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record: Prevent a crash on recording client disconnect.

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Execute the following steps to reproduce the issue.

  1. Run at least two recording clients simultaneously.
     $ cnee --record --request-range 1-127 &
     $ cnee --record --request-range 1-127 &
  2. Kill the recording clients.
     $ killall cnee
  3. Give X server something to do so that the clients are closed.
     $ xinput list
     $ xinput list

As a result RecordUninstallHooks accesses NullClient, because
RecordAClientStateChange doesn't clean the recording clients up
properly.

Fix RecordUninstallHooks to fail locally on an assertion instead of
much later in privates code, if NullClient is still accessed because
of some other bug. Fix RecordAClientStateChange to iterate through all
contexts so that modifications of the iterated array during iteration
don't cause contexts to be skipped.

Signed-off-by: Rami Ylimäki <ext-rami.ylimaki@nokia.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
This commit is contained in:
Rami Ylimäki 2010-06-22 14:57:20 +03:00 committed by Keith Packard
parent 660f6ab549
commit 8b65f2edb4
1 changed files with 17 additions and 5 deletions
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22
record/record.c
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@ -997,10 +997,11 @@ RecordUninstallHooks(RecordClientsAndProtocolPtr pRCAP, XID oneclient)
ClientPtr pClient = clients[CLIENT_ID(client)];
int c;
Bool otherRCAPwantsProcVector = FALSE;
RecordClientPrivatePtr pClientPriv =
RecordClientPrivate(pClient);
RecordClientPrivatePtr pClientPriv = NULL;
assert (pClient && RecordClientPrivate(pClient));
assert (pClient);
pClientPriv = RecordClientPrivate(pClient);
assert (pClientPriv);
memcpy(pClientPriv->recordVector, pClientPriv->originalVector,
sizeof (pClientPriv->recordVector));
@ -2813,6 +2814,8 @@ RecordAClientStateChange(CallbackListPtr *pcbl, pointer nulldata, pointer callda
NewClientInfoRec *pci = (NewClientInfoRec *)calldata;
int i;
ClientPtr pClient = pci->client;
RecordContextPtr *ppAllContextsCopy = NULL;
int numContextsCopy = 0;
switch (pClient->clientState)
{
@ -2834,10 +2837,17 @@ RecordAClientStateChange(CallbackListPtr *pcbl, pointer nulldata, pointer callda
case ClientStateGone:
case ClientStateRetained: /* client disconnected */
for (i = 0; i < numContexts; i++)
/* RecordDisableContext modifies contents of ppAllContexts. */
numContextsCopy = numContexts;
ppAllContextsCopy = malloc(numContextsCopy * sizeof(RecordContextPtr));
assert(ppAllContextsCopy);
memcpy(ppAllContextsCopy, ppAllContexts, numContextsCopy * sizeof(RecordContextPtr));
for (i = 0; i < numContextsCopy; i++)
{
RecordClientsAndProtocolPtr pRCAP;
RecordContextPtr pContext = ppAllContexts[i];
RecordContextPtr pContext = ppAllContextsCopy[i];
int pos;
if (pContext->pRecordingClient == pClient)
@ -2851,6 +2861,8 @@ RecordAClientStateChange(CallbackListPtr *pcbl, pointer nulldata, pointer callda
RecordDeleteClientFromRCAP(pRCAP, pos);
}
}
free(ppAllContextsCopy);
break;
default: