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SubjectRe: task_struct and uid of a task
Hi Robin,

I have applied this to my local testing code and indendation is looking
perfectly good.

indent -kr -i8 -psl -npcs -cp9 loadavg.c

Robin Thanks a lot for that.

Sena Seneviratne
Computer engineering Lab
Sydney University
Sydney



Robin Holt wrote:

>On Wed, Dec 31, 2003 at 07:06:52AM +1100, sena wrote:
>
>Sena,
>
>Why don't you pester me about this instead of bothering Rusty.
>
>What are you trying to accomplish? Please be specific about what
>you are trying to find out and not how you are trying to do it.
>
>Another thing, I would _GREATLY_ appreciate code which has
>decent variable names and good indentation. Assuming you are
>writing this on a Linux box with a standard development install,
>you should be able to do:
>
>indent -kr -i8 -psl -npcs -cp9 myfile.c
>
>and get very kernel-style code. Won't fix the variable names, but
>at least braces will be indented.
>
>Thanks,
>Robin Holt
>
>
>
>>Dear Rusty,
>>
>>Thank you for your previous reply. I feel like you would be able to
>>assist me.
>>
>>Say a computer has 5 user logins name1(500), name2(501),
>>name3(502).........name5(504) apart from root. If these 5 people
>>remotely login and runs there jobs, then the user name of those jobs are
>>name1,name2 and name3.
>>
>>Say if they use telnet to remotely login then those Tasks will be
>>started under telnet server as children.
>>
>>As the children inherits uid, euid etc of the parents. That means telnet
>>is run as root and it inherits uid<500.
>>
>>task_struct has uid and it is updated accordingly.
>>
>>
>>I have built the kernel 2.4.19sena1 successfully but this is my problem.
>>The problem because child process inherits uid etc if I start any
>>process through telnet
>>
>>My code is as follows:
>>
>>unsigned long a; //for root uid<500, I am getting this uidArray[0] is
>>for storing uid (assumed 100 for all <500)
>>unsigned long b; //for 500
>>unsigned long c; //for 501
>>unsigned long d; //for 502
>>unsigned long e; //for 503
>>unsigned long f; // for 504
>>
>>unsigned int uidArray[7];
>>
>>static unsigned long count_active_tasks(void)
>>{
>> struct task_struct *p;
>> unsigned long nr = 0;
>>
>> int s = 0;
>>
>> int i=0;
>> int j=0;
>> int k=0;
>> int m=0;
>>
>> a=b=c=d=e=f=0;
>>
>> read_lock(&tasklist_lock);
>>
>> for_each_task(p)
>> {
>> if ((p->state == TASK_RUNNING ||
>> (p->state & TASK_UNINTERRUPTIBLE)))
>> {
>>
>> nr += FIXED_1; //nr total tasks
>>
>> if(i==0)
>> {
>> uidArray[0] = 100;
>>
>> if(p->uid < 500)
>> {
>>
>> a += FIXED_1;
>> }
>> else
>> {
>> uidArray[1] = p->uid;
>> b += FIXED_1;
>> k++;
>> }
>> k++;
>> }
>> else
>> {
>> for(j=0; j < k ; j++)
>> {
>>
>> if((j==0)&& (p->uid < 500) && (s==0))
>> {
>> a += FIXED_1;
>> s = 1;
>> break;
>> }
>> else if((uidArray[j] == p->uid) && s==0)
>> {
>> if(j==1){
>> b += FIXED_1;}
>> if(j==2){
>> c += FIXED_1;}
>> if(j==3){
>> d += FIXED_1;}
>> if(j==4){
>> e += FIXED_1;}
>> if(j==5){
>> f += FIXED_1;}
>> s=1;
>> break;
>> }
>> }
>>
>> if(s==0)
>> {
>>
>> if(k < 6)
>> {
>> k++;
>> j = k-1;
>> uidArray[j] = p->uid;
>> if(j==1){
>> b += FIXED_1;}
>> if(j==2){
>> c += FIXED_1;}
>> if(j==3){
>> d += FIXED_1;}
>> if(j==4){
>> e += FIXED_1;}
>> if(j==5){
>> f += FIXED_1;}
>> }
>>
>>
>> }
>>
>> s=0;
>> }
>>
>> i++;
>>
>> }
>>
>> }
>>
>> read_unlock(&tasklist_lock);
>> return nr;
>>
>>}
>>
>>unsigned long avenrun[6];
>>
>>unsigned long avenrunT;
>>
>>static inline void calc_load(unsigned long ticks)
>>{
>> unsigned long active_tasks; /*fixed-point */
>> static int count = LOAD_FREQ;
>>
>> count -= ticks;
>> if (count < 0) {
>> count += LOAD_FREQ;
>> active_tasks = count_active_tasks();
>>
>> CALC_LOAD(avenrunT, EXP_5, active_tasks);
>> CALC_LOAD(avenrun[0], EXP_5, a);
>> CALC_LOAD(avenrun[1], EXP_5, b);
>> CALC_LOAD(avenrun[2], EXP_5, c);
>> CALC_LOAD(avenrun[3], EXP_5, d);
>> CALC_LOAD(avenrun[4], EXP_5, e);
>> CALC_LOAD(avenrun[5], EXP_5, f);
>>
>> }
>>}
>>
>>I have updated all the other places(all .h and .c files) to suit this code.
>>
>>And the result is stored in proc/loadavg as
>>
>> 0.21 0.21 100 0.00 0 0.00 0 0.00
>>0 0.00 0 0.00 0
>> T a 1 uid b1 500 c 1 501 d1
>> 502 e1 503 f1 504
>>
>>T- for totall
>>a1- root or uid < 500
>>b1,c1,di etc for uid>=500
>>
>>In this perticular case I have login as root so that uid 100 is seen.
>>There is no 500 or above. they are all 0.
>>
>>But even if I start login remotely those processors started through
>>telnet inherits uid <500. Then they will be shown under a1
>>
>>I get uids from task_struct
>>
>>Thanks
>>Sena Seneviratne
>>Computer Engineering Lab
>>School of Electrical and Information Engineering
>>Sydney University
>>
>>-
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>>
>>
>
>
>



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