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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2011-02-21 21:18:13 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2011-02-21 21:18:13 -0500 |
| commit | 15907c36236d638437a1ed3efc0794fda2c9ad22 (patch) | |
| tree | bed4f29709b4352a47cfb43fb56e65e3b61c2104 /src/include/commands/trigger.h | |
| parent | b22e2d6b0254e480f7ffa83ba17cd7a9e4cace98 (diff) | |
Fix dangling-pointer problem in before-row update trigger processing.
ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new
tuple value by seeing if the returned tuple was pointer-equal to the old
one. But the "old one" was in estate->es_junkFilter's result slot, which
would be scribbled on if we had done an EvalPlanQual update in response to
a concurrent update of the target tuple; therefore we were comparing a
dangling pointer to a live one. Given the right set of circumstances we
could get a false match, resulting in not forcing the tuple to be stored in
the slot we thought it was stored in. In the case reported by Maxim Boguk
in bug #5798, this led to "cannot extract system attribute from virtual
tuple" failures when trying to do "RETURNING ctid". I believe there is a
very-low-probability chance of more serious errors, such as generating
incorrect index entries based on the original rather than the
trigger-modified version of the row.
In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers,
ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to
have similar APIs. In the back branches I just changed
ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers
case.
Diffstat (limited to 'src/include/commands/trigger.h')
| -rw-r--r-- | src/include/commands/trigger.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/include/commands/trigger.h b/src/include/commands/trigger.h index db79eb4be73..07ad698e7ff 100644 --- a/src/include/commands/trigger.h +++ b/src/include/commands/trigger.h @@ -149,11 +149,11 @@ extern void ExecBSUpdateTriggers(EState *estate, ResultRelInfo *relinfo); extern void ExecASUpdateTriggers(EState *estate, ResultRelInfo *relinfo); -extern HeapTuple ExecBRUpdateTriggers(EState *estate, +extern TupleTableSlot *ExecBRUpdateTriggers(EState *estate, EPQState *epqstate, ResultRelInfo *relinfo, ItemPointer tupleid, - HeapTuple newtuple); + TupleTableSlot *slot); extern void ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo, ItemPointer tupleid, |