RE: Learning things
-Original Message- From: kernelnewbies-boun...@kernelnewbies.org [mailto:kernelnewbies-boun...@kernelnewbies.org] On Behalf Of Joris Bolsens Sent: Monday, April 06, 2015 10:07 AM To: valdis.kletni...@vt.edu Cc: kernelnewbies@kernelnewbies.org Subject: Re: Learning things -BEGIN PGP SIGNED MESSAGE- Hash: SHA256 In that case do you have any general recommendations? Or is there some sort of project that covers most of the basics? I learn best by doing and most stuff I found online goes pretty slow and is a bit boring :/ Thanks a ton On 04/06/2015 10:02 AM, valdis.kletni...@vt.edu wrote: On Mon, 06 Apr 2015 10:43:46 -0700, Joris Bolsens said: I'm working on trying to teach myself C and was wondering if you had any kernel specific recommendations. Don't bother trying until you have an actual good working knowledge of C. Work in userspace where your screw-ups just take the process out, not the entire system, until stuff like a SIGSEGV becomes a rarity. *THEN* start considering kernel work. A google search on open source projects written in c yielded this: http://www.quora.com/What-are-open-source-projects-that-are-written-in-C-C++-are-easy-to-contribute-to Jeff Haran ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Learning things
On Mon, Apr 06, 2015 at 10:43:46AM -0700, Joris Bolsens wrote: Hey list, I'm working on trying to teach myself C and was wondering if you had any kernel specific recommendations. I started the eudyptula challenge but so far it seems to be mostly learning the standards and whatnot. Are there any kernel/C books or online tutorials you guys think would help? Don't learn C with kernel code, please take a few years really learning the language in userspace, with one of the other thousands of other userspace programs that could use help that are written in C. Good luck, greg k-h ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Learning things
I'm working on trying to teach myself C and was wondering if you had any kernel specific recommendations. I started the eudyptula challenge but so far it seems to be mostly learning the standards and whatnot. Are there any kernel/C books or online tutorials you guys think would help? As others mention, using the Linux kernel to come up to speed with C is the wrong approach. If you have a strong desire to learn kernel programming concepts while coming up to speed on C, I would suggest getting the latest book on Xinu, buying an Intel Galileo board and working your way through that book. Xinu is what I cut my teeth on 25 years ago and I remember it being a terrific learning environment. Xinu is not Linux (or Unix), but for starting at the ground level all the concepts will map over when you are ready to tackle Linux kernel work. Information for Xinu can be found here: http://www.xinu.cs.purdue.edu/ Good luck on your learning... Mike Thompson On Mon, Apr 6, 2015 at 10:17 AM, Greg KH g...@kroah.com wrote: On Mon, Apr 06, 2015 at 10:43:46AM -0700, Joris Bolsens wrote: Hey list, I'm working on trying to teach myself C and was wondering if you had any kernel specific recommendations. I started the eudyptula challenge but so far it seems to be mostly learning the standards and whatnot. Are there any kernel/C books or online tutorials you guys think would help? Don't learn C with kernel code, please take a few years really learning the language in userspace, with one of the other thousands of other userspace programs that could use help that are written in C. Good luck, greg k-h ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
packet_mmap: How to kernel address from user-space address
I'm trying to accelerate snort with a hardware Pattern Matching Engine. snort gets packets using libpcap which uses packet mmap. snort gets the mmap-ed address, it does all header parsing, now I want to offload the content detection to hardware. PME driver currently provides and ioctl interface to pass the packet. Driver does copy_from_user to get packet data to kernel and try to match it against pre-loaded contents. I'm trying to avoid this copy. What is the best way to get the kernel address from user address in this case? ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
cross-compiling kernel using a 32-bit toolchain on a 64-bit machine
Hi All, I'm having trouble compiling my kernel using a 32-bit toolchain (for ARM) on a 64-bit host (Ubuntu 14.10). The kernel version is 3.14.17. I understand that 32-bit binaries require ia32-libs (or equivalent) for compiling on 64-bit hosts. I installed the required packages (lib32z1 lib32ncurses5 lib32bz2-1.0 for Ubuntu 14.10), but still keep getting errors: $ make CROSS_COMPILE=arm-none-linux-gnueabi- all Makefile:616: Cannot use CONFIG_CC_STACKPROTECTOR_REGULAR: -fstack-protector not supported by compiler make: arm-none-linux-gnueabi-gcc: Command not found CHK include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h make[1]: `include/generated/mach-types.h' is up to date. CC kernel/bounds.s /bin/sh: 1: arm-none-linux-gnueabi-gcc: not found make[1]: *** [kernel/bounds.s] Error 127 make: *** [prepare0] Error 2 I've ensured that the PATH to the toolchain binaries is correct. If I try to export CROSS_COMPILE to my environment, then too I get an error (although it's for a different reason): $ make all Makefile:616: Cannot use CONFIG_CC_STACKPROTECTOR_REGULAR: -fstack-protector not supported by compiler CHK include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h make[1]: `include/generated/mach-types.h' is up to date. CC kernel/bounds.s gcc: error: unrecognized argument in option ‘-mabi=aapcs-linux’ gcc: note: valid arguments to ‘-mabi=’ are: ms sysv gcc: error: unrecognized command line option ‘-mlittle-endian’ gcc: error: unrecognized command line option ‘-mapcs’ gcc: error: unrecognized command line option ‘-mno-sched-prolog’ gcc: error: unrecognized command line option ‘-mno-thumb-interwork’ gcc: error: unrecognized command line option ‘-mfpu=vfp’ make[1]: *** [kernel/bounds.s] Error 1 make: *** [prepare0] Error 2 It looks like make is starting a new shell which does not have either PATH (1st case) or CROSS_COMPILE (2nd case) set. Any hints on how to get make to use the toolchain? Thanks, -mandeep ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Learning things
-BEGIN PGP SIGNED MESSAGE- Hash: SHA256 Thanks for the suggestions, I'll look into those, hopefully ill find something I can help out with and learn at the same time xD - -Joris -BEGIN PGP SIGNATURE- Version: GnuPG v2 iQIcBAEBCAAGBQJVIxJCAAoJEORnMHMHY2Frq1IP/21ZJWUnTseYFnD1HOaDgGmo MQSEqHdNKS07aWffsRNyndGo2ht7niM4K0g7yhUJMbPi9ek+tsU5sC1WOXvCXSFF HrIlbZzbFWmhzHag3G5gD2QHZ93FslwhZrWzI/N+C0wQ11e1ekTtJ7ZLDHIdXXvz GemFehrPw28OebyJChCnuNfBsqw8zP6O7r3TaWo2iWmcnI3hZDdZbtTSewypBuxd mkKlvCkQ9HQM3VKeBbVzHtyS5ok0/3pIIh2GNHzORTqasKCz5dIlTCefzujOkaOp E8ooy5v0i8nDIEmLogWm0xY4p/bu+df8OmAgjtpRLvv2d0+VrCZ7Eg6hUYpTTG6p NP8ADVAljWYePnE9l+US6rEiA9CmXvqHQ1SB9xI2dVGlBckpGV0hSMGr5Q3WgOaC UFWbWr//PU0Asx5AAcnYr7p8O/iBj/3hB6lWBAFVMikoBo/cOa8D9qkf9e4G6l16 obgwP0e7JtExJWP3FLFYft2uPKn0SLr1SCFfeB4soTjju+t0NqrWwxaZFSDUatMj dZo64K4XPRgOZD64royXnh1UroDmEVyyJLob/4Q7jnL+PPw8+M0LgHQ9fDrIJt5O J23b2Q+VQiF0Dnn1VDolYBaWLg53lb5VGW4iutwtr9NjKZQj93ujfNklyD8a6hUy YWtFegGEjHZ5h7fwONjT =cU/x -END PGP SIGNATURE- ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: cross-compiling kernel using a 32-bit toolchain on a 64-bit machine
On Mon, Apr 06, 2015 at 03:50:41PM -0700, Mandeep Sandhu wrote: I'm having trouble compiling my kernel using a 32-bit toolchain (for ARM) on a 64-bit host (Ubuntu 14.10). The kernel version is 3.14.17. Any hints on how to get make to use the toolchain? after you export CROSS_COMPILE export ARCH=arm ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
VFS/driver core overhead
Greetings All, After reading through the code for the usb and vfs core infrastructure, I was wondering if after reading it if I am correct in my notion of there being very little overhead or none at all int these areas of the kernel. This is due to be noticing most drivers and file systems wrap around the core/vfs and therefore the overhead is very little and no need to worry about it like the overhead of the kernel's process structures based off task_struct .Honestly, I could benchmark this area of the kernel but it's hard to remove the file system/drivers interfering with my benchmarks due to me not knowing of any one way to do that. If someone either points me to a benchmark for me to test this or answers it that would be very helpful. Thanks, Nick ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Learning things
[2015-04-07T00:08:10+0530]: Mike Thompson (mike-thompson): ,[ mike-thompson ] | As others mention, using the Linux kernel to come up to speed with C is the | wrong approach. If you have a strong desire to learn kernel programming | concepts while coming up to speed on C, I would suggest getting the latest | book on Xinu, buying an Intel Galileo board and working your way through | that book. Xinu is what I cut my teeth on 25 years ago and I remember it | being a terrific learning environment. Xinu is not Linux (or Unix), but | for starting at the ground level all the concepts will map over when you | are ready to tackle Linux kernel work. | | Information for Xinu can be found here: http://www.xinu.cs.purdue.edu/ ` or there is always xv6 (http://pdos.csail.mit.edu/6.828/2014/) which might be useful... -- kind regards anupam ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: cross-compiling kernel using a 32-bit toolchain on a 64-bit machine
On 2015/4/7 6:50, Mandeep Sandhu wrote: Hi All, I'm having trouble compiling my kernel using a 32-bit toolchain (for ARM) on a 64-bit host (Ubuntu 14.10). The kernel version is 3.14.17. I understand that 32-bit binaries require ia32-libs (or equivalent) for compiling on 64-bit hosts. I installed the required packages (lib32z1 lib32ncurses5 lib32bz2-1.0 for Ubuntu 14.10), but still keep getting errors: $ make CROSS_COMPILE=arm-none-linux-gnueabi- all Makefile:616: Cannot use CONFIG_CC_STACKPROTECTOR_REGULAR: -fstack-protector not supported by compiler make: arm-none-linux-gnueabi-gcc: Command not found CHK include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h make[1]: `include/generated/mach-types.h' is up to date. CC kernel/bounds.s /bin/sh: 1: arm-none-linux-gnueabi-gcc: not found make[1]: *** [kernel/bounds.s] Error 127 make: *** [prepare0] Error 2 I've ensured that the PATH to the toolchain binaries is correct. If I try to export CROSS_COMPILE to my environment, then too I get an error (although it's for a different reason): $ make all Makefile:616: Cannot use CONFIG_CC_STACKPROTECTOR_REGULAR: -fstack-protector not supported by compiler CHK include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h make[1]: `include/generated/mach-types.h' is up to date. CC kernel/bounds.s gcc: error: unrecognized argument in option ‘-mabi=aapcs-linux’ gcc: note: valid arguments to ‘-mabi=’ are: ms sysv gcc: error: unrecognized command line option ‘-mlittle-endian’ gcc: error: unrecognized command line option ‘-mapcs’ gcc: error: unrecognized command line option ‘-mno-sched-prolog’ gcc: error: unrecognized command line option ‘-mno-thumb-interwork’ gcc: error: unrecognized command line option ‘-mfpu=vfp’ make[1]: *** [kernel/bounds.s] Error 1 make: *** [prepare0] Error 2 It looks like make is starting a new shell which does not have either PATH (1st case) or CROSS_COMPILE (2nd case) set. Any hints on how to get make to use the toolchain? Thanks, -mandeep ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies Edit .config and set CONFIG_CROSS_COMPILE to the path where your cross compiler is located. ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Hurr durr I'ma sheep
Hi, what does Hurr durr I'ma sheep mean in context to kernel version Linux 4.0? Regards, Kaushal ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Hurr durr I'ma sheep
Thanks Alan for the reply. Regards, Kaushal On Mon, Apr 6, 2015 at 1:01 PM, Alan Braithwaite asbraithwa...@gmail.com wrote: Linus put up a poll for the 4.0 code name on google+ https://plus.google.com/+LinusTorvalds/posts/TvigQqA9m3w That was the result. - Alan On Mon, Apr 6, 2015 at 12:08 AM, Kaushal Shriyan kaushalshri...@gmail.com wrote: Hi, what does Hurr durr I'ma sheep mean in context to kernel version Linux 4.0? Regards, Kaushal ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
/sys/module/ info for pci driver
Hi After loading pci driver for proprietary ethernet card, i dont see the few module detail in in /sys/module/module-name/drivers/pci:module-name/net . Can someone tell what APIs should be used to get the ethernet interface name , mac address details . Thanks ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
RE: /sys/module/ info for pci driver
From: kernelnewbies-bounces+jharan=bytemobile@kernelnewbies.org [mailto:kernelnewbies-bounces+jharan=bytemobile@kernelnewbies.org] On Behalf Of rahul b Sent: Monday, April 06, 2015 4:37 AM To: kernelnewbies@kernelnewbies.org Subject: /sys/module/ info for pci driver Hi After loading pci driver for proprietary ethernet card, i dont see the few module detail in in /sys/module/module-name/drivers/pci:module-name/net . Can someone tell what APIs should be used to get the ethernet interface name , mac address details . Thanks You probably want to grep/google for rtnetlink. I am pretty sure the iproute2 ip command uses it to generate output like this: $ ip link show dev lo 1: lo: LOOPBACK,UP,LOWER_UP mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 Jeff Haran ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Learning things
Hey list, I'm working on trying to teach myself C and was wondering if you had any kernel specific recommendations. I started the eudyptula challenge but so far it seems to be mostly learning the standards and whatnot. Are there any kernel/C books or online tutorials you guys think would help? signature.asc Description: OpenPGP digital signature ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
RE: Learning things
-Original Message- From: kernelnewbies-boun...@kernelnewbies.org [mailto:kernelnewbies-boun...@kernelnewbies.org] On Behalf Of Joris Bolsens Sent: Monday, April 06, 2015 10:44 AM To: kernelnewbies@kernelnewbies.org Subject: Learning things Hey list, I'm working on trying to teach myself C and was wondering if you had any kernel specific recommendations. I started the eudyptula challenge but so far it seems to be mostly learning the standards and whatnot. Are there any kernel/C books or online tutorials you guys think would help? Well, I have to credit you for jumping into the deep end. 8^) You might want to get familiar with C in user space first where if you get it wrong you have an OS and a memory manager on your side to generate a nice clean core file and debuggers like gdb to look at what happened when something goes bad. Bugs in the kernel are notorious for being difficult to track down. Jeff Haran ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Learning things
On Mon, 06 Apr 2015 10:43:46 -0700, Joris Bolsens said: I'm working on trying to teach myself C and was wondering if you had any kernel specific recommendations. Don't bother trying until you have an actual good working knowledge of C. Work in userspace where your screw-ups just take the process out, not the entire system, until stuff like a SIGSEGV becomes a rarity. *THEN* start considering kernel work. pgpyCUaExIqBu.pgp Description: PGP signature ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Learning things
-BEGIN PGP SIGNED MESSAGE- Hash: SHA256 In that case do you have any general recommendations? Or is there some sort of project that covers most of the basics? I learn best by doing and most stuff I found online goes pretty slow and is a bit boring :/ Thanks a ton On 04/06/2015 10:02 AM, valdis.kletni...@vt.edu wrote: On Mon, 06 Apr 2015 10:43:46 -0700, Joris Bolsens said: I'm working on trying to teach myself C and was wondering if you had any kernel specific recommendations. Don't bother trying until you have an actual good working knowledge of C. Work in userspace where your screw-ups just take the process out, not the entire system, until stuff like a SIGSEGV becomes a rarity. *THEN* start considering kernel work. -BEGIN PGP SIGNATURE- Version: GnuPG v2 iQIcBAEBCAAGBQJVIr1HAAoJEORnMHMHY2Frm+UP/0moBmxc1KWrMHrSRSkqGlOG lmiNZh1KJBw51mm8Ye6ML6cQlUyiA4XBe7vBnt/zJ0exou0hTDgHBFfXddXjnPyr 687HYOxH8uKymXh3qHTRxI8tjbnOUHdwXtzjOBxms62FNKmkvdnvbkDF0PGiu4+c eqi0eiFZ00DuNntzvkM375+swR1D/BnW44hWGaFv7sEjvREFSgmcYwmjZuFBNn8D 8FoYans5y4vM91+MnEE7A34niuqXgz3ZHUXyTz5ZfB/ZZWQKnaymfU4Yew7pD2og aP/dwrjmPogg4n21WMJnBG1Aj0b/heXZWzVIknGeQEHzyKJNtoAz5P92EEdyIRTB ZeGZm8333IpJcQ7VtG0VQMzs8xwJ889fo7Prp0c/pxDgsUqy2AaWSiKhMXhy5Yzy 6Dq4uYZWZehOf99tZxl21+eadMeYokBvyvpBQPZqeKw4V1J90tg9D7stXrszLlwZ cxFxp/1xeHTcy45yJ8L9klVnIaZCqLu7DFej/fI5I0xhRokDz+ArmP7BqxgMCaAg vYrBqDEdTSvyJZn+6tQ6KZFGJGhavbkbvSMgmzbv/NS1mzMZ17sM6xoyNeC/DHkZ keeypFtW/u8b96cNDTqLl9wWI7wYudaeH9d5XnpAGmyUldApMAkmEyKXykSmdbwq W0jRXuJpwmCxftmD/qBu =TUgV -END PGP SIGNATURE- ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
