RE: Sharing data between user space and kernel
>sleeping(). What you probably want to do is >actually allocate wired kernel pages and export them to >userspace. Take a >look at the GEOM gstat(8) implementation, which does >exactly that. >However, you have to make sure that if you ever decide >to reuse that >kernel memory for something else (i.e., free it back to >the allocator), >you've GC'd all userspace references to it. Could you please point me to the place where "GEOM gstat" is implemented ? I don't seem to find it :-( Thanks a lot, neo Découvrez le nouveau Yahoo! Mail : 250 Mo d'espace de stockage pour vos mails ! Créez votre Yahoo! Mail sur http://fr.mail.yahoo.com/ ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
intercepting RSVP packets with netgraph
Hi all, I've read every thing I could find about netgraph but I still can not figure out how to intercept (divert) all IP packets of a certain type (say RSVP) and call my own function to process them. Notice that the processing has to occur at the kernel level. Any help is appreciated. Thanks in advance. Aziz Kezzou ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
generic network protocols parser ?
Hi all, I am wondering if any one knows about a generic parser which takes a packet (mbuf) of a certain protocol (e.g RSVP ) as input and generates some data structre representing the packet ? I've been searching for a while and found that ethereal and tcpdump for example use specific data structres and functions to dissect each protocol packets. Is this the only approach possible ? My supervisor suggested using a TLV (Type/Length/Value) approach instead. Any opinions about that? If no such a parser exists is there any practical reason why ? Thanks, Aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
How to send a signal from inside the kernel?
Hi all,
I would like to send a signal (e.g SIGUSR1) to a user process from
inside the kernel (kld module).
Can any one tell me how to do it ?
I tried the following code inspired from sys/kern/kern_sig.c :
==
#include
#include
int process_pid;
struct kill_args {
int pid;
int signum;
};
void send_SIGUSR1() {
struct kill_args uap;
uap.pid = process_pid;
uap.signum = SIGUSR1;
kill((struct thread *)0, &uap);
}
===
but that causes a page fault in kernel mode (ie. Kernel panic :-)
Any help is appreciated, thanks.
Aziz
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Re: How to send a signal from inside the kernel?
> Aziz KEZZOU wrote this message on Thu, Mar 17, 2005 at 12:34 -0500:
> > Hi all,
> > I would like to send a signal (e.g SIGUSR1) to a user process from
> > inside the kernel (kld module).
> > Can any one tell me how to do it ?
> > I tried the following code inspired from sys/kern/kern_sig.c :
> > ==
> > #include
> > #include
> >
> > int process_pid;
> > struct kill_args {
> > int pid;
> > int signum;
> > };
> >
> > void send_SIGUSR1() {
> > struct kill_args uap;
> > uap.pid = process_pid;
> > uap.signum = SIGUSR1;
> > kill((struct thread *)0, &uap);
> > }
> > ===
> >
> > but that causes a page fault in kernel mode (ie. Kernel panic :-)
> >
> > Any help is appreciated, thanks.
>
> Take a look at psignal(9)... You'll need to look up the struct proc
> for psignal with pfind(9)... and then PROC_UNLOCK the struct proc
> after you've used psignal...
>
> so:
> struct proc *p;
>
> p = pfind(pid);
> if (p != NULL) {
> psignal(p, SIGUSR1);
> PROC_UNLOCK(p);
> }
>
> I haven't tried the code above, but that should do what you want...
It works, thanks a lot !!
Here are the headers needed in case someone reads this thread:
#include /*needed only for NULL, can be removed*/
#include
#include
#include
#include
#include
Have fun,
Aziz
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running freebsd in qemu using the "-nographic" option ?
Hi all, I am running freebsd 5.3 under qemu (a fast IA32 emulator). My host system is linux. Everything works fine, but I want to get rid of this small non-scrollable window, not practical when gcc says I made many many errors :-)... Instead I want to get a console. In qemu's documentation it says : == `-nographic' Normally, QEMU uses SDL to display the VGA output. With this option, you can totally disable graphical output so that QEMU is a simple command line application. The emulated serial port is redirected on the console. Therefore, you can still use QEMU to debug a Linux kernel with a serial console. == So basically what I need is, some how, to tell the freebsd kernel to forward its output/input to a serial port. In linux this is done by supplying the parameter "console=ttyS0". Is there something equivalent in FreeBSD ? Thanks for your help, Aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: running freebsd in qemu using the "-nographic" option ?
> Aziz KEZZOU wrote: > > >Hi all, > >I am running freebsd 5.3 under qemu (a fast IA32 emulator). My host > >system is linux. Everything works fine, but I want to get rid of this > >small non-scrollable window, not practical when gcc says I made many > >many errors :-)... > > > > > > you can scroll it after hittong tthe "scroll lock" key > > >Instead I want to get a console. In qemu's documentation it says : > >== > >`-nographic' > >Normally, QEMU uses SDL to display the VGA output. With this > >option, you can totally disable graphical output so that QEMU is a > >simple command line application. The emulated serial port is > >redirected on the console. Therefore, you can still use QEMU to debug > >a Linux kernel with a serial console. > >== > > > >So basically what I need is, some how, to tell the freebsd kernel to > >forward its output/input to a serial port. In linux this is done by > >supplying the parameter "console=ttyS0". Is there something equivalent > >in FreeBSD ? > > > > > > > > in /boot/loader.conf add: > > console="comconsole" > > that should do it.. Thank you guys, that seems easy to do...but I don't have access to /etc/boot.conf : all I have is a disk image generated by bximage, which I can't mount !! The pb is that with my new install the SDL window doesn't work any more : qemu says "Could not initialize SDL - exit". I did "xhost +" but didn't change any thing ?! Anyway I am not spending any more time to get the SDL window which I don't really need :-) So basically what I want to do now is mount the freeBSD image in a loopback and modify the boot.conf file directly. Anyone knows how to do this under linux (2.6 if relevant) ? BSD seems to have a "weird" way of organizing the disk. Which file system shoud I support ? Thanks, Aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: running freebsd in qemu using the "-nographic" option ?
> > >So basically what I want to do now is mount the freeBSD image in a > > >loopback and modify the boot.conf file directly. Anyone knows how to > > >do this under linux (2.6 if relevant) ? BSD seems to have a "weird" > > >way of organizing the disk. Which file system shoud I support ? > > I would just do it on FreeBSD - man mdconfig. Last I looked (years ago) the > UFS > support on linux was not actively maintained and I would be very surprised if > they have UFS2 support. I've had to create my own root images for doing work > on > xen so I know it works just fine. If you insist on doing it on Linux, the > command is losetup. > to bind: > > losetup /dev/loop0 > to unbind: > > losetup -d /dev/loop0 Hi, I am now trying to do it now on a FreeBSD machine so I did : su-2.05b#mdconfig -a -t vnode -f freebsd.img => response : "md0" Then I mounted successfully : /dev/md0s1d (/var), /dev/md0s1e(/tmp) and /dev/md0s1f (/usr). But I can not mount /dev/md0s1a which is the root directory where "/boot/boot.conf" is located : su-2.05b# mount /dev/md0s1a /mnt/a mount: /dev/md0s1a: Operation not permitted Any hint ? -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
clear/set/test_bit header ??
Hi hackers, I am trying to port a software from Linux to FreeBSD (5.3). But, I can't find the equivalent header in FreeBSD of in Linux ? Here are the prototypes of the functions I am using: int clear_bit(int offset, int * flag); int set_bit(int offset, int * flag); int test_bit(int offset, int * flag); Any hints? Also if you know about a website which does this header-mapping (Linux<->FreeBSD), I am interested to know about it ;-) Thanks, -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
KLD module with C++ iostreams ?
Hi hackers,
I am wondering if I can use c++ iostreams inside the kernel ?
After all the code : cout << "Hello world!" << endl;
ends accessing the stdout just like : printf("Hello world!\n"); right ?
So if I could compile my KLD module with static linkage to libstdc++,
that should be ok, right ?
Any one did or knows how to do this ?
Thanks,
-aziz
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Re: KLD module with C++ iostreams ?
> David Leimbach wrote:
> > Interesting question. People usually have to implement the C++
> > runtime to be usable from within the kernel. Things like exceptions
> > and "stdout" may not be defined in kernel space :)
> >
> > I'm not terribly familiar with how it works on FreeBSD but I know it
> > took a special effort to get C++ support into linux.
> >
> > Dave
> >
> > On 4/20/05, Aziz KEZZOU <[EMAIL PROTECTED]> wrote:
> >
> >>Hi hackers,
> >>I am wondering if I can use c++ iostreams inside the kernel ?
> >>After all the code : cout << "Hello world!" << endl;
> >>ends accessing the stdout just like : printf("Hello world!\n"); right ?
>
> No, that's not true, all the iostreams stuff is totally independent.
> The iostreams stuff is coming from some of the ugliest code in C++.
> But, that's not the question, or at very least, it shouldn't BE the
> question. There is ZERO need to bring in features from C++, all it will
> do is to directly confuse the code base by greatly adding to the
> complexity of the code, without giving anything like equivalent features.
>
> Some very, very elegant work has been code, OO-ing the kernel code,
> adding OO features, all without violating the C language code base.
> Adding in C++ features over stdio stuff is so senseless, it's nearly
> obscene.
>
> If the gain at the end of the road was large enough, I wouldn't be
> against it so stridently, but I see *so* little gain.
>
> BTW, you know where the ugliest code in computer science today is: half
> is in the actual implementation of the cstdio/template code, the other
> half is the iostreams stuff. The fact that they energize some very
> elegant code is causing many folks never to see the fact of the horrible
> code lumps that exist out in the backyard.
>
> >>
> >>So if I could compile my KLD module with static linkage to libstdc++,
> >>that should be ok, right ?
> >>
> >>Any one did or knows how to do this ?
> >>
Thank you guys for responding to my post.
Certainly, it is not a good idea to use _all_ C++ stuff inside the
kernel ; in the linux community a similar suggestion resulted in a big
discussion of pros & cons. I was asking because I have a big portion
of C++ code that I am planning to move inside the kernel.
But, having compared the effort/time required to port C++ iostreams
into the kernel and the effort/time required to get rid of iostreams ,
I think I will abandon this challenge for now ;-)
Just to let you know "virtual methods" and "templates", among others,
are supported inside the kernel...
Greetings,
-aziz
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weird NFS problem ?
Hi all, I am experiencing a weird problem while mounting nfs files. Configuration : - NFS client : FreeBSD 5.3 running on QEMU, IP = 192.168.0.2 - NFS server : FC3, the host, IP = 192.168.0.1 Firewalling: absolutely everything is authorized from 192.168.0.2 on 192.168.0.1 Problem : some UDP ports on 192.168.0.2 are unreachable without any reason I know of ?!! Command: arwen# mount -t nfs 192.168.0.1:/home/akezzou/pfe/cvs /mnt/host [udp] 192.168.0.1:/home/akezzou/pfe/cvs: RPCPROG_MNT: RPC: Timed out [udp] 192.168.0.1:/home/akezzou/pfe/cvs: RPCPROG_MNT: RPC: Timed out Tcpdump output : [EMAIL PROTECTED] bin]# /usr/sbin/tcpdump -i tun0 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on tun0, link-type EN10MB (Ethernet), capture size 96 bytes 21:04:51.560121 IP 192.168.0.2.675 > 192.168.0.1.sunrpc: UDP, length 56 21:04:51.561806 arp who-has 192.168.0.2 tell 192.168.0.1 21:04:51.564088 arp reply 192.168.0.2 is-at 52:54:00:12:34:56 21:04:51.564118 IP 192.168.0.1.sunrpc > 192.168.0.2.675: UDP, length 28 21:04:51.570214 IP 192.168.0.2.1117046890 > 192.168.0.1.nfs: 40 null 21:04:51.570368 IP 192.168.0.1.nfs > 192.168.0.2.1117046890: reply ok 24 null 21:04:51.575164 IP 192.168.0.2.954 > 192.168.0.1.sunrpc: UDP, length 56 21:04:51.576338 IP 192.168.0.1.sunrpc > 192.168.0.2.954: UDP, length 28 21:04:51.581561 IP 192.168.0.2.621 > 192.168.0.1.650: UDP, length 108 21:05:04.528129 IP 192.168.0.1.650 > 192.168.0.2.621: UDP, length 68 21:05:04.530154 IP 192.168.0.2 > 192.168.0.1: icmp 36: 192.168.0.2 udp port 62 1 unreachable 21:06:01.613750 IP 192.168.0.2.1006 > 192.168.0.1.sunrpc: UDP, length 56 21:06:01.616083 IP 192.168.0.1.sunrpc > 192.168.0.2.1006: UDP, length 28 21:06:01.622336 IP 192.168.0.2.1117192688 > 192.168.0.1.nfs: 40 null 21:06:01.626734 IP 192.168.0.1.nfs > 192.168.0.2.1117192688: reply ok 24 null 21:06:01.637315 IP 192.168.0.2.843 > 192.168.0.1.sunrpc: UDP, length 56 21:06:01.641915 IP 192.168.0.1.sunrpc > 192.168.0.2.843: UDP, length 28 21:06:01.646715 IP 192.168.0.2.792 > 192.168.0.1.650: UDP, length 108 21:06:06.614378 arp who-has 192.168.0.2 tell 192.168.0.1 21:06:06.615755 arp reply 192.168.0.2 is-at 52:54:00:12:34:56 21:06:16.682754 IP 192.168.0.1.650 > 192.168.0.2.792: UDP, length 68 21:06:16.684556 IP 192.168.0.2 > 192.168.0.1: icmp 36: 192.168.0.2 udp port 79 2 unreachable 21:07:11.659900 IP 192.168.0.2.764 > 192.168.0.1.sunrpc: UDP, length 56 21:07:11.662292 IP 192.168.0.1.sunrpc > 192.168.0.2.764: UDP, length 28 21:07:11.668228 IP 192.168.0.2.1117147813 > 192.168.0.1.nfs: 40 null 21:07:11.671916 IP 192.168.0.1.nfs > 192.168.0.2.1117147813: reply ok 24 null 21:07:11.676171 IP 192.168.0.2.693 > 192.168.0.1.sunrpc: UDP, length 56 21:07:11.683197 IP 192.168.0.1.sunrpc > 192.168.0.2.693: UDP, length 28 21:07:11.688238 IP 192.168.0.2.958 > 192.168.0.1.650: UDP, length 108 21:07:16.660731 arp who-has 192.168.0.2 tell 192.168.0.1 21:07:16.661668 arp reply 192.168.0.2 is-at 52:54:00:12:34:56 Any hint is greatly appreciated. thanks, -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Pseudo-device driver & select ??
Hi all, I am trying to implement a small kld pseudo-device driver on FreeBSD 5.3 that behaves just like a socket with regards to the select system call. Currently, I am using the sample echo pseudo-device driver from http://www.freebsd.org/doc/en_US.ISO8859-1/books/arch-handbook/driverbasics-char.html as an example. However, whenever I call select on the file descriptor of "/dev/echo" it always returns even when there is no data to be read. I looked at the socket code and it looks like I need to provide my own "fo_select" function in the fileops data structure. Am i right ? How do I do that ? The sample echo pseudo-device driver above uses "struct cdevsw" instead... Thanks -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Pseudo-device driver & select ??
>
> Aziz Kezzou wrote:
> > Hi all,
> > I am trying to implement a small kld pseudo-device driver on FreeBSD 5.3
> > that
> > behaves just like a socket with regards to the select system call.
> >
> > Currently, I am using the sample echo pseudo-device driver from
> > http://www.freebsd.org/doc/en_US.ISO8859-1/books/arch-handbook/driverbasics-char.html
> > as an example. However, whenever I call select on the file
> > descriptor of "/dev/echo" it always returns even when there is no data
> > to be read.
> >
> > I looked at the socket code and it looks like I need to provide my own
> > "fo_select" function in the fileops data structure. Am i right ? How
> > do I do that ? The sample echo pseudo-device driver above uses
> > "struct cdevsw" instead...
> >
> > Thanks
> > -aziz
> > ___
> > freebsd-net@freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-net
> > To unsubscribe, send any mail to "[EMAIL PROTECTED]"
> >
> >
> look at spec_poll()
> I beleive that when your device is opened the fileops{} will
> point to the spec ops and you're code will be entered via
> spec_poll() - now you just need to implement the poll/select notion
> for your device.
>
Thanks,
Actually, il turned out to be very simple.
I needed only to provide a "d_poll" function as part of the structure
cdevsw, as follows :
/* Character device entry points */
static struct cdevsw echo_cdevsw = {
.d_version = D_VERSION,
.d_open = echo_open,
.d_close = echo_close,
.d_read = echo_read,
.d_write = echo_write,
.d_poll = echo_poll,
.d_name = "echo",
};
with echo_poll :
static int
echo_poll(struct cdev *dev, int events, struct thread *td)
{
uprintf( "echo_poll called : data_available = %d!\n", data_available );
if(data_available == 0)
return 0;
data_available = 0;
return 1;
}
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Re: Pseudo-device driver & select ??
> >
> > Aziz Kezzou wrote:
> > > Hi all,
> > > I am trying to implement a small kld pseudo-device driver on FreeBSD 5.3
> > > that
> > > behaves just like a socket with regards to the select system call.
> > >
> > > Currently, I am using the sample echo pseudo-device driver from
> > > http://www.freebsd.org/doc/en_US.ISO8859-1/books/arch-handbook/driverbasics-char.html
> > > as an example. However, whenever I call select on the file
> > > descriptor of "/dev/echo" it always returns even when there is no data
> > > to be read.
> > >
> > > I looked at the socket code and it looks like I need to provide my own
> > > "fo_select" function in the fileops data structure. Am i right ? How
> > > do I do that ? The sample echo pseudo-device driver above uses
> > > "struct cdevsw" instead...
> > >
> > > Thanks
> > > -aziz
> > > ___
> > > freebsd-net@freebsd.org mailing list
> > > http://lists.freebsd.org/mailman/listinfo/freebsd-net
> > > To unsubscribe, send any mail to "[EMAIL PROTECTED]"
> > >
> > >
> > look at spec_poll()
> > I beleive that when your device is opened the fileops{} will
> > point to the spec ops and you're code will be entered via
> > spec_poll() - now you just need to implement the poll/select notion
> > for your device.
> >
>
> Thanks,
> Actually, il turned out to be very simple.
> I needed only to provide a "d_poll" function as part of the structure
> cdevsw, as follows :
>
> /* Character device entry points */
> static struct cdevsw echo_cdevsw = {
> .d_version = D_VERSION,
> .d_open = echo_open,
> .d_close = echo_close,
> .d_read = echo_read,
> .d_write = echo_write,
> .d_poll = echo_poll,
> .d_name = "echo",
> };
>
> with echo_poll :
> static int
> echo_poll(struct cdev *dev, int events, struct thread *td)
> {
>
> uprintf( "echo_poll called : data_available = %d!\n", data_available );
> if(data_available == 0)
> return 0;
> data_available = 0;
> return 1;
> }
>
Now the question is, if I don't have any data available when select
(i.e d_poll ) is called, how do I notify select when data arrives ?
looks like "d_poll" is called only once (the name is a bit misleading
here ;-) , isn't it ?
Any hints ?
Thanks.
-aziz
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Routing loop + raw IP packets : looking for clues ...
Hi all, For the purpose of my project I am simpulating a 3-hop network with QEMU on my workstation, as follows : |-| |---| |-| |Daemon1(user process)|---tun0---| Daemon 2 on QEMU |---tun1---| Daemon 3 (user porcess) | |-| |---| |-| My workstation is running FC3 and QEMU is running FreeBSD5.3 I am tryning to exchange raw IP packets between daemon 1 and 3 through daemon 2. I've succeded to by pass the system routing and get packets sent from daemon 1 to daemon 2 and from daemon 2 to daemon 3. BUT, on daemon 3 I can not receive them ??!! However, when I listen with tcpdump on tun0 and tun1 I see the packets travelling as expected : daemon1(192.168.0.1)-->(192.168.0.2)daemon2(192.168.1.2)--> daemon3(192.168.0.2) What could prevent me from receiving packets intended for daemon 3? I am suspecting some hard coded rule to prevent routing loops (which is my case) in the Linux kernel, am I on the right track ? Note : I disabled completely my firewalls, so this could not be the reason. Any help is highly appreciated. -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Fork mystries....
Hi all,
It's probably not the right mailing list to ask but I am really
surprised about global variable sharing in a multithreaded C
application. If I remember well my multithreading course global
variables are shared between threads, right ?
Example :
int counter = 0;
int main() {
if( fork()==0) {
while(1) {
sleep(1);
counter++;
printf("Son : counter = %d\n", counter);
}
} else {
while(1) {
sleep(1);
printf("Parent : counter = %d\n", counter);
}
}
return 0;
}
All I get is :
Parent : counter = 0
Son : counter = 1
Son : counter = 2
Parent : counter = 0
Son : counter = 3
Parent : counter = 0
Son : counter = 4
Parent : counter = 0
why counter isn't shared between the two threads ??!
thanks,
-aziz
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Re: Fork mystries....
Thank you guys,
I got it fork is creating a different process.
Currently, I am working a lot that I forget even the basic principales ;-)
I need a break ...
-aziz
On 6/3/05, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> Aziz,
>
> Fork is for process creation. Look up pthread_create() and/or POSIX
> thread
> creation, etc. You should be able to find a lot of info on google with a
> quick
> search:
>
> http://math.arizona.edu/~swig/documentation/pthreads/
>
> From the OS standpoint a process is like a different program when you fork
> it.
> A thread is more like a single program with a bunch of subsections all
> running
> at the same time, then the OS and CPU jump back and forth giving a little
> run-time to each subsection. Threads share a common space; processes [as
> far as
> I recal] do not (which is where inter process communication comes into
> play).
>
> Anyway, have fun! :)
>
> Ray
>
>
> At 07:55 PM 6/3/2005 -0400, Aziz Kezzou wrote:
> | Hi all,
> | It's probably not the right mailing list to ask but I am really
> | surprised about global variable sharing in a multithreaded C
> | application. If I remember well my multithreading course global
> | variables are shared between threads, right ?
> |
> | Example :
> |
> | int counter = 0;
> | int main() {
> | if( fork()==0) {
> | while(1) {
> | sleep(1);
> | counter++;
> | printf("Son : counter = %d\n", counter);
> | }
> | } else {
> | while(1) {
> | sleep(1);
> | printf("Parent : counter = %d\n", counter);
> | }
> | }
> | return 0;
> | }
> |
> |
> | All I get is :
> | Parent : counter = 0
> | Son : counter = 1
> | Son : counter = 2
> | Parent : counter = 0
> | Son : counter = 3
> | Parent : counter = 0
> | Son : counter = 4
> | Parent : counter = 0
> |
> | why counter isn't shared between the two threads ??!
> | thanks,
> | -aziz
> | ___
> | freebsd-hackers@freebsd.org mailing list
> | http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
> | To unsubscribe, send any mail to
> "[EMAIL PROTECTED]"
> |
> |
>
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How to do a routing lookup inside the kernel in FreeBSD ?
Hi all, I am trying to figure out from the kernel source code (FreeBSD 5.3) how can I perform a routing lookup in a KLD module. Since I am short in time, if anyone knows how do to do this I would appreciate. Any pointers to the right portion of the code are also apperciated. Thanks, -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
FreeBSD Memory Management questions ?
Hi all, I have two questions concerning FreeBSD Memory management : 1 - Right now to access the memory address space of a user process from kernel mode, I only have to set, on x86 systems, the register CR3 to the right value. How can I do that on other architectures ? is there an architecture-independant way of doing that ? 2- I have noticed that while in kernel mode the value of CR3 is equal to that of the user process beeing interrupted. Doesn't the kernel supposed to have its "own" page-directory, i.e it's own CR3 value ? or is kernel virtual address resolution does not go through CR3 at all ? Thanks for your help, -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
How to check root powers on a struct proc ?
Hi all, I am trying to check that a process (struct proc) has root powers when it calls my KLD system call. I know from kern_jail.c that I can use suser() but this function takes a struct thread* instead of struct proc* although the credentials (struct ucred *p_ucred;) are stored in proc ! Is there an esay way to get a struct thread* from a struct proc* ? or should I simply use the function: int suser_cred(struct ucred *cred, int flag); with cred = p-> p_ucred BTW what would the value of flag be? Thanks, -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: How to check root powers on a struct proc ?
> Aziz Kezzou wrote:
> > Hi all,
> > I am trying to check that a process (struct proc) has root powers when
> > it calls my KLD system call.
> > I know from kern_jail.c that I can use suser() but this function takes
> > a struct thread* instead of struct proc* although the credentials
> > (struct ucred *p_ucred;) are stored in proc !
>
> no.. the thread has a credential that it inherrits from the proc.
> when a thread changes the credential of the process as a whole, the
> other threads in the kernel don't notice until they return from their
> syscalls.. in the mean time they continue to use the reference they
> hold to the old credential. This is so that a credential doesn;t change half
> way
> through a syscall. the active credential at entry will be the active
> credential
> for that thread until it completes its time in the kernel.
>
> >
> > Is there an esay way to get a struct thread* from a struct proc* ? or
> > should I simply use the function: int suser_cred(struct ucred *cred,
> > int flag); with cred = p-> p_ucred
>
> why get a struct proc? the thread has a pointer to the cred it is running
> under.
>
>
I probably didn't make myself clear enough.
When my KLD system call is called I get a reference on the calling
process as "struct proc *p". Now how do I check if the calling process
has root powers ?
Would the following work ? :
static int ukcoe_register_ud( struct proc *p, struct
ukcoe_register_ud_args* arg ) {
int error;
error = suser_cred(p->p_cred, 0);
if(error) return error;
/* do the actual work*/
return 0;
}
Thanks,
-aziz
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Re: FreeBSD Memory Management questions ?
> On Tue, Jun 14, 2005 at 04:21:41AM -0400, Aziz Kezzou wrote: > > > > 1 - Right now to access the memory address space of a user process > > from kernel mode, I only have to set, on x86 systems, the register CR3 > > to the right value. How can I do that on other architectures ? is > > there an architecture-independant way of doing that ? > > Addition to the previous answer. It is also possible to temporally > map several pages of user memory into the kernel address space. > Check pmap_qenter(9) and see physio -> vmapbuf, for example, how to > use it. Another method, it is possible to COW a single user page and > then use it in the kernel, but with this method an user process will > not see any modification in this page made by the kernel and vice > versa. Check socow_setup -> vm_page_cowsetup, for example, how to > use it. Very interesting ! Right now I am using the fact that the kernel address space is maped on i386 machines into the user address space. So when I am executing a system call I can access kernel memory. I am wondering if there is an architecture-independant way of doing that ? (Notice that I need not only read kernel memory but also free it. e.g, mbufs ) or at least could you tell me if that's possible on other architectures ? Thanks for your help, -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: FreeBSD Memory Management questions ?
On 6/20/05, John Baldwin <[EMAIL PROTECTED]> wrote: > On Sunday 19 June 2005 10:49 pm, Aziz Kezzou wrote: > > > On Tue, Jun 14, 2005 at 04:21:41AM -0400, Aziz Kezzou wrote: > > > > 1 - Right now to access the memory address space of a user process > > > > from kernel mode, I only have to set, on x86 systems, the register CR3 > > > > to the right value. How can I do that on other architectures ? is > > > > there an architecture-independant way of doing that ? > > > > > > Addition to the previous answer. It is also possible to temporally > > > map several pages of user memory into the kernel address space. > > > Check pmap_qenter(9) and see physio -> vmapbuf, for example, how to > > > use it. Another method, it is possible to COW a single user page and > > > then use it in the kernel, but with this method an user process will > > > not see any modification in this page made by the kernel and vice > > > versa. Check socow_setup -> vm_page_cowsetup, for example, how to > > > use it. > > > > Very interesting ! > > > > Right now I am using the fact that the kernel address space is maped > > on i386 machines into the user address space. So when I am executing a > > system call I can access kernel memory. > > I am wondering if there is an architecture-independant way of doing > > that ? (Notice that I need not only read kernel memory but also free > > it. e.g, mbufs ) or at least could you tell me if that's possible on > > other architectures ? > > Are you modifying kernel memory from userland or are you trying to access user > memory from kernel code? > I want to be able to modify BOTH user and kernel memory in kernel mode. Typically, a user process invoques a system call. While executing the system call I need to have r/w access to the calling process's memory (which is normally OK) and also r/w access to kernel's memory. Note : the user pages that are access from kernel mode are wired to avoid a page-fault inside the kernel, is that necessary ? Also is there a way of sharing part of the user memory space with the kernel. In a way that both have access to it and both see each others work (i.e, no copy-on-write ) ? Thanks, -aziz ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
