Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261739AbUKRNvi (ORCPT ); Thu, 18 Nov 2004 08:51:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261775AbUKRNvi (ORCPT ); Thu, 18 Nov 2004 08:51:38 -0500 Received: from mail.convergence.de ([212.227.36.84]:29646 "EHLO email.convergence2.de") by vger.kernel.org with ESMTP id S261739AbUKRNvd (ORCPT ); Thu, 18 Nov 2004 08:51:33 -0500 Date: Thu, 18 Nov 2004 14:55:22 +0100 From: Johannes Stezenbach To: Rusty Russell Cc: lkml - Kernel Mailing List , Gerd Knorr Subject: Re: modprobe + request_module() deadlock Message-ID: <20041118135522.GA16910@linuxtv.org> Mail-Followup-To: Johannes Stezenbach , Rusty Russell , lkml - Kernel Mailing List , Gerd Knorr References: <20041117222949.GA9006@linuxtv.org> <1100749702.5865.39.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1100749702.5865.39.camel@localhost.localdomain> User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5157 Lines: 113 On Thu, Nov 18, 2004 at 02:48:22PM +1100, Rusty Russell wrote: > On Wed, 2004-11-17 at 23:29 +0100, Johannes Stezenbach wrote: > > Hi, > > > > it seems that modprobe in newer versions of module-init-tools > > (here: 3.1-pre6) gets an exclusive lock on the module's .ko file: > > > > struct flock lock; > > lock.l_type = F_WRLCK; > > lock.l_whence = SEEK_SET; > > lock.l_start = 0; > > lock.l_len = 1; > > fcntl(fd, F_SETLKW, &lock); > > > > This leads to a deadlock when the loaded module calls > > request_module() in its module_init() function, to load > > a module which in turn depends on the first module. > > My bug, I think. Does this help? Yes and no. The deadlock is gone, but now I get: Nov 18 14:30:03 abc kernel: saa7130/34: v4l2 driver version 0.2.12 loaded Nov 18 14:30:03 abc kernel: saa7134[0]: found at 0000:02:0c.0, rev: 1, irq: 20, latency: 64, mmio: 0xfeafec00 Nov 18 14:30:03 abc kernel: saa7134[0]: subsystem: 1131:6752, board: BMK MPEX Tuner [card=23,insmod option] Nov 18 14:30:03 abc kernel: saa7134[0]: board init: gpio is 10000 Nov 18 14:30:04 abc kernel: saa7134[0]: i2c eeprom 00: 31 11 52 67 06 80 00 01 00 00 00 00 00 00 01 00 Nov 18 14:30:04 abc kernel: saa7134[0]: i2c eeprom 10: 00 ff c2 0f ff ff ff ff ff ff ff ff ff ff ff ff Nov 18 14:30:04 abc kernel: saa7134[0]: i2c eeprom 20: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff Nov 18 14:30:04 abc kernel: saa7134[0]: i2c eeprom 30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff Nov 18 14:30:04 abc kernel: saa7134[0]/irq[10,91590999]: r=0x4000 s=0x00 GPIO16? Nov 18 14:30:04 abc kernel: saa7134[0]/irq: looping -- clearing all enable bits (Maybe Gerd has an idea what's wrong with the irq. BTW, Documentation/video4linux/CARDLIST.saa7134 is out of date wrt drivers/media/video/saa7134/saa7134.h) Nov 18 14:30:04 abc kernel: tuner: chip found at addr 0xc0 i2c-bus saa7134[0] Nov 18 14:30:04 abc kernel: tuner: type set to 5 (Philips PAL_BG (FI1216 and compatibles)) by saa7134[0] Nov 18 14:30:04 abc udev[16759]: configured rule in '/etc/udev/rules.d/compat-full.rules' at line 29 applied, added symlNov 18 14:30:04 abc udev[16759]: configured rule in '/etc/udev/rules.d/devfs.rules' at line 70 applied, 'i2c-2' becomes Nov 18 14:30:04 abc udev[16759]: creating device node '/dev/i2c/2' Nov 18 14:30:04 abc kernel: saa7134_empress: Unknown symbol saa7134_devlist Nov 18 14:30:04 abc kernel: saa7134_empress: Unknown symbol saa7134_common_ioctl Nov 18 14:30:04 abc kernel: saa7134_empress: Unknown symbol saa7134_boards Nov 18 14:30:04 abc kernel: saa7134_empress: Unknown symbol saa7134_ts_register Nov 18 14:30:04 abc kernel: saa7134_empress: Unknown symbol saa7134_print_ioctl Nov 18 14:30:04 abc kernel: saa7134_empress: Unknown symbol saa7134_ts_qops Nov 18 14:30:04 abc kernel: saa7134_empress: Unknown symbol saa7134_i2c_call_clients Nov 18 14:30:04 abc kernel: saa7134_empress: Unknown symbol saa7134_ts_unregister Nov 18 14:30:04 abc modprobe: FATAL: Error inserting saa7134_empress (/lib/modules/2.6.10-rc2/kernel/drivers/media/video/saa7134/saa7134-empress.ko): Unknown symbol in module, or unknown parameter (see dmesg) However, the symbols are exported: $ grep EXPORT_SYMBOL *.c saa7134-core.c:EXPORT_SYMBOL(saa7134_ts_register); saa7134-core.c:EXPORT_SYMBOL(saa7134_ts_unregister); saa7134-core.c:EXPORT_SYMBOL(saa7134_print_ioctl); saa7134-core.c:EXPORT_SYMBOL(saa7134_i2c_call_clients); saa7134-core.c:EXPORT_SYMBOL(saa7134_devlist); saa7134-core.c:EXPORT_SYMBOL(saa7134_boards); saa7134-ts.c:EXPORT_SYMBOL_GPL(saa7134_ts_qops); saa7134-video.c:EXPORT_SYMBOL(saa7134_common_ioctl); If I 'modprobe saa7134-empress' manually after saa7134.ko is loaded, it works. This is an unpatched 2.6.10-rc2 kernel, BTW. Johannes > --- modprobe.c.~70~ 2004-09-30 20:16:19.000000000 +1000 > +++ modprobe.c 2004-11-18 14:44:57.000000000 +1100 > @@ -735,6 +735,11 @@ > strip_vermagic, strip_modversion); > } > > + /* Don't do ANYTHING if already in kernel. */ > + if (!ignore_proc > + && module_in_kernel(newname ?: mod->modname, NULL) == 1) > + goto exists_error; > + > fd = lock_file(mod->filename); > if (fd < 0) { > error("Could not open '%s': %s\n", > @@ -742,11 +747,6 @@ > goto out_optstring; > } > > - /* Don't do ANYTHING if already in kernel. */ > - if (!ignore_proc > - && module_in_kernel(newname ?: mod->modname, NULL) == 1) > - goto exists_error; > - > command = find_command(mod->modname, commands); > if (command && !ignore_commands) { > /* It might recurse: unlock. */ > @@ -799,7 +799,7 @@ > if (first_time) > error("Module %s already in kernel.\n", > newname ?: mod->modname); > - goto out_unlock; > + goto out_optstring; > } > > /* Do recursive removal. */ > > -- > A bad analogy is like a leaky screwdriver -- Richard Braakman > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/