May 2012 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

Re: Incremental Linking
by Sarbojit Ganguly May 23, 2012

May 23, 2012

Can you please elaborate on that? What exactly you are trying to find out and other details. On 23 May 2012 12:51, somanath sahoo <bapi_mvit2004(a)yahoo.com> wrote: > Hi Sarbojit, > > Does the Incremental link correspond to "incremental build" ? > > I think that incremental link corresponds to lazy binding by which kernel > modules are being inserted into running kernel. > > please CMIIW. > > Regards, > Somanath > > From: Sarbojit Ganguly <unixman.linuxboy(a)gmail.com> > To: somanath sahoo <bapi_mvit2004(a)yahoo.com> > Sent: Wednesday, May 23, 2012 11:20 AM > Subject: Re: Incremental Linking > > Somanath, IMHO linux kernel build system _uses_ incremental build. It > checks which object files are out dated and then updates. > > On 23 May 2012 11:09, somanath sahoo <bapi_mvit2004(a)yahoo.com> wrote: >> Hi Jonathan, >> >> I came to know about "incremental linking" while reading "Embedded linux >> Primer". >> >> >> Regards, >> Somanath >> >> From: Jonathan Neuschäfer <j.neuschaefer(a)gmx.net> >> To: somanath sahoo <bapi_mvit2004(a)yahoo.com> >> Cc: "kernelnewbies(a)kernelnewbies.org" <kernelnewbies(a)kernelnewbies.org> >> Sent: Tuesday, May 22, 2012 8:47 PM >> Subject: Re: Incremental Linking >> >> On Tue, May 22, 2012 at 02:56:35AM -0700, somanath sahoo wrote: >>> Hi, >>> >>> As newbie in linux kernel, I would like to understand the concept of >>> "incremental linking " w.r.t to linux kernel module. >>> >>> I have read that kernel loadable modules are being generated and >>> inserted into a running kernel due to this "incremental linking " >>> technology. >> >> Can you give us a pointer to where you read this? >> >> Thanks, >> Jonathan Neuschäfer >> >>> >>> If anyone can provide me some pointers to understand the "incremental >>> linking" concept, it will be needful. >>> >>> >>> Thanks, >>> Somanath >> >> >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies(a)kernelnewbies.org >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> > >

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stop
by Adhir Ramjiawan May 22, 2012

May 22, 2012

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ISO 8601 Timestamp <-> UNIX Timestamp
by Dan Luedtke May 22, 2012

May 22, 2012

Hi everyone, are there any functions to convert from and to ISO 8601 formatted timestamps? (Besides the mktime()-way) Either ASCII/char* or maybe some kind of struct? Although I am trying to avoid using them, I am just keen if there would be something like this. Regards. Dan -- Dan Luedtke http://www.danrl.de

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Why I can't compile a simple netfilter hook module?
by Chir0n May 22, 2012

May 22, 2012

I'm using this Makefile: *obj-m += hello.o all: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules clean: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean* The hello.c is this: *#include <linux/kernel.h> #include <linux/module.h> #include <linux/netfilter.h> #include <linux/netfilter_ipv4.h> static struct nf_hook_ops nfho; //struct holding set of hook function options //function to be called by hook unsigned int hook_func(unsigned int hooknum, struct sk_buff **skb, const struct net_device *in, const struct net_device *out, int (*okfn)(struct sk_buff *)) { printk(KERN_INFO "packet dropped\n"); //log to var/log/messages return NF_DROP; //drops the packet } //Called when module loaded using 'insmod' int init_module() { nfho.hook = hook_func; //function to call when conditions below met nfho.hooknum = NF_IP_PRE_ROUTING; //called right after packet recieved, first hook in Netfilter nfho.pf = PF_INET; //IPV4 packets nfho.priority = NF_IP_PRI_FIRST; //set to highest priority over all other hook functions nf_register_hook(&nfho); //register hook return 0; //return 0 for success } //Called when module unloaded using 'rmmod' void cleanup_module() { nf_unregister_hook(&nfho); //cleanup – unregister hook }* Here are the error message: *$ make make -C /lib/modules/3.3.2-6.fc16.x86_64/build M=/home/fabio/Desktop/modules modules make[1]: Entering directory `/usr/src/kernels/3.3.2-6.fc16.x86_64' CC [M] /home/fabio/Desktop/modules/hello.o /home/fabio/Desktop/modules/hello.c: In function ‘init_module’: /home/fabio/Desktop/modules/hello.c:18:13: warning: assignment from incompatible pointer type [enabled by default] /home/fabio/Desktop/modules/hello.c:19:18: error: ‘NF_IP_PRE_ROUTING’ undeclared (first use in this function) /home/fabio/Desktop/modules/hello.c:19:18: note: each undeclared identifier is reported only once for each function it appears in make[2]: *** [/home/fabio/Desktop/modules/hello.o] Error 1 make[1]: *** [_module_/home/fabio/Desktop/modules] Error 2 make[1]: Leaving directory `/usr/src/kernels/3.3.2-6.fc16.x86_64' make: *** [all] Error 2*

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[Q] USB urb completion handler
by Ezequiel Garcia May 22, 2012

May 22, 2012

Hi, I have a very simple question: Is it possible for an urb completion handler (the function that you put in the urb->complete field) to execute concurrently with itself? And in what context does it get called? Is it in interrupt context or in the context of a kernel thread? Hope my question is clear enough, Regards, Ezequiel.

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Question about tlv message support
by NorthPole May 18, 2012

May 18, 2012

Hello everyone I'm completely new to linux kernel and I would be grateful if you could help me get started. I read some basic things about the kernel. But I couldnt find anything relevant to the question below. So: Does the kernel have any support for the construction and encoding of type/length/value (TLV) or other information element messages? if it has(or if you dont know) where can I find a list or more documentation?

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Re: Can't find macro SAVE_ALL
by 王哲 May 18, 2012

May 18, 2012

2012/5/18 HWSW Development <hwsw.development(a)googlemail.com> > The macro is defined in arch/x86/include/asm/calling.h > > Regards, > Rooney > > > 2012/5/18 Bill Traynor <wmat(a)alphatroop.com> > >> >> >> On Thu, May 17, 2012 at 10:37 PM, 王哲 <wangzhe5004(a)gmail.com> wrote: >> >>> >>> >>> 2012/5/17 Javier Martinez Canillas <martinez.javier(a)gmail.com> >>> >>>> On Thu, May 17, 2012 at 3:59 PM, 王哲 <wangzhe5004(a)gmail.com> wrote: >>>> > Hi all: >>>> > i am a kernelnewbies.during studying the linux system call,and >>>> > analysis the following code (linux kernel 2.6.38) >>>> > >>>> > 529ENTRY(system_call) >>>> > 530 RING0_INT_FRAME # can't unwind into user space anyway >>>> > 531 pushl %eax # save orig_eax >>>> > 532 CFI_ADJUST_CFA_OFFSET 4 >>>> > 533 SAVE_ALL >>>> > 534 GET_THREAD_INFO(%ebp) >>>> > 535 # system call tracing in operation / emulation >>>> > 536 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp) >>>> > 537 jnz syscall_trace_entry >>>> > 538 cmpl $(nr_syscalls), %eax >>>> > 539 jae syscall_badsys >>>> > 540syscall_call: >>>> > 541 call *sys_call_table(,%eax,4) >>>> > 542 movl %eax,PT_EAX(%esp) # store the return value >>>> > >>>> > Question: >>>> > i want to see what the SAVE_ALL have done.and can't find >>>> the >>>> > Macro SAVE_ALL >>>> > if anyone knows please help >>>> >>> > >>>> > Thanks >>>> > >>>> > _______________________________________________ >>>> > Kernelnewbies mailing list >>>> > Kernelnewbies(a)kernelnewbies.org >>>> > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>>> > >>>> >>>> http://lxr.free-electrons.com/ident?i=SAVE_ALL >>>> >>>> Thank you Javier Martinez Canillas for reply! >>> but the rearch result : >>> Defined as a preprocessor macro in: >>> >>> - arch/cris/include/arch-v32/arch/irq.h, line 32<http://lxr.free-electrons.com/source/arch/cris/include/arch-v32/arch/irq.h#…> >>> - arch/cris/include/arch-v10/arch/irq.h, line 85<http://lxr.free-electrons.com/source/arch/cris/include/arch-v10/arch/irq.h#…> >>> - arch/sparc/include/asm/asmmacro.h, line 27<http://lxr.free-electrons.com/source/arch/sparc/include/asm/asmmacro.h#L27> >>> >>> is not in x86 Architecture. >>> >> >> Couldn't you find it by doing something like this? In your kernel source >> tree: >> >> $cd arch/x86 >> $grep -ircl ".macro SAVE_ALL" * >> >> >> >> >>> Best regards, >>>> >>>> -- >>>> Javier Martínez Canillas >>>> (+34) 682 39 81 69 >>>> Barcelona, Spain >>>> >>> >>> >>> _______________________________________________ >>> Kernelnewbies mailing list >>> Kernelnewbies(a)kernelnewbies.org >>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>> >>> >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies(a)kernelnewbies.org >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> >> Thanks for all. > I have sloved the problem. this macro is written with assembly ，not c . No wonder that i don't search it out in the lxr.linux.no arch/x86/kernel/entry_32.s 192 .macro SAVE_ALL 193 cld 194 PUSH_GS 195 pushl_cfi %fs 196 /*CFI_REL_OFFSET fs, 0;*/ 197 pushl_cfi %es 198 /*CFI_REL_OFFSET es, 0;*/ 199 pushl_cfi %ds 200 /*CFI_REL_OFFSET ds, 0;*/ 201 pushl_cfi %eax 202 CFI_REL_OFFSET eax, 0 203 pushl_cfi %ebp 204 CFI_REL_OFFSET ebp, 0 205 pushl_cfi %edi 206 CFI_REL_OFFSET edi, 0 207 pushl_cfi %esi 208 CFI_REL_OFFSET esi, 0 209 pushl_cfi %edx 210 CFI_REL_OFFSET edx, 0 211 pushl_cfi %ecx 212 CFI_REL_OFFSET ecx, 0 213 pushl_cfi %ebx 214 CFI_REL_OFFSET ebx, 0 215 movl $(__USER_DS), %edx 216 movl %edx, %ds 217 movl %edx, %es 218 movl $(__KERNEL_PERCPU), %edx 219 movl %edx, %fs 220 SET_KERNEL_GS %edx 221 .endm -- ---------------------------------------------------------------------------------------------- WangZhe Xi'an Shanxi CHINA qq 785924174 blog blog.163.com/zhe_wang_2009 ----------------------------------------------------------------------------------------------

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Can't find macro SAVE_ALL
by 王哲 May 18, 2012

May 18, 2012

Hi all: i am a kernelnewbies.during studying the linux system call,and analysis the following code (linux kernel 2.6.38) 529 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L529> ENTRY(system_call) 530 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L530>RING0_INT_FRAME # can't unwind into user space anyway 531 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L531> pushl %eax # save orig_eax 532 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L532>CFI_ADJUST_CFA_OFFSET 4 533 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L533> SAVE_ALL 534 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L534>GET_THREAD_INFO(%ebp) 535 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L535> # system call tracing in operation / emulation 536 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L536> testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp) 537 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L537> jnz syscall_trace_entry 538 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L538> cmpl $(nr_syscalls), %eax 539 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L539> jae syscall_badsys 540 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L540> syscall_call: 541 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L541> call *sys_call_table(,%eax,4) 542 <http://lxr.linux.no/linux+*/arch/x86/kernel/entry_32.S#L542> movl %eax,PT_EAX(%esp) # store the return value Question: i want to see what the SAVE_ALL have done.and can't find the Macro SAVE_ALL if anyone knows please help Thanks

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Re: where is the formula for calculating kernel process priority?
by Dilip Madhavan May 17, 2012

May 17, 2012

I think its sched_fair.c -- Thank you, Dilip -----Original Message----- From: "Robert P. J. Day" <rpjday(a)crashcourse.ca> Date: Thu, 17 May 2012 23:04:46 To: <kernelnewbies(a)kernelnewbies.org> Subject: where is the formula for calculating kernel process priority? in which source file is the actual formula for calculating a process' priority based on its niceness, behaviour, etc? thanks. rday -- ======================================================================== Robert P. J. Day Ottawa, Ontario, CANADA http://crashcourse.ca Twitter: http://twitter.com/rpjday LinkedIn: http://ca.linkedin.com/in/rpjday ======================================================================== _______________________________________________ Kernelnewbies mailing list Kernelnewbies(a)kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

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where is the formula for calculating kernel process priority?
by Robert P. J. Day May 17, 2012

May 17, 2012

in which source file is the actual formula for calculating a process' priority based on its niceness, behaviour, etc? thanks. rday -- ======================================================================== Robert P. J. Day Ottawa, Ontario, CANADA http://crashcourse.ca Twitter: http://twitter.com/rpjday LinkedIn: http://ca.linkedin.com/in/rpjday ========================================================================

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