Strace and lsof do not work

[Vimal]

Hi,

Why am I unable to strace / lsof into certain processes, even as "root" 
user? I am unable to find a concrete answer for this. Please assist.

========
root     14940  0.0  0.1  10380  2552 ?        SN   13:02   0:00  \_ 
/usr/sbin/exim -q

root at dedicated100 [~]# lsof -p 14940
COMMAND   PID USER   FD      TYPE DEVICE SIZE NODE NAME
exim    14940 root  cwd   unknown                  /proc/14940/cwd 
(readlink: Permission denied)
exim    14940 root  rtd   unknown                  /proc/14940/root 
(readlink: Permission denied)
exim    14940 root  txt   unknown                  /proc/14940/exe 
(readlink: Permission denied)
exim    14940 root    0   unknown                  /proc/14940/fd/0 
(readlink: Permission denied)
exim    14940 root    1   unknown                  /proc/14940/fd/1 
(readlink: Permission denied)
exim    14940 root    2   unknown                  /proc/14940/fd/2 
(readlink: Permission denied)
exim    14940 root    3   unknown                  /proc/14940/fd/3 
(readlink: Permission denied)
exim    14940 root    4   unknown                  /proc/14940/fd/4 
(readlink: Permission denied)

root at dedicated100 [~]# strace -p 14940
attach: ptrace(PTRACE_ATTACH, ...): Operation not permitted
========

-- 
Regards,
Vimal Kumar K

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