Re: Invoking a signal handler
On Sun, Feb 07, 2010 at 10:55:53PM -0800, Shrivats wrote: Hi, I am trying to understand how the kernel invokes the signal handler for a process, to deliver an asynchronous signal posted by another process. I was looking at the sendsig() function which saves the current user context. My question is, when and how does the transition from the kernel mode to the user mode take place so that the signal handler is invoked? The sendsig() does two things. First, it copies out the currently saved user context to the user stack. Then, it modifies the current context to arrange the call to the signal handler when return to user mode is done. After that, when the thread does usual return from the kernel to user mode, be it return from the interrupt, or syscall, the modified context causes execution to jump to signal trampoline code implanted to the user mode stack by image activator. Trampoline is supplied required data by sendsig() to call signal handler with the right arguments. More, upon return from the signal handler, the trampoline on the stack gets the control again, and calls sigreturn(2) syscall that restores the old, pre-signal context saved by sendsig(). This is the model used on i386/amd64 FreeBSD, and I think that other architectures are quite similar. pgprkXgawGUyo.pgp Description: PGP signature
Re: our little daemon abused as symbol of the evil
Ruben de Groot mai...@bzerk.org wrote: On Fri, Feb 05, 2010 at 08:05:10PM +0100, Julian H. Stacey typed: PS an undefended trade mark loses its right to further defence or some such, (I'm not a lawyer). It's not a trade mark, is it? It's copyrighted. That's a whole other set of laws. On the bottom of this page ... http://www.freebsd.org/art.html .. the text states that Marshall Kirk McKusick is the trademark holder for the BSD Daemon image. However, on another page (I don't have the URL right now) it says that Kirk owns the copyright of the daemon. I guess one of the web pages needs to be corrected, but I don't know which one. :-) Best regards Oliver -- Oliver Fromme, secnetix GmbH Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd A language that doesn't have everything is actually easier to program in than some that do. -- Dennis M. Ritchie ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
How can I force boot from alternate drive with boot.config?
I've asked this on the -questions list but haven't had any feedback. I have a system configured with multiple identical drives each loaded with FreeBSD. When I was using MBR partitioning, I could create a boot.config to force the system to boot from a specific drive. For example, if I wanted to boot from the second drive, I'd create a boot.config with: 1:ad(1,a)/boot/loader We've switched to GPT partitioning and I can't seem to find a way to do this same trick. The boot loader only seems to recognize MBR partitions when it comes to this feature. I looked at the boot.c source code and there doesn't seem to be anything specifically related to GPT partitioning. I cannot for example say something like: 1:ad(1,p3)/boot/loader where p3 is the root partition in my GPT partitioned drives. So I'm puzzled: If I have a two drive system with BSD loaded on both drives and the drives are configured with GPT partitions, how can I force the system to boot from the second drive using boot.config? ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
Re: How can I force boot from alternate drive with boot.config?
On Mon, Feb 08, 2010 at 10:25:54AM -0600, Peter Steele wrote: I've asked this on the -questions list but haven't had any feedback. I have a system configured with multiple identical drives each loaded with FreeBSD. When I was using MBR partitioning, I could create a boot.config to force the system to boot from a specific drive. For example, if I wanted to boot from the second drive, I'd create a boot.config with: 1:ad(1,a)/boot/loader We've switched to GPT partitioning and I can't seem to find a way to do this same trick. The boot loader only seems to recognize MBR partitions when it comes to this feature. I looked at the boot.c source code and there doesn't seem to be anything specifically related to GPT partitioning. I cannot for example say something like: 1:ad(1,p3)/boot/loader where p3 is the root partition in my GPT partitioned drives. So I'm puzzled: If I have a two drive system with BSD loaded on both drives and the drives are configured with GPT partitions, how can I force the system to boot from the second drive using boot.config? I use: ad(0p3)/boot/loader John -- John Hay -- j...@meraka.csir.co.za / j...@freebsd.org ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
RE: How can I force boot from alternate drive with boot.config?
I use: ad(0p3)/boot/loader So, more precisely, if I wanted to boot from drive 1, I'd use this? 1:ad(1p3)/boot/loader ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
Re: How can I force boot from alternate drive with boot.config?
On Mon, Feb 08, 2010 at 12:13:20PM -0600, Peter Steele wrote: I use: ad(0p3)/boot/loader So, more precisely, if I wanted to boot from drive 1, I'd use this? 1:ad(1p3)/boot/loader Yes, unless there are more bugs hiding. :-) I fixed a few in August last year. John -- John Hay -- j...@meraka.csir.co.za / j...@freebsd.org ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
Re: our little daemon abused as symbol of the evil
Oliver Fromme wrote:
Ruben de Groot mai...@bzerk.org wrote:
On Fri, Feb 05, 2010 at 08:05:10PM +0100, Julian H. Stacey typed:
PS an undefended trade mark loses its right to further defence or some
such,
(I'm not a lawyer).
It's not a trade mark, is it? It's copyrighted. That's a whole other set
of laws.
On the bottom of this page ...
http://www.freebsd.org/art.html
Nice page :-)
. the text states that Marshall Kirk McKusick is the
trademark holder for the BSD Daemon image.
However, on another page (I don't have the URL right
now) it says that Kirk owns the copyright of the daemon.
I guess one of the web pages needs to be corrected,
but I don't know which one. :-)
Best regards
Oliver
I asked someone who registers trademarks as part of her job:
One can apply to register a trademark in {(my (Julian) brackets) at
least all of} Germany Britain America {etc}. She spoke of
an international form where one ticks the countries one
wants {to apply to}.
I recall there's initial recuring fees ( admin) on getting
renewing trademarks. So questions could be:
Has Kirk (or A.N.Other) registered it [which, what] as a
trademark ? In which countries ? When ? URLs please.
Have they already/ when will they expire
Whose crontab file reminder who Kirk ? to pay renewal
fees [to which countries] ?
I guess if Kirk didn't/ doesn't want that [future] bother, it's the sort of
thing [Free]BSD Foundation might handle ? (Assuming that [Free] bit
doesn't provoke Net Open Dragon PC etc BSD who also use the BSD daemon.
Occasionaly (eg with Disney graphics ?) one sees some mark under
the graphic. Might it be wise to have a tiny C. symbol or other
text under the graphic's feet ? (A question for a trademark specialist,
Bcc'd :-)
Editing an ASCII readable copyright string into eg a .gif image is
probably not a bad idea too.
Kirk wrote Fri, 05 Feb 2010 11:19:39 -0800 (20:19 CET)
I have gotten word from the authors that they are aware of the
problem and are correcting it (e.g., taking out the daemon).
Mon Feb 8 20:48:01 CET 2010 (TZ=GMT+01:00)
http://www.iseclab.org/papers/sonda-TR.pdf
Page 4
BSD graphic is no longer present, replaced by word Attacker.
Firefox graphic is no longer present, replaced by word Victim
Cheers,
Julian
--
Julian Stacey: BSD Unix Linux C Sys Eng Consultants Munich http://berklix.com
Mail plain text not quoted-printable, HTML or Base64 http://www.asciiribbon.org
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Invoking a signal handler
Hi, I am trying to understanding how the kernel invokes a signal handler for a currently executing process, to deliver an asynchronous signal posted by another process. I was looking at the sendsig() function which saves the ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
