Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

I don’t remember when it happened, but sometime in the past four years,
the Makefiles for the kernel named Linux changed. I can’t remember
exactly, but I do recall sometime “recently” that the
kernel build output stopped looking like what I remember from 1991,
and started looking like this:

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

gcc -m32 -Wp,-MD,arch/i386/kernel/.semaphore.o.d -nostdinc -isystem /usr/lib/gcc/i486-linux-gnu/4.0.3/include -D__KERNEL__ -Iinclude -include include/linux/autoconf.h -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -ffreestanding -Os -fomit-frame-pointer -pipe -msoft-float -mpreferred-stack-boundary=2 -march=i686 -mtune=pentium4 -Iinclude/asm-i386/mach-default -Wdeclaration-after-statement -Wno-pointer-sign -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(semaphore)" -D"KBUILD_MODNAME=KBUILD_STR(semaphore)" -c -o arch/i386/kernel/semaphore.o arch/i386/kernel/semaphore.c gcc -m32 -Wp,-MD,arch/i386/kernel/.signal.o.d -nostdinc -isystem /usr/lib/gcc/i486-linux-gnu/4.0.3/include -D__KERNEL__ -Iinclude -include include/linux/autoconf.h -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -ffreestanding -Os -fomit-frame-pointer -pipe -msoft-float -mpreferred-stack-boundary=2 -march=i686 -mtune=pentium4 -Iinclude/asm-i386/mach-default -Wdeclaration-after-statement -Wno-pointer-sign -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(signal)" -D"KBUILD_MODNAME=KBUILD_STR(signal)" -c -o arch/i386/kernel/signal.o arch/i386/kernel/signal.c

I never gave it much thought, since the new form was easier to read. I
figured that those folks who still eat kernel code for breakfast knew
about this change well ahead of time. Of course, they were the only
ones who needed to see the verbose output of the gcc
command lines. I could live with seeing the simpler CC
lines for my purposes, until today.

I was compiling kernel code and for the first time since this change in
the Makefiles, I was using a non-default gcc to build
Linux. I wanted to double-check that I’d given the right options to
make throughout the process. I therefore found myself
looking for a way to see the full output again (and for the first
time). It was easy enough to figure out: giving the variable setting
V=1 to make gives you the verbose version.
For you Debian folks like me, we’re using make-kpkg, so
the line we need looks like: MAKEFLAGS="V=1" make-kpkg kernel_image.

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

Remember the Verbosity (A Brief Note)

2007-04-17 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/17/linux-verbose-build.html

CC arch/i386/kernel/semaphore.o CC arch/i386/kernel/signal.o

This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:

It’s nice sometimes to pretend I’m compiling 0.99pl12 again and not
2.6.20.7. 🙂 No matter which options you give make, it is
still a whole lot easier to bootstrap Linux these days.

I Am Free Again!

2007-04-12 Lennart Poettering

Post Syndicated from Lennart Poettering original https://0pointer.net/blog/thesis.html

Es ist vollbracht! Today, at 10:54 am — 66 min before deadline — I
handed in my diploma thesis ^[1]. In a few weeks time you may call me
Diplom-Informatiker… Herr Diplom-Informatiker.

That’s all.

Footnotes:

[1] Thesis title is Diensteverwaltung in Ad-Hoc-Netzwerken
(which roughly translates to Service Discovery in Ad-Hoc Networks).
Basically, the thesis is about “Mesh-DNS”, a protocol akin to Multicast DNS (mDNS), which scales
better, fixes a few things and takes Mesh network architectures into account.
It is intended to be integrated into Avahi and
to be used as service discovery protocol in OLPC. It is compatible with DNS-SD, but replaces mDNS. Due to that all
existing software linking against Avahi can make use of it without any major
changes. It adds a zone .mesh which is organized by Mesh-DNS side-by-side to the mDNS-maintained zone .local. You will be able to enable support for Mesh-DNS at Avahi
compile time. Most likely most distros won’t enable it in their default builds,
although it offers quite a few features even outside OLPC, such as
automatic, idiot-proof router transparency.

What’s going on with LinuxTag?

2007-04-10 Lennart Poettering

Post Syndicated from Lennart Poettering original https://0pointer.net/blog/projects/linuxtag.html

Does anybody know what’s going on with LinuxTag? I submitted a presentation
proposal a few months ago. I haven’t yet received an email whether my talk has been
accepted or not. According to their
website notification emails should have been sent out on march 13th. Which
is nearly a month ago now. When I login to the “virtual conference
center” I see that my paper is still “In Review”. They didn’t respond to my emails (twice).

Does anyone have an idea what is going on?

User-Empowered Security via encfs

2007-04-10 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/10/encfs.html

One of my biggest worries in using a laptop is that data
can suddenly become available to anyone in the world if a laptop is
lost or stolen. I was reminded of this during the mainstream
media coverage¹ of this issue last year.

There’s the old security through obscurity perception of running
GNU/Linux systems. Proponents of this theory argue that most thieves
(or impromptu thieves, who find a lost laptop but decide not to return
it to its owner) aren’t likely to know how to use a GNU/Linux system,
and will probably wipe the drive before selling it or using it.
However, with the popularity of Free Software rising, this old standby
(which never should have been a standby anyway, of course) doesn’t
even give an illusion of security anymore.

I have been known as a computer security paranoid in my time, and I
keep a rather strict regiment of protocols for my own personal
computer security. But, I don’t like to inflict new onerous security
procedures on the otherwise unwilling. Generally, people will find
methods around security procedures when they aren’t fully convinced
they are necessary, and you’re often left with a situation just as bad
or worse than when you started implementing your new procedures.

My solution for the lost/stolen laptop security problem was therefore
two-fold: (a) education among the userbase about how common it is to
have a laptop lost or stolen, and (b) providing a simple user-space
mechanism for encrypting sensitive data on the laptop. Since (a) is
somewhat obvious, I’ll talk about (b) in detail.

I was fortunate that, in parallel, my friend Paul and one of my
coworkers discovered how easy it is to use encfs and
told me about it. encfs uses the Filesystem in
Userspace (FUSE) to store encrypted data right in a user’s own home
directory. And, it is trivially easy to set up! I used Paul’s tutorial
myself, but there are many published all over the Internet.

My favorite part of this solution is that rather than an onerous
mandated procedure, encfs turns security into user
empowerment. My colleague James wrote up a tutorial for our internal
Wiki, and I’ve simply encouraged users to take a look and consider
encrypting their confidential data. Even though not everyone has
taken it up yet, many already have. When a new security measure
requires substantial change in behavior of the user, the measure works
best when users are given an opportunity to adopt it at their own
pace. FUSE deserves a lot of credit in this regard, since it lets
users switch their filesystem to encryption in pieces (unlike other
cryptographic filesystems that require some planning ahead). For my
part, I’ve been slowly moving parts of my filesystem into an encrypted
area as I move aside old habits gradually.

I should note that this solution isn’t completely without cost. First,
there is no metadata encryption, but I am really not worried about
interlopers finding out how big our nameless files and directories are
and who created them (anyway, with an SVN checkout, the interesting
metadata is in .svn, so it’s encrypted in this case).
Second, we’ve found that I/O intensive file operations take
approximately twice as long (both under ext3 and XFS) when using
encfs. I haven’t moved my email archives to my encrypted
area yet because of the latter drawback. However, for all my other
sensitive data (confidential text documents, IRC chat logs, financial
records, ~/.mozilla, etc.), I don’t really notice the
slow-down using a 1.6 Ghz CPU with ample free RAM. YMMV.

¹
BTW, I’m skeptical about the FBI’s claim in that
old Washington Post article which states
“review of the equipment by computer forensic teams has
determined that the data base remains intact and has not been
accessed since it was stolen”. I am mostly clueless about
computer forensics; however, barring any sort of physical seal on
the laptop or hard drive casing, could a forensics expert tell if
someone had pulled out the drive, put it in another computer, did a
dd if=/dev/hdb of=/dev/hda, and then put it back as it
was found?

User-Empowered Security via encfs

2007-04-10 Bradley M. Kuhn

Post Syndicated from Bradley M. Kuhn original http://ebb.org/bkuhn/blog/2007/04/10/encfs.html

Noise

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

Remember the Verbosity (A Brief Note)

I Am Free Again!

What’s going on with LinuxTag?

User-Empowered Security via encfs

User-Empowered Security via encfs

The collective thoughts of the interwebz