[Bug libfortran/25697] New: libfortran - Segmentation fault/ Bad Address on unformatted read

[Bug libfortran/25697] New: libfortran - Segmentation fault/ Bad Address on unformatted read

[dir at lanl dot gov]

On the Macintosh this program gives a "Segmentation fault" on Linux it gives
"Fortran runtime error: Bad address"

dranta:~/tests/gfortran-D] dir% gfortran -o write19 write19.f
[dranta:~/tests/gfortran-D] dir% write19
Segmentation fault
[dranta:~/tests/gfortran-D] dir% cat write19.f
      integer data(500)
      do i = 1,500
        data(i)=-1
      enddo
      open(unit=11,status='scratch',form='unformatted')
       read(11,end=        1000 )data
 1000  continue
       backspace 11
       write(11)data
       read(11,end=        1001 )data
 1001  continue
       backspace 11
       backspace 11
       write(11)data
       rewind 11
       backspace 11
       read(11,end=        1002 )data
 1002  continue
       read(11,end=        1003 )data
 1003  continue
       close(11)
       end

dranta:~/tests/gfortran-D] dir% gfortran --v
Using built-in specs.
Target: powerpc-apple-darwin8.3.0
Configured with: ../gcc/configure --prefix=/Users/dir/gfortran
--enable-languages=c,f95
Thread model: posix
gcc version 4.2.0 20060106 (experimental)
[dranta:~/tests/gfortran-D] dir%


-- 
           Summary: libfortran - Segmentation fault/ Bad Address on
                    unformatted read
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dir at lanl dot gov


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[dir at lanl dot gov]

------- Comment #1 from dir at lanl dot gov  2006-01-06 20:11 -------
Here is a shorter one that also crashes on the Macintosh -

[dranta:~/tests/gfortran-D] dir% gfortran -o write20 write20.f
[dranta:~/tests/gfortran-D] dir% write20
Segmentation fault
[dranta:~/tests/gfortran-D] dir% cat write20.f
      integer data(500)
      do i = 1,500
        data(i)=-1
      enddo
      open(unit=11,status='scratch',form='unformatted')
       write(11)data
       read(11,end=        1000 )data
 1000  continue
       backspace 11
       backspace 11
       write(11)data
       rewind 11
       read(11,end=        1001 )data
 1001  continue
       read(11,end=        1002 )data
 1002  continue
       close(11)
       end


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #2 from jvdelisle at gcc dot gnu dot org  2006-01-07 00:59 -------
Confirmed


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-01-07 00:59:33
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #3 from jvdelisle at gcc dot gnu dot org  2006-01-08 09:40 -------
I will take a gander at this.


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jvdelisle at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2006-01-07 00:59:33         |2006-01-08 09:40:18
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[dir at lanl dot gov]

------- Comment #4 from dir at lanl dot gov  2006-01-09 01:52 -------
Having a read immediately follow a write - seems to cause the errors.  I have
run several million I/O tests where the only legal thing not permitted is a
read immediately after a write -  without getting a single error.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #5 from jvdelisle at gcc dot gnu dot org  2006-01-09 05:27 -------
This one is cute.  We have user space data showing up in the bytes_left
counter.  Really!  I may have found the root of all evils.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[dir at lanl dot gov]

------- Comment #6 from dir at lanl dot gov  2006-01-09 18:18 -------
  Hurray - Let there be an end to I/O problems.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #7 from jvdelisle at gcc dot gnu dot org  2006-01-11 03:45 -------
Created an attachment (id=10618)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10618&action=view)
Prposed patch for pr 25697

Dale, can you give this s spin.  I think this fixes it.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[dir at lanl dot gov]

------- Comment #8 from dir at lanl dot gov  2006-01-11 15:34 -------
That fixed all the posted examples and it passed the 1048576 tests of all
combinations of read,write,backspace, and rewind taken 10 at a time writing a
single word, but when I increased the write size to 500 words it failed. The
strange thing with this example is that if one of the five writes is removed it
no longer fails (buffer flush problem ?) -

[dranta:~/tests/gfortran-D] dir% gfortran -o write21 write21.f
[dranta:~/tests/gfortran-D] dir% write21
Segmentation fault
[dranta:~/tests/gfortran-D] dir% cat write21.f
      integer data(500)
      do i = 1,500
        data(i)=-1
      enddo
      open(unit=11,status='scratch',form='unformatted')
       write(11)data
       write(11)data
       write(11)data
       write(11)data
       write(11)data
       read(11,end=        1000 )data
       call abort()
 1000  continue
       backspace 11
       backspace 11
       read(11,end=        1001 )data
 1001  continue
       read(11,end=        1002 )data
       call abort()
 1002  continue
       close(11)
       end


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[dir at lanl dot gov]

------- Comment #9 from dir at lanl dot gov  2006-01-11 16:02 -------
With a larger amount of data it only takes one write -


[dranta:~/tests/gfortran-D] dir% gfortran -o write22 write22.f
[dranta:~/tests/gfortran-D] dir% write22
Bus error
[dranta:~/tests/gfortran-D] dir% cat write22.f
      integer data(10000)
      do i = 1,10000
        data(i)=-1
      enddo
      open(unit=11,status='scratch',form='unformatted')
       data(1)=1
       data(10000)=-1
       write(11)data
       read(11,end=        1000 )data
       call abort()
 1000  continue
       backspace 11
       backspace 11
       read(11,end=        1001 )data
        if(data(1).ne.   1.or.data(10000).ne.  -1)then
            call abort()
        endif
 1001  continue
       read(11,end=        1002 )data
       call abort()
 1002  continue
       close(11)
       end


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[dir at lanl dot gov]

------- Comment #10 from dir at lanl dot gov  2006-01-11 16:50 -------
My thought on a possible fix is that the I/O buffers should be dumped before
the read whenever a read immediately follows a write, but I have no idea how
you would detect the situation. 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #11 from jvdelisle at gcc dot gnu dot org  2006-01-12 06:46 -------
This is interesting.  I noticed before that with the previous test case i could
get two different error message depending on the size of the data.  I will have
to study this a bit closer.

BTW Thanks for the testing.  We really wantthis I/O bullet proof as we can get
it.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #12 from jvdelisle at gcc dot gnu dot org  2006-01-18 06:21 -------
Subject: Bug 25697

Author: jvdelisle
Date: Wed Jan 18 06:21:28 2006
New Revision: 109870

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=109870
Log:
2006-01-17  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

        PR libgfortran/25697
        * io/transfer.c (us_read): Detect end of file condition from previous
        operations and bail out (no need to pre-position).

Modified:
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/io/transfer.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #13 from jvdelisle at gcc dot gnu dot org  2006-01-18 06:23 -------
Subject: Bug 25697

Author: jvdelisle
Date: Wed Jan 18 06:23:24 2006
New Revision: 109872

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=109872
Log:
2006-01-17  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

        PR fortran/25697
        * gfortran.dg/read_eof.f90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/read_eof.f90
Modified:
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #14 from jvdelisle at gcc dot gnu dot org  2006-01-18 06:41 -------
Fixed on 4.2, will commit to 4.1 in a few days.  PR 25835 remains a separate
problem.  Cases in comment #8 and #9 go to PR25835.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #15 from jvdelisle at gcc dot gnu dot org  2006-01-21 07:19 -------
Subject: Bug 25697

Author: jvdelisle
Date: Sat Jan 21 07:19:39 2006
New Revision: 110061

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=110061
Log:
2006-01-20  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

        PR libgfortran/25697
        * io/transfer.c (us_read): Detect end of file condition from previous
        operations and bail out (no need to pre-position).

Modified:
    branches/gcc-4_1-branch/libgfortran/ChangeLog
    branches/gcc-4_1-branch/libgfortran/io/transfer.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #16 from jvdelisle at gcc dot gnu dot org  2006-01-21 07:21 -------
Subject: Bug 25697

Author: jvdelisle
Date: Sat Jan 21 07:21:11 2006
New Revision: 110062

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=110062
Log:
2006-01-20  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

        PR fortran/25697
        * gfortran.dg/read_eof.f90: New test.

Added:
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/read_eof.f90
Modified:
    branches/gcc-4_1-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697

[Bug libfortran/25697] libfortran - Segmentation fault/ Bad Address on unformatted read

[jvdelisle at gcc dot gnu dot org]

------- Comment #17 from jvdelisle at gcc dot gnu dot org  2006-01-25 07:41 -------
Fixed on 4.1 and 4.2


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25697