Re: mISDNcapid still segfaults sometimes

Am 24.05.2012 13:22, schrieb Tobias Powalowski:

> plci_cc_disconnect_ind():PLCI 0101: Got Disconnect with cause 16 (0x10)
> loc 01
> 
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 0xb7b85b40 (LWP 6543)]
> 0x080580ca in get_lPLCI4Id (plci=0xb7201e90, appId=2) at mplci.c:245
> 245     mplci.c: Datei oder Verzeichnis nicht gefunden.
> (gdb) backtrace
> #0  0x080580ca in get_lPLCI4Id (plci=0xb7201e90, appId=2) at mplci.c:245
> #1  0x08057930 in plciAttach_lPLCI (plci=0xb7201e90, lp=0xb7201e90)
>     at mplci.c:77
> #2  0x08057bc4 in plciHandleSetupInd (plci=0xb7201e90, pr=5, mc=0xb6849b70)
>     at mplci.c:138
> #3  0x08057e6a in plci_l3l4 (plci=0xb7201e90, pr=5, l3m=0xb72004a8)
>     at mplci.c:185
> #4  0x0804d34a in l3_callback (l3=0x8093c68, cmd=5, pid=65629,
> l3m=0xb72004a8)
>     at daemon.c:951
> #5  0xb7f98fe0 in mISDN_l3up (l3p=0xb7201df8, prim=5, l3m=0xb72004a8)
>     at layer3/layer3.c:393
> #6  0xb7f94718 in l3dss1_setup (pc=0xb7201df8, pr=12552, l3m=0xb72004a8)
>     at layer3/dss1user.c:879
> #7  0xb7f97669 in dss1_fromdown (l3=0x8093c68, msg=0xb7200468)
>     at layer3/dss1user.c:2247
> #8  0xb7f9a1c3 in handle_l2msg (l3=0x8093c68, mb=0xb7200468)
>     at layer3/layer3.c:784
> #9  0xb7f9acd4 in layer3_thread (arg=0x8093c68) at layer3/layer3.c:922
> #10 0xb7e36ce8 in start_thread () from /lib/libpthread.so.0
> #11 0xb7d754de in clone () from /lib/libc.so.6
> 

OK this would be at
if (appId == lp->lc->Appl->AppId)

so I assume lp->lc is NULL or lp->lc->Appl is NULL.

This patch should prevent this crash, but maybe it is not the final
solution. (Is also on git.misdn.eu).

Karsten

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From 78179356a6c6f78118e366b6cb49e433604a2f7f Mon Sep 17 00:00:00 2001
From: Karsten Keil <[email protected]>
Date: Thu, 24 May 2012 15:25:48 +0200
Subject: [PATCH] Avoid crash in get_lPLCI4Id()

Maybe in a race on setup/cleanup the links
are broken.

Signed-off-by: Karsten Keil <[email protected]>
---
 capi20/mplci.c |   14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/capi20/mplci.c b/capi20/mplci.c
index 9ea5885..e46ece3 100644
--- a/capi20/mplci.c
+++ b/capi20/mplci.c
@@ -237,13 +237,23 @@ int mPLCISendMessage(struct lController *lc, struct mc_buf *mc)
 struct lPLCI *get_lPLCI4Id(struct mPLCI *plci, uint16_t appId)
 {
 	struct lPLCI *lp;
+	struct lController *lc;
+	struct mApplication *app;
 
 	if (!plci)
 		return NULL;
 	lp = plci->lPLCIs;
 	while (lp) {
-		if (appId == lp->lc->Appl->AppId)
-			break;
+		lc = lp->lc;
+		if (lc) {
+			app = lc->Appl;
+			if (app) {
+				if (appId == app->AppId)
+					break;
+			} else
+				wprint("PLCI:%04x lc no application assigned\n", plci->plci);
+		} else
+			wprint("PLCI:%04x lp no lc assigned\n", plci->plci);
 		lp = lp->next;
 	}
 	return lp;
-- 
1.7.3.4