Sponsored Content
Full Discussion: Problem about Kernel oops
Top Forums Programming Problem about Kernel oops Post 302588173 by homeboy on Saturday 7th of January 2012 08:39:39 AM
Old 01-07-2012
Problem about Kernel oops

hello,everyone,I'm reading LDD3.Topics about oops,it said the code bellow would cause a fault condition because "this method copies a string to a local variable,unfortunately,the string is longer than the destination array".Well,hard to understand....Is that right?I thought the fault should be caused by the wrong memset,it overwrite the function stack,the value of __user is 0xff now.will anyone tell me what happened here?Thanks;
Code:
size_t fauly_read(struct file *filp, char __user *buf, size_t count, loff_t *pos)
{
      int ret;
      char stack_buf[4];

      memset(stack_buf, 0xff, 20);
      if(count > 4)
           count  = 4;

      ret = copy_to_user(buf, stack_buf, count);
      if(!ret)
          return count;

      return ret;
}

 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

oops! Style Manager

Solaris 2.6, using CDE: agh. I accidentally set an ugly palette as my Home Session. The problem is, when I change the palette back to Default, I am informed that my change will be apparent in my next session. But when I log out and in, it's still the Ugly Palette. Doesn't matter if I set the... (1 Reply)
Discussion started by: kristy
1 Replies

2. UNIX for Advanced & Expert Users

oops on mount

When ever i mount any of my 2 scsi cdroms, I get a kernel crash with the folfollowing oops kernel output. I understand that it is impossible to anwser my question WHY but could you give me some advice where i should look to debug the problem or advice me some tools to detect what might be... (3 Replies)
Discussion started by: progressdll
3 Replies

3. Solaris

oops...accidentally overwrote postfix aliases file

I have directory/dns server running sparc solaris 9. while troubleshooting another issue, i overwrote the aliases file on accident. my question is: is there any way to revert this? any help super appreciated...especially since this a production box! (2 Replies)
Discussion started by: JeepResQ
2 Replies

4. UNIX for Advanced & Expert Users

kernel call problem

hi all I want to make a kernel call which takes as input an integer x and prints 2*x Anyone who knows how could i do that? (1 Reply)
Discussion started by: sasa
1 Replies

5. Programming

Oops

Hi All, Can any one please differenciate between the Data Abstraction and Encapsulation? If possible, with code. Thanks in Advance, Naga:cool: (2 Replies)
Discussion started by: Nagapandi
2 Replies

6. Ubuntu

500 OOPS: vsftpd: cannot locate user specified in 'ftp_username':ftp

I've been tearing my hair out over this: vsftp does not work on any of my RedHat Server 5.x systems - I keep getting a variation on 500 OOPS: vsftpd: cannot locate user specified in 'ftp_username':ftp or 500 OOPS: cannot locate user entry:nobody (different errors on different systems). I spent... (2 Replies)
Discussion started by: thomn8r
2 Replies

7. Red Hat

Kernel Panic problem

Hi all, When i load my block device driver in Fedoracore10 kernel 2.6.27. i got this type of error kernel panic - not syncing : Fatal exception in interrupt. I am unable to save the log file.... Can any one help me..... regards sundar (4 Replies)
Discussion started by: sundhar
4 Replies

8. UNIX for Dummies Questions & Answers

chmod 777 * - oops

I can belive I really did this... chmod 777 /home :eek: I have my /home directory synced to another machine. Can anyone tell me how to get the permissions from back up server /home to production server /home It's important that I dont over write the files on the... (1 Reply)
Discussion started by: shunter63
1 Replies

9. Linux

Kernel/DISK problem

Hey guys i got this error in my logs: from dmesg: What does this error indicates? (6 Replies)
Discussion started by: sbn
6 Replies

10. Linux

500 OOPS: vsftpd: cannot locate user specified in 'ftp_username':ftp

I've been fighting this for about a year: vsftp does not work on any of my RedHat Server 5.x systems - I keep getting a variation on 500 OOPS: vsftpd: cannot locate user specified in 'ftp_username':ftp or 500 OOPS: cannot locate user entry:nobody (different errors on different systems). I spent... (0 Replies)
Discussion started by: thomn8r
0 Replies
PAPI_remove_named_event(3)					       PAPI						PAPI_remove_named_event(3)

NAME
PAPI_remove_named_event - removes a named hardware event from a PAPI event set. SYNOPSIS
Detailed Description A hardware event can be either a PAPI Preset or a native hardware event code. For a list of PAPI preset events, see PAPI_presets or run the papi_avail utility in the PAPI distribution. PAPI Presets can be passed to PAPI_query_event to see if they exist on the underlying architecture. For a list of native events available on the current platform, run papi_native_avail in the PAPI distribution. @par C Interface: int PAPI_remove_event( int EventSet, int EventCode ); @param[in] EventSet -- an integer handle for a PAPI event set as created by PAPI_create_eventset @param[in] EventName -- a defined event such as PAPI_TOT_INS or a native event. @retval PAPI_OK Everything worked. @retval PAPI_EINVAL One or more of the arguments is invalid. @retval PAPI_ENOINIT The PAPI library has not been initialized. @retval PAPI_ENOEVST The EventSet specified does not exist. @retval PAPI_EISRUN The EventSet is currently counting events. @retval PAPI_ECNFLCT The underlying counter hardware can not count this event and other events in the EventSet simultaneously. @retval PAPI_ENOEVNT The PAPI preset is not available on the underlying hardware. @par Example: * char EventName = "PAPI_TOT_INS"; * int EventSet = PAPI_NULL; * int ret; * * // Create an empty EventSet * ret = PAPI_create_eventset(&EventSet); * if (ret != PAPI_OK) handle_error(ret); * * // Add Total Instructions Executed to our EventSet * ret = PAPI_add_named_event(EventSet, EventName); * if (ret != PAPI_OK) handle_error(ret); * * // Start counting * ret = PAPI_start(EventSet); * if (ret != PAPI_OK) handle_error(ret); * * // Stop counting, ignore values * ret = PAPI_stop(EventSet, NULL); * if (ret != PAPI_OK) handle_error(ret); * * // Remove event * ret = PAPI_remove_named_event(EventSet, EventName); * if (ret != PAPI_OK) handle_error(ret); * See Also: PAPI_remove_event PAPI_query_named_event PAPI_add_named_event Author Generated automatically by Doxygen for PAPI from the source code. Version 5.2.0.0 Tue Jun 17 2014 PAPI_remove_named_event(3)
All times are GMT -4. The time now is 12:14 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy