[makedumpfile PATCH v2] Add the --partial-dmesg option to dump only non-cleared dmesg

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello Ivan,

>This option will make --dump-dmesg save only the part of the dmesg
>buffer since it was last cleared on the crashed kernel (with
>dmesg --clear and such) instead of the whole buffer since boot or
>wrap-around. It works on kernels with commit f468908bb55a ("printk:
>add clear_idx symbol to vmcoreinfo") merged in v4.6 and otherwise
>will default to the regular behavior.
>
>Signed-off-by: Ivan Delalande <colona at arista.com>

Thanks, I'll merge this patch into v1.6.2.

Regards,
Atsushi Kumagai

>---
> makedumpfile.8 |  8 +++++++-
> makedumpfile.c | 24 ++++++++++++++++++++++--
> makedumpfile.h |  3 +++
> 3 files changed, 32 insertions(+), 3 deletions(-)
>
>diff --git a/makedumpfile.8 b/makedumpfile.8
>index 9932364..76a8d6e 100644
>--- a/makedumpfile.8
>+++ b/makedumpfile.8
>@@ -20,7 +20,7 @@ makedumpfile \- make a small dumpfile of kdump
> .br
> \fBmakedumpfile\fR    [\fIOPTION\fR] [\-\-xen-syms \fIXEN-SYMS\fR|\-\-xen-vmcoreinfo \fIVMCOREINFO\fR] \fIVMCORE\fR
>\fIDUMPFILE\fR
> .br
>-\fBmakedumpfile\fR \-\-dump-dmesg [\-x \fIVMLINUX\fR|\-i \fIVMCOREINFO\fR] \fIVMCORE\fR \fILOGFILE\fR
>+\fBmakedumpfile\fR \-\-dump-dmesg [\-\-partial-dmesg] [\-x \fIVMLINUX\fR|\-i \fIVMCOREINFO\fR] \fIVMCORE\fR
>\fILOGFILE\fR
> .br
> \fBmakedumpfile\fR    [\fIOPTION\fR] \-x \fIVMLINUX\fR \-\-diskset=\fIVMCORE1\fR \-\-diskset=\fIVMCORE2\fR
>[\-\-diskset=\fIVMCORE3\fR ..] \fIDUMPFILE\fR
> .br
>@@ -586,6 +586,12 @@ it is necessary to specfiy [\-x \fIVMLINUX\fR] or [\-i \fIVMCOREINFO\fR].
>
>
> .TP
>+\fB\-\-partial-dmesg\fR
>+This option will make --dump-dmesg extract only dmesg logs since that buffer was
>+last cleared on the crashed kernel, through "dmesg --clear" for example.
>+
>+
>+.TP
> \fB\-\-mem-usage\fR
> This option is only for x86_64.
> This option is used to show the page numbers of current system in different
>diff --git a/makedumpfile.c b/makedumpfile.c
>index 95cc5ef..6c5fa4c 100644
>--- a/makedumpfile.c
>+++ b/makedumpfile.c
>@@ -1498,6 +1498,7 @@ get_symbol_info(void)
> 	SYMBOL_INIT(log_buf_len, "log_buf_len");
> 	SYMBOL_INIT(log_end, "log_end");
> 	SYMBOL_INIT(log_first_idx, "log_first_idx");
>+	SYMBOL_INIT(clear_idx, "clear_idx");
> 	SYMBOL_INIT(log_next_idx, "log_next_idx");
> 	SYMBOL_INIT(max_pfn, "max_pfn");
> 	SYMBOL_INIT(modules, "modules");
>@@ -2115,6 +2116,7 @@ write_vmcoreinfo_data(void)
> 	WRITE_SYMBOL("log_buf_len", log_buf_len);
> 	WRITE_SYMBOL("log_end", log_end);
> 	WRITE_SYMBOL("log_first_idx", log_first_idx);
>+	WRITE_SYMBOL("clear_idx", clear_idx);
> 	WRITE_SYMBOL("log_next_idx", log_next_idx);
> 	WRITE_SYMBOL("max_pfn", max_pfn);
> 	WRITE_SYMBOL("high_memory", high_memory);
>@@ -2509,6 +2511,7 @@ read_vmcoreinfo(void)
> 	READ_SYMBOL("log_buf_len", log_buf_len);
> 	READ_SYMBOL("log_end", log_end);
> 	READ_SYMBOL("log_first_idx", log_first_idx);
>+	READ_SYMBOL("clear_idx", clear_idx);
> 	READ_SYMBOL("log_next_idx", log_next_idx);
> 	READ_SYMBOL("max_pfn", max_pfn);
> 	READ_SYMBOL("high_memory", high_memory);
>@@ -5025,6 +5028,7 @@ dump_dmesg()
> 	int log_buf_len, length_log, length_oldlog, ret = FALSE;
> 	unsigned long index, log_buf, log_end;
> 	unsigned int idx, log_first_idx, log_next_idx;
>+	unsigned long long first_idx_sym;
> 	unsigned long log_end_2_6_24;
> 	unsigned      log_end_2_6_25;
> 	char *log_buffer = NULL, *log_ptr = NULL;
>@@ -5058,7 +5062,13 @@ dump_dmesg()
> 			ERRMSG("Can't find variable-length record symbols");
> 			return FALSE;
> 		} else {
>-			if (!readmem(VADDR, SYMBOL(log_first_idx), &log_first_idx,
>+			if (info->flag_partial_dmesg
>+			    && SYMBOL(clear_idx) != NOT_FOUND_SYMBOL)
>+				first_idx_sym = SYMBOL(clear_idx);
>+			else
>+				first_idx_sym = SYMBOL(log_first_idx);
>+
>+			if (!readmem(VADDR, first_idx_sym, &log_first_idx,
> 			    sizeof(log_first_idx))) {
> 				ERRMSG("Can't get log_first_idx.\n");
> 				return FALSE;
>@@ -5102,7 +5112,10 @@ dump_dmesg()
> 	DEBUG_MSG("log_buf       : %lx\n", log_buf);
> 	DEBUG_MSG("log_end       : %lx\n", log_end);
> 	DEBUG_MSG("log_buf_len   : %d\n", log_buf_len);
>-	DEBUG_MSG("log_first_idx : %u\n", log_first_idx);
>+	if (info->flag_partial_dmesg)
>+		DEBUG_MSG("clear_idx : %u\n", log_first_idx);
>+	else
>+		DEBUG_MSG("log_first_idx : %u\n", log_first_idx);
> 	DEBUG_MSG("log_next_idx  : %u\n", log_next_idx);
>
> 	if ((log_buffer = malloc(log_buf_len)) == NULL) {
>@@ -10618,6 +10631,9 @@ check_param_for_creating_dumpfile(int argc, char *argv[])
> 		}
> 	}
>
>+	if (info->flag_partial_dmesg && !info->flag_dmesg)
>+		return FALSE;
>+
> 	if ((argc == optind + 2) && !info->flag_flatten
> 				 && !info->flag_split
> 				 && !info->flag_sadump_diskset) {
>@@ -11022,6 +11038,7 @@ static struct option longopts[] = {
> 	{"message-level", required_argument, NULL, OPT_MESSAGE_LEVEL},
> 	{"vtop", required_argument, NULL, OPT_VTOP},
> 	{"dump-dmesg", no_argument, NULL, OPT_DUMP_DMESG},
>+	{"partial-dmesg", no_argument, NULL, OPT_PARTIAL_DMESG},
> 	{"config", required_argument, NULL, OPT_CONFIG},
> 	{"help", no_argument, NULL, OPT_HELP},
> 	{"diskset", required_argument, NULL, OPT_DISKSET},
>@@ -11135,6 +11152,9 @@ main(int argc, char *argv[])
> 		case OPT_DUMP_DMESG:
> 			info->flag_dmesg = 1;
> 			break;
>+		case OPT_PARTIAL_DMESG:
>+			info->flag_partial_dmesg = 1;
>+			break;
> 		case OPT_MEM_USAGE:
> 		       info->flag_mem_usage = 1;
> 		       break;
>diff --git a/makedumpfile.h b/makedumpfile.h
>index 6ea8cc4..d3b7532 100644
>--- a/makedumpfile.h
>+++ b/makedumpfile.h
>@@ -1241,6 +1241,7 @@ struct DumpInfo {
> 	int		flag_force;	     /* overwrite existing stuff */
> 	int		flag_exclude_xen_dom;/* exclude Domain-U from xen-kdump */
> 	int             flag_dmesg;          /* dump the dmesg log out of the vmcore file */
>+	int             flag_partial_dmesg;  /* dmesg dump only from the last cleared index*/
> 	int             flag_mem_usage;  /*show the page number of memory in different use*/
> 	int		flag_use_printk_log; /* did we read printk_log symbol name? */
> 	int		flag_nospace;	     /* the flag of "No space on device" error */
>@@ -1529,6 +1530,7 @@ struct symbol_table {
> 	unsigned long long	log_buf_len;
> 	unsigned long long	log_end;
> 	unsigned long long	log_first_idx;
>+	unsigned long long	clear_idx;
> 	unsigned long long	log_next_idx;
> 	unsigned long long	max_pfn;
> 	unsigned long long	node_remap_start_vaddr;
>@@ -2268,6 +2270,7 @@ struct elf_prstatus {
> #define OPT_SPLITBLOCK_SIZE	OPT_START+14
> #define OPT_WORKING_DIR         OPT_START+15
> #define OPT_NUM_THREADS	OPT_START+16
>+#define OPT_PARTIAL_DMESG	OPT_START+17
>
> /*
>  * Function Prototype.
>--
>2.13.1




[Index of Archives]     [LM Sensors]     [Linux Sound]     [ALSA Users]     [ALSA Devel]     [Linux Audio Users]     [Linux Media]     [Kernel]     [Gimp]     [Yosemite News]     [Linux Media]

  Powered by Linux