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noptrace.stp - Disable ptrace from Hierarchies of Processes
Blocks ptrace(2) attempts from processes identified by stap -c/-x,
as also specifiable from /proc/systemtap/stap_XXX/ control files.
Processes may be added or removed from the blocked list.
------------------------------------------------------------------------
Example: block ptrace(2) from a given subprocess hierarchy.
% echo $$
9898
(in other shell)
# stap -g noptrace.stp -x 9898 &
(in original shell)
% strace ls
strace: ptrace(PTRACE_TRACEME, ...): No such process
+++ exited with 1 +++
% bash # create a child process
bash-4.3$ strace ls
strace: ptrace(PTRACE_TRACEME, ...): No such process
+++ exited with 1 +++
bash-4.3$
------------------------------------------------------------------------
Example: block ptrace(2) with a manually managed process list
% echo $$
8282
(in other shell)
# stap -g noptrace.stp &
# cd /proc/systemtap/stap_*
# cat blocked
[empty]
# echo 8282 > block
(in original shell)
% do stuff
% strace ls
[doesn't work]
% do more stuff
(in other shell)
# cat blocked # child processes
8282
8294
8322
8348
# echo 8282 > unblock
(in original shell)
% strace ls
[now works]
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