[BZ-2226] Based_Pointer_Test::mmap_remap_test incorrectly fails if remap'd region overlaps

[jwillemsen]

Field	Value
Bugzilla ID	2226
Reporter	James Megquier
Assigned to	Steve Williams
Product	ACE
Component	ACE Tests
Version	5.4.7
Platform / OS	x86 / Linux
Priority	P3
Severity	minor
Status	RESOLVED
Resolution	FIXED
Created	2005-08-29 19:52:34 -0500
Depends on	#2218

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Originally posted by James Megquier on 2005-08-29 19:52:34 -0500

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In Based_Pointer_Test::mmap_remap_test (around line 305 in the CVS trunk), the
final test checks that the old base address ('oba') has not only been removed
from the Based_Pointer_Repo, but that it also does not fall within the new
mmap'd address range.

However, on this platform at least, the OS has decided to grow the mmap area
downwards, but overlapping the original area. This generates the error "Old
base address not removed after MMAP remap", even though the old base addr is
correctly removed.

Old alloc: 0x1000 @ 0xb7fd3000
New alloc: 0x3000 @ 0xb7fd1000

Both end at 0xb7fd4000; old base address is within the new mapping.

I think the Right Thing(tm) is to remove the test at line 305 of
tests/Based_Pointer_Test.cpp

[jwillemsen]

Originally posted by James Megquier on 2005-08-29 19:53:37 -0500 (Bugzilla comment 1)

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Noting bug 2218 as a dependency.

[jwillemsen]

Originally posted by @jwillemsen on 2005-08-30 01:09:26 -0500 (Bugzilla comment 2)

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Steve, as author of this test, can you have a look at this report?

[jwillemsen]

Originally posted by James Megquier on 2005-08-30 07:59:34 -0500 (Bugzilla comment 3)

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Actually, I think the test could be rewritten as:

if (ba == oba)
... error ...

Since we required the new mapping to be at a different address than oba, this check should tell us if the
entry at "oba" has been successfully removed from the repo.

[jwillemsen]

Originally posted by Steve Williams on 2005-08-30 13:42:01 -0500 (Bugzilla comment 4)

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I agree the test should be changed. The test as it is now assumes that the old
and new region do not overlap. The check should be that the old base address has
been removed, not that is doesn't map to an existing segment.

Changing line 305 from:

if(ba)

to

if(ba == oba)

as suggested should do the trick.

[jwillemsen]

Originally posted by @jwillemsen on 2005-08-30 13:52:14 -0500 (Bugzilla comment 5)

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Tue Aug 30 18:50:12 UTC 2005 Johnny Willemsen jwillemsen@remedy.nl

    * tests/Based_Pointer_Test.cpp:
      Corrected remap test, some platforms grow the mmap area
      downwards. This fixes bugzilla bug 2226. Thanks to
      <jmegq at radiance dot com> for reporting this and
      Steve Williams <steve at telxio dot com> for validating this.