`open(0,0)` cases page fault...

bash

LINUX=$1
if [ ! -f "init" ]; then
        if [ -d "tmps" ]; then
                sudo umount tmps
                rmdir tmps
        fi
        dd if=/dev/zero of=init bs=4k count=400
        mkfs.ext4 init
        mkdir tmps
        sudo mount -o loop init tmps
        sudo mkdir tmps/sbin
        cat << EOF > example.c
#include <fcntl.h>
int main(){
        while(1) open(0,0);
}
EOF
        gcc -static example.c -o example
        sudo mv example tmps/sbin/init
        rm example.c
        sudo umount tmps
        rmdir tmps
fi

qemu-system-x86_64 -s -m 128 --enable-kvm -nographic -kernel $LINUX/arch/x86_64/boot/bzImage -append "nokaslr root=/dev/sda rw" -drive file=init,format=raw &>/dev/null &
echo -e "To kill run:\n$ kill -9 $!"
cat << EOF > gdb.script
cd $LINUX
file vmlinux
add-auto-load-safe-path $LINUX
source vmlinux-gdb.py
target remote :1234
b do_strncpy_from_user
c
b asm_exc_page_fault
si 6
EOF

echo -e "Run:\n$ gdb --command=gdb.script\nThen in gdb run:\n(gdb) si"