- kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

Using sendfile() between sockets
by mark zhu Sept. 9, 2013

Sept. 9, 2013

Hi there, Two splice() system calls are needed for splicing 2 sockets. It is costly with respect to context switching. What would be the reason for_not_ letting sendfile() support socket-to-socket splicing if the offset argument is ignored? Thanks, Mark

1 0

Using sendfile() between sockets
by mark zhu Sept. 9, 2013

Sept. 9, 2013

Hi there, Two splice() system calls are needed for splicing 2 sockets. It is costly with respect to context switching. What would be the reason for_not_ letting sendfile() support socket-to-socket splicing if the offset argument is ignored? Thanks, Mark

1 0

Kernel Module load problem
by Tushar Dave Sept. 6, 2013

Sept. 6, 2013

Hi, I am facing an unusual problem.I have a ubuntu PC with 11.10 installed on it and it has a driver called cdc_ether.ko.Now when I connect a mobile phone to the PC the driver does not get loaded automatically.I had made a lot of changes in the udev rules earlier and then replaced it with the default one ( I had kept it as a backup).Earlier the phone used to connect properly and the driver got loaded automatically and I also used to see a new interface on doing an ifconfig but now that is not the case.I think I have changed some settings in my Ubuntu PC which has lead to this. Any suggestions Thanks Dave

1 0

Re: module_param does not work in Ubuntu 13.10 - Kernel 3.10.0-4
by Sudip Mukherjee Sept. 6, 2013

Sept. 6, 2013

Hi I just tested it on my Ubutu 13.04 (default kernel) , it is working . [30971.042909] Demonstrating module parameters [30971.042913] =============================== [30971.042915] myshort is a short integer: 1 [30971.042916] myint is an integer: 420 [30971.042918] mylong is a long integer: 9999 [30971.042919] mystring is a string: blah [30971.042921] myintArray[0] = -1 [30971.042922] myintArray[1] = -1 [30971.042923] got 0 arguments for myintArray. [30985.316843] Goodbye... [30985.316847] =============================== [31009.307672] Demonstrating module parameters [31009.307675] =============================== [31009.307676] myshort is a short integer: 1 [31009.307677] myint is an integer: 420 [31009.307678] mylong is a long integer: 9999 [31009.307678] mystring is a string: abcd [31009.307679] myintArray[0] = -1 [31009.307680] myintArray[1] = -1 [31009.307680] got 0 arguments for myintArray. [31020.217402] Goodbye... [31020.217407] =============================== [31027.604150] Demonstrating module parameters [31027.604153] =============================== [31027.604155] myshort is a short integer: 1 [31027.604157] myint is an integer: 420 [31027.604159] mylong is a long integer: 9999 [31027.604160] mystring is a string: vectordefefe [31027.604162] myintArray[0] = -1 [31027.604163] myintArray[1] = -1 [31027.604164] got 0 arguments for myintArray. sudip@sudip-PC:~/modules$ uname -a Linux sudip-PC 3.8.0-19-generic #29-Ubuntu SMP Wed Apr 17 18:16:28 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux sudip@sudip-PC:~/modules$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 13.04 Release: 13.04 Codename: raring Regards Sudip On Fri, Sep 6, 2013 at 6:40 PM, Sudip Mukherjee <sudipm.mukherjee(a)gmail.com>wrote: > Hi > I just tested it on my Ubutu 13.04 (default kernel) , it is working . > > [30971.042909] Demonstrating module parameters > [30971.042913] =============================== > [30971.042915] myshort is a short integer: 1 > [30971.042916] myint is an integer: 420 > [30971.042918] mylong is a long integer: 9999 > [30971.042919] mystring is a string: blah > [30971.042921] myintArray[0] = -1 > [30971.042922] myintArray[1] = -1 > [30971.042923] got 0 arguments for myintArray. > [30985.316843] Goodbye... > [30985.316847] =============================== > [31009.307672] Demonstrating module parameters > [31009.307675] =============================== > [31009.307676] myshort is a short integer: 1 > [31009.307677] myint is an integer: 420 > [31009.307678] mylong is a long integer: 9999 > [31009.307678] mystring is a string: abcd > [31009.307679] myintArray[0] = -1 > [31009.307680] myintArray[1] = -1 > [31009.307680] got 0 arguments for myintArray. > [31020.217402] Goodbye... > [31020.217407] =============================== > [31027.604150] Demonstrating module parameters > [31027.604153] =============================== > [31027.604155] myshort is a short integer: 1 > [31027.604157] myint is an integer: 420 > [31027.604159] mylong is a long integer: 9999 > [31027.604160] mystring is a string: vectordefefe > [31027.604162] myintArray[0] = -1 > [31027.604163] myintArray[1] = -1 > [31027.604164] got 0 arguments for myintArray. > sudip@sudip-PC:~/modules$ uname -a > Linux sudip-PC 3.8.0-19-generic #29-Ubuntu SMP Wed Apr 17 18:16:28 UTC > 2013 x86_64 x86_64 x86_64 GNU/Linux > sudip@sudip-PC:~/modules$ lsb_release -a > No LSB modules are available. > Distributor ID: Ubuntu > Description: Ubuntu 13.04 > Release: 13.04 > Codename: raring > > Regards > Sudip > > > > On Fri, Sep 6, 2013 at 4:47 PM, <binoy.jayan(a)wipro.com> wrote: > >> Hi Srinivas, >> >> Thank you for the inputs. The modules works fine with the kernels that >> come with Ubuntu 10.04, 11.04, 12.04 and 12.10. >> But, we are supporting a product for every latest Ubuntu versions. So, I >> need to make it work with the kernel which comes with the distro alone. >> So I cannot use a custom kernel from kernel.org. >> >> >> Regards, >> *Binoy Jayan* >> >> ------------------------------ >> *From:* Srinivas Ganji [srinivasganji.kernel(a)gmail.com] >> *Sent:* Friday, September 06, 2013 4:34 PM >> >> *To:* Binoy Jayan (WT01 - Manufacturing & Hi Tech) >> *Cc:* kernelnewbies(a)kernelnewbies.org >> *Subject:* Re: module_param does not work in Ubuntu 13.10 - Kernel >> 3.10.0-4 >> >> I have also tested, build KO file using your C file, on my kernel and >> it is working fine. The kernel version is 3.2.11 >> >> Why don't you try any other kernel version and see whether you are >> getting same error or not? I guess, it works. >> >> Regards, >> Srinivas G >> >> >> On Fri, Sep 6, 2013 at 10:22 AM, <binoy.jayan(a)wipro.com> wrote: >> >>> Hi all, >>> >>> I use the kernel version "3.10.0-4" that came with Ubuntu distribution. >>> When I compile the example module I got from LKMPG (hello-5.c) and try >>> to load the driver by passing the module with the following command, it >>> gives the following error: >>> >>> # insmod parameter.ko mystring="bebop" >>> Error: could not insert module parameter.ko: Unknown symbol in module >>> >>> Error in dmesg: >>> >>> [ 3687.132110] parameter: Unknown parameter `mystring' >>> >>> However, if I insert the module without any parameters, it gets inserted >>> just fine. >>> >>> # insmod parameter.ko >>> >>> I am attaching the source code for reference. Kindly let me know what >>> could be done. >>> >>> Thanks, >>> Binoy >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> Regards, >>> Binoy Jayan >>> WIPRO TECHNOLOGIES >>> | Electronic City 5 >>> | >>> Bangalore >>> | Mob: >>> +91-9742870916, >>> +91-9745783048 >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> Please do not print this email unless it is absolutely necessary. >>> >>> The information contained in this electronic message and any attachments >>> to this message are intended for the exclusive use of the addressee(s) and >>> may contain proprietary, confidential or privileged information. If you are >>> not the intended recipient, you should not disseminate, distribute or copy >>> this e-mail. Please notify the sender immediately and destroy all copies of >>> this message and any attachments. >>> >>> WARNING: Computer viruses can be transmitted via email. The recipient >>> should check this email and any attachments for the presence of viruses. >>> The company accepts no liability for any damage caused by any virus >>> transmitted by this email. >>> >>> www.wipro.com >>> >>> _______________________________________________ >>> Kernelnewbies mailing list >>> Kernelnewbies(a)kernelnewbies.org >>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>> >>> >> * Please do not print this email unless it is absolutely necessary. *** >> ** >> >> The information contained in this electronic message and any attachments >> to this message are intended for the exclusive use of the addressee(s) and >> may contain proprietary, confidential or privileged information. If you are >> not the intended recipient, you should not disseminate, distribute or copy >> this e-mail. Please notify the sender immediately and destroy all copies of >> this message and any attachments. >> >> WARNING: Computer viruses can be transmitted via email. The recipient >> should check this email and any attachments for the presence of viruses. >> The company accepts no liability for any damage caused by any virus >> transmitted by this email. >> >> www.wipro.com >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies(a)kernelnewbies.org >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> >> >

1 0

module_param does not work in Ubuntu 13.10 - Kernel 3.10.0-4
by binoy.jayan＠wipro.com Sept. 6, 2013

Sept. 6, 2013

Hi all, I use the kernel version "3.10.0-4" that came with Ubuntu distribution. When I compile the example module I got from LKMPG (hello-5.c) and try to load the driver by passing the module with the following command, it gives the following error: # insmod parameter.ko mystring="bebop" Error: could not insert module parameter.ko: Unknown symbol in module Error in dmesg: [ 3687.132110] parameter: Unknown parameter `mystring' However, if I insert the module without any parameters, it gets inserted just fine. # insmod parameter.ko I am attaching the source code for reference. Kindly let me know what could be done. Thanks, Binoy Regards, Binoy Jayan WIPRO TECHNOLOGIES | Electronic City 5 | Bangalore | Mob: +91-9742870916, +91-9745783048 Please do not print this email unless it is absolutely necessary. The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com

3 5

IOCTLs versus netlink
by Kevin Wilson Sept. 6, 2013

Sept. 6, 2013

Hi, Can someone please explain why are netlink sockets a better communication method between kernel space and userspace ? I know that with IOCTLs we cannot send asynchronous messages to userspace from kernel, and with netlink we can. Are there more things to it? I once heard something about that when passing with IOCTL a pointer from userspace, you can mess it, by advancing it too much for example. But I am not sure. regards, Kevin

4 3

"make install" error
by Arun M Kumar Sept. 5, 2013

Sept. 5, 2013

I am building Kernel 3.9.10 and i have given the following Commands during the Process 1. make mrproper 2. make defconfig 3. make oldconfig 4. make -j 8 5. make modules_install 6. make install on the last step, i face the following error ------------------------------------------------------------------------------- sh /home/temp/Linux_Build/linux-3.9.10/arch/x86/boot/install.sh 3.9.10 arch/x86/boot/bzImage \ System.map "/boot" Kernel image: /boot/vmlinuz-3.9.10 Initrd image: /boot/initrd-3.9.10 Root device: /dev/disk/by-id/ata-HGST_HTS725050A7E630_TF655AY9JP1H5C-part2 (/dev/sda2) (mounted on / as ext4) Resume device: /dev/disk/by-id/ata-HGST_HTS725050A7E630_TF655AY9JP1H5C-part1 (/dev/sda1) find: `/lib/modules/3.9.10/kernel/drivers/scsi': No such file or directory modprobe: Module xhci_hcd not found. WARNING: no dependencies for kernel module 'xhci-hcd' found. modprobe: Module hid_logitech_dj not found. WARNING: no dependencies for kernel module 'hid-logitech-dj' found. Features: acpi plymouth block usb resume.userspace resume.kernel -------------------------------------------------------------------------------------- what could have gone wrong during the process ?

3 2

Dcache_lock replacement
by Saket Sinha Sept. 5, 2013

Sept. 5, 2013

I have a driver which I have ported from 2.6.18 kernel to 3.8 kernel. Now the driver has become unstable when I ported it to 3.8 kernel. Since lot of things have changed from 2.6.18 to 3.8 and I have taken a lot of care to replace the old kernel APIs with the newer ones but then too there have been certain things I haven't been able to replace and dcache_lock is one of them. Due to the absence of dcache_lock, I have not been able to properly lock stuff and writing/reading data that are being changed that maybe one of the reasons for instability. I specifically list down the link to my kernel driver below where I haven't been able to do the same, below- https://github.com/HeisSpiter/hepunion/blob/master/fs/hepunion/helpers.c#L3… If someone can suggest an alternative, I shall be grateful. Regards, Saket Sinha

2 3

[PATCH 1/1] Squashfs-Optimized-uncompressed-buffer-loop-v3
by Manish Sharma Sept. 4, 2013

Sept. 4, 2013

Signed-off-by: Manish Sharma <manishrma(a)gmail.com> --- fs/squashfs/block.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c index fb50652..41d108e 100644 --- a/fs/squashfs/block.c +++ b/fs/squashfs/block.c @@ -167,17 +167,14 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index, /* * Block is uncompressed. */ - int i, in, pg_offset = 0; - - for (i = 0; i < b; i++) { - wait_on_buffer(bh[i]); - if (!buffer_uptodate(bh[i])) - goto block_release; - } + int in, pg_offset = 0; for (bytes = length; k < b; k++) { in = min(bytes, msblk->devblksize - offset); bytes -= in; + wait_on_buffer(bh[k]); + if (!buffer_uptodate(bh[k])) + goto block_release; while (in) { if (pg_offset == PAGE_CACHE_SIZE) { page++; -- 1.7.9.5

1 0

RE: Introducing Myself, Looking to Learn
by Varad Gautam Sept. 4, 2013

Sept. 4, 2013

> I have external sata to usb3 adapter that is not supported by the > kernel. I'm willing to buy one for someone willing to get the kernel > support done. > - > This is my second offer. No takers the first time. > > Fyi: I expect no true code is needed, just updating a pid / vid table > somewhere. I don't know the usb driver stack so I have no idea where > said table is. > > Fyi2: I tend to focus on filesystems recently so diving into usb is not > a goal of mine. > > Greg Hi Greg, thanks for the offer. I'd be happy to. I shall let you know once I catch some speed, and then I'll start.

1 0