From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA595C4361A for ; Fri, 4 Dec 2020 15:56:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4B6D22B30 for ; Fri, 4 Dec 2020 15:56:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730682AbgLDP4E (ORCPT ); Fri, 4 Dec 2020 10:56:04 -0500 Received: from smtprelay0226.hostedemail.com ([216.40.44.226]:45136 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727125AbgLDP4E (ORCPT ); Fri, 4 Dec 2020 10:56:04 -0500 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay01.hostedemail.com (Postfix) with ESMTP id 96467100E7B46; Fri, 4 Dec 2020 15:55:23 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: foot04_4212f4e273c5 X-Filterd-Recvd-Size: 5091 Received: from XPS-9350.home (unknown [47.151.137.21]) (Authenticated sender: joe@perches.com) by omf07.hostedemail.com (Postfix) with ESMTPA; Fri, 4 Dec 2020 15:55:22 +0000 (UTC) Message-ID: <189ad2584d80d915d3c9f76c044947f83ca5ebf8.camel@perches.com> Subject: Re: [PATCH] powerpc/xmon: Change printk() to pr_cont() From: Joe Perches To: Michael Ellerman , Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Fri, 04 Dec 2020 07:55:21 -0800 In-Reply-To: <87h7p1vnym.fsf@mpe.ellerman.id.au> References: <87h7p1vnym.fsf@mpe.ellerman.id.au> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.38.1-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2020-12-04 at 21:56 +1100, Michael Ellerman wrote: > Christophe Leroy writes: > > Since some time now, printk() adds carriage return, leading to > > unusable xmon output: > > > > [ 54.288722] sysrq: Entering xmon > > [ 54.292209] Vector: 0 at [cace3d2c] > > [ 54.292274] pc: > > [ 54.292331] c0023650 > > ... > > > diff --git a/arch/powerpc/xmon/nonstdio.c b/arch/powerpc/xmon/nonstdio.c > > index 5c1a50912229..9b0d85bff021 100644 > > --- a/arch/powerpc/xmon/nonstdio.c > > +++ b/arch/powerpc/xmon/nonstdio.c > > @@ -178,7 +178,7 @@ void xmon_printf(const char *format, ...) > >   > > > >   if (n && rc == 0) { > >   /* No udbg hooks, fallback to printk() - dangerous */ > > - printk("%s", xmon_outbuf); > > + pr_cont("%s", xmon_outbuf); > >   } > > Ah OK, in the case where there's no udbg backend. We basically always > have a udbg backend on 64-bit, via hvc console. Which explains why we > haven't noticed it. > > Will pick up the patch. > > cheers Perhaps all of these bare printks should be inspected for defects: $ git grep -P -n '\bprintk\s*\(\s*(?!KERN_\w+)"[^\\n]*"' arch/powerpc arch/powerpc/kernel/process.c:1475: printk("NIP: "REG" LR: "REG" CTR: "REG"\n", arch/powerpc/kernel/process.c:1479: printk("MSR: "REG" ", regs->msr); arch/powerpc/kernel/process.c:1513: printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip); arch/powerpc/kernel/process.c:1514: printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link); arch/powerpc/kernel/process.c:2157: printk("%s["REG"] ["REG"] %pS", arch/powerpc/kernel/traps.c:621: printk("Caused by (from MCSR=%lx): ", reason); arch/powerpc/kernel/traps.c:726: printk("Caused by (from MCSR=%lx): ", reason); arch/powerpc/kernel/traps.c:766: printk("Caused by (from MCSR=%lx): ", reason); arch/powerpc/kernel/traps.c:791: printk("Caused by (from SRR1=%lx): ", reason); arch/powerpc/kernel/udbg.c:95: printk("%s", s); arch/powerpc/math-emu/fabs.c:13: printk("%s: D %p, B %p: ", __func__, frD, frB); arch/powerpc/math-emu/fctiw.c:22: printk("%s: D %p, B %p: ", __func__, frD, frB); arch/powerpc/math-emu/fctiwz.c:29: printk("%s: D %p, B %p: ", __func__, frD, frB); arch/powerpc/math-emu/fmr.c:13: printk("%s: D %p, B %p: ", __func__, frD, frB); arch/powerpc/math-emu/fnabs.c:13: printk("%s: D %p, B %p: ", __func__, frD, frB); arch/powerpc/math-emu/fneg.c:13: printk("%s: D %p, B %p: ", __func__, frD, frB); arch/powerpc/math-emu/lfd.c:15: printk("%s: D %p, ea %p: ", __func__, frD, ea); arch/powerpc/math-emu/stfd.c:11: printk("%s: S %p, ea %p: ", __func__, frS, ea); arch/powerpc/mm/nohash/44x.c:192: printk("%d ", i); arch/powerpc/platforms/4xx/machine_check.c:19: printk("Data"); arch/powerpc/platforms/chrp/pci.c:256: printk(" at %llx", (unsigned long long)r.start); arch/powerpc/platforms/embedded6xx/ls_uart.c:47: printk("%c", in_8(avr_addr + UART_RX)); arch/powerpc/platforms/powermac/pfunc_core.c:83: printk("%s", title); arch/powerpc/platforms/powermac/pfunc_core.c:85: printk("%02x ", *((u8 *)blob)); arch/powerpc/platforms/powernv/pci-ioda.c:81: printk("%spci %s: [PE# %.2x] %pV", arch/powerpc/sysdev/tsi108_pci.c:63: printk("PCI CFG write : "); arch/powerpc/sysdev/tsi108_pci.c:64: printk("%d:0x%x:0x%x ", bus->number, devfunc, offset); arch/powerpc/sysdev/tsi108_pci.c:65: printk("%d ADDR=0x%08x ", len, (uint) cfg_addr); arch/powerpc/sysdev/tsi108_pci.c:164: printk("PCI CFG read : "); arch/powerpc/sysdev/tsi108_pci.c:165: printk("%d:0x%x:0x%x ", bus->number, devfn, offset); arch/powerpc/sysdev/tsi108_pci.c:166: printk("%d ADDR=0x%08x ", len, (uint) cfg_addr); arch/powerpc/sysdev/tsi108_pci.c:315: printk("cfg_ctl=0x%08x ", temp); arch/powerpc/xmon/nonstdio.c:181: printk("%s", xmon_outbuf);