Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756630Ab1FJMXI (ORCPT ); Fri, 10 Jun 2011 08:23:08 -0400 Received: from cantor2.suse.de ([195.135.220.15]:46979 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755452Ab1FJMXF (ORCPT ); Fri, 10 Jun 2011 08:23:05 -0400 Date: Fri, 10 Jun 2011 14:23:00 +0200 Message-ID: From: Takashi Iwai To: Maarten Lankhorst Cc: Linux Kernel Mailing List , alsa-devel@alsa-project.org Subject: Re: Regression in 3.0: oops with module RO/NX in snd_printk when loading snd-hda-intel (gold linker bug?) In-Reply-To: <4DF1EE76.6070001@gmail.com> References: <4DF1EE76.6070001@gmail.com> User-Agent: Wanderlust/2.15.6 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.7 Emacs/23.2 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8627 Lines: 188 At Fri, 10 Jun 2011 12:14:14 +0200, Maarten Lankhorst wrote: > > > Since 3.0.0rc1 I get an oops in alc_auto_parse_customize_define, when it's calling snd_printk, I have module NX/RO enabled, and linked the kernel with gold. the only command I do is 'modprobe snd debug=8; modprobe snd-hda-intel' after init=/bin/bash > > ld --version: GNU gold (GNU Binutils for Ubuntu 2.21.0.20110327) 1.11 > > [ 43.327003] HDA Intel 0000:00:1b.0: enabling device (0000 -> 0002) > [ 43.327012] HDA Intel 0000:00:1b.0: PCI INT A -> GSI 22 (level, low) -> IRQ 22 > [ 43.327063] HDA Intel 0000:00:1b.0: irq 46 for MSI/MSI-X > [ 43.327090] HDA Intel 0000:00:1b.0: setting latency timer to 64 > [ 43.327097] BUG: unable to handle kernel paging request at ffffffffa003c80a > [ 43.327253] IP: [] __snd_printk+0x71/0x110 [snd] > [ 43.327392] PGD 1a25067 PUD 1a29063 PMD 231bce067 PTE 0 > [ 43.327523] Oops: 0000 [#1] PREEMPT SMP > [ 43.327620] CPU 1 > [ 43.327660] Modules linked in: snd_hda_intel(+) snd_hda_codec snd_hwdep snd_pcm_oss snd_pcm snd_page_alloc snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device > snd_timer snd soundcore > [ 43.328104] > [ 43.328134] Pid: 149, comm: modprobe Not tainted 3.0.0-rc2-patser+ #34 To Be Filled By O.E.M. To Be Filled By O.E.M./P67 Pro3 > [ 43.328393] RIP: 0010:[] [] __snd_printk+0x71/0x110 [snd] > [ 43.328581] RSP: 0018:ffff8802310a9c38 EFLAGS: 00010216 > [ 43.328696] RAX: ffff8802310a9c78 RBX: 0000000000000002 RCX: ffffffffa00bea30 > [ 43.328851] RDX: 0000000000000a1a RSI: ffffffffa00be00a RDI: ffffffffa00be00a > [ 43.329006] RBP: ffff8802310a9cb8 R08: 0000000000004401 R09: 0000000000000040 > [ 43.329161] R10: 00000000000000d8 R11: 0000000000000002 R12: ffffffffa00bea30 > [ 43.329316] R13: ffff88023110e800 R14: ffff88023110e800 R15: 0000000000004401 > [ 43.329472] FS: 00007fc62e05c720(0000) GS:ffff88023f480000(0000) knlGS:0000000000000000 > [ 43.329647] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 43.329772] CR2: ffffffffa003c80a CR3: 00000002310b6000 CR4: 00000000000406e0 > [ 43.329927] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 43.330082] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > [ 43.330237] Process modprobe (pid: 149, threadinfo ffff8802310a8000, task ffff8802311216f0) > [ 43.330418] Stack: > [ 43.330462] ffff8802310a9c58 ffffffff81a05080 ffff880200000020 ffff8802310a9cc8 > [ 43.330640] ffff8802310a9c78 ffffffff810bab78 ffff8802310a9c98 0000000005411735 > [ 43.330815] ffff88023110e800 40ff880232ad3000 ffff880232ad3000 ffff880232ad3000 > [ 43.330991] Call Trace: > [ 43.331044] [] ? synchronize_irq+0x58/0xf0 > [ 43.336434] [] azx_probe+0x48b/0x9fb [snd_hda_intel] > [ 43.341867] [] local_pci_probe+0x5f/0xd0 > [ 43.347300] [] pci_device_probe+0x119/0x120 > [ 43.352744] [] ? driver_sysfs_add+0x7a/0xb0 > [ 43.358193] [] driver_probe_device+0xa3/0x2a0 > [ 43.363649] [] __driver_attach+0xab/0xb0 > [ 43.369038] [] ? driver_probe_device+0x2a0/0x2a0 > [ 43.374387] [] bus_for_each_dev+0x5e/0x90 > [ 43.379725] [] driver_attach+0x1e/0x20 > [ 43.385029] [] bus_add_driver+0x160/0x2b0 > [ 43.390172] [] ? 0xffffffffa0020fff > [ 43.395151] [] driver_register+0x74/0x130 > [ 43.400133] [] ? 0xffffffffa0020fff > [ 43.405010] [] __pci_register_driver+0x56/0xd0 > [ 43.409827] [] ? set_memory_nx+0x43/0x50 > [ 43.414645] [] alsa_card_azx_init+0x1e/0x1000 [snd_hda_intel] > [ 43.419550] [] do_one_initcall+0x45/0x170 > [ 43.424489] [] sys_init_module+0xfa/0x250 > [ 43.429420] [] system_call_fastpath+0x16/0x1b > [ 43.434403] Code: 00 00 00 75 6b 48 8b 5d f0 4c 8b 65 f8 c9 c3 48 8d 45 10 c7 45 90 20 00 00 00 48 89 45 98 48 8d 45 c0 48 89 45 a0 80 3e 2f 74 78 <8b> 05 73 d0 00 00 85 db 89 45 b0 48 c7 c6 b3 23 03 a0 48 c7 c0 > [ 43.444891] RIP [] __snd_printk+0x71/0x110 [snd] > [ 43.450012] RSP > [ 43.450013] CR2: ffffffffa003c80a > [ 43.450014] ---[ end trace 890ffb2c861edf22 ]--- > > everything sound loaded modular, all hda codecs too. > > CONFIG_SND_VERBOSE_PRINTK=y > CONFIG_SND_DEBUG=y > CONFIG_SND_DEBUG_VERBOSE=y > > module RO/NX is set, which I assume is causing the problem. > > I don't understand the oops, but disassembly of the specific offset is below, from objdump -S: > > 7de1 is the location of the crash > > #ifdef CONFIG_SND_VERBOSE_PRINTK > /* strip the leading path if the given path is absolute */ > static const char *sanity_file_name(const char *path) > { > if (*path == '/') > 7ddc: 80 3e 2f cmpb $0x2f,(%rsi) > 7ddf: 74 78 je 7e59 <__snd_printk+0xe9> > /* print file and line with a certain printk prefix */ > static int print_snd_pfx(unsigned int level, const char *path, int line, > const char *format) > { > const char *file = sanity_file_name(path); > char tmp[] = "<0>"; > 7de1: 8b 05 00 00 00 00 mov 0x0(%rip),%eax # 7de7 <__snd_printk+0x77> > const char *pfx = level ? KERN_DEBUG : KERN_DEFAULT; > 7de7: 85 db test %ebx,%ebx > /* print file and line with a certain printk prefix */ > static int print_snd_pfx(unsigned int level, const char *path, int line, > const char *format) > { > const char *file = sanity_file_name(path); > char tmp[] = "<0>"; > 7de9: 89 45 b0 mov %eax,-0x50(%rbp) > const char *pfx = level ? KERN_DEBUG : KERN_DEFAULT; > 7dec: 48 c7 c6 00 00 00 00 mov $0x0,%rsi > 7df3: 48 c7 c0 00 00 00 00 mov $0x0,%rax > 7dfa: 48 0f 44 f0 cmove %rax,%rsi > > --- > Seems to me like it's segfaulting when loading <0>\0 (4 bytes, so fits in an integer) to %eax. building all modules with the normal binutils works fine, and makes this crash disappear. > > Is this bug interesting enough that I'll see if I can find the commit which caused this regression? The snd_printk() stuff can be nowadays better presented with %pV. Does the patch below work for you? thanks, Takashi --- diff --git a/sound/core/misc.c b/sound/core/misc.c index 2c41825..095e423 100644 --- a/sound/core/misc.c +++ b/sound/core/misc.c @@ -59,25 +59,8 @@ static const char *sanity_file_name(const char *path) return path; } -/* print file and line with a certain printk prefix */ -static int print_snd_pfx(unsigned int level, const char *path, int line, - const char *format) -{ - const char *file = sanity_file_name(path); - char tmp[] = "<0>"; - const char *pfx = level ? KERN_DEBUG : KERN_DEFAULT; - int ret = 0; - - if (format[0] == '<' && format[2] == '>') { - tmp[1] = format[1]; - pfx = tmp; - ret = 1; - } - printk("%sALSA %s:%d: ", pfx, file, line); - return ret; -} #else -#define print_snd_pfx(level, path, line, format) 0 +#define verbose_printk(level, path, line, fmt, args) printk(fmt, args) #endif #if defined(CONFIG_SND_DEBUG) || defined(CONFIG_SND_VERBOSE_PRINTK) @@ -85,15 +68,29 @@ void __snd_printk(unsigned int level, const char *path, int line, const char *format, ...) { va_list args; - +#ifdef CONFIG_SND_VERBOSE_PRINTK + struct va_format vaf; + char verbose_fmt[] = KERN_DEFAULT "ALSA %s:%d %pV"; +#endif + #ifdef CONFIG_SND_DEBUG if (debug < level) return; #endif + va_start(args, format); - if (print_snd_pfx(level, path, line, format)) - format += 3; /* skip the printk level-prefix */ +#ifdef CONFIG_SND_VERBOSE_PRINTK + vaf.fmt = format; + vaf.va = &args; + if (format[0] == '<' && format[2] == '>') { + memcpy(verbose_fmt, format, 3); + vaf.fmt = format + 3; + } else if (level) + memcpy(verbose_fmt, KERN_DEBUG, 3); + printk(verbose_fmt, sanity_file_name(path), line, &vaf); +#else vprintk(format, args); +#endif va_end(args); } EXPORT_SYMBOL_GPL(__snd_printk); -- 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/