July 2014 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

How to get the inode - no path_lookup
by Rishi Agrawal Sept. 17, 2015

Sept. 17, 2015

Hi All, I had a module which used the path_lookup function to print the details of any file's inode. I now want to rewrite that module in order to show some juniors how to write some code in kernel. I am using 3.4.6 kernel, I tried finding out path_lookup but google showed that it has been removed. I tried the following code then which did not work . . . dentry = kern_path_create(AT_FDCWD, filename, &path, 1); if (IS_ERR(dentry)) { printk("Failed to obtain the dentry"); return; } its not returning dentry I again tried after seeing the implementation of vfs_stat function user_path_at(AT_FDCWD, filename, lookup_flags, &path); but this also fails. I am using a proc interface to pass the filename, and copying the filename into a kernel buffer. How can I get a copy of vfs inode for a file name. -- Regards, Rishi Agrawal

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Problem facing while running checkpatch.pl on linux-next tree
by Rahul Garg Dec. 25, 2014

Dec. 25, 2014

Hi All, I am trying to run checkpatch.pl on linux-next tree's staging folder. But whatever sub directory, I try to run it on. It is giving me the same error for all the files : ERROR: Does not appear to be a unified-diff format patch I thought that it might be a problem with my git. So I clone the git tree again. So can anyone help me, what am I missing ? Regards Rahul

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How to submit for eudyptula-challenge
by wangyubin Dec. 19, 2014

Dec. 19, 2014

Hello, I have dive into the eudyptula-challenge, but when I submit my result for task 01. I received a reply below: > Please print to the kernel debug log level. I have sended module(c file), Makefile, and dmesg output for load/unload the module. Could anyone to tell me what does this message mean? Thanks a lot! -- Best Regards! wangyubin

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Re: [PATCH] reformat_with_checkpatch: Add automation to checkpatch
by Greg KH Oct. 30, 2014

Oct. 30, 2014

On Fri, Jul 11, 2014 at 06:46:52PM -0700, Joe Perches wrote: > On Fri, 2014-07-11 at 18:39 -0700, Greg KH wrote: > > On Fri, Jul 11, 2014 at 06:21:27PM -0700, Joe Perches wrote: > > > A simple script to run checkpatch --fix for various types of > > > of cleanups. > ] > > drivers/staging/lustre/include/linux/lnet/api.h has no obvious style problems and is ready for submission. > > file: <drivers/staging/lustre/include/linux/lnet/api.h> description: <update c90 comment style> types:<c99_comments> > > Useless use of greediness modifier '+' in regex; marked by <-- HERE in m/(^\+.*) {8,8}+ <-- HERE \t/ at ./scripts/checkpatch.pl line 2217. > [] > > drivers/staging/lustre/include/linux/lnet/api.h has no obvious style problems and is ready for submission. > [] > > Is that expected? > > No, I haven't seen that. > > Can you tell me what git tree you're working on? My staging-next branch of staging.git on git.kernel.org > Also, can you use the scripts/checkpatch from -next > tag next-20140711 that will take a bit to checkout, I'll do that afterward. > My system has: > > $ perl --version > > This is perl 5, version 18, subversion 2 (v5.18.2) built for i686-linux-gnu-thread-multi-64int > (with 41 registered patches, see perl -V for more detail) I think this started showing up for me for perl 5.20. Let me go checkout linux-next and see if that fixes anything or not... thanks, greg k-h

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userspace stack start and end
by Xin Tong Aug. 1, 2014

Aug. 1, 2014

I am trying to find the start and end address of the userspace stack. I see in the task_struct there is start_stack. But I could not find end_start anywhere in the kernel code ? Can someone please tell me how to find the end of the stack ? Thanks, Xin

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Work
by Nick Krause Aug. 1, 2014

Aug. 1, 2014

Is there any work for a kernel newbie that you guys known of? Cheers Nick

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Makedumpfile from Raw file
by Lucas Tanure Aug. 1, 2014

Aug. 1, 2014

Hi, Can I create a vmcore (elf format) using makedumpfile from a Raw file ? So I can debug using vmlinux and gdb ? thanks -- Lucas Tanure +55 (19) 988176559

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/sys documentation
by David kiarie July 31, 2014

July 31, 2014

Hi there, Is it possible I could get documentation for the information in /sys somewhere?I understand libudev reads from /sys and would like to have some good knowledge about /sys before I use libudev in an application. Cheers, David.

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HugePage by default
by Xin Tong July 31, 2014

July 31, 2014

Hi Is there anyway for me to turn on HugePage by default in the Linux X86 kernel, i.e. allocate a 2MB page by default in place of 4KB now ? Thanks, Xin

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building kernel with -O
by Xin Tong July 31, 2014

July 31, 2014

Hi Ive heard that one can not build the entire Linux kernel with -O0 option. why is that ? being a compiler developer, i can not think of reasons why that is the case. Thanks, Xin

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