how to make loadable kernel module on solaris? no linux - unix

Question

1. how to create loadable kernel module on solaris 11?
simple loadable kernel module (hello world).
I searched, but only showed how to create a Linux kernel module.
in linux, header linux/kernel.h, but not included header on solaris
2. how to compile loadable kernel module on solaris 11?
gcc -D_KERNEL -m64 -c cpluscplus.cpp
Is it appropriate to compile as above?
64bit, x86

Answer 1

Here's the minimal hello world kernel module I can come up with:
#include <sys/modctl.h>
#include <sys/cmn_err.h>
/*
* Module linkage information for the kernel.
*/
static struct modlmisc modlmisc = {
&mod_miscops, "test module"
};
static struct modlinkage modlinkage = {
MODREV_1, (void *)&modlmisc, NULL
};
int
_init(void)
{
return (mod_install(&modlinkage));
}
int
_fini(void)
{
return (mod_remove(&modlinkage));
}
int
_info(struct modinfo *modinfop)
{
cmn_err(CE_NOTE, "hello kernel");
return (mod_info(&modlinkage, modinfop));
}
Compiling this as 64-bit binary with Oracle Developer Studio 12.6 and the Solaris linker like so:
cc -D_KERNEL -I include -m64 -c foomod.c
ld -64 -z type=kmod -znodefs -o foomod foomod.o
For GCC you will likely need a distinct set of options.
Then load it with:
modload ./foomod
This will complain about signature verification. This is innocuous unless you are running the system with Verified Boot enabled.
Check that module is loaded:
# modinfo -i foomod
ID LOADADDR SIZE INFO REV NAMEDESC
312 fffffffff7a8ddc0 268 -- 1 foomod (test module)
# dmesg | tail -1
Mar 16 12:22:57 ST091 foomod: [ID 548715 kern.notice] NOTICE: hello kernel
This works on Solaris 11.4 SRU 33 running on x86 machine (VirtualBox instance in fact).