Date: Tue, 15 Apr 2014 23:54:20 -0300 From: carlos antonio neira bustos <cneirabustos@gmail.com> To: Mark Johnston <markj@freebsd.org> Cc: "freebsd-dtrace@freebsd.org" <freebsd-dtrace@freebsd.org> Subject: Re: uaddr and friends Message-ID: <CACiB22h-fzbb8ErJEV5ci%2BonRKm3d69UWPD8ELwuTkhrLDeLsw@mail.gmail.com> In-Reply-To: <CAMw1wOw0SwAHRWCBTBX6FczU=cWZwri-p9--MdaC956WtZ5sGw@mail.gmail.com> References: <CACiB22g4JHWhj9ZPWmKKg1FAF376J3TBcrOtgOFrs4JHkFvkOw@mail.gmail.com> <CAMw1wOxWUpCtrYhkp-NUfigPZUewpyesYzTYG2s=uHLmMXhQwg@mail.gmail.com> <CACiB22hQ-9bBeFcFNeEfcrRu2MK0VxAUP1taHFCxJoW0eypxcg@mail.gmail.com> <CAMw1wOw0SwAHRWCBTBX6FczU=cWZwri-p9--MdaC956WtZ5sGw@mail.gmail.com>
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Thanks Mark. You are right, I did not look at dt_subr.c, uaddr is a short version of ustack, I'll update to current now and try to pick on something else from the list. Bests On Tue, Apr 15, 2014 at 11:36 PM, Mark Johnston <markj@freebsd.org> wrote: > On Tue, Apr 15, 2014 at 10:15 PM, carlos antonio neira bustos > <cneirabustos@gmail.com> wrote: > > Hi Mark, > > > > I was looking at this document > > > https://wikis.oracle.com/display/DTrace/Actions+and+Subroutines#ActionsandSubroutines-%7B%7Busym%7D%7D > > currently looking at the code uaddr is the same as usym, but according to > > this document > > > > usym will print the symbol for a specified address. This is analogous to > how > > uaddr works, but without the hexadecimal offsets. > > > > uaddr: date`clock_val+0x1 > > usym: date`clock_val > > > > > > here are my outputs from usym and uaddr : > > > > root@bsd:/home/cneira # dtrace -n > 'pid$target::main:{usym(uregs[R_PC])}' -c > > ./test > > dtrace: description 'pid$target::main:' matched 2 probes > > abCPU ID FUNCTION:NAME > > 0 56282 main:entry test`main > > 0 56281 main:return test`main > > dtrace: pid 10588 has exited > > > > root@bsd:/home/cneira # dtrace -n > 'pid$target::main:{uaddr(uregs[R_PC])}' -c > > ./test > > dtrace: description 'pid$target::main:' matched 2 probes > > abCPU ID FUNCTION:NAME > > 0 56282 main:entry > > test`main+0x1 > > > > 0 56281 main:return > > test`main+0x23 > > > > dtrace: pid 10591 has exited > > > > As current is only using dt_print_usym for uaddr the output should not > have > > the hexadecimal offset specified in that documentation. > > So I'm somewhat lost about which is the correct behavior , Do you have a > > uaddr and usym output example in current to check this?, all my changes > > were done in 10 prod release. > > You're right, dt_print_usym handles both usym and uaddr. In the usym > case, there's some special handling which looks up the symbol name > corresponding to the given pc, and then sets the pc variable to the > address of the symbol. Then dtrace_uaddr2str only prints the offset > from the symbol if that offset is non-zero, so in the uaddr case you > get "+0x1" and "+0x23" above. > > > > > Bests > > > > > > > > > > > > > > > > On Tue, Apr 15, 2014 at 10:09 PM, Mark Johnston <markj@freebsd.org> > wrote: > >> > >> On Tue, Apr 15, 2014 at 8:35 PM, carlos antonio neira bustos > >> <cneirabustos@gmail.com> wrote: > >> > Hi All, > >> > > >> > I was looking at Dtrace todo list from > >> > https://wiki.freebsd.org/DTraceTODO > >> > and started to work on : Get uaddr(), ufunc(), umod(), and usym() > action > >> > funtions working. > >> > I have the data recording action (uaddr) working now, here is an > >> > example: > >> > >> Hi! > >> > >> Hm, these should have been (at least mostly) working since r258902: > >> http://svnweb.freebsd.org/base?view=revision&revision=258902 > >> > >> > > >> > root@bsd:/home/cneira # dtrace -n > >> > 'pid$target::main:{uaddr(uregs[R_PC])}' > >> > -c ./test > >> > dtrace: description 'pid$target::main:' matched 2 probes > >> > abCPU ID FUNCTION:NAME > >> > 0 56282 main:entry > >> > test`main+0x1 > >> > > >> > 0 56281 main:return > >> > test`main+0x23 > >> > > >> > dtrace: pid 9687 has exited > >> > > >> > Here is the output of nm from the test binary I have used to check > this > >> > change. > >> > > >> > U _init_tls@@FBSD_1.0 > >> > 08048380 T _start > >> > 080483a0 t _start1 > >> > 0804814c r abitag > >> > U atexit@@FBSD_1.0 > >> > 08048164 r crt_noinit_tag > >> > 080485c0 T dosomething > >> > 08049764 B environ > >> > U exit@@FBSD_1.0 > >> > 080484f0 t finalizer > >> > 08048560 t frame_dummy > >> > 08048590 T main > >> > U putchar@@FBSD_1.0 > >> > > >> > > >> > root@bsd:/home/cneira # dtrace -c ./test -n 'pid$target::main:entry{ > >> > uaddr(0x080485c0); }' > >> > dtrace: description 'pid$target::main:entry' matched 1 probe > >> > abCPU ID FUNCTION:NAME > >> > 0 56281 main:entry > >> > test`dosomething > >> > > >> > dtrace: pid 9736 has exited > >> > > >> > I'll continue working on the rest, how do I submit a patch with these > >> > changes ? > >> > >> Pasting it inline is generally fine if it's not too large. It's also > >> ok to put it in a public directory somewhere and post a link to it. > >> > >> -Mark > > > > >
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