[tor-bugs] #9299 [Tor]: Dump stack traces on assertion, crash, or general trouble

Tor Bug Tracker & Wiki blackhole at torproject.org
Fri Feb 21 03:49:39 UTC 2014


#9299: Dump stack traces on assertion, crash, or general trouble
-----------------------------+---------------------------------
     Reporter:  nickm        |      Owner:
         Type:  enhancement  |     Status:  closed
     Priority:  normal       |  Milestone:  Tor: 0.2.5.x-final
    Component:  Tor          |    Version:
   Resolution:  implemented  |   Keywords:  tor-relay debugging
Actual Points:               |  Parent ID:
       Points:               |
-----------------------------+---------------------------------

Comment (by cypherpunks):

 {{{
 -fomit-frame-pointer
     Don't keep the frame pointer in a register for functions that don't
 need one. This avoids the instructions to save, set up and restore frame
 pointers; it also makes an extra register available in many functions. It
 also makes debugging impossible on some machines.

     On some machines, such as the VAX, this flag has no effect, because
 the standard calling sequence automatically handles the frame pointer and
 nothing is saved by pretending it doesn't exist. The machine-description
 macro FRAME_POINTER_REQUIRED controls whether a target machine supports
 this flag. See Register Usage.

     Starting with GCC version 4.6, the default setting (when not
 optimizing for size) for 32-bit GNU/Linux x86 and 32-bit Darwin x86
 targets has been changed to -fomit-frame-pointer. The default can be
 reverted to -fno-omit-frame-pointer by configuring GCC with the --enable-
 frame-pointer configure option.

     Enabled at levels -O, -O2, -O3, -Os.
 }}}
 Even better. Lets assume FPO was enabled for Tor.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9299#comment:12>
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