On Fri, 31 Aug 2018 08:53:29 +0800, "phind@gmail.com" said:
> Thank for your time, I'm new to linux kernel. I am reading LDD3 chapter
> 15, Dirrect Memory Access section. I see that when I call function
> /dma_map_single/ and /dma_unmap_single/, I need to pass a direction as a
> parameter.
On Thu, 05 Jul 2018 19:30:22 -0300, "Daniel." said:
> Sometime we have a machine that we work on and that is really really slow
> when doing I/O. I know that kernel will use memory to avoid doing I/O, and
> that it would be a kind of conservative in avoiding keep to much data on
> volatile memory
On Sun, 08 Jul 2018 15:46:32 -0400, Ruben Safir said:
> What are you saying? That is the filesystem bus sends a HW interupt on
Error while parsing statement., What is a "filesystem bus" and when does it
issue a HW interrupt?
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On Tue, 10 Jul 2018 12:08:25 +0530, Sriram said:
> I m working on linux-3.12.19 kernel.
You have our condolences. Note that the fix for your problem has
probably already been found, somewhere in the millions of lines of
changes since then.
[/usr/src/linux-next] git diff --shortstat v3.12
On Tue, 10 Jul 2018 09:42:03 +1000, "Tobin C. Harding" said:
> I was under the impression that each maintainer constantly rebased their
> next branches and that was why one has to checkout the tagged linux-next
> each day instead of just pulling.
Close, but no cigar. The maintainers don't
On Tue, 10 Jul 2018 22:51:34 +0800, bing zhu said:
> Thank you ,I use this func for both kernel and user ,result are same.
> void *memcpy(void *dest, const void *src, size_t n)
> {
Might want to use 'void *my_memcpy(..)' instead, just in case the build
environment plays #define games with you
On Fri, 06 Jul 2018 20:06:29 +0200, Ahmed Soliman said:
> I have a memory page allocated with mmap() from user space, This
> address is passed to some kernel module (kvm_intel to be specific) and
> i want to know how can I change the page permission from inside there
> My goal is to achieve
On Fri, 06 Jul 2018 08:26:52 -0300, "Daniel." said:
> I'll try using a disk on memory (residing on a tmpfs mount) for improving
> this. Good idea!
Of course, actually getting the data *onto* the tmpfs will involve a lot of
I/O, and
it doesn't really fix the problem (just moves it around) unless
On Fri, 06 Jul 2018 23:59:30 +0200, Ahmed Soliman said:
> ROE can be enabled by the guest kernel and once enabled the hypervisor
> will make sure it never gets disabled again, so if even if the kernel
> decided to modify a paged that has ROE, it can't without a reboot.
So in essence, you're
On Sat, 07 Jul 2018 01:31:45 +0200, Ahmed Soliman said:
> > You missed the point - your protection can be bypassed without manipulating
> > a ROE page.
> Changing the virtual memory pointer table is ok but again these memory
> mappings will never
> make it to the TLB and will be caught during by
On Fri, 06 Jul 2018 21:29:40 +0200, you said:
> Implementing some kernel protection against subset of rootkits that
> manipulates kernel static data (memory pages as well as their
> mappings) by having them enforced by hypervisor which is KVM in our
Can you give an actual example of a case where
On Sat, 07 Jul 2018 19:36:47 +0800, bing zhu said:
> and in user space i do the same thing,I noticed that kernel is faster than
> user ,
How did you measure the times? Doing this right is actually harder than it
looks...
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On Thu, 12 Jul 2018 18:44:43 -, David Frank said:
> Hi,How do I enable the MAP_SYNC flag in mmap for linux 4.15, my code does not
> compile with that flag on linux 4.15.0-041500rc7-generic #201801072330
Get your distro to ship an update to /usr/include/linux (kernel-headers) that
contains
On Thu, 12 Jul 2018 20:10:36 -, David Frank said:
> Thanks Valdis.Looks like the failure is that I can not write to a 2GB buffer
> (char bf[2GB size]).Where do I get the distro include file?
>From the same exact place you got the distro kernel from. (I'm guessing
it's a distro kernel from
On Thu, 12 Jul 2018 20:33:32 -, David Frank said:
> I got it from hereHow To Install Kernel 4.15 RC7 on Ubuntu, Linux Mint,
> Elementary OS And Other Ubuntu Derivatives | LinuxG.net
Looks like you got the linux-image-... .deb but didn't do the linux-headers-...
.deb(s).
(And I have no
On Fri, 13 Jul 2018 11:02:13 +0800, bing zhu said:
> Iâm trying to write a simple fs in user space,if memcpy is slower than
> kernel , i think it's unfair,as for only cpu for my task,
> it's a bit of arbitrary ï¼i just want my task not interrupted during a
> specific time is that possible ?
On Thu, 12 Jul 2018 22:27:37 +0800, bing zhu said:
> as for memcpy ,kernel is faster than user ,might because schedule ,can i
> try to make user as fast as kernel ?
Do you have an actual issue where the difference in speed of these two
things makes a difference? Or is this primarily a mental
On Sun, 08 Jul 2018 11:21:08 +0530, inventsekar said:
> I read this page few times but I am unable to understand what's Linus's
> idea..Why he disagree ...
> whether the Linux kernel should include code that makes it easier to boot
> Linux on Windows PCs.
The issue is "trusted boot", and it
On Mon, 09 Jul 2018 19:34:44 +0530, Himanshu Jha said:
> I think for these benchmarking stuff, to evaluate the cycles and time
> correctly you should use the __rdtscp(more info at "AMD64 Architecture
> Programmerâs Manual Volume 3: General-Purpose and System Instructions"
> Pg 401)
Just beware
On Mon, 09 Jul 2018 09:30:51 -0400, Ruben Safir said:
> On 07/08/2018 04:44 PM, valdis.kletni...@vt.edu wrote:
> > Error while parsing statement., What is a "filesystem bus" and when does it
> > issue a HW interrupt?
> You have a hard drive on the system bus and it sends interupts...
That's
On Tue, 03 Jul 2018 10:28:48 +0800, you said:
> yes ! but there are days when people have to do a real-time work with no
> delay in kernel space ,i think i can feed the dog
> a percpu variable "nmi_touch" looks suspiciousï¼thanksï¼
1) The Linux kernel community convention is t use 'reply all'
On Mon, 22 Jan 2018 20:18:47 +0800, Rock Lee said:
> I think in order to keep the consistency, the whole transaction should
> be discarded, as long as not all the metadata blocks have the right
> crc value in the transaction. But why jbd2 still copies the metadata
> block(with the right crc) to
On Tue, 23 Jan 2018 18:07:25 +0530, Pintu Kumar said:
> My uname says:
> 4.9--amd-x86-64
Literally 4.9-? No 3rd number? And why ''? (Hint - obfuscating doesn't
help here, it's hard to debug when we don't see the *actual* string.)
Some unames from my various machines:
On Mon, 12 Mar 2018 12:26:38 -0700, Joe Smith said:
> I understand the guidelines for submitting a PATCH and they are quite
> rigorous. What about submitting an RFC, since RFC is just to get early
> comments do I have to make sure that each patch in the RFC compiles or
> is it OK if all patches
On Tue, 13 Mar 2018 08:52:01 -0700, Joe Smith said:
> By conformant I mean for example that it has to compile or if the
> patch consists of a series of patches each patch applied individually
> should compile. That is a lot of work for something that is just being
> presented to ask for an
On Wed, 14 Mar 2018 11:53:33 +0530, jitendra kumar khasdev said:
> eg. when we do shutdown, which (network or storage)stack goes down first?
Hint:
What order do these *have* to happen in?
What happens if you shut down the network before unmounting an NFS share, or if
you pixie-booted onto an
On Wed, 14 Mar 2018 17:46:16 +0100, Greg KH said:
> On Wed, Mar 14, 2018 at 12:32:21PM -0400, valdis.kletni...@vt.edu wrote:
> > That's *totally* device dependent. The things a driver needs to do to
> > ensure
> > consistency for a 40Gbit ethernet adapter are *totally* different from that
> >
On Wed, 14 Mar 2018 11:27:41 +0800, Larry Chen said:
> > 3. If ioctl() still running even after we terminate this process, where doe
s the return value ioctl() will return to?
> That sounds insane.
That's because it *is* insane.
The ioctl() *can't* "still be running" after the kill -9, because
On Wed, 04 Apr 2018 18:29:21 -0300, Martin Galvan said:
> PS: Yes, I'm aware I could just add $(bar-objs) to mydriver-y and
> avoid building bar.a, but I really need to have those files as a
> separate library.
What's driving the requirement for a separate library?
On Wed, 04 Apr 2018 11:46:01 +0300, Kevin Wilson said:
> Hello,
> I have an x86_64 host with 4GB of Physical RAM running Fedora 25.
>
> I have a question about hugepages allocation on this host.
> In:
> https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt
>
> I see that you can use
On Fri, 06 Apr 2018 12:12:31 +0530, Rupesh Kumar said:
> My question is : Can STANDBY IMMEDIATE command be issued directly to
> SSD device ? How can I achieve it in most efficient way ?
In the source tree, see tools/laptop/freefall/freefall.c for how to do the
daemon. The sample code does a
On Fri, 20 Apr 2018 23:39:10 +0800, Yubin Ruan said:
> On 2018-04-19 13:28, valdis.kletni...@vt.edu wrote:
> > On Thu, 19 Apr 2018 16:58:40 +0800, sizel said:
> > > How can I disable compile optimization in kernel for friendly
> > > debugging, Thanks
> >
> > First off, there are parts of the
On Sat, 21 Apr 2018 21:15:10 +0800, Yubin Ruan said:
> From this, I have a related question, can I treat __builtin_return_address()
> as a "builtin" stack unwinder (but only check for return addresses, or, where
> a function is called).
It would seem possible, but it doesn't actually work that
On Sun, 15 Apr 2018 13:17:27 +0530, Ivid Suvarna said:
> I had tried with the module where I put a busy loop inside spinlock
> but was not able to cause any lockups. Maybe this is because of SMP
> which schedule the job to other CPU. "How do I make a task to run on
> single CPU only?"
So you get
On Thu, 19 Apr 2018 16:58:40 +0800, sizel said:
> How can I disable compile optimization in kernel for friendly debugging,
> Thanks
First off, there are parts of the kernel that *WILL* explode if you try to build
with -O0 - in particular, any code that expects static inlines to be treated as
On Fri, 30 Mar 2018 11:38:07 +0530, MUHAMMED ASAD P T said:
> In reference sensor drivers, they used the V4L2_CID_DV_RX_POWER_PRESENT v4l2
> ctrl.
> It is a standard ctrl and created using v4l2_ctrl_new_std().
> 1. Whether in our sensor driver, we need to create this Control Id or not.
> How to
On Thu, 29 Mar 2018 22:48:24 +0800, Hao Lee said:
> I'm confused about the meaning of the PAGE_SIZE macro in x86_64
> kernel. Its value is 4KB and I once thought it was the size of a
> physical page frame, but now I think I'm wrong. I find that most of
> the physical address space is mapped by PMD
On Sat, 24 Mar 2018 04:43:42 -0400, Jeffrey Walton said:
> My question is, is a futex with a 2147483647 or -1 expected? Where
> should I be looking to begin to narrow the problem down?
'man 7 futex' says:
Semantics
Any futex operation starts in user space, but it may be necessary
On Mon, 02 Apr 2018 13:00:32 +0530, Madhu K said:
> what is the difference between atomic context and interrupt context.
> are they both same?
Interrupt context means we're dealing with an interrupt.
Atomic context means we're doing something that *itself* should not be
interrupted.
On Sun, 25 Mar 2018 22:32:42 +0800, Hao Lee said:
> In arch/x86/mm/init.c, there is a function called split_mem_range[0].
> Its logic is very complicated and I can't figure out what it does. I
> have added some debug statements in this function to print all
> variable, but I still can't
On Tue, 20 Mar 2018 09:14:30 -, Lucas Tanure said:
> > We are starting meetings every Tuesday night (starting on 20th March
> > at 3pm PST) and we will probably have lots of questions in the
> > #kernelnewbies IRC channel coming from the students during the
> > workshops.
Umm.. What GMT
On Mon, 19 Mar 2018 00:08:10 -, John Whitmore said:
> Sometimes however you get a module which don't give this information. Is this
> intentional, signify something, or just an oversight for that config option?
> For example SND_HDA_CORE:
> Symbol: SND_HDA_CORE [=m]
> Type : tristate
>
On Wed, 21 Mar 2018 17:26:57 +0100, Martin Kaiser said:
> I have a driver that is an spi device on one side and a miscdevice on
> the other.
This way usually leads to either madness or heavy drinking.
> Surprisingly to me, I can unbind the driver from the spi device on the
> bus while there's a
On Sun, 04 Mar 2018 06:59:46 +, tali.pe...@nuvoton.com said:
> It is not secure because it is not fixed for these issues:
> https://meltdownattack.com/
Note that saying "The CPU isn't vulnerable to Meltdown/Spectre, therefor
the 4.1 kernel is OK" is *incredibly* wrong.
For the record, since
On Sun, 04 Mar 2018 20:47:15 +, Alex Arvelaez said:
> You can kexec into the newer kernel to avoid rebooting if you absolutely must
> but yeah the best practice is to keep your system up to date and that requires
> some disruption of service.
If you can't afford the disruption of service a
On Sun, 04 Mar 2018 21:54:03 +0100, Greg KH said:
> To be fair, the next 4.1.y release to come out in a few days should have
> almost all of these issues resolved. So as long as you are keeping your
> systems up to date, all should be fine.
So the next one will be the "So long, and thanks for
On Sun, 04 Mar 2018 21:21:13 -0500, Ruben Safir said:
> I am not setting up a high availability cluster in my house, thank you.
> And fwiw, I've run systems for 6-8 years without rebooting on pc
> hardware. My little fanless fit/pc service running an intel atom had at
> one time run 5 years
On Sun, 04 Mar 2018 23:50:32 -0500, Ruben Safir said:
> Don't pretend to understand what I can and can not afford. Your not
> picking security policy for Google. What your failing to address,
> because you are so blinded to your own frame of reference, is that your
> solution leaves out well
On Mon, 05 Mar 2018 07:20:35 -0500, Ruben Safir said:
> So any system where you need to, or want to install it and forget about
> it for a long period of time, the Linux kernel can not be considered a
> choice for that usage because it needs contact oversite and upgrades.
That's true for *any*
On Mon, 26 Feb 2018 14:15:53 +0100, Piotr Figiel said:
> According to kernel.org website 4.1 has projected EOL in May 2018. Is
> the information about kernel releases on kernel.org irrelevant/
> shouldn't be trusted? Or my understanding of longterm kernel trees is
> incorrect?
Do you *really*
On Thu, 11 Oct 2018 14:42:56 +0400, o...@goosey.org said:
> 10.10.2018, 19:36, "Carter Cheng" :
> >2. Is there some good way to figure out how to update knowledge gained
> > from
> >this book to what is in the 4.x series of kernels?
> I think all C code-based drivers will work on all
On Thu, 11 Oct 2018 21:45:16 +0800, Carter Cheng said:
> There are some detaills about the current procedures for linking the kernel
> that I am unfamiliar with. My understanding is that GCC and Clang both have
> the ability to do link time analysis and transforms on code but is it
> possible to
On Tue, 16 Oct 2018 01:23:45 +0800, Carter Cheng said:
> I am actually looking at some changes that litter the kernel with short
> code snippets and thus according to papers i have read can result in CPU
> hits of around 48% when applied is userspace.
You're going to need to be more specific.
On Tue, 23 Oct 2018 13:56:42 +1100, "Tobin C. Harding" said:
> I'd like to build and boot an allyesconfig kernel with QEMU. Building
> is no problem but when I try to boot it I get problems because the host
> system does not support features requested by the VM.
>
> How does one go about testing
On Mon, 22 Oct 2018 22:32:14 +0530, jitendra kumar khasdev said:
> Working on a custom driver that tracks I/Os on block level. For some use
> case, I need to write metadata of tracked I/Os from driver in shutdown
> sequence (more likely in reboot handler). In reboot handler, performing I/O
> on
On Mon, 15 Oct 2018 23:42:03 +0800, Carter Cheng said:
> I was wondering what are some good ways to assess the performance impact of
> kernel modifications. Are there some papers in the literature where this is
> done? Does one need to differentiate between CPU bound and different types
> of I/O
On Wed, 17 Oct 2018 20:02:46 +0800, Carter Cheng said:
> The problem is I have to do something special with the clang options. I
> have to add an interprocedural link time optimization pass spitting out
> bitcode files and tying them together using llvm-link.
As I said back on Friday, this is
On Mon, 29 Oct 2018 00:08:12 +0800, Carter Cheng said:
> Where do I find the code in the kernel related to the MMU and resolving
> memory addresses? I am trying to understand what the implications are if
> code like this has bugs and the impact on the various functions that return
> chunks of
On Tue, 30 Oct 2018 21:19:08 +0300, Lev Olshvang said:
> As I stated, I have no option to come to customer and ask to upgrade his
> kernel, but I will try to put his attention to mentioned by you cease of
> security updates.
If you can't get him to upgrade the installed kernel, it's not worth
On Mon, 05 Nov 2018 20:31:46 +0530, Pintu Agarwal said:
> I wanted to have a swapfile (64MB to 256MB) on my system.
> But I wanted the data to be compressed and stored on the disk in my swapfile.
> [Similar to zram, but compressed data should be moved to disk, instead of
> RAM].
What platform
On Mon, 05 Nov 2018 11:07:12 -0500, "Austin S. Hemmelgarn" said:
> Performance isn't _too_ bad for the BTRFS case though (I've actually
> tested this before), just make sure you disable direct I/O mode on the
> loop device, otherwise you run the risk of data corruption.
Did you test that for
On Mon, 05 Nov 2018 11:28:49 -0500, "Austin S. Hemmelgarn" said:
> Also, it's probably worth noting that BTRFS doesn't need to decompress
> the entire file to read or write blocks in the middle, it splits the
> file into 128k blocks and compresses each of those independent of the
> others, so it
On Mon, 12 Nov 2018 02:00:02 +0800, Carter Cheng said:
> Thanks for the reply but the link doesn't quite answer the question. I am
> wondering how the pointer is handled so that there is one per thread by the
> compiler. I perhaps was under the perhaps mistaken impression that the
> stack pointer
On Thu, 15 Nov 2018 18:52:39 +0530, Pintu Agarwal said:
> Currently, when I tested this (as a proc interface), I got the below output:
> CPUUNUSED-STACKACTUAL-STACK
> 0 16368 16384
> 3) How should I test it to get the different usage values for unused stack ?
On Thu, 15 Nov 2018 23:53:56 +0800, "Larry" said:
> I'm curious when multiple process has the same PTE which points to the
> samepage,
> how can kernel differenciate which page from swap space should be swappedin?
The PTE tells where in /dev/swap to find the page. If it's a shared page, the
On Fri, 16 Nov 2018 11:44:36 +0530, Pintu Agarwal said:
> > If your question is "Did one
> > of the CPUs blow out its IRQ stack (or come close to doing so)?" there's
> > better
> > approaches.
> >
> Yes, exactly, this is what the main intention.
> If you have any better idea about this approach,
On Thu, 04 Oct 2018 21:44:14 +0300, Boian Karatotev said:
> I am a Computer Science student and for my last year I need to make and
> present a 'diploma project' at the end of June. So far I want to make a
> kernel module, whose description is in the following paragraph. I feel
> comfortable with
On Fri, 05 Oct 2018 02:58:23 +0100, Mike Krinkin said:
> This might be of interest to you: https://www.criu.org
That's got two problems - first, it's userspace. And second, it's fairly
mature software, which means it's not suitable for a student project
by itself, and all the low-hanging fruit
On Mon, 08 Oct 2018 23:05:56 +0300, Lev Olshvang said:
> Of cause the simplest way which comes to my mind is to send SIGPAUSE to all
> processes, except mine.
Actually, the *simplest* way is to just boot the machine into single-user mode
and
run your test there.
pgp1ddCl5hh2I.pgp
On Tue, 09 Oct 2018 20:07:08 +0100, John Whitmore said:
> #define alloc_ieee80211 alloc_ieee80211_rsl
>
> So what am I missing or why are a number of functions being redefined
> as another name, which doesn't exist?
There's areas in the kernel which use the preprocessor ##
On Sun, 30 Sep 2018 16:04:13 +0300, Shubham Singh said:
> Regarding the warning of checkpatch.pl,
> " 'str' object has no attribute 'decode' "
> This warning is related to spdxcheck.py which is because of version of python
> In python3 str has no attribute decode(), while it works fine in
On Wed, 10 Oct 2018 23:35:20 +0800, Carter Cheng said:
> 1. After finishing the book and perhaps Understanding the Linux Kernel and
> Linux Device Drivers. What is the best way to dig deeper.
There's multiple answers to that question, as it depends on the questioner's
preferred
learning style
On Thu, 04 Oct 2018 12:44:00 +0100, Paul Nader said:
> I'm trying to enable the max98357a codec in sound/soc/codecs.
> In the Kconfig file it is listed with an empty tristate so it doesn't show
> up when I do a make menu config.
That's usually a result of the variable being enabled by a
On Sun, 02 Sep 2018 20:58:14 +0530, Abhinav Misra said:
> But if in new kernel this implementation is changed then why we need so
> many options to defer the work as all of them are basically getting
> executed in almost the same way.* In that case code running softirq,
> tasklet, workqueue and
On Mon, 03 Sep 2018 21:12:35 +0200, Thomas Bracht Laumann Jespersen said:
> The challenge is that my application needs to act within 100 tbits, ie in
> around
> ~.066ms. That is the window in which I need to begin transmitting a reply. Is
> there a way to achieve this with the ftdi_sio driver or
John notes that if the kzalloc of ieee->pHTInfo fails, we fail to call
ieee80211_networks_free(). In addition, that function has an un-needed check
before kfree().
Reported-by: John Whitmore
Signed-off-by: Valdis Kletnieks
---
diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_modul
On Wed, 26 Sep 2018 16:52:03 +0100, John Whitmore said:
> This might all be a mute point as I seem to remember someone saying
> that memory allocation never fails in Linux and this can only happen
> if the first two allocations work and the third fails.
If memory allocation never fails, it would
On Wed, 26 Sep 2018 13:25:35 -0700, don fisher said:
> Would you tell me how to tell the driver that it is to be eth0, ip
> address etc. Maybe on linux command line, but I do not know the format.
To quote some guy named Don Fisher:
> my kernel and including the proper command (as shown below) in
On Wed, 26 Sep 2018 21:38:27 -0700, don fisher said:
> Thanks. I tried building with the driver embedded in the kernel, but the
> compile failed with a halt. No crash is apparent, just a halt. It turned
> out that this was repeated until I removed the netconsole command during
> boot. System
On Tue, 25 Sep 2018 18:26:06 -0700, don fisher said:
> The wicked message eth0: up comes at Sep 24 22:02:01.173616. The
> difference is maybe 36 seconds? There is an eth0: avail message at Sep
> 24 22:01:34.112744, don't know if that would suffice for netconsole Both
> are after netconsole has
On Sun, 16 Sep 2018 20:47:41 +0200, Daan Wendelen said:
> The latest nvidia driver is incompatible with 4.19-rc3 because
> "drm_mode_connector_update_edid_property" got renamed to
> "drm_connector_update_edid_property" and
> "drm_mode_connector_attach_encoder" to "drm_connector_attach_encoder" in
On Fri, 16 Nov 2018 20:10:28 +0530, Pintu Agarwal said:
> > Look at the code controlled by '#ifdef CONFIG_DEBUG_STACK_USAGE'
> For example: is it possible to keep storing the irq_stack_usage (for
> each cpu in a variable) information from boot time, and then use this
> variable to dump the
On Fri, 16 Nov 2018 23:13:48 +0530, Pintu Agarwal said:
> On Fri, Nov 16, 2018 at 10:16 PM wrote:
> > Congrats. You just re-invented DEBUG_STACK_USAGE, which just keeps a
> > high-water mark
> > for stack usage.
>
> So, you mean to say, my implementation is good enough to get the
> irq_stack
On Mon, 31 Dec 2018 14:53:30 -0500, "Robert P. J. Day" said:
> #define S_IRWXUGO (S_IRWXU|S_IRWXG|S_IRWXO)
> #define S_IALLUGO (S_ISUID|S_ISGID|S_ISVTX|S_IRWXUGO)
> #define S_IRUGO (S_IRUSR|S_IRGRP|S_IROTH)
> #define S_IWUGO (S_IWUSR|S_IWGRP|S_IWOTH)
>
On Sat, 05 Jan 2019 18:30:01 +0300, Lev Olshvang said:
> Some articles, ex
> https://shanetully.com/2013/12/writing-a-self-mutating-x86_64-c-program/
> state that mprotect() can change protection of executable section.
Note that appears to be a 5 year old article, and one that tries to be
On Sun, 06 Jan 2019 21:13:26 +0300, Lev Olshvang said:
> I am trying to harden the embedded system.
> I have embedded system with systemd .
OK, you've already got a problem right there.
It's an embedded system. Therefor, you know everything that should be running,
and what order it should
On Wed, 23 Jan 2019 23:25:59 +0530, Bharath Vedartham said:
> I am trying to add the 3-axis compass data channels to the
> simple_dummy_channel. I have mounted configfs and am able to load the
> modules correctly. Is this the right approach? printk is not printing
> anything to syslogs.
Do you
On Thu, 20 Dec 2018 13:33:09 +0300, Lev Olshvang said:
> I use kernel_read to read file in chunks of 4K size in a process context
> On several files, like libc, libm, I got -EINTR error.
What are you trying to accomplish? This is not a recommended way to do things.
> I do not understand who
On Sun, 23 Dec 2018 11:41:30 +0300, Lev Olshvang said:
> I use security_mmap_file hook.
And what are you trying to accomplish in there?
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On Fri, 21 Dec 2018 16:51:29 +0300, Lev Olshvang said:
> I need to read file inside LSM hook and I can not do it in user space
Why? And which LSM hook are you trying to do this?
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On Fri, 07 Dec 2018 23:13:45 +0300, Lev Olshvang said:
> Existing file encryption tools, like dm-crypt, fscrypt and eCryptfs provide
> only encryption of files only until file system is mounted. (data at rest)
> The moment it became mounted, every user of computer can try to access the
> data.
On Fri, 30 Nov 2018 20:35:54 +0300, Lev Olshvang said:
> I saw many times that kernel keeps kernel module with reference count of 0 in
> a
> running system until explicit rmmod command is entered/
> Is there any way to require that unused module will be removed from kernel by
> the kernel
On Tue, 20 Nov 2018 18:21:33 +0530, Pintu Agarwal said:
> + sp = current_stack_pointer;
> + if (on_irq_stack(sp, cpu)) {
> + stack_start = (unsigned long)per_cpu(irq_stack, cpu);
> + last_usage = per_cpu(irq_stack_usage, cpu);
> + curr_usage = sp - stack_start;
> +
On Tue, 20 Nov 2018 00:04:03 +0200, Ranran said:
> That's interesting...
> I think the name is confusing, because this chips are also writable.
>
> Not only this, but in arm the eeprom (at24) is writable!
> But in the x86 I am using, it is readonly in kernel code:
>
On Wed, 21 Nov 2018 17:20:50 +0300, Lev Olshvang said:
> So the questioned config option seems obsolete ?
> Wheher LSM always consulted last ?
If an LSM is configured/loaded, it is always consulted *after* applying
standard DAC file permission bits checks. (Discretionary Access Control- the
On Tue, 20 Nov 2018 10:16:41 -0500, Cindy-Sue Causey said:
> First reference is near the top under "AIX 4.3.2+ Deferred Paging
> #2) AIX 5L Differences Guide Version 5.3 Edition
I feel sorry for anybody still running either of these AIX versions (4.3.2
is late 1998, 5.3 is from 2005).
Word of
On Sat, 12 Jan 2019 16:19:00 +0300, Lev Olshvang said:
> The fact that the text segment could be modified is bad news from the
> security standpoint.
We've known that for at least a decade now. Maybe longer. And we
already had this discussion once, about a week ago.
> I am not sure whether it
On Wed, 12 Sep 2018 22:40:50 +0530, inventsekar said:
> So, please suggest some subsystems or some small puedes of code, where i
> can "dwell" sometimes and submit my first patch.
0) subsystems? Anything under drivers/staging is fair game and certain to
provide hours of amusement...
1) Install
On Sat, 15 Sep 2018 07:33:51 +0530, inventsekar said:
> Around last year I was searching for Linux Kernel FS design and
> implementation, and I found out a book by someone,.. a full length book,
> particularly, at the end of the book he/she included source code as well...
That sounds like the
On Sat, 15 Sep 2018 01:19:24 +0530, inventsekar said:
> I didnt get you... I thanked Valdis for his detailed mail..
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in
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