From: Prem K. <pre...@ly...> - 2002-05-14 12:59:02
|
Hi everybody, I have a problem in running the gdb utility in UML. My problem is as follows: The Problem : To trace the flow of an application executing in UML. To know about the exact mechanism used by UML to trace an application thread. Description : I have an application(any linux executable file) being executed in UML,now I need to trace it's behaviour. If i use 'gdb' to trace through the application's execution path, I get a message saying that "ptrace: Operation not permitted". What might be the reason for this error message ? If i need to know how the UML exactly traces the system call occurrence, how can i do it using a debugger tool? An Example program: I had written a program that gets an integer input and prints it. This program is run in the UML kernel. I obtain the process ID of this program using 'ps -ef' on the native kernel ,which gave the following result for the specified program.I run the 'gdb' debug utility in the native kernel and attach the process ID of theexecuting process to it(ie) 3151. At this time the error message "ptrace : Operation not permitted" pops up. -------------------------------------------------------The program: file name: "example.c" #include<unistd.h> int main() { int n; scanf("%d",&n); printf("%d",n); return 0; } [mandrake@prem prem]$ ./example Using 'ps -ef' i get the process id root 3151 1 0 16:19 pts/1 00:00:00 ./linux [./example] [root@prem prem]gdb -q (gdb) att 3151 Attaching to process 3151 ptrace : Operation not permitted (gdb) -------------------------------------------------------Note: I am using the UML kernel and the patch that was provided in your website. Details of kernel: Kernel version : 2.4.18 Patch used : uml-patch-2.4.18 Native kernel version : 2.4.2 ------------------------------------------------------- Now is there any mechanism that would help me in using the gdb utility in the UML kernel itself, so that the aplication execution path can be traced. Can someone suggest me a solution for my problem. Regards, Prem Kumar ________________________________________________________ Outgrown your current e-mail service? Get a 25MB Inbox, POP3 Access, No Ads and No Taglines with LYCOS MAIL PLUS. http://login.mail.lycos.com/brandPage.shtml?pageId=plus |
From: Prem K. <pre...@ly...> - 2002-05-14 13:00:25
|
Hi everybody, I have a problem in running the gdb utility in UML. My problem is as follows: The Problem : To trace the flow of an application executing in UML. To know about the exact mechanism used by UML to trace an application thread. Description : I have an application(any linux executable file) being executed in UML,now I need to trace it's behaviour. If i use 'gdb' to trace through the application's execution path, I get a message saying that "ptrace: Operation not permitted". What might be the reason for this error message ? If i need to know how the UML exactly traces the system call occurrence, how can i do it using a debugger tool? An Example program: I had written a program that gets an integer input and prints it. This program is run in the UML kernel. I obtain the process ID of this program using 'ps -ef' on the native kernel ,which gave the following result for the specified program.I run the 'gdb' debug utility in the native kernel and attach the process ID of theexecuting process to it(ie) 3151. At this time the error message "ptrace : Operation not permitted" pops up. -------------------------------------------------------The program: file name: "example.c" #include<unistd.h> int main() { int n; scanf("%d",&n); printf("%d",n); return 0; } [mandrake@prem prem]$ ./example Using 'ps -ef' i get the process id root 3151 1 0 16:19 pts/1 00:00:00 ./linux [./example] [root@prem prem]gdb -q (gdb) att 3151 Attaching to process 3151 ptrace : Operation not permitted (gdb) -------------------------------------------------------Note: I am using the UML kernel and the patch that was provided in your website. Details of kernel: Kernel version : 2.4.18 Patch used : uml-patch-2.4.18 Native kernel version : 2.4.2 ------------------------------------------------------- Now is there any mechanism that would help me in using the gdb utility in the UML kernel itself, so that the aplication execution path can be traced. Can someone suggest me a solution for my problem. Regards, Prem Kumar ________________________________________________________ Outgrown your current e-mail service? Get a 25MB Inbox, POP3 Access, No Ads and No Taglines with LYCOS MAIL PLUS. http://login.mail.lycos.com/brandPage.shtml?pageId=plus |
From: Prem K. <pre...@ly...> - 2002-05-14 13:02:09
|
Hi everybody, I have a problem in running the gdb utility in UML. My problem is as follows: The Problem : To trace the flow of an application executing in UML. To know about the exact mechanism used by UML to trace an application thread. Description : I have an application(any linux executable file) being executed in UML,now I need to trace it's behaviour. If i use 'gdb' to trace through the application's execution path, I get a message saying that "ptrace: Operation not permitted". What might be the reason for this error message ? If i need to know how the UML exactly traces the system call occurrence, how can i do it using a debugger tool? An Example program: I had written a program that gets an integer input and prints it. This program is run in the UML kernel. I obtain the process ID of this program using 'ps -ef' on the native kernel ,which gave the following result for the specified program.I run the 'gdb' debug utility in the native kernel and attach the process ID of theexecuting process to it(ie) 3151. At this time the error message "ptrace : Operation not permitted" pops up. -------------------------------------------------------The program: file name: "example.c" #include<unistd.h> int main() { int n; scanf("%d",&n); printf("%d",n); return 0; } [mandrake@prem prem]$ ./example Using 'ps -ef' i get the process id root 3151 1 0 16:19 pts/1 00:00:00 ./linux [./example] [root@prem prem]gdb -q (gdb) att 3151 Attaching to process 3151 ptrace : Operation not permitted (gdb) -------------------------------------------------------Note: I am using the UML kernel and the patch that was provided in your website. Details of kernel: Kernel version : 2.4.18 Patch used : uml-patch-2.4.18 Native kernel version : 2.4.2 ------------------------------------------------------- Now is there any mechanism that would help me in using the gdb utility in the UML kernel itself, so that the aplication execution path can be traced. Can someone suggest me a solution for my problem. Regards, Prem Kumar ________________________________________________________ Outgrown your current e-mail service? Get a 25MB Inbox, POP3 Access, No Ads and No Taglines with LYCOS MAIL PLUS. http://login.mail.lycos.com/brandPage.shtml?pageId=plus |