Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753925Ab1BAJaA (ORCPT ); Tue, 1 Feb 2011 04:30:00 -0500 Received: from mail-vw0-f46.google.com ([209.85.212.46]:39893 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751495Ab1BAJ36 (ORCPT ); Tue, 1 Feb 2011 04:29:58 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:content-transfer-encoding :in-reply-to:user-agent; b=iS32ps8kdKVfRqpBti6z6BKqzFrgbQYug8XySgcAsm1tP32Pk6UebJK/d/izSrSNos lPlNHAypPtqXNEA2+ZLBq9QgtXwzRS7ChS50Q3YtoB2PnDZ3Jeq+7t+LC94N/fYRHOW8 Z+Yt2pPsuHd3ZQQNXzOAeHMae2Uqz5IdSl4GE= Date: Tue, 1 Feb 2011 17:29:42 +0800 From: =?utf-8?Q?Am=C3=A9rico?= Wang To: Seiji Aguchi Cc: "rdunlap@xenotime.net" , "tony.luck@intel.com" , "fenghua.yu@intel.com" , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "x86@kernel.org" , "tj@kernel.org" , "akpm@linux-foundation.org" , "a.p.zijlstra@chello.nl" , "arnd@arndb.de" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-ia64@vger.kernel.org" , "dle-develop@lists.sourceforge.net" , "shiyer@redhat.com" , "pjones@redhat.com" , Satoru Moriya Subject: Re: [RFC][PATCH] kmsg_dumper for NVRAM Message-ID: <20110201092942.GD21239@cr0.nay.redhat.com> References: <5C4C569E8A4B9B42A84A977CF070A35B2C1472ACC8@USINDEVS01.corp.hds.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5C4C569E8A4B9B42A84A977CF070A35B2C1472ACC8@USINDEVS01.corp.hds.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6224 Lines: 218 On Mon, Jan 31, 2011 at 11:21:17AM -0500, Seiji Aguchi wrote: >Hi, > >This prototype patch introduces kmsg_dumper for NVRAM(Non-Volatile RAM). > Hi, This looks like what Tony wanted, pstore. ... >[Patch Description] >This patch adds following boot paremeters. > > - nvram_kmsg_dump_enable > Enable kmsg_dumper for NVRAM with UEFI. > > - nvram_kmsg_dump_len > Size of kernel messages dumped to NVRAM. > default size is 1KB.(because I would like to use efivars for reading them from userspace.) > Maximum size is 32KB. > >On the next boot, sysfs files are created as follows and through these files we can see >the kernel messages stored in NVRAM. > > /sys/firmware/efi/vars/LinuxKmsgDump001-8be4df61-93ca-11d2-aa0d-00e098032b8c/data > /sys/firmware/efi/vars/LinuxKmsgDump002-8be4df61-93ca-11d2-aa0d-00e098032b8c/data > . > . > /sys/firmware/efi/vars/LinuxKmsgDump032-8be4df61-93ca-11d2-aa0d-00e098032b8c/data > >　　- Size of each entry is 1KB. 32 entries are created at a maximum. >　　- "8be4df61-93ca-11d2-aa0d-00e098032b8c" is EFI_GLOBAL_VARIABLE which is defined in > UEFI specification. > So, 'cat /sys/firmware/efi/vars/LinuxKmsgDump*/data' will show the whole kernel messages? And in the right order? Also ,will these data be flushed after the next next boot? If not, how can they be flushed/deleted? > >--- > Documentation/kernel-parameters.txt | 9 +++ > arch/ia64/kernel/efi.c | 4 + > arch/x86/platform/efi/efi.c | 135 +++++++++++++++++++++++++++++++++++ > include/linux/efi.h | 4 + > init/main.c | 5 +- > 5 files changed, 156 insertions(+), 1 deletions(-) Some comments below. >+static int __init setup_nvram_kmsg_dump_enable(char *arg) >+{ >+ nvram_kmsg_dump_enabled = 1; >+ return 0; >+} >+__setup("nvram_kmsg_dump_enable", setup_nvram_kmsg_dump_enable); >+ >+static int __init setup_nvram_kmsg_dump_len(char *str) >+{ >+ unsigned size = memparse(str, &str); You ignored errors here. >+ >+ if (!efi_enabled) { >+ printk(KERN_INFO "setup_nvram_kmsg_dump_len: EFI is disabled\n"); >+ return 1; >+ } >+ >+ if (size) >+ size = roundup_pow_of_two(size); >+ if (size > nvram_kmsg_dump_len) { >+ char *new_nvram_kmsg_dump; >+ >+ new_nvram_kmsg_dump = alloc_bootmem(size); >+ if (!new_nvram_kmsg_dump) { >+ printk(KERN_WARNING "nvram_kmsg_dump_len: \ >+allocation failed\n"); We don't split strings like this. >+ return 1; >+ } >+ nvram_kmsg_dump_len = size; >+ nvram_kmsg_dump_buf = new_nvram_kmsg_dump; >+ } >+ printk(KERN_NOTICE "nvram_kmsg_dump_len: %d\n", nvram_kmsg_dump_len); >+ >+ return 0; >+ >+} >+__setup("nvram_kmsg_dump_len=", setup_nvram_kmsg_dump_len); >+ >+static void nvram_do_kmsg_dump(struct kmsg_dumper *dumper, >+ enum kmsg_dump_reason reason, const char *s1, unsigned long l1, >+ const char *s2, unsigned long l2) >+{ >+ unsigned long s1_start, s2_start, l1_cpy, l2_cpy; >+ unsigned long attribute = 0xf, total, tmp, cpy_size; >+ int i; >+ efi_status_t efi_status; >+ void *tmp_buf; >+ >+ l2_cpy = min(l2, (unsigned long)nvram_kmsg_dump_len); >+ l1_cpy = min(l1, (unsigned long)nvram_kmsg_dump_len - l2_cpy); >+ >+ s2_start = l2 - l2_cpy; >+ s1_start = l1 - l1_cpy; >+ >+ memcpy(nvram_kmsg_dump_buf, s1 + s1_start, l1_cpy); >+ memcpy(nvram_kmsg_dump_buf + l1_cpy, s2 + s2_start, l2_cpy); >+ >+ /* initialize */ >+ for (i = 0; i < MAX_ENTRY; i++) >+ efi.set_variable(kmsg_dump_value_utf16[i], >+ &EFI_GLOBAL_VARIABLE_GUID, >+ attribute, 0, NULL); >+ >+ /* write data */ >+ total = l1_cpy + l2_cpy; >+ tmp_buf = (void *)nvram_kmsg_dump_buf + total; >+ cpy_size = 0; >+ for (i = 0; i < MAX_ENTRY; i++) { >+ tmp = min(total - cpy_size, (unsigned long)SET_VARIABLE_LEN); >+ tmp_buf -= tmp; >+ efi_status = efi.set_variable(kmsg_dump_value_utf16[i], >+ &EFI_GLOBAL_VARIABLE_GUID, >+ attribute, tmp, tmp_buf); >+ if (efi_status) { >+ printk(KERN_WARNING "nvram_do_kmsg_dump: \ >+set_variable %d failed 0x%lx\n", i, efi_status); Ditto. >+ efi.set_variable(kmsg_dump_value_utf16[i], >+ &EFI_GLOBAL_VARIABLE_GUID, >+ attribute, 0, NULL); >+ tmp_buf += tmp; >+ cpy_size -= tmp; >+ } >+ cpy_size += tmp; >+ if (cpy_size >= total) >+ break; >+ } >+} >+ >+void nvram_kmsg_dump_init(void) >+{ >+ >+ int i, outlen, err; >+ >+ for (i = 0; i < MAX_ENTRY; i++) { >+ snprintf(kmsg_dump_value, sizeof(kmsg_dump_value), >+ "%s%04d", LINUX_KMSG_DUMP_PREFIX, i + 1); >+ outlen = utf8s_to_utf16s((u8 *)kmsg_dump_value, >+ sizeof(kmsg_dump_value), >+ (wchar_t *)kmsg_dump_value_utf16[i]); >+ if (outlen != LINUX_KMSG_DUMP_LEN - 1) { >+ printk(KERN_ERR >+ "nvram_kmsg_dump_init: utf8s_to_utf16s %d\n", >+ outlen); >+ return; >+ } >+ } >+ >+ memset(&nvram_kmsg_dumper, 0, sizeof(nvram_kmsg_dumper)); You don't need to memset a static gloabl var to 0. >+ nvram_kmsg_dumper.dump = nvram_do_kmsg_dump; >+ err = kmsg_dump_register(&nvram_kmsg_dumper); >+ if (err) { >+ printk(KERN_ERR "nvram_kmsg_dump_init: kmsg_dump_register %d\n", >+ err); >+ return; >+ } >+ printk(KERN_NOTICE "nvram_kmsg_dump initialized\n"); >+ >+ return; >+} >diff --git a/include/linux/efi.h b/include/linux/efi.h >index fb737bc..d0d1a3c 100644 >--- a/include/linux/efi.h >+++ b/include/linux/efi.h >@@ -300,6 +300,7 @@ extern void efi_initialize_iomem_resources(struct resource *code_resource, > extern unsigned long efi_get_time(void); > extern int efi_set_rtc_mmss(unsigned long nowtime); > extern struct efi_memory_map memmap; >+extern void nvram_kmsg_dump_init(void); > > /** > * efi_range_is_wc - check the WC bit on an address range >@@ -333,11 +334,14 @@ extern int __init efi_setup_pcdp_console(char *); > #ifdef CONFIG_EFI > # ifdef CONFIG_X86 > extern int efi_enabled; >+ extern int nvram_kmsg_dump_enabled; > # else > # define efi_enabled 1 >+# define nvram_kmsg_dump_enabled 1 There is a global var with the same name, right? -- 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/