New Probe Points for Unprivileged Users

[Dave Brolley]

Hi,

Support for limited probing by unprivileged users (not root, stapdev or 
stapusr) was recently pushed to our git sources (see the NEWS file). The 
number and type of probe points available to these users has 
intentionally been restricted in the early stages of development and 
testing.

Overall, the philosophy is that an unprivileged user should not be able 
to use systemtap to affect the system in ways they would not normally be 
able to or to obtain information that they would not normally be able to 
obtain.

The current set of allowed probes is:

begin
begin(N)
end()
end(N)
error
error(N)
never
timer.*
process.begin
process.end
process("xxx").begin
process("xxx").end
process(N).begin
process(N).end

where process.* probes are restricted to the user's own processes.

I would like to expand the list of available probes to include the 
remainder of the process.* probes where, once again, probes are 
restricted to the user's own processes. Before doing so, I just wanted 
to double check that this would not be exposing anything in violation of 
the philosophy mentioned above. If you see any problems with exposing 
the probe points below to unprivileged users, for their own processes, 
then please let me know.

Thanks,
Dave
-------------------------------------
process.syscall
process.syscall.return
process.thread.begin
process.thread.end
process("xxx").function("yyy")
process("xxx").function("yyy").inline
process("xxx").function("yyy").call
process("xxx").function("yyy").return
process("xxx").function("yyy").return.maxactive
process("xxx").function("yyy").label("lll")
process("xxx").function(N)
process("xxx").function(N).inline
process("xxx").function(N).call
process("xxx").function(N).return
process("xxx").function(N).return.maxactive
process("xxx").insn
process("xxx").insn.block
process("xxx").mark("mmm")
process("xxx").mark(N)
process("xxx").statement("yyy")
process("xxx").statement(N)
process("xxx").syscall
process("xxx").syscall.return
process("xxx").thread.begin
process("xxx").thread.end
process(N).statement(N).absolute
process(N).statement(N).absolute.return
process(N).insn
process(N).insn.block
process(N).syscall
process(N).syscall.return
process(N).thread.begin
process(N).thread.end