[Bug libitm/51855] New: improve calculation of stack bottom in libitm's undolog

[Bug libitm/51855] New: improve calculation of stack bottom in libitm's undolog

[torvald at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51855

             Bug #: 51855
           Summary: improve calculation of stack bottom in libitm's
                    undolog
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: libitm
        AssignedTo: torvald@gcc.gnu.org
        ReportedBy: torvald@gcc.gnu.org
                CC: aldyh@gcc.gnu.org, rth@gcc.gnu.org


It would be good to improve how libitm calculates the bottom of the stack space
of the current thread.  It needs to do that to prevent rolling back
transactional writes to this space because this would corrupt the stack frames
of the transaction rollback functions.  For 4.7, we handle this with
__builtin_dwarf_cfa() and an additional buffer zone of 256 bytes to deal with
another __builtin_memcpy() call that we need during rollback and whose stack
frame size we can't measure at runtime.  For 4.8, we should think about
improving that, perhaps based on the existing boehm-gc code for this
(GC_get_stack_base() in os_dep.c).

[Bug libitm/51855] improve calculation of stack bottom in libitm's undolog

[torvald at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51855

torvald at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-01-13
   Target Milestone|---                         |4.8.0
     Ever Confirmed|0                           |1

[Bug libitm/51855] improve calculation of stack bottom in libitm's undolog

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51855

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-01-13 23:41:44 UTC ---
Hmm, do you know if this works with a split stack?

[Bug libitm/51855] improve calculation of stack bottom in libitm's undolog

[torvald at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51855

--- Comment #2 from torvald at gcc dot gnu.org 2012-01-13 23:45:12 UTC ---
Author: torvald
Date: Fri Jan 13 23:45:06 2012
New Revision: 183172

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=183172
Log:
libitm: Filter out undo writes that overlap with the libitm stack.

    PR libitm/51855
    * config/generic/tls.h (GTM::mask_stack_top): New.
    (GTM::mask_stack_bottom): Declare.
    * config/generic/tls.c (GTM::mask_stack_bottom): New.
    * local.cc (gtm_undolog::rollback): Filter out any updates that
    overlap the libitm stack.  Add current transaction as parameter.
    * libitm_i.h (GTM::gtm_undolog::rollback): Adapt.
    * beginend.cc (GTM::gtm_thread::rollback): Adapt.
    * testsuite/libitm.c/stackundo.c: New test.

Added:
    trunk/libitm/testsuite/libitm.c/stackundo.c
Modified:
    trunk/libitm/ChangeLog
    trunk/libitm/beginend.cc
    trunk/libitm/config/generic/tls.cc
    trunk/libitm/config/generic/tls.h
    trunk/libitm/libitm_i.h
    trunk/libitm/local.cc

[Bug libitm/51855] improve calculation of stack bottom in libitm's undolog

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51855

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.0                       |4.8.1

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-03-22 14:44:17 UTC ---
GCC 4.8.0 is being released, adjusting target milestone.

[Bug libitm/51855] improve calculation of stack bottom in libitm's undolog

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51855

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.1                       |4.8.2

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.1 has been released.

[Bug libitm/51855] improve calculation of stack bottom in libitm's undolog

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51855

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.2                       |4.8.3

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.2 has been released.

[Bug libitm/51855] improve calculation of stack bottom in libitm's undolog

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51855

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.3                       |---