January 2012 - kernelnewbies@kernelnewbies.org

network Driver interface to the stack
by V l Jan. 15, 2012

Jan. 15, 2012

I studied through my network interface driver and gained sufficient understanding of the network stack. I have a network stack for my ARM device and now in stage of interfacing this stack to my network driver in the ARMDevice . I know now that I have to just replace for(q = p; q != NULL; q = q->next) { /* Send the data from the pbuf to the interface, one pbuf at a time. The size of the data in each pbuf is kept in the ->len variable. */ send data from(q->payload, q->len); } send data from(q->payload, q->len); with my driver specific code to send the packet . Very nice ! But when I compile this code , its going to ask where this driver specific senddata is defined , the header file or library . How do I resolve this part of the riddle . Its a little newbie kind of question . But I have tried , I give up now. Plz help. Regards Sraddha

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Does LAN speed distributes among connected terminals on load
by Manavendra Nath Manav Jan. 12, 2012

Jan. 12, 2012

Hi All, I have a 100Mbps LAN with 10 connected terminals through a Switch. Now, I understand 100Mbps is the max speed at which a terminal can send/receive data. If every terminal sends data at this speed, then does this speed distributes/divides according to load, or is it dedicated for each terminal. How to measure it? -- Manavendra Nath Manav

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Filtering USB storage data in kernel module
by Abhijit Pawar Jan. 12, 2012

Jan. 12, 2012

Hi All, I need to filter the data written/read to and from the USB storage disk. Now the way USB is made known to OS is through SCSI and then respective filesystem ( mostly usbfs). So is there any way I can intercept this stack and have my kernel module invoked so that I will get the data. I have been thinking on two approaches: 1. Use VFS and write a proxy filesystem for USB device which will filter the data. 2. checking SCSI and any intercepting point. I am currently looking at USBMONITOR source code as well. Please let me know if there is any other way to achieve this. Regards, Abhijit Pawar

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Re: Does Linux process exist information leakage?
by 夏业添 Jan. 12, 2012

Jan. 12, 2012

Thanks! I do not want to access other PAS when other process is alive, and it seems impossible because each process has its own page table. But after its death, some information might be left in the memory if the OS does not clean the physical pages, I guess. When the OS load a binary program, some physical pages are rewrited. I read it from one book that the variable and array which are in the .bss and .data are directly loaded into memory and will rewirte physical pages. So I decided to use malloc to dynamically get memory and seek whether there is some information left in such memory. 2012/1/12 beyond.hack <beyond.hack(a)gmail.com> > Luk frnd.. > First of all.. U just cannt acess other PAS i.e.process address space via > other process.. > Ex--malloc some memory n then free it twice.. > First tym it will b freed bt d nxt time u try to free it. U cant .. So it > will report the illegal access to memory bcz now that adress is not in your > pas..errors r handled by some compiler in a standard way..they may show > some fixed area of memory when u try to access such areas of memory which > are not allocated for ur process.. > Ex.gcc may show you glibc or give a segv > > N > > Since we know that we r having virtual memory management.. So how r u > going back to that only address... > I tried to save the pointer value (obtained by malloc) by writing it in a > file..n later on use it from that value. Bt > cant initiallise a pointer by giving an virtual address n printing from > there ..(i tried it getting errors).. > Also..as soon as your first process is over...previous malloc'd address > are mostly get corrupted bcz. Of the use by various other processes.. > On 11 Jan 2012 18:24, "夏业添" <summerxyt(a)gmail.com> wrote: > >> Hi, >> My tutor asked me to test whether one process leaves information in >> memory after it is dead. I tried to search some article about such thing on >> the Internet but there seems to be no one discuss about it. And after that, >> I tried to write some program in the User Mode to test it, using fork() to >> create lots of processes and filling char 'a' into a 102400 bytes char >> array in each process. Then I used malloc() to get some memory to seek char >> 'a' in a new one process or many new processes, but failed. All memory I >> malloced was full of zero. >> As the man page of malloc said:"The memory is not initialized", I >> believe that the memory which was got by malloc() could be used by other >> process, and therefor information leakage exists. But how can I test it? Or >> where can I get related information? >> Thanks! >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies(a)kernelnewbies.org >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> >>

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Some help about backporting a nic module to 2.6.32 longterm
by André Ferraz Jan. 11, 2012

Jan. 11, 2012

Hi, I'm using the 2.6.32.x longterm series for our servers but we are facing a problem with the bnx2x driver module in our latest G7 HP blade servers, the module exists but it doenst ping and cant access any node in the network, i saw too that the broadcom and hp driver specs can't build on 2.6.32 kernel because they only support the 2.6.18 redhat series. The version maintained by CentOS/Redhat om 5.x release works but it is based on 2.6.18 kernel. My initial idea was pull the CentOS 6 kernel source (based on 2.6.32) and make a patch of the bnx2x driver for my kernel source, the patch applies but when i boot the kernel the version it remains the same, i saw that the /firmware directory has some bnx2x files on it, my question to you is that i couldnt find anywhere is how the .c file and the .fw correlates , or , how can i create a real backport of this driver so i can use an usable version of the driver for the longterm release? I'm starting to read Linux Device Drivers but i really don't know if this question will be answered on it, if you guys have more sources of information so i can read i'll be glad if send me some . Thanks in advance,

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TCP MD5 Verification - 2.6.35.14
by Nitin Sharma Jan. 10, 2012

Jan. 10, 2012

Is there an equivalent of (freeBSD) sysctl net.inet.tcp.signature_verify_input=0 in linux? 2.6.35.14-x How is the MD5 verification of incoming TCP packets done? Thanks, Nitin

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Re: BCM4313 802.11b/g/n Wireless LAN Controller error in kernel 3.0
by Julie Sullivan Jan. 9, 2012

Jan. 9, 2012

(oops, sorry, replying to the list as well this time) > > Ubuntu SMP Fri Oct 7 14:56:25 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux > > > > Please let me know if this needs to be taken up with broadcom or with linux community.. > > > > Regards > Rajaneesh > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies(a)kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies Hi Rajaneesh If you are using a distro kernel (i.e. if you did not configure/build the Broadcom driver in yourself) you should tell your distro maintainers (i.e. Ubuntu support), because they are likely to be the quickest to respond to you, and they will be in the best position to find out/chase up what this is with whoever is responsible. Also if this is a bug they will need to get it fixed for their other users too. If it's caused by an open source driver that's in the kernel tree they _should_ then push their fix to the wireless/Broadcom devs working on the mainline kernel, that is not your responsibility ;-) Cheers Julie

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hey Kernel
by Jestin Joy Jan. 9, 2012

Jan. 9, 2012

hey Kernel dont thank me thank yourself for getting started http://www.newsonthefly10.com

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BCM4313 802.11b/g/n Wireless LAN Controller error in kernel 3.0
by rajaneesh acharya Jan. 9, 2012

Jan. 9, 2012

Hi This is with regards to broadcom wifi driver in 3.0..I am getting the following error while activating the wifi ffff8800638451b8), AE_AML_BUFFER_LIMIT (20110413/psparse-536) [ 335.317544] ACPI Error: Field [B128] at 1152 exceeds Buffer [NULL] size 160 (bits) (20110413/dsopcode-236) [ 335.317576] ACPI Error: Method parse/execution failed [\_SB_.WMID.HWCD] (Node ffff880063854b90), AE_AML_BUFFER_LIMIT (20110413/psparse-536) [ 335.317619] ACPI Error: Method parse/execution failed [\_SB_.WMID.WMAD] (Node ffff8800638451b8), AE_AML_BUFFER_LIMIT (20110413/psparse-536) LSPCI shows the following device registered 07:00.0 Network controller: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller (rev 01) Uname -a gives the follwoing Ubuntu SMP Fri Oct 7 14:56:25 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux Please let me know if this needs to be taken up with broadcom or with linux community.. Regards Rajaneesh

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DEFINE Macro
by Fredrick Jan. 6, 2012

Jan. 6, 2012

Hi, I am not able to understand the DEFINE macro used in arch/powerpc/kernel/asm-offsets.c I suppose the DEFINE is present in include/linux/kbuild.h where it says #define DEFINE(sym, val) \ asm volatile("\n->" #sym " %0 " #val : : "i" (val)) What does the above mean? -Fredrick

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