. The trick
-here is to steal the initrd file used on your Linux laptop, Ubuntu in
-this case. There are probably much better ways of doing this.
+The rcutorture scripting tools automatically create the needed initrd
+directory using dracut. Failing that, this tool will create an initrd
+containing a single statically linked binary named "init" that loops
+over a very long sleep() call. In both cases, this creation is done
+by tools/testing/selftests/rcutorture/bin/mkinitrd.sh.
-That said, here are the commands:
+However, if you are attempting to run rcutorture on a system that does
+not have dracut installed, and if you don't like the notion of static
+linking, you might wish to press an existing initrd into service:
------------------------------------------------------------------------
cd tools/testing/selftests/rcutorture
@@ -11,22 +14,7 @@ zcat /initrd.img > /tmp/initrd.img.zcat
mkdir initrd
cd initrd
cpio -id < /tmp/initrd.img.zcat
-------------------------------------------------------------------------
-
-Another way to create an initramfs image is using "dracut"[1], which is
-available on many distros, however the initramfs dracut generates is a cpio
-archive with another cpio archive in it, so an extra step is needed to create
-the initrd directory hierarchy.
-
-Here are the commands to create a initrd directory for rcutorture using
-dracut:
-
-------------------------------------------------------------------------
-dracut --no-hostonly --no-hostonly-cmdline --module "base bash shutdown" /tmp/initramfs.img
-cd tools/testing/selftests/rcutorture
-mkdir initrd
-cd initrd
-/usr/lib/dracut/skipcpio /tmp/initramfs.img | zcat | cpio -id < /tmp/initramfs.img
+# Manually verify that initrd contains needed binaries and libraries.
------------------------------------------------------------------------
Interestingly enough, if you are running rcutorture, you don't really
@@ -39,75 +27,12 @@ with 0755 mode.
------------------------------------------------------------------------
#!/bin/sh
-[ -d /dev ] || mkdir -m 0755 /dev
-[ -d /root ] || mkdir -m 0700 /root
-[ -d /sys ] || mkdir /sys
-[ -d /proc ] || mkdir /proc
-[ -d /tmp ] || mkdir /tmp
-mkdir -p /var/lock
-mount -t sysfs -o nodev,noexec,nosuid sysfs /sys
-mount -t proc -o nodev,noexec,nosuid proc /proc
-# Some things don't work properly without /etc/mtab.
-ln -sf /proc/mounts /etc/mtab
-
-# Note that this only becomes /dev on the real filesystem if udev's scripts
-# are used; which they will be, but it's worth pointing out
-if ! mount -t devtmpfs -o mode=0755 udev /dev; then
- echo "W: devtmpfs not available, falling back to tmpfs for /dev"
- mount -t tmpfs -o mode=0755 udev /dev
- [ -e /dev/console ] || mknod --mode=600 /dev/console c 5 1
- [ -e /dev/kmsg ] || mknod --mode=644 /dev/kmsg c 1 11
- [ -e /dev/null ] || mknod --mode=666 /dev/null c 1 3
-fi
-
-mkdir /dev/pts
-mount -t devpts -o noexec,nosuid,gid=5,mode=0620 devpts /dev/pts || true
-mount -t tmpfs -o "nosuid,size=20%,mode=0755" tmpfs /run
-mkdir /run/initramfs
-# compatibility symlink for the pre-oneiric locations
-ln -s /run/initramfs /dev/.initramfs
-
-# Export relevant variables
-export ROOT=
-export ROOTDELAY=
-export ROOTFLAGS=
-export ROOTFSTYPE=
-export IP=
-export BOOT=
-export BOOTIF=
-export UBIMTD=
-export break=
-export init=/sbin/init
-export quiet=n
-export readonly=y
-export rootmnt=/root
-export debug=
-export panic=
-export blacklist=
-export resume=
-export resume_offset=
-export recovery=
-
-for i in /sys/devices/system/cpu/cpu*/online
-do
- case $i in
- '/sys/devices/system/cpu/cpu0/online')
- ;;
- '/sys/devices/system/cpu/cpu*/online')
- ;;
- *)
- echo 1 > $i
- ;;
- esac
-done
-
while :
do
sleep 10
done
------------------------------------------------------------------------
-References:
-[1]: https://dracut.wiki.kernel.org/index.php/Main_Page
-[2]: http://blog.elastocloud.org/2015/06/rapid-linux-kernel-devtest-with-qemu.html
-[3]: https://www.centos.org/forums/viewtopic.php?t=51621
+This approach also allows most of the binaries and libraries in the
+initrd filesystem to be dispensed with, which can save significant
+space in rcutorture's "res" directory.
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH tip/core/rcu 3/8] rcutorture: Make initrd/init execute in userspace
2018-11-11 20:01 [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0 Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 1/8] rcutorture: Automatically create initrd directory Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 2/8] rcutorture: Add initrd support for systems lacking dracut Paul E. McKenney
@ 2018-11-11 20:01 ` Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 4/8] rcutorture: Add cross-compile capability to initrd.sh Paul E. McKenney
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Paul E. McKenney @ 2018-11-11 20:01 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg, joel,
Paul E. McKenney
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Currently, the initrd/init script and executable remain blocked almost
all the time. However, it is necessary to test nohz_full userspace
execution, which both variants of initrd/init fail to do. This commit
therefore causes initrd/init to spend about a millisecond per second
executing in userspace.
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
.../selftests/rcutorture/bin/mkinitrd.sh | 43 +++++++++++++++++--
1 file changed, 39 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
index 87a87ffeaa85..b48c504edfe1 100755
--- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
+++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
@@ -39,9 +39,22 @@ mkdir $T
cat > $T/init << '__EOF___'
#!/bin/sh
+# Run in userspace a few milliseconds every second. This helps to
+# exercise the NO_HZ_FULL portions of RCU.
while :
do
- sleep 1000000
+ q=
+ for i in \
+ a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \
+ a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \
+ a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \
+ a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \
+ a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \
+ a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
+ do
+ q="$q $i"
+ done
+ sleep 1
done
__EOF___
@@ -70,15 +83,37 @@ mkdir initrd
cd initrd
cat > init.c << '___EOF___'
#include <unistd.h>
+#include <sys/time.h>
+
+volatile unsigned long delaycount;
int main(int argc, int argv[])
{
- for (;;)
- sleep(1000*1000*1000); /* One gigasecond is ~30 years. */
+ int i;
+ struct timeval tv;
+ struct timeval tvb;
+
+ for (;;) {
+ sleep(1);
+ /* Need some userspace time. */
+ if (gettimeofday(&tvb, NULL))
+ continue;
+ do {
+ for (i = 0; i < 1000 * 100; i++)
+ delaycount = i * i;
+ if (gettimeofday(&tv, NULL))
+ break;
+ tv.tv_sec -= tvb.tv_sec;
+ if (tv.tv_sec > 1)
+ break;
+ tv.tv_usec += tv.tv_sec * 1000 * 1000;
+ tv.tv_usec -= tvb.tv_usec;
+ } while (tv.tv_usec < 1000);
+ }
return 0;
}
___EOF___
-gcc -static -Os -o init init.c
+cc -static -Os -o init init.c
strip init
rm init.c
echo "Done creating a statically linked C-language initrd"
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH tip/core/rcu 4/8] rcutorture: Add cross-compile capability to initrd.sh
2018-11-11 20:01 [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0 Paul E. McKenney
` (2 preceding siblings ...)
2018-11-11 20:01 ` [PATCH tip/core/rcu 3/8] rcutorture: Make initrd/init execute in userspace Paul E. McKenney
@ 2018-11-11 20:01 ` Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 5/8] rcutorture: Always strip using the cross-compiler Paul E. McKenney
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Paul E. McKenney @ 2018-11-11 20:01 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg, joel,
Paul E. McKenney
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
This adds the CROSS_COMPILE environment to the initrd.sh script's
gcc command to enable cross compilation.
Reported-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
tools/testing/selftests/rcutorture/bin/mkinitrd.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
index b48c504edfe1..70661457e3d6 100755
--- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
+++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
@@ -113,7 +113,7 @@ int main(int argc, int argv[])
return 0;
}
___EOF___
-cc -static -Os -o init init.c
+${CROSS_COMPILE}gcc -static -Os -o init init.c
strip init
rm init.c
echo "Done creating a statically linked C-language initrd"
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH tip/core/rcu 5/8] rcutorture: Always strip using the cross-compiler
2018-11-11 20:01 [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0 Paul E. McKenney
` (3 preceding siblings ...)
2018-11-11 20:01 ` [PATCH tip/core/rcu 4/8] rcutorture: Add cross-compile capability to initrd.sh Paul E. McKenney
@ 2018-11-11 20:01 ` Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 6/8] rcutorture: Check initrd/init instead of initrd only Paul E. McKenney
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Paul E. McKenney @ 2018-11-11 20:01 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg, joel,
Willy Tarreau, Paul E . McKenney
From: Willy Tarreau <w@1wt.eu>
Strip using -s on the compiler command line instead of calling the "strip"
utility as the latter isn't necessarily compatible with the target arch.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
tools/testing/selftests/rcutorture/bin/mkinitrd.sh | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
index 70661457e3d6..dbb6f0160281 100755
--- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
+++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
@@ -113,8 +113,7 @@ int main(int argc, int argv[])
return 0;
}
___EOF___
-${CROSS_COMPILE}gcc -static -Os -o init init.c
-strip init
+${CROSS_COMPILE}gcc -s -static -Os -o init init.c
rm init.c
echo "Done creating a statically linked C-language initrd"
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH tip/core/rcu 6/8] rcutorture: Check initrd/init instead of initrd only
2018-11-11 20:01 [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0 Paul E. McKenney
` (4 preceding siblings ...)
2018-11-11 20:01 ` [PATCH tip/core/rcu 5/8] rcutorture: Always strip using the cross-compiler Paul E. McKenney
@ 2018-11-11 20:01 ` Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 7/8] rcutorture: Import a copy of nolibc Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 8/8] rcutorture: Make use of nolibc when available Paul E. McKenney
7 siblings, 0 replies; 9+ messages in thread
From: Paul E. McKenney @ 2018-11-11 20:01 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg, joel,
Willy Tarreau, Paul E . McKenney
From: Willy Tarreau <w@1wt.eu>
If the build fails, we can end up with an empty initrd directory which
prevents the build script from operating again. Better rely on the
resulting init executable instead.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
tools/testing/selftests/rcutorture/bin/mkinitrd.sh | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
index dbb6f0160281..56a56ea06983 100755
--- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
+++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
@@ -28,8 +28,8 @@ if [ ! -d "$D" ]; then
echo >&2 "$D does not exist: Malformed kernel source tree?"
exit 1
fi
-if [ -d "$D/initrd" ]; then
- echo "$D/initrd already exists, no need to create it"
+if [ -s "$D/initrd/init" ]; then
+ echo "$D/initrd/init already exists, no need to create it"
exit 0
fi
@@ -65,7 +65,7 @@ then
# Filesystem creation
dracut --force --no-hostonly --no-hostonly-cmdline --module "base" $T/initramfs.img
cd $D
- mkdir initrd
+ mkdir -p initrd
cd initrd
zcat $T/initramfs.img | cpio -id
cp $T/init init
@@ -79,7 +79,7 @@ fi
# future-proof than dracut.
echo "Could not find dracut, attempting C initrd"
cd $D
-mkdir initrd
+mkdir -p initrd
cd initrd
cat > init.c << '___EOF___'
#include <unistd.h>
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH tip/core/rcu 7/8] rcutorture: Import a copy of nolibc
2018-11-11 20:01 [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0 Paul E. McKenney
` (5 preceding siblings ...)
2018-11-11 20:01 ` [PATCH tip/core/rcu 6/8] rcutorture: Check initrd/init instead of initrd only Paul E. McKenney
@ 2018-11-11 20:01 ` Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 8/8] rcutorture: Make use of nolibc when available Paul E. McKenney
7 siblings, 0 replies; 9+ messages in thread
From: Paul E. McKenney @ 2018-11-11 20:01 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg, joel,
Willy Tarreau, Paul E . McKenney
From: Willy Tarreau <w@1wt.eu>
This is a definition of the most common syscalls needed in minimalist
init executables, allowing to statically build them with no external
dependencies. It is sufficient in its current form to build rcutorture's
init on x86_64, i386, arm, and arm64. Others have not been ported or
tested. Updates may be found here :
http://git.formilux.org/?p=people/willy/nolibc.git
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
.../testing/selftests/rcutorture/bin/nolibc.h | 2197 +++++++++++++++++
1 file changed, 2197 insertions(+)
create mode 100644 tools/testing/selftests/rcutorture/bin/nolibc.h
diff --git a/tools/testing/selftests/rcutorture/bin/nolibc.h b/tools/testing/selftests/rcutorture/bin/nolibc.h
new file mode 100644
index 000000000000..f98f5b92d3eb
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/bin/nolibc.h
@@ -0,0 +1,2197 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/* nolibc.h
+ * Copyright (C) 2017-2018 Willy Tarreau <w@1wt.eu>
+ */
+
+/* some archs (at least aarch64) don't expose the regular syscalls anymore by
+ * default, either because they have an "_at" replacement, or because there are
+ * more modern alternatives. For now we'd rather still use them.
+ */
+#define __ARCH_WANT_SYSCALL_NO_AT
+#define __ARCH_WANT_SYSCALL_NO_FLAGS
+#define __ARCH_WANT_SYSCALL_DEPRECATED
+
+#include <asm/unistd.h>
+#include <asm/ioctls.h>
+#include <asm/errno.h>
+#include <linux/fs.h>
+#include <linux/loop.h>
+
+#define NOLIBC
+
+/* Build a static executable this way :
+ * $ gcc -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \
+ * -static -include nolibc.h -lgcc -o hello hello.c
+ *
+ * Useful calling convention table found here :
+ * http://man7.org/linux/man-pages/man2/syscall.2.html
+ *
+ * This doc is even better :
+ * https://w3challs.com/syscalls/
+ */
+
+
+/* this way it will be removed if unused */
+static int errno;
+
+#ifndef NOLIBC_IGNORE_ERRNO
+#define SET_ERRNO(v) do { errno = (v); } while (0)
+#else
+#define SET_ERRNO(v) do { } while (0)
+#endif
+
+/* errno codes all ensure that they will not conflict with a valid pointer
+ * because they all correspond to the highest addressable memry page.
+ */
+#define MAX_ERRNO 4095
+
+/* Declare a few quite common macros and types that usually are in stdlib.h,
+ * stdint.h, ctype.h, unistd.h and a few other common locations.
+ */
+
+#define NULL ((void *)0)
+
+/* stdint types */
+typedef unsigned char uint8_t;
+typedef signed char int8_t;
+typedef unsigned short uint16_t;
+typedef signed short int16_t;
+typedef unsigned int uint32_t;
+typedef signed int int32_t;
+typedef unsigned long long uint64_t;
+typedef signed long long int64_t;
+typedef unsigned long size_t;
+typedef signed long ssize_t;
+typedef unsigned long uintptr_t;
+typedef signed long intptr_t;
+typedef signed long ptrdiff_t;
+
+/* for stat() */
+typedef unsigned int dev_t;
+typedef unsigned long ino_t;
+typedef unsigned int mode_t;
+typedef signed int pid_t;
+typedef unsigned int uid_t;
+typedef unsigned int gid_t;
+typedef unsigned long nlink_t;
+typedef signed long off_t;
+typedef signed long blksize_t;
+typedef signed long blkcnt_t;
+typedef signed long time_t;
+
+/* for poll() */
+struct pollfd {
+ int fd;
+ short int events;
+ short int revents;
+};
+
+/* for select() */
+struct timeval {
+ long tv_sec;
+ long tv_usec;
+};
+
+/* for pselect() */
+struct timespec {
+ long tv_sec;
+ long tv_nsec;
+};
+
+/* for gettimeofday() */
+struct timezone {
+ int tz_minuteswest;
+ int tz_dsttime;
+};
+
+/* for getdents64() */
+struct linux_dirent64 {
+ uint64_t d_ino;
+ int64_t d_off;
+ unsigned short d_reclen;
+ unsigned char d_type;
+ char d_name[];
+};
+
+/* commonly an fd_set represents 256 FDs */
+#define FD_SETSIZE 256
+typedef struct { uint32_t fd32[FD_SETSIZE/32]; } fd_set;
+
+/* needed by wait4() */
+struct rusage {
+ struct timeval ru_utime;
+ struct timeval ru_stime;
+ long ru_maxrss;
+ long ru_ixrss;
+ long ru_idrss;
+ long ru_isrss;
+ long ru_minflt;
+ long ru_majflt;
+ long ru_nswap;
+ long ru_inblock;
+ long ru_oublock;
+ long ru_msgsnd;
+ long ru_msgrcv;
+ long ru_nsignals;
+ long ru_nvcsw;
+ long ru_nivcsw;
+};
+
+/* stat flags (WARNING, octal here) */
+#define S_IFDIR 0040000
+#define S_IFCHR 0020000
+#define S_IFBLK 0060000
+#define S_IFREG 0100000
+#define S_IFIFO 0010000
+#define S_IFLNK 0120000
+#define S_IFSOCK 0140000
+#define S_IFMT 0170000
+
+#define S_ISDIR(mode) (((mode) & S_IFDIR) == S_IFDIR)
+#define S_ISCHR(mode) (((mode) & S_IFCHR) == S_IFCHR)
+#define S_ISBLK(mode) (((mode) & S_IFBLK) == S_IFBLK)
+#define S_ISREG(mode) (((mode) & S_IFREG) == S_IFREG)
+#define S_ISFIFO(mode) (((mode) & S_IFIFO) == S_IFIFO)
+#define S_ISLNK(mode) (((mode) & S_IFLNK) == S_IFLNK)
+#define S_ISSOCK(mode) (((mode) & S_IFSOCK) == S_IFSOCK)
+
+#define DT_UNKNOWN 0
+#define DT_FIFO 1
+#define DT_CHR 2
+#define DT_DIR 4
+#define DT_BLK 6
+#define DT_REG 8
+#define DT_LNK 10
+#define DT_SOCK 12
+
+/* all the *at functions */
+#ifndef AT_FDWCD
+#define AT_FDCWD -100
+#endif
+
+/* lseek */
+#define SEEK_SET 0
+#define SEEK_CUR 1
+#define SEEK_END 2
+
+/* reboot */
+#define LINUX_REBOOT_MAGIC1 0xfee1dead
+#define LINUX_REBOOT_MAGIC2 0x28121969
+#define LINUX_REBOOT_CMD_HALT 0xcdef0123
+#define LINUX_REBOOT_CMD_POWER_OFF 0x4321fedc
+#define LINUX_REBOOT_CMD_RESTART 0x01234567
+#define LINUX_REBOOT_CMD_SW_SUSPEND 0xd000fce2
+
+
+/* The format of the struct as returned by the libc to the application, which
+ * significantly differs from the format returned by the stat() syscall flavours.
+ */
+struct stat {
+ dev_t st_dev; /* ID of device containing file */
+ ino_t st_ino; /* inode number */
+ mode_t st_mode; /* protection */
+ nlink_t st_nlink; /* number of hard links */
+ uid_t st_uid; /* user ID of owner */
+ gid_t st_gid; /* group ID of owner */
+ dev_t st_rdev; /* device ID (if special file) */
+ off_t st_size; /* total size, in bytes */
+ blksize_t st_blksize; /* blocksize for file system I/O */
+ blkcnt_t st_blocks; /* number of 512B blocks allocated */
+ time_t st_atime; /* time of last access */
+ time_t st_mtime; /* time of last modification */
+ time_t st_ctime; /* time of last status change */
+};
+
+#define WEXITSTATUS(status) (((status) & 0xff00) >> 8)
+#define WIFEXITED(status) (((status) & 0x7f) == 0)
+
+
+/* Below comes the architecture-specific code. For each architecture, we have
+ * the syscall declarations and the _start code definition. This is the only
+ * global part. On all architectures the kernel puts everything in the stack
+ * before jumping to _start just above us, without any return address (_start
+ * is not a function but an entry pint). So at the stack pointer we find argc.
+ * Then argv[] begins, and ends at the first NULL. Then we have envp which
+ * starts and ends with a NULL as well. So envp=argv+argc+1.
+ */
+
+#if defined(__x86_64__)
+/* Syscalls for x86_64 :
+ * - registers are 64-bit
+ * - syscall number is passed in rax
+ * - arguments are in rdi, rsi, rdx, r10, r8, r9 respectively
+ * - the system call is performed by calling the syscall instruction
+ * - syscall return comes in rax
+ * - rcx and r8..r11 may be clobbered, others are preserved.
+ * - the arguments are cast to long and assigned into the target registers
+ * which are then simply passed as registers to the asm code, so that we
+ * don't have to experience issues with register constraints.
+ * - the syscall number is always specified last in order to allow to force
+ * some registers before (gcc refuses a %-register at the last position).
+ */
+
+#define my_syscall0(num) \
+({ \
+ long _ret; \
+ register long _num asm("rax") = (num); \
+ \
+ asm volatile ( \
+ "syscall\n" \
+ : "=a" (_ret) \
+ : "0"(_num) \
+ : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall1(num, arg1) \
+({ \
+ long _ret; \
+ register long _num asm("rax") = (num); \
+ register long _arg1 asm("rdi") = (long)(arg1); \
+ \
+ asm volatile ( \
+ "syscall\n" \
+ : "=a" (_ret) \
+ : "r"(_arg1), \
+ "0"(_num) \
+ : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall2(num, arg1, arg2) \
+({ \
+ long _ret; \
+ register long _num asm("rax") = (num); \
+ register long _arg1 asm("rdi") = (long)(arg1); \
+ register long _arg2 asm("rsi") = (long)(arg2); \
+ \
+ asm volatile ( \
+ "syscall\n" \
+ : "=a" (_ret) \
+ : "r"(_arg1), "r"(_arg2), \
+ "0"(_num) \
+ : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall3(num, arg1, arg2, arg3) \
+({ \
+ long _ret; \
+ register long _num asm("rax") = (num); \
+ register long _arg1 asm("rdi") = (long)(arg1); \
+ register long _arg2 asm("rsi") = (long)(arg2); \
+ register long _arg3 asm("rdx") = (long)(arg3); \
+ \
+ asm volatile ( \
+ "syscall\n" \
+ : "=a" (_ret) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), \
+ "0"(_num) \
+ : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall4(num, arg1, arg2, arg3, arg4) \
+({ \
+ long _ret; \
+ register long _num asm("rax") = (num); \
+ register long _arg1 asm("rdi") = (long)(arg1); \
+ register long _arg2 asm("rsi") = (long)(arg2); \
+ register long _arg3 asm("rdx") = (long)(arg3); \
+ register long _arg4 asm("r10") = (long)(arg4); \
+ \
+ asm volatile ( \
+ "syscall\n" \
+ : "=a" (_ret), "=r"(_arg4) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
+ "0"(_num) \
+ : "rcx", "r8", "r9", "r11", "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
+({ \
+ long _ret; \
+ register long _num asm("rax") = (num); \
+ register long _arg1 asm("rdi") = (long)(arg1); \
+ register long _arg2 asm("rsi") = (long)(arg2); \
+ register long _arg3 asm("rdx") = (long)(arg3); \
+ register long _arg4 asm("r10") = (long)(arg4); \
+ register long _arg5 asm("r8") = (long)(arg5); \
+ \
+ asm volatile ( \
+ "syscall\n" \
+ : "=a" (_ret), "=r"(_arg4), "=r"(_arg5) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
+ "0"(_num) \
+ : "rcx", "r9", "r11", "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
+({ \
+ long _ret; \
+ register long _num asm("rax") = (num); \
+ register long _arg1 asm("rdi") = (long)(arg1); \
+ register long _arg2 asm("rsi") = (long)(arg2); \
+ register long _arg3 asm("rdx") = (long)(arg3); \
+ register long _arg4 asm("r10") = (long)(arg4); \
+ register long _arg5 asm("r8") = (long)(arg5); \
+ register long _arg6 asm("r9") = (long)(arg6); \
+ \
+ asm volatile ( \
+ "syscall\n" \
+ : "=a" (_ret), "=r"(_arg4), "=r"(_arg5) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
+ "r"(_arg6), "0"(_num) \
+ : "rcx", "r11", "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+/* startup code */
+asm(".section .text\n"
+ ".global _start\n"
+ "_start:\n"
+ "pop %rdi\n" // argc (first arg, %rdi)
+ "mov %rsp, %rsi\n" // argv[] (second arg, %rsi)
+ "lea 8(%rsi,%rdi,8),%rdx\n" // then a NULL then envp (third arg, %rdx)
+ "and $-16, %rsp\n" // x86 ABI : esp must be 16-byte aligned when
+ "sub $8, %rsp\n" // entering the callee
+ "call main\n" // main() returns the status code, we'll exit with it.
+ "movzb %al, %rdi\n" // retrieve exit code from 8 lower bits
+ "mov $60, %rax\n" // NR_exit == 60
+ "syscall\n" // really exit
+ "hlt\n" // ensure it does not return
+ "");
+
+/* fcntl / open */
+#define O_RDONLY 0
+#define O_WRONLY 1
+#define O_RDWR 2
+#define O_CREAT 0x40
+#define O_EXCL 0x80
+#define O_NOCTTY 0x100
+#define O_TRUNC 0x200
+#define O_APPEND 0x400
+#define O_NONBLOCK 0x800
+#define O_DIRECTORY 0x10000
+
+/* The struct returned by the stat() syscall, equivalent to stat64(). The
+ * syscall returns 116 bytes and stops in the middle of __unused.
+ */
+struct sys_stat_struct {
+ unsigned long st_dev;
+ unsigned long st_ino;
+ unsigned long st_nlink;
+ unsigned int st_mode;
+ unsigned int st_uid;
+
+ unsigned int st_gid;
+ unsigned int __pad0;
+ unsigned long st_rdev;
+ long st_size;
+ long st_blksize;
+
+ long st_blocks;
+ unsigned long st_atime;
+ unsigned long st_atime_nsec;
+ unsigned long st_mtime;
+
+ unsigned long st_mtime_nsec;
+ unsigned long st_ctime;
+ unsigned long st_ctime_nsec;
+ long __unused[3];
+};
+
+#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__)
+/* Syscalls for i386 :
+ * - mostly similar to x86_64
+ * - registers are 32-bit
+ * - syscall number is passed in eax
+ * - arguments are in ebx, ecx, edx, esi, edi, ebp respectively
+ * - all registers are preserved (except eax of course)
+ * - the system call is performed by calling int $0x80
+ * - syscall return comes in eax
+ * - the arguments are cast to long and assigned into the target registers
+ * which are then simply passed as registers to the asm code, so that we
+ * don't have to experience issues with register constraints.
+ * - the syscall number is always specified last in order to allow to force
+ * some registers before (gcc refuses a %-register at the last position).
+ *
+ * Also, i386 supports the old_select syscall if newselect is not available
+ */
+#define __ARCH_WANT_SYS_OLD_SELECT
+
+#define my_syscall0(num) \
+({ \
+ long _ret; \
+ register long _num asm("eax") = (num); \
+ \
+ asm volatile ( \
+ "int $0x80\n" \
+ : "=a" (_ret) \
+ : "0"(_num) \
+ : "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall1(num, arg1) \
+({ \
+ long _ret; \
+ register long _num asm("eax") = (num); \
+ register long _arg1 asm("ebx") = (long)(arg1); \
+ \
+ asm volatile ( \
+ "int $0x80\n" \
+ : "=a" (_ret) \
+ : "r"(_arg1), \
+ "0"(_num) \
+ : "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall2(num, arg1, arg2) \
+({ \
+ long _ret; \
+ register long _num asm("eax") = (num); \
+ register long _arg1 asm("ebx") = (long)(arg1); \
+ register long _arg2 asm("ecx") = (long)(arg2); \
+ \
+ asm volatile ( \
+ "int $0x80\n" \
+ : "=a" (_ret) \
+ : "r"(_arg1), "r"(_arg2), \
+ "0"(_num) \
+ : "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall3(num, arg1, arg2, arg3) \
+({ \
+ long _ret; \
+ register long _num asm("eax") = (num); \
+ register long _arg1 asm("ebx") = (long)(arg1); \
+ register long _arg2 asm("ecx") = (long)(arg2); \
+ register long _arg3 asm("edx") = (long)(arg3); \
+ \
+ asm volatile ( \
+ "int $0x80\n" \
+ : "=a" (_ret) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), \
+ "0"(_num) \
+ : "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall4(num, arg1, arg2, arg3, arg4) \
+({ \
+ long _ret; \
+ register long _num asm("eax") = (num); \
+ register long _arg1 asm("ebx") = (long)(arg1); \
+ register long _arg2 asm("ecx") = (long)(arg2); \
+ register long _arg3 asm("edx") = (long)(arg3); \
+ register long _arg4 asm("esi") = (long)(arg4); \
+ \
+ asm volatile ( \
+ "int $0x80\n" \
+ : "=a" (_ret) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
+ "0"(_num) \
+ : "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
+({ \
+ long _ret; \
+ register long _num asm("eax") = (num); \
+ register long _arg1 asm("ebx") = (long)(arg1); \
+ register long _arg2 asm("ecx") = (long)(arg2); \
+ register long _arg3 asm("edx") = (long)(arg3); \
+ register long _arg4 asm("esi") = (long)(arg4); \
+ register long _arg5 asm("edi") = (long)(arg5); \
+ \
+ asm volatile ( \
+ "int $0x80\n" \
+ : "=a" (_ret) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
+ "0"(_num) \
+ : "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+/* startup code */
+asm(".section .text\n"
+ ".global _start\n"
+ "_start:\n"
+ "pop %eax\n" // argc (first arg, %eax)
+ "mov %esp, %ebx\n" // argv[] (second arg, %ebx)
+ "lea 4(%ebx,%eax,4),%ecx\n" // then a NULL then envp (third arg, %ecx)
+ "and $-16, %esp\n" // x86 ABI : esp must be 16-byte aligned when
+ "push %ecx\n" // push all registers on the stack so that we
+ "push %ebx\n" // support both regparm and plain stack modes
+ "push %eax\n"
+ "call main\n" // main() returns the status code in %eax
+ "movzbl %al, %ebx\n" // retrieve exit code from lower 8 bits
+ "movl $1, %eax\n" // NR_exit == 1
+ "int $0x80\n" // exit now
+ "hlt\n" // ensure it does not
+ "");
+
+/* fcntl / open */
+#define O_RDONLY 0
+#define O_WRONLY 1
+#define O_RDWR 2
+#define O_CREAT 0x40
+#define O_EXCL 0x80
+#define O_NOCTTY 0x100
+#define O_TRUNC 0x200
+#define O_APPEND 0x400
+#define O_NONBLOCK 0x800
+#define O_DIRECTORY 0x10000
+
+/* The struct returned by the stat() syscall, 32-bit only, the syscall returns
+ * exactly 56 bytes (stops before the unused array).
+ */
+struct sys_stat_struct {
+ unsigned long st_dev;
+ unsigned long st_ino;
+ unsigned short st_mode;
+ unsigned short st_nlink;
+ unsigned short st_uid;
+ unsigned short st_gid;
+
+ unsigned long st_rdev;
+ unsigned long st_size;
+ unsigned long st_blksize;
+ unsigned long st_blocks;
+
+ unsigned long st_atime;
+ unsigned long st_atime_nsec;
+ unsigned long st_mtime;
+ unsigned long st_mtime_nsec;
+
+ unsigned long st_ctime;
+ unsigned long st_ctime_nsec;
+ unsigned long __unused[2];
+};
+
+#elif defined(__ARM_EABI__)
+/* Syscalls for ARM in ARM or Thumb modes :
+ * - registers are 32-bit
+ * - stack is 8-byte aligned
+ * ( http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka4127.html)
+ * - syscall number is passed in r7
+ * - arguments are in r0, r1, r2, r3, r4, r5
+ * - the system call is performed by calling svc #0
+ * - syscall return comes in r0.
+ * - only lr is clobbered.
+ * - the arguments are cast to long and assigned into the target registers
+ * which are then simply passed as registers to the asm code, so that we
+ * don't have to experience issues with register constraints.
+ * - the syscall number is always specified last in order to allow to force
+ * some registers before (gcc refuses a %-register at the last position).
+ *
+ * Also, ARM supports the old_select syscall if newselect is not available
+ */
+#define __ARCH_WANT_SYS_OLD_SELECT
+
+#define my_syscall0(num) \
+({ \
+ register long _num asm("r7") = (num); \
+ register long _arg1 asm("r0"); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_num) \
+ : "memory", "cc", "lr" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall1(num, arg1) \
+({ \
+ register long _num asm("r7") = (num); \
+ register long _arg1 asm("r0") = (long)(arg1); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_arg1), \
+ "r"(_num) \
+ : "memory", "cc", "lr" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall2(num, arg1, arg2) \
+({ \
+ register long _num asm("r7") = (num); \
+ register long _arg1 asm("r0") = (long)(arg1); \
+ register long _arg2 asm("r1") = (long)(arg2); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_arg1), "r"(_arg2), \
+ "r"(_num) \
+ : "memory", "cc", "lr" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall3(num, arg1, arg2, arg3) \
+({ \
+ register long _num asm("r7") = (num); \
+ register long _arg1 asm("r0") = (long)(arg1); \
+ register long _arg2 asm("r1") = (long)(arg2); \
+ register long _arg3 asm("r2") = (long)(arg3); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), \
+ "r"(_num) \
+ : "memory", "cc", "lr" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall4(num, arg1, arg2, arg3, arg4) \
+({ \
+ register long _num asm("r7") = (num); \
+ register long _arg1 asm("r0") = (long)(arg1); \
+ register long _arg2 asm("r1") = (long)(arg2); \
+ register long _arg3 asm("r2") = (long)(arg3); \
+ register long _arg4 asm("r3") = (long)(arg4); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
+ "r"(_num) \
+ : "memory", "cc", "lr" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
+({ \
+ register long _num asm("r7") = (num); \
+ register long _arg1 asm("r0") = (long)(arg1); \
+ register long _arg2 asm("r1") = (long)(arg2); \
+ register long _arg3 asm("r2") = (long)(arg3); \
+ register long _arg4 asm("r3") = (long)(arg4); \
+ register long _arg5 asm("r4") = (long)(arg5); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r" (_arg1) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
+ "r"(_num) \
+ : "memory", "cc", "lr" \
+ ); \
+ _arg1; \
+})
+
+/* startup code */
+asm(".section .text\n"
+ ".global _start\n"
+ "_start:\n"
+#if defined(__THUMBEB__) || defined(__THUMBEL__)
+ /* We enter here in 32-bit mode but if some previous functions were in
+ * 16-bit mode, the assembler cannot know, so we need to tell it we're in
+ * 32-bit now, then switch to 16-bit (is there a better way to do it than
+ * adding 1 by hand ?) and tell the asm we're now in 16-bit mode so that
+ * it generates correct instructions. Note that we do not support thumb1.
+ */
+ ".code 32\n"
+ "add r0, pc, #1\n"
+ "bx r0\n"
+ ".code 16\n"
+#endif
+ "pop {%r0}\n" // argc was in the stack
+ "mov %r1, %sp\n" // argv = sp
+ "add %r2, %r1, %r0, lsl #2\n" // envp = argv + 4*argc ...
+ "add %r2, %r2, $4\n" // ... + 4
+ "and %r3, %r1, $-8\n" // AAPCS : sp must be 8-byte aligned in the
+ "mov %sp, %r3\n" // callee, an bl doesn't push (lr=pc)
+ "bl main\n" // main() returns the status code, we'll exit with it.
+ "and %r0, %r0, $0xff\n" // limit exit code to 8 bits
+ "movs r7, $1\n" // NR_exit == 1
+ "svc $0x00\n"
+ "");
+
+/* fcntl / open */
+#define O_RDONLY 0
+#define O_WRONLY 1
+#define O_RDWR 2
+#define O_CREAT 0x40
+#define O_EXCL 0x80
+#define O_NOCTTY 0x100
+#define O_TRUNC 0x200
+#define O_APPEND 0x400
+#define O_NONBLOCK 0x800
+#define O_DIRECTORY 0x4000
+
+/* The struct returned by the stat() syscall, 32-bit only, the syscall returns
+ * exactly 56 bytes (stops before the unused array). In big endian, the format
+ * differs as devices are returned as short only.
+ */
+struct sys_stat_struct {
+#if defined(__ARMEB__)
+ unsigned short st_dev;
+ unsigned short __pad1;
+#else
+ unsigned long st_dev;
+#endif
+ unsigned long st_ino;
+ unsigned short st_mode;
+ unsigned short st_nlink;
+ unsigned short st_uid;
+ unsigned short st_gid;
+#if defined(__ARMEB__)
+ unsigned short st_rdev;
+ unsigned short __pad2;
+#else
+ unsigned long st_rdev;
+#endif
+ unsigned long st_size;
+ unsigned long st_blksize;
+ unsigned long st_blocks;
+ unsigned long st_atime;
+ unsigned long st_atime_nsec;
+ unsigned long st_mtime;
+ unsigned long st_mtime_nsec;
+ unsigned long st_ctime;
+ unsigned long st_ctime_nsec;
+ unsigned long __unused[2];
+};
+
+#elif defined(__aarch64__)
+/* Syscalls for AARCH64 :
+ * - registers are 64-bit
+ * - stack is 16-byte aligned
+ * - syscall number is passed in x8
+ * - arguments are in x0, x1, x2, x3, x4, x5
+ * - the system call is performed by calling svc 0
+ * - syscall return comes in x0.
+ * - the arguments are cast to long and assigned into the target registers
+ * which are then simply passed as registers to the asm code, so that we
+ * don't have to experience issues with register constraints.
+ *
+ * On aarch64, select() is not implemented so we have to use pselect6().
+ */
+#define __ARCH_WANT_SYS_PSELECT6
+
+#define my_syscall0(num) \
+({ \
+ register long _num asm("x8") = (num); \
+ register long _arg1 asm("x0"); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_num) \
+ : "memory", "cc" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall1(num, arg1) \
+({ \
+ register long _num asm("x8") = (num); \
+ register long _arg1 asm("x0") = (long)(arg1); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_arg1), \
+ "r"(_num) \
+ : "memory", "cc" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall2(num, arg1, arg2) \
+({ \
+ register long _num asm("x8") = (num); \
+ register long _arg1 asm("x0") = (long)(arg1); \
+ register long _arg2 asm("x1") = (long)(arg2); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_arg1), "r"(_arg2), \
+ "r"(_num) \
+ : "memory", "cc" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall3(num, arg1, arg2, arg3) \
+({ \
+ register long _num asm("x8") = (num); \
+ register long _arg1 asm("x0") = (long)(arg1); \
+ register long _arg2 asm("x1") = (long)(arg2); \
+ register long _arg3 asm("x2") = (long)(arg3); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), \
+ "r"(_num) \
+ : "memory", "cc" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall4(num, arg1, arg2, arg3, arg4) \
+({ \
+ register long _num asm("x8") = (num); \
+ register long _arg1 asm("x0") = (long)(arg1); \
+ register long _arg2 asm("x1") = (long)(arg2); \
+ register long _arg3 asm("x2") = (long)(arg3); \
+ register long _arg4 asm("x3") = (long)(arg4); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
+ "r"(_num) \
+ : "memory", "cc" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
+({ \
+ register long _num asm("x8") = (num); \
+ register long _arg1 asm("x0") = (long)(arg1); \
+ register long _arg2 asm("x1") = (long)(arg2); \
+ register long _arg3 asm("x2") = (long)(arg3); \
+ register long _arg4 asm("x3") = (long)(arg4); \
+ register long _arg5 asm("x4") = (long)(arg5); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r" (_arg1) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
+ "r"(_num) \
+ : "memory", "cc" \
+ ); \
+ _arg1; \
+})
+
+#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
+({ \
+ register long _num asm("x8") = (num); \
+ register long _arg1 asm("x0") = (long)(arg1); \
+ register long _arg2 asm("x1") = (long)(arg2); \
+ register long _arg3 asm("x2") = (long)(arg3); \
+ register long _arg4 asm("x3") = (long)(arg4); \
+ register long _arg5 asm("x4") = (long)(arg5); \
+ register long _arg6 asm("x5") = (long)(arg6); \
+ \
+ asm volatile ( \
+ "svc #0\n" \
+ : "=r" (_arg1) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
+ "r"(_arg6), "r"(_num) \
+ : "memory", "cc" \
+ ); \
+ _arg1; \
+})
+
+/* startup code */
+asm(".section .text\n"
+ ".global _start\n"
+ "_start:\n"
+ "ldr x0, [sp]\n" // argc (x0) was in the stack
+ "add x1, sp, 8\n" // argv (x1) = sp
+ "lsl x2, x0, 3\n" // envp (x2) = 8*argc ...
+ "add x2, x2, 8\n" // + 8 (skip null)
+ "add x2, x2, x1\n" // + argv
+ "and sp, x1, -16\n" // sp must be 16-byte aligned in the callee
+ "bl main\n" // main() returns the status code, we'll exit with it.
+ "and x0, x0, 0xff\n" // limit exit code to 8 bits
+ "mov x8, 93\n" // NR_exit == 93
+ "svc #0\n"
+ "");
+
+/* fcntl / open */
+#define O_RDONLY 0
+#define O_WRONLY 1
+#define O_RDWR 2
+#define O_CREAT 0x40
+#define O_EXCL 0x80
+#define O_NOCTTY 0x100
+#define O_TRUNC 0x200
+#define O_APPEND 0x400
+#define O_NONBLOCK 0x800
+#define O_DIRECTORY 0x4000
+
+/* The struct returned by the newfstatat() syscall. Differs slightly from the
+ * x86_64's stat one by field ordering, so be careful.
+ */
+struct sys_stat_struct {
+ unsigned long st_dev;
+ unsigned long st_ino;
+ unsigned int st_mode;
+ unsigned int st_nlink;
+ unsigned int st_uid;
+ unsigned int st_gid;
+
+ unsigned long st_rdev;
+ unsigned long __pad1;
+ long st_size;
+ int st_blksize;
+ int __pad2;
+
+ long st_blocks;
+ long st_atime;
+ unsigned long st_atime_nsec;
+ long st_mtime;
+
+ unsigned long st_mtime_nsec;
+ long st_ctime;
+ unsigned long st_ctime_nsec;
+ unsigned int __unused[2];
+};
+
+#elif defined(__mips__) && defined(_ABIO32)
+/* Syscalls for MIPS ABI O32 :
+ * - WARNING! there's always a delayed slot!
+ * - WARNING again, the syntax is different, registers take a '$' and numbers
+ * do not.
+ * - registers are 32-bit
+ * - stack is 8-byte aligned
+ * - syscall number is passed in v0 (starts at 0xfa0).
+ * - arguments are in a0, a1, a2, a3, then the stack. The caller needs to
+ * leave some room in the stack for the callee to save a0..a3 if needed.
+ * - Many registers are clobbered, in fact only a0..a2 and s0..s8 are
+ * preserved. See: https://www.linux-mips.org/wiki/Syscall as well as
+ * scall32-o32.S in the kernel sources.
+ * - the system call is performed by calling "syscall"
+ * - syscall return comes in v0, and register a3 needs to be checked to know
+ * if an error occured, in which case errno is in v0.
+ * - the arguments are cast to long and assigned into the target registers
+ * which are then simply passed as registers to the asm code, so that we
+ * don't have to experience issues with register constraints.
+ */
+
+#define my_syscall0(num) \
+({ \
+ register long _num asm("v0") = (num); \
+ register long _arg4 asm("a3"); \
+ \
+ asm volatile ( \
+ "addiu $sp, $sp, -32\n" \
+ "syscall\n" \
+ "addiu $sp, $sp, 32\n" \
+ : "=r"(_num), "=r"(_arg4) \
+ : "r"(_num) \
+ : "memory", "cc", "at", "v1", "hi", "lo", \
+ \
+ ); \
+ _arg4 ? -_num : _num; \
+})
+
+#define my_syscall1(num, arg1) \
+({ \
+ register long _num asm("v0") = (num); \
+ register long _arg1 asm("a0") = (long)(arg1); \
+ register long _arg4 asm("a3"); \
+ \
+ asm volatile ( \
+ "addiu $sp, $sp, -32\n" \
+ "syscall\n" \
+ "addiu $sp, $sp, 32\n" \
+ : "=r"(_num), "=r"(_arg4) \
+ : "0"(_num), \
+ "r"(_arg1) \
+ : "memory", "cc", "at", "v1", "hi", "lo", \
+ \
+ ); \
+ _arg4 ? -_num : _num; \
+})
+
+#define my_syscall2(num, arg1, arg2) \
+({ \
+ register long _num asm("v0") = (num); \
+ register long _arg1 asm("a0") = (long)(arg1); \
+ register long _arg2 asm("a1") = (long)(arg2); \
+ register long _arg4 asm("a3"); \
+ \
+ asm volatile ( \
+ "addiu $sp, $sp, -32\n" \
+ "syscall\n" \
+ "addiu $sp, $sp, 32\n" \
+ : "=r"(_num), "=r"(_arg4) \
+ : "0"(_num), \
+ "r"(_arg1), "r"(_arg2) \
+ : "memory", "cc", "at", "v1", "hi", "lo", \
+ \
+ ); \
+ _arg4 ? -_num : _num; \
+})
+
+#define my_syscall3(num, arg1, arg2, arg3) \
+({ \
+ register long _num asm("v0") = (num); \
+ register long _arg1 asm("a0") = (long)(arg1); \
+ register long _arg2 asm("a1") = (long)(arg2); \
+ register long _arg3 asm("a2") = (long)(arg3); \
+ register long _arg4 asm("a3"); \
+ \
+ asm volatile ( \
+ "addiu $sp, $sp, -32\n" \
+ "syscall\n" \
+ "addiu $sp, $sp, 32\n" \
+ : "=r"(_num), "=r"(_arg4) \
+ : "0"(_num), \
+ "r"(_arg1), "r"(_arg2), "r"(_arg3) \
+ : "memory", "cc", "at", "v1", "hi", "lo", \
+ \
+ ); \
+ _arg4 ? -_num : _num; \
+})
+
+#define my_syscall4(num, arg1, arg2, arg3, arg4) \
+({ \
+ register long _num asm("v0") = (num); \
+ register long _arg1 asm("a0") = (long)(arg1); \
+ register long _arg2 asm("a1") = (long)(arg2); \
+ register long _arg3 asm("a2") = (long)(arg3); \
+ register long _arg4 asm("a3") = (long)(arg4); \
+ \
+ asm volatile ( \
+ "addiu $sp, $sp, -32\n" \
+ "syscall\n" \
+ "addiu $sp, $sp, 32\n" \
+ : "=r" (_num), "=r"(_arg4) \
+ : "0"(_num), \
+ "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4) \
+ : "memory", "cc", "at", "v1", "hi", "lo", \
+ \
+ ); \
+ _arg4 ? -_num : _num; \
+})
+
+#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
+({ \
+ register long _num asm("v0") = (num); \
+ register long _arg1 asm("a0") = (long)(arg1); \
+ register long _arg2 asm("a1") = (long)(arg2); \
+ register long _arg3 asm("a2") = (long)(arg3); \
+ register long _arg4 asm("a3") = (long)(arg4); \
+ register long _arg5 = (long)(arg5); \
+ \
+ asm volatile ( \
+ "addiu $sp, $sp, -32\n" \
+ "sw %7, 16($sp)\n" \
+ "syscall\n " \
+ "addiu $sp, $sp, 32\n" \
+ : "=r" (_num), "=r"(_arg4) \
+ : "0"(_num), \
+ "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) \
+ : "memory", "cc", "at", "v1", "hi", "lo", \
+ \
+ ); \
+ _arg4 ? -_num : _num; \
+})
+
+/* startup code, note that it's called __start on MIPS */
+asm(".section .text\n"
+ ".set nomips16\n"
+ ".global __start\n"
+ ".set noreorder\n"
+ ".option pic0\n"
+ ".ent __start\n"
+ "__start:\n"
+ "lw $a0,($sp)\n" // argc was in the stack
+ "addiu $a1, $sp, 4\n" // argv = sp + 4
+ "sll $a2, $a0, 2\n" // a2 = argc * 4
+ "add $a2, $a2, $a1\n" // envp = argv + 4*argc ...
+ "addiu $a2, $a2, 4\n" // ... + 4
+ "li $t0, -8\n"
+ "and $sp, $sp, $t0\n" // sp must be 8-byte aligned
+ "addiu $sp,$sp,-16\n" // the callee expects to save a0..a3 there!
+ "jal main\n" // main() returns the status code, we'll exit with it.
+ "nop\n" // delayed slot
+ "and $a0, $v0, 0xff\n" // limit exit code to 8 bits
+ "li $v0, 4001\n" // NR_exit == 4001
+ "syscall\n"
+ ".end __start\n"
+ "");
+
+/* fcntl / open */
+#define O_RDONLY 0
+#define O_WRONLY 1
+#define O_RDWR 2
+#define O_APPEND 0x0008
+#define O_NONBLOCK 0x0080
+#define O_CREAT 0x0100
+#define O_TRUNC 0x0200
+#define O_EXCL 0x0400
+#define O_NOCTTY 0x0800
+#define O_DIRECTORY 0x10000
+
+/* The struct returned by the stat() syscall. 88 bytes are returned by the
+ * syscall.
+ */
+struct sys_stat_struct {
+ unsigned int st_dev;
+ long st_pad1[3];
+ unsigned long st_ino;
+ unsigned int st_mode;
+ unsigned int st_nlink;
+ unsigned int st_uid;
+ unsigned int st_gid;
+ unsigned int st_rdev;
+ long st_pad2[2];
+ long st_size;
+ long st_pad3;
+ long st_atime;
+ long st_atime_nsec;
+ long st_mtime;
+ long st_mtime_nsec;
+ long st_ctime;
+ long st_ctime_nsec;
+ long st_blksize;
+ long st_blocks;
+ long st_pad4[14];
+};
+
+#endif
+
+
+/* Below are the C functions used to declare the raw syscalls. They try to be
+ * architecture-agnostic, and return either a success or -errno. Declaring them
+ * static will lead to them being inlined in most cases, but it's still possible
+ * to reference them by a pointer if needed.
+ */
+static __attribute__((unused))
+void *sys_brk(void *addr)
+{
+ return (void *)my_syscall1(__NR_brk, addr);
+}
+
+static __attribute__((noreturn,unused))
+void sys_exit(int status)
+{
+ my_syscall1(__NR_exit, status & 255);
+ while(1); // shut the "noreturn" warnings.
+}
+
+static __attribute__((unused))
+int sys_chdir(const char *path)
+{
+ return my_syscall1(__NR_chdir, path);
+}
+
+static __attribute__((unused))
+int sys_chmod(const char *path, mode_t mode)
+{
+#ifdef __NR_fchmodat
+ return my_syscall4(__NR_fchmodat, AT_FDCWD, path, mode, 0);
+#else
+ return my_syscall2(__NR_chmod, path, mode);
+#endif
+}
+
+static __attribute__((unused))
+int sys_chown(const char *path, uid_t owner, gid_t group)
+{
+#ifdef __NR_fchownat
+ return my_syscall5(__NR_fchownat, AT_FDCWD, path, owner, group, 0);
+#else
+ return my_syscall3(__NR_chown, path, owner, group);
+#endif
+}
+
+static __attribute__((unused))
+int sys_chroot(const char *path)
+{
+ return my_syscall1(__NR_chroot, path);
+}
+
+static __attribute__((unused))
+int sys_close(int fd)
+{
+ return my_syscall1(__NR_close, fd);
+}
+
+static __attribute__((unused))
+int sys_dup(int fd)
+{
+ return my_syscall1(__NR_dup, fd);
+}
+
+static __attribute__((unused))
+int sys_dup2(int old, int new)
+{
+ return my_syscall2(__NR_dup2, old, new);
+}
+
+static __attribute__((unused))
+int sys_execve(const char *filename, char *const argv[], char *const envp[])
+{
+ return my_syscall3(__NR_execve, filename, argv, envp);
+}
+
+static __attribute__((unused))
+pid_t sys_fork(void)
+{
+ return my_syscall0(__NR_fork);
+}
+
+static __attribute__((unused))
+int sys_fsync(int fd)
+{
+ return my_syscall1(__NR_fsync, fd);
+}
+
+static __attribute__((unused))
+int sys_getdents64(int fd, struct linux_dirent64 *dirp, int count)
+{
+ return my_syscall3(__NR_getdents64, fd, dirp, count);
+}
+
+static __attribute__((unused))
+pid_t sys_getpgrp(void)
+{
+ return my_syscall0(__NR_getpgrp);
+}
+
+static __attribute__((unused))
+pid_t sys_getpid(void)
+{
+ return my_syscall0(__NR_getpid);
+}
+
+static __attribute__((unused))
+int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+ return my_syscall2(__NR_gettimeofday, tv, tz);
+}
+
+static __attribute__((unused))
+int sys_ioctl(int fd, unsigned long req, void *value)
+{
+ return my_syscall3(__NR_ioctl, fd, req, value);
+}
+
+static __attribute__((unused))
+int sys_kill(pid_t pid, int signal)
+{
+ return my_syscall2(__NR_kill, pid, signal);
+}
+
+static __attribute__((unused))
+int sys_link(const char *old, const char *new)
+{
+#ifdef __NR_linkat
+ return my_syscall5(__NR_linkat, AT_FDCWD, old, AT_FDCWD, new, 0);
+#else
+ return my_syscall2(__NR_link, old, new);
+#endif
+}
+
+static __attribute__((unused))
+off_t sys_lseek(int fd, off_t offset, int whence)
+{
+ return my_syscall3(__NR_lseek, fd, offset, whence);
+}
+
+static __attribute__((unused))
+int sys_mkdir(const char *path, mode_t mode)
+{
+#ifdef __NR_mkdirat
+ return my_syscall3(__NR_mkdirat, AT_FDCWD, path, mode);
+#else
+ return my_syscall2(__NR_mkdir, path, mode);
+#endif
+}
+
+static __attribute__((unused))
+long sys_mknod(const char *path, mode_t mode, dev_t dev)
+{
+#ifdef __NR_mknodat
+ return my_syscall4(__NR_mknodat, AT_FDCWD, path, mode, dev);
+#else
+ return my_syscall3(__NR_mknod, path, mode, dev);
+#endif
+}
+
+static __attribute__((unused))
+int sys_mount(const char *src, const char *tgt, const char *fst,
+ unsigned long flags, const void *data)
+{
+ return my_syscall5(__NR_mount, src, tgt, fst, flags, data);
+}
+
+static __attribute__((unused))
+int sys_open(const char *path, int flags, mode_t mode)
+{
+#ifdef __NR_openat
+ return my_syscall4(__NR_openat, AT_FDCWD, path, flags, mode);
+#else
+ return my_syscall3(__NR_open, path, flags, mode);
+#endif
+}
+
+static __attribute__((unused))
+int sys_pivot_root(const char *new, const char *old)
+{
+ return my_syscall2(__NR_pivot_root, new, old);
+}
+
+static __attribute__((unused))
+int sys_poll(struct pollfd *fds, int nfds, int timeout)
+{
+ return my_syscall3(__NR_poll, fds, nfds, timeout);
+}
+
+static __attribute__((unused))
+ssize_t sys_read(int fd, void *buf, size_t count)
+{
+ return my_syscall3(__NR_read, fd, buf, count);
+}
+
+static __attribute__((unused))
+ssize_t sys_reboot(int magic1, int magic2, int cmd, void *arg)
+{
+ return my_syscall4(__NR_reboot, magic1, magic2, cmd, arg);
+}
+
+static __attribute__((unused))
+int sys_sched_yield(void)
+{
+ return my_syscall0(__NR_sched_yield);
+}
+
+static __attribute__((unused))
+int sys_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout)
+{
+#if defined(__ARCH_WANT_SYS_OLD_SELECT) && !defined(__NR__newselect)
+ struct sel_arg_struct {
+ unsigned long n;
+ fd_set *r, *w, *e;
+ struct timeval *t;
+ } arg = { .n = nfds, .r = rfds, .w = wfds, .e = efds, .t = timeout };
+ return my_syscall1(__NR_select, &arg);
+#elif defined(__ARCH_WANT_SYS_PSELECT6) && defined(__NR_pselect6)
+ struct timespec t;
+
+ if (timeout) {
+ t.tv_sec = timeout->tv_sec;
+ t.tv_nsec = timeout->tv_usec * 1000;
+ }
+ return my_syscall6(__NR_pselect6, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL);
+#else
+#ifndef __NR__newselect
+#define __NR__newselect __NR_select
+#endif
+ return my_syscall5(__NR__newselect, nfds, rfds, wfds, efds, timeout);
+#endif
+}
+
+static __attribute__((unused))
+int sys_setpgid(pid_t pid, pid_t pgid)
+{
+ return my_syscall2(__NR_setpgid, pid, pgid);
+}
+
+static __attribute__((unused))
+pid_t sys_setsid(void)
+{
+ return my_syscall0(__NR_setsid);
+}
+
+static __attribute__((unused))
+int sys_stat(const char *path, struct stat *buf)
+{
+ struct sys_stat_struct stat;
+ long ret;
+
+#ifdef __NR_newfstatat
+ /* only solution for arm64 */
+ ret = my_syscall4(__NR_newfstatat, AT_FDCWD, path, &stat, 0);
+#else
+ ret = my_syscall2(__NR_stat, path, &stat);
+#endif
+ buf->st_dev = stat.st_dev;
+ buf->st_ino = stat.st_ino;
+ buf->st_mode = stat.st_mode;
+ buf->st_nlink = stat.st_nlink;
+ buf->st_uid = stat.st_uid;
+ buf->st_gid = stat.st_gid;
+ buf->st_rdev = stat.st_rdev;
+ buf->st_size = stat.st_size;
+ buf->st_blksize = stat.st_blksize;
+ buf->st_blocks = stat.st_blocks;
+ buf->st_atime = stat.st_atime;
+ buf->st_mtime = stat.st_mtime;
+ buf->st_ctime = stat.st_ctime;
+ return ret;
+}
+
+
+static __attribute__((unused))
+int sys_symlink(const char *old, const char *new)
+{
+#ifdef __NR_symlinkat
+ return my_syscall3(__NR_symlinkat, old, AT_FDCWD, new);
+#else
+ return my_syscall2(__NR_symlink, old, new);
+#endif
+}
+
+static __attribute__((unused))
+mode_t sys_umask(mode_t mode)
+{
+ return my_syscall1(__NR_umask, mode);
+}
+
+static __attribute__((unused))
+int sys_umount2(const char *path, int flags)
+{
+ return my_syscall2(__NR_umount2, path, flags);
+}
+
+static __attribute__((unused))
+int sys_unlink(const char *path)
+{
+#ifdef __NR_unlinkat
+ return my_syscall3(__NR_unlinkat, AT_FDCWD, path, 0);
+#else
+ return my_syscall1(__NR_unlink, path);
+#endif
+}
+
+static __attribute__((unused))
+pid_t sys_wait4(pid_t pid, int *status, int options, struct rusage *rusage)
+{
+ return my_syscall4(__NR_wait4, pid, status, options, rusage);
+}
+
+static __attribute__((unused))
+pid_t sys_waitpid(pid_t pid, int *status, int options)
+{
+ return sys_wait4(pid, status, options, 0);
+}
+
+static __attribute__((unused))
+pid_t sys_wait(int *status)
+{
+ return sys_waitpid(-1, status, 0);
+}
+
+static __attribute__((unused))
+ssize_t sys_write(int fd, const void *buf, size_t count)
+{
+ return my_syscall3(__NR_write, fd, buf, count);
+}
+
+
+/* Below are the libc-compatible syscalls which return x or -1 and set errno.
+ * They rely on the functions above. Similarly they're marked static so that it
+ * is possible to assign pointers to them if needed.
+ */
+
+static __attribute__((unused))
+int brk(void *addr)
+{
+ void *ret = sys_brk(addr);
+
+ if (!ret) {
+ SET_ERRNO(ENOMEM);
+ return -1;
+ }
+ return 0;
+}
+
+static __attribute__((noreturn,unused))
+void exit(int status)
+{
+ sys_exit(status);
+}
+
+static __attribute__((unused))
+int chdir(const char *path)
+{
+ int ret = sys_chdir(path);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int chmod(const char *path, mode_t mode)
+{
+ int ret = sys_chmod(path, mode);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int chown(const char *path, uid_t owner, gid_t group)
+{
+ int ret = sys_chown(path, owner, group);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int chroot(const char *path)
+{
+ int ret = sys_chroot(path);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int close(int fd)
+{
+ int ret = sys_close(fd);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int dup2(int old, int new)
+{
+ int ret = sys_dup2(old, new);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int execve(const char *filename, char *const argv[], char *const envp[])
+{
+ int ret = sys_execve(filename, argv, envp);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+pid_t fork(void)
+{
+ pid_t ret = sys_fork();
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int fsync(int fd)
+{
+ int ret = sys_fsync(fd);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int getdents64(int fd, struct linux_dirent64 *dirp, int count)
+{
+ int ret = sys_getdents64(fd, dirp, count);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+pid_t getpgrp(void)
+{
+ pid_t ret = sys_getpgrp();
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+pid_t getpid(void)
+{
+ pid_t ret = sys_getpid();
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+ int ret = sys_gettimeofday(tv, tz);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int ioctl(int fd, unsigned long req, void *value)
+{
+ int ret = sys_ioctl(fd, req, value);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int kill(pid_t pid, int signal)
+{
+ int ret = sys_kill(pid, signal);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int link(const char *old, const char *new)
+{
+ int ret = sys_link(old, new);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+off_t lseek(int fd, off_t offset, int whence)
+{
+ off_t ret = sys_lseek(fd, offset, whence);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int mkdir(const char *path, mode_t mode)
+{
+ int ret = sys_mkdir(path, mode);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int mknod(const char *path, mode_t mode, dev_t dev)
+{
+ int ret = sys_mknod(path, mode, dev);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int mount(const char *src, const char *tgt,
+ const char *fst, unsigned long flags,
+ const void *data)
+{
+ int ret = sys_mount(src, tgt, fst, flags, data);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int open(const char *path, int flags, mode_t mode)
+{
+ int ret = sys_open(path, flags, mode);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int pivot_root(const char *new, const char *old)
+{
+ int ret = sys_pivot_root(new, old);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int poll(struct pollfd *fds, int nfds, int timeout)
+{
+ int ret = sys_poll(fds, nfds, timeout);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+ssize_t read(int fd, void *buf, size_t count)
+{
+ ssize_t ret = sys_read(fd, buf, count);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int reboot(int cmd)
+{
+ int ret = sys_reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, 0);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+void *sbrk(intptr_t inc)
+{
+ void *ret;
+
+ /* first call to find current end */
+ if ((ret = sys_brk(0)) && (sys_brk(ret + inc) == ret + inc))
+ return ret + inc;
+
+ SET_ERRNO(ENOMEM);
+ return (void *)-1;
+}
+
+static __attribute__((unused))
+int sched_yield(void)
+{
+ int ret = sys_sched_yield();
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout)
+{
+ int ret = sys_select(nfds, rfds, wfds, efds, timeout);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int setpgid(pid_t pid, pid_t pgid)
+{
+ int ret = sys_setpgid(pid, pgid);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+pid_t setsid(void)
+{
+ pid_t ret = sys_setsid();
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+unsigned int sleep(unsigned int seconds)
+{
+ struct timeval my_timeval = { seconds, 0 };
+
+ if (sys_select(0, 0, 0, 0, &my_timeval) < 0)
+ return my_timeval.tv_sec + !!my_timeval.tv_usec;
+ else
+ return 0;
+}
+
+static __attribute__((unused))
+int stat(const char *path, struct stat *buf)
+{
+ int ret = sys_stat(path, buf);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int symlink(const char *old, const char *new)
+{
+ int ret = sys_symlink(old, new);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int tcsetpgrp(int fd, pid_t pid)
+{
+ return ioctl(fd, TIOCSPGRP, &pid);
+}
+
+static __attribute__((unused))
+mode_t umask(mode_t mode)
+{
+ return sys_umask(mode);
+}
+
+static __attribute__((unused))
+int umount2(const char *path, int flags)
+{
+ int ret = sys_umount2(path, flags);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+int unlink(const char *path)
+{
+ int ret = sys_unlink(path);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+pid_t wait4(pid_t pid, int *status, int options, struct rusage *rusage)
+{
+ pid_t ret = sys_wait4(pid, status, options, rusage);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+pid_t waitpid(pid_t pid, int *status, int options)
+{
+ pid_t ret = sys_waitpid(pid, status, options);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+pid_t wait(int *status)
+{
+ pid_t ret = sys_wait(status);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+ssize_t write(int fd, const void *buf, size_t count)
+{
+ ssize_t ret = sys_write(fd, buf, count);
+
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
+
+/* some size-optimized reimplementations of a few common str* and mem*
+ * functions. They're marked static, except memcpy() and raise() which are used
+ * by libgcc on ARM, so they are marked weak instead in order not to cause an
+ * error when building a program made of multiple files (not recommended).
+ */
+
+static __attribute__((unused))
+void *memmove(void *dst, const void *src, size_t len)
+{
+ ssize_t pos = (dst <= src) ? -1 : (long)len;
+ void *ret = dst;
+
+ while (len--) {
+ pos += (dst <= src) ? 1 : -1;
+ ((char *)dst)[pos] = ((char *)src)[pos];
+ }
+ return ret;
+}
+
+static __attribute__((unused))
+void *memset(void *dst, int b, size_t len)
+{
+ char *p = dst;
+
+ while (len--)
+ *(p++) = b;
+ return dst;
+}
+
+static __attribute__((unused))
+int memcmp(const void *s1, const void *s2, size_t n)
+{
+ size_t ofs = 0;
+ char c1 = 0;
+
+ while (ofs < n && !(c1 = ((char *)s1)[ofs] - ((char *)s2)[ofs])) {
+ ofs++;
+ }
+ return c1;
+}
+
+static __attribute__((unused))
+char *strcpy(char *dst, const char *src)
+{
+ char *ret = dst;
+
+ while ((*dst++ = *src++));
+ return ret;
+}
+
+static __attribute__((unused))
+char *strchr(const char *s, int c)
+{
+ while (*s) {
+ if (*s == (char)c)
+ return (char *)s;
+ s++;
+ }
+ return NULL;
+}
+
+static __attribute__((unused))
+char *strrchr(const char *s, int c)
+{
+ const char *ret = NULL;
+
+ while (*s) {
+ if (*s == (char)c)
+ ret = s;
+ s++;
+ }
+ return (char *)ret;
+}
+
+static __attribute__((unused))
+size_t nolibc_strlen(const char *str)
+{
+ size_t len;
+
+ for (len = 0; str[len]; len++);
+ return len;
+}
+
+#define strlen(str) ({ \
+ __builtin_constant_p((str)) ? \
+ __builtin_strlen((str)) : \
+ nolibc_strlen((str)); \
+})
+
+static __attribute__((unused))
+int isdigit(int c)
+{
+ return (unsigned int)(c - '0') <= 9;
+}
+
+static __attribute__((unused))
+long atol(const char *s)
+{
+ unsigned long ret = 0;
+ unsigned long d;
+ int neg = 0;
+
+ if (*s == '-') {
+ neg = 1;
+ s++;
+ }
+
+ while (1) {
+ d = (*s++) - '0';
+ if (d > 9)
+ break;
+ ret *= 10;
+ ret += d;
+ }
+
+ return neg ? -ret : ret;
+}
+
+static __attribute__((unused))
+int atoi(const char *s)
+{
+ return atol(s);
+}
+
+static __attribute__((unused))
+const char *ltoa(long in)
+{
+ /* large enough for -9223372036854775808 */
+ static char buffer[21];
+ char *pos = buffer + sizeof(buffer) - 1;
+ int neg = in < 0;
+ unsigned long n = neg ? -in : in;
+
+ *pos-- = '\0';
+ do {
+ *pos-- = '0' + n % 10;
+ n /= 10;
+ if (pos < buffer)
+ return pos + 1;
+ } while (n);
+
+ if (neg)
+ *pos-- = '-';
+ return pos + 1;
+}
+
+__attribute__((weak,unused))
+void *memcpy(void *dst, const void *src, size_t len)
+{
+ return memmove(dst, src, len);
+}
+
+/* needed by libgcc for divide by zero */
+__attribute__((weak,unused))
+int raise(int signal)
+{
+ return kill(getpid(), signal);
+}
+
+/* Here come a few helper functions */
+
+static __attribute__((unused))
+void FD_ZERO(fd_set *set)
+{
+ memset(set, 0, sizeof(*set));
+}
+
+static __attribute__((unused))
+void FD_SET(int fd, fd_set *set)
+{
+ if (fd < 0 || fd >= FD_SETSIZE)
+ return;
+ set->fd32[fd / 32] |= 1 << (fd & 31);
+}
+
+/* WARNING, it only deals with the 4096 first majors and 256 first minors */
+static __attribute__((unused))
+dev_t makedev(unsigned int major, unsigned int minor)
+{
+ return ((major & 0xfff) << 8) | (minor & 0xff);
+}
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH tip/core/rcu 8/8] rcutorture: Make use of nolibc when available
2018-11-11 20:01 [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0 Paul E. McKenney
` (6 preceding siblings ...)
2018-11-11 20:01 ` [PATCH tip/core/rcu 7/8] rcutorture: Import a copy of nolibc Paul E. McKenney
@ 2018-11-11 20:01 ` Paul E. McKenney
7 siblings, 0 replies; 9+ messages in thread
From: Paul E. McKenney @ 2018-11-11 20:01 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg, joel,
Willy Tarreau, Paul E . McKenney
From: Willy Tarreau <w@1wt.eu>
This reduces the size of the init executable from ~800 kB to ~800 bytes
on x86_64. This is only implemented for x86_64, i386, arm and arm64.
Others not tested.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
.../selftests/rcutorture/bin/mkinitrd.sh | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
index 56a56ea06983..da298394daa2 100755
--- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
+++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh
@@ -82,8 +82,10 @@ cd $D
mkdir -p initrd
cd initrd
cat > init.c << '___EOF___'
+#ifndef NOLIBC
#include <unistd.h>
#include <sys/time.h>
+#endif
volatile unsigned long delaycount;
@@ -113,7 +115,21 @@ int main(int argc, int argv[])
return 0;
}
___EOF___
-${CROSS_COMPILE}gcc -s -static -Os -o init init.c
+
+# build using nolibc on supported archs (smaller executable) and fall
+# back to regular glibc on other ones.
+if echo -e "#if __x86_64__||__i386__||__i486__||__i586__||__i686__" \
+ "||__ARM_EABI__||__aarch64__\nyes\n#endif" \
+ | ${CROSS_COMPILE}gcc -E -nostdlib -xc - \
+ | grep -q '^yes'; then
+ # architecture supported by nolibc
+ ${CROSS_COMPILE}gcc -fno-asynchronous-unwind-tables -fno-ident \
+ -nostdlib -include ../bin/nolibc.h -lgcc -s -static -Os \
+ -o init init.c
+else
+ ${CROSS_COMPILE}gcc -s -static -Os -o init init.c
+fi
+
rm init.c
echo "Done creating a statically linked C-language initrd"
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2018-11-11 20:02 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-11-11 20:01 [PATCH tip/core/rcu 0/8] Automate initrd generation for v4.21/v5.0 Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 1/8] rcutorture: Automatically create initrd directory Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 2/8] rcutorture: Add initrd support for systems lacking dracut Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 3/8] rcutorture: Make initrd/init execute in userspace Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 4/8] rcutorture: Add cross-compile capability to initrd.sh Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 5/8] rcutorture: Always strip using the cross-compiler Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 6/8] rcutorture: Check initrd/init instead of initrd only Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 7/8] rcutorture: Import a copy of nolibc Paul E. McKenney
2018-11-11 20:01 ` [PATCH tip/core/rcu 8/8] rcutorture: Make use of nolibc when available Paul E. McKenney
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