From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XON0v-0004bO-Fz for barebox@lists.infradead.org; Mon, 01 Sep 2014 08:31:02 +0000 Date: Mon, 1 Sep 2014 10:30:33 +0200 From: Sascha Hauer Message-ID: <20140901083033.GF5352@pengutronix.de> References: <1409212205.4914.6.camel@lws-gamez.phytec.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1409212205.4914.6.camel@lws-gamez.phytec.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [BUG] readline history To: Teresa Gamez Cc: barebox@lists.infradead.org Hi Teresa, On Thu, Aug 28, 2014 at 09:50:05AM +0200, Teresa Gamez wrote: > Hello Sascha, > > I noticed a bug on the latest master. > When no history is present and I hit the arrow up key, I get: > > unable to handle NULL pointer dereference at address 0x00000001 > pc : [<9fe243ba>] lr : [<9fe268cf>] > sp : 9ffff9d0 ip : 00000016 fp : 00000002 > r10: 00000001 r9 : 9fe549dc r8 : 9fe65d08 > r7 : 00000400 r6 : 00000001 r5 : 00000000 r4 : 9fe66258 > r3 : 00000000 r2 : 00000000 r1 : 00000001 r0 : 9fe66258 > Flags: nZCv IRQs off FIQs on Mode SVC_32 > [<9fe243ba>] (strcpy+0xa/0xe) from [<9fe268cf>] (readline+0x363/0x4e0) > [<9fe268cf>] (readline+0x363/0x4e0) from [<9fe05469>] (file_get > +0x49/0x110) > > I could bisect it to this commit: > > > ada160a34a1ec8421d5bb7b9dd746294668a5130 is the first bad commit > commit ada160a34a1ec8421d5bb7b9dd746294668a5130 > Author: Sascha Hauer > Date: Tue Jul 29 11:54:26 2014 +0200 Damned. While working on that patch I had exactly this problem and thought I tested this case. Apparantly I didn't :( The following should fix this: Sascha >From 7fd0d972f71610c25276ca387164b1fd71fb74be Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Mon, 1 Sep 2014 10:21:44 +0200 Subject: [PATCH] readline: Fix history prev when history is empty We cannot use list_entry() on an empty list. Without history we have to return an empty line. This fixes a crash when the cursor up button is pressed and no command has been entered previously. Broken since: commit ada160a34a1ec8421d5bb7b9dd746294668a5130 Author: Sascha Hauer Date: Tue Jul 29 11:54:26 2014 +0200 readline: reimplement history functions Signed-off-by: Sascha Hauer Reported-by: Teresa Gamez --- lib/readline.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/lib/readline.c b/lib/readline.c index b70bca8..e855abd 100644 --- a/lib/readline.c +++ b/lib/readline.c @@ -68,6 +68,9 @@ static const char *hist_prev(void) struct history *history; if (history_current->prev == &history_list) { + if (list_empty(&history_list)) + return ""; + history = list_entry(history_current, struct history, list); getcmd_cbeep(); return history->line; -- 2.1.0 -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox