dtracing static symbols

[Prashanth Kumar]

If you run 
# env DTRACE_DEBUG=1 dtrace -Ppid\$target -l  -c ./static
you will notice that lot of probe creation will fail, also no probes are created for instruction offsets.
    you will have to update the libproc library and fasttrap code to trace all the 
functions. 
--------------------------------------------
On Wed, 12/3/14, Daniel O'Connor <doconnor at gsoft.com.au> wrote:

 Subject: Re: dtracing static symbols
 To: "Robert Mustacchi" <rm at joyent.com>
 Cc: freebsd-dtrace at freebsd.org
 Date: Wednesday, 12 March, 2014, 2:54 AM
 
 
 On 12 Mar 2014, at 2:30, Robert Mustacchi <rm at joyent.com>
 wrote:
 > On 03/10/2014 10:34 PM, Daniel O'Connor wrote:
 >> 
 >> On 11 Mar 2014, at 15:34, Prashanth Kumar <pra_udupi at yahoo.co.in>
 wrote:
 >>> If the binary being traced has static symbols
 in its symbol table, DTrace should
 >>> be able to trace the function. Can you describe
 the example where you found this
 >>> difference in FreeBSD and OSX?
 >> 
 >> Unfortunately the static symbols don't show up in
 the symbol table (as shown by nm).
 >> 
 >> Is there a compile or link flag which will change
 that?
 > 
 > Because it's a static function the compiler may inline
 it, which may be
 > why you don't actually see an entry in nm nor that it
 can be found by
 > DTrace. You'll want to look at the disassembled output
 of your program
 > to see if it was inlined. Different compilers can and
 will do different
 > things. There generally are flags you can pass to the
 compiler to tell
 > it not to inline it, but that's compiler specific.
 
 I just realised that my test contradicted the statement I
 made earlier..
 However I checked my test program (static.c) and it the
 functions definitely appear in the symbol table.
 [mdtest 21:13] ~ >nm static|egrep '(foo|bar)'
 0000000000400600 T bar
 0000000000400620 t foo
 
 I also added the noinline attribute for good measure.
 
 It seems that _nothing_ shows up for executables, only
 shared libraries, this is OK for me since my code resides in
 a library but it is a bit surprised nonetheless..
 
 >> (I'm not sure what the various numbers mean)
 > 
 > The pid provider can instrument any instruction in a
 function, those are
 > the instruction offsets.
 
 Ahh, thanks.
 
 --
 Daniel O'Connor software and network engineer
 for Genesis Software - http://www.gsoft.com.au
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